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Associate Professor
Nesri Padayatchi

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Current Organisation

Centre for the AIDS Programme of Research in South Africa

Current Job Title

SENIOR SCIENTIST

Biography

Publications

Authors:
Naidoo A Naidoo K Ramsuran V Reddy M Padayatchi N

Journal:
Pharmacogenomics and Personalized Medicine 2017 August; 10: 233-234. doi: 10.2147/PGPM.S146787. PMC5574687

Content:

Open access full text article.

Date:
2017-08-23

Authors:

Journal:
Lancet Respiratory Medicine

Content:

The Lancet Respiratory Medicine Commission on drug-resistant tuberculosis was published in 2017, which comprehensively reviewed and provided recommendations on various aspects of the disease. Several key new developments regarding drug-resistant tuberculosis are outlined in this Commission Update. The WHO guidelines on treating drug-resistant tuberculosis were updated in 2019 with a reclassification of second line anti-tuberculosis drugs. An injection-free MDR tuberculosis treatment regimen is now recommended. Over the past 3 years, advances in treatment include the recognition of the safety and mortality benefit of bedaquiline, the finding that the 9-11 month injectable-based 'Bangladesh' regimen was non-inferior to longer regimens, and promising interim results of a novel 6 month 3-drug regimen (bedaquiline, pretomanid, and linezolid). Studies of explanted lungs from patients with drug-resistant tuberculosis have shown substantial drug-specific gradients across pulmonary cavities, suggesting that alternative dosing and drug delivery strategies are needed to reduce functional monotherapy at the site of disease. Several controversies are discussed including the optimal route of drug administration, optimal number of drugs constituting a regimen, selection of individual drugs for a regimen, duration of the regimen, and minimal desirable standards of antibiotic stewardship. Newer rapid nucleic acid amplification test platforms, including point-of-care systems that facilitate active case-finding, are discussed. The rapid diagnosis of resistance to other drugs, (notably fluoroquinolones), and detection of resistance by targeted or whole genome sequencing will probably change the diagnostic landscape in the near future.

Date:
2019-09-28

Authors:

Journal:
Lancet Microbe

Content:

Background: Bedaquiline and clofazimine are important drugs in the treatment of drug-resistant tuberculosis and are commonly used across southern Africa, although drug susceptibility testing is not routinely performed. In this study, we did a genotypic and phenotypic analysis of drug-resistant Mycobacterium tuberculosis isolates from cohort studies in hospitals in KwaZulu-Natal, South Africa, to identify resistance-associated variants (RAVs) and assess the extent of clofazimine and bedaquiline cross-resistance. We also used a comprehensive dataset of whole-genome sequences to investigate the phylogenetic and geographical distribution of bedaquiline and clofazimine RAVs in southern Africa.

Methods: In this study, we included M tuberculosis isolates reported from the PRAXIS study of patients with drug-resistant tuberculosis treated with bedaquiline (King Dinuzulu Hospital, Durban) and three other cohort studies of drug-resistant tuberculosis in other KwaZulu-Natal hospitals, and sequential isolates from six persistently culture-positive patients with extensively drug-resistant tuberculosis at the KwaZulu-Natal provincial referral laboratory. Samples were collected between 2013 and 2019. Microbiological cultures were done as part of all parent studies. We sequenced whole genomes of included isolates and measured bedaquiline and clofazimine minimum inhibitory concentrations (MICs) for isolates identified as carrying any Rv0678 variant or previously published atpE, pepQ, and Rv1979c RAVs, which were the subject of the phenotypic study. We combined all whole-genome sequences of M tuberculosis obtained in this study with publicly available sequence data from other tuberculosis studies in southern Africa (defined as the countries of the Southern African Development Community), including isolates with Rv0678 variants identified by screening public genomic databases. We used this extended dataset to reconstruct phylogenetic relationships across lineage 2 and 4 M tuberculosis isolates.

Findings: We sequenced the whole genome of 648 isolates from 385 patients with drug-resistant tuberculosis recruited into cohort studies in KwaZulu-Natal, and 28 isolates from six patients from the KwaZulu-Natal referral laboratory. We identified 30 isolates with Rv0678 RAVs from 16 (4%) of 391 patients. We did not identify any atpE, pepQ, or Rv1979c RAVs. MICs were measured for 21 isolates with Rv0678 RAVs. MICs were above the critical concentration for bedaquiline resistance in nine (43%) of 21 isolates, in the intermediate category in nine (43%) isolates, and within the wild-type range in three (14%) isolates. Clofazimine MICs in genetically wild-type isolates ranged from 0·12-0·5 μg/mL, and in isolates with RAVs from 0·25-4·0 μg/mL. Phylogenetic analysis of the extended dataset including M tuberculosis isolates from southern Africa resolved multiple emergences of Rv0678 variants in lineages 2 and 4, documented two likely nosocomial transmission events, and identified the spread of a possibly bedaquiline and clofazimine cross-resistant clone in eSwatini. We also identified four patients with pepQ frameshift mutations that may confer resistance.

Interpretation: Bedaquiline and clofazimine cross-resistance in southern Africa is emerging repeatedly, with evidence of onward transmission largely due to Rv0678 mutations in M tuberculosis. Roll-out of bedaquiline and clofazimine treatment in the setting of limited drug susceptibility testing could allow further spread of resistance. Designing strong regimens would help reduce the emergence of resistance. Drug susceptibility testing is required to identify where resistance does emerge.

Date:
2020-08-28

Authors:
Naidoo A Naidoo K McIlleron H Essack S Padayatchi N

Journal:
Journal of Clinical Pharmacology 2017 November; 57(11):1369-1386. doi: 10.1002/jcph.968. PMC5663285

Content:

Moxifloxacin, an 8-methoxy quinolone, is an important drug in the treatment of multidrug-resistant tuberculosis and is being investigated in novel drug regimens with pretomanid, bedaquiline, and pyrazinamide, or rifapentine, for the treatment of drug-susceptible tuberculosis. Early results of these studies are promising. Although current evidence does not support the use of moxifloxacin in treatment-shortening regimens for drug-susceptible tuberculosis, it may be recommended in patients unable to tolerate standard first-line drug regimens or for isoniazid monoresistance. Evidence suggests that the standard 400-mg dose of moxifloxacin used in the treatment of tuberculosis may be suboptimal in some patients, leading to worse tuberculosis treatment outcomes and emergence of drug resistance. Furthermore, a drug interaction with the rifamycins results in up to 31% reduced plasma concentrations of moxifloxacin when these are combined for treatment of drug-susceptible tuberculosis, although the clinical relevance of this interaction is unclear. Moxifloxacin exhibits extensive interindividual pharmacokinetic variability. Higher doses of moxifloxacin may be needed to achieve drug exposures required for improved clinical outcomes. Further study is, however, needed to determine the safety of proposed higher doses and clinically validated targets for drug exposure to moxifloxacin associated with improved tuberculosis treatment outcomes. We discuss in this review the evidence for the use of moxifloxacin in drug-susceptible tuberculosis and explore the role of moxifloxacin pharmacokinetics, pharmacodynamics, and drug interactions with rifamycins, on tuberculosis treatment outcomes when used in first-line tuberculosis drug regimens.

Date:
2017-11-30

Authors:

Journal:
Clinical Infectious Diseases

Content:

Background: New onset or worsening drug-induced liver injury challenges coinfected patients on antiretroviral therapy (ART) initiation during antituberculosis (TB) treatment.

Methods: Post hoc analysis within a randomized trial, the Starting Antiretroviral Therapy at Three Points in Tuberculosis trial, was conducted. Patients were randomized to initiate ART either early or late during TB treatment or after TB treatment completion. Liver enzymes were measured at baseline, 6-month intervals, and when clinically indicated.

Results: Among 642 patients enrolled, the median age was 34 years (standard deviation, 28-40), and 17.6% had baseline CD4+ cell counts <50 cells/mm3. Overall, 146/472 patients (52, 47, and 47: early, late, and sequential arms) developed new-onset liver injury following TB treatment initiation. The incidence of liver injury post-ART initiation in patients with CD4+ cell counts <200 cells/mm3 and ≥200 cells/ mm3 was 27.4 (95% confidence interval [CI], 18.0-39.8), 19.0 (95% CI, 10.9-30.9), and 18.4 (95% CI, 8.8-33.8) per 100 person-years, and 32.1 (95% CI, 20.1-48.5), 11.8 (95% CI, 4.3-25.7), and 28.2 (95% CI, 13.5-51.9) per 100 person-years in the early, late integrated, and sequential treatment arms, respectively. Severe and life-threatening liver injury occurred in 2, 7, and 3 early, late, and sequential treatment arm patients, respectively. Older age and hepatitis B positivity predicted liver injury.

Conclusions: High incidence rates of liver injury among cotreated human immunodeficiency virus (HIV)-TB coinfected patients were observed. Clinical guidelines and policies must provide guidance on frequency of liver function monitoring for HIV-TB coinfected patients.

Date:
2020-06-10

Authors:

Journal:
Lancet HIV

Content:

People living with HIV have a higher risk of developing tuberculosis, and tuberculosis is one of the leading causes of death among people living with HIV globally. Treating HIV and tuberculosis concurrently has morbidity and mortality benefits. However, HIV and tuberculosis co-treatment is challenging due to drug-drug interactions, overlapping toxicities, tuberculosis-associated immune reconstitution syndrome, and concerns for treatment failure or drug resistance. Drug-drug interactions between antiretrovirals and tuberculosis drugs are driven mainly by the rifamycins (for example, the first-line tuberculosis drug rifampicin), and dose adjustments or drug switches during co-treatment are commonly required. Several implementation challenges and research gaps exist when combining the integrase strand transfer inhibitors (INSTIs), highly potent antiretroviral drugs recommended as first-line treatment of HIV, and drugs used for the treatment and prevention of tuberculosis. Ongoing and planned studies will address some critical questions on the use of INSTIs in settings with a high tuberculosis burden, including dosing of dolutegravir, bictegravir, and cabotegravir when used with the rifamycins for both tuberculosis treatment and prevention. Failure, in the past, to include people with tuberculosis in HIV clinical treatment trials has been responsible for some of the research gaps still evident for informing optimisation of HIV and tuberculosis co-treatment.

Date:
2022-02-28

Authors:

Journal:
American Journal of Tropical Medicine American Journal of Tropical Medicine

Content:

Stigma is an important social determinant of health-seeking behavior; however, the nature and extent of its association with depression among people living with multidrug-resistant tuberculosis (MDR-TB) are not well-understood. We enrolled 200 microbiologically confirmed MDR-TB inpatients at a TB specialist hospital in KwaZulu-Natal Province, an area considered the epicenter for MDR-TB coinfection in South Africa. Four aspects of stigma and their association with major depression were assessed through individual interviews: 1) community and 2) patient perspectives toward TB, and 3) community and 4) patient perspectives toward HIV. A major depressive episode (MDE), HIV coinfection, and low income were significantly associated with greater stigma subscales. Based on an adjusted regression model, the MDE was the only factor independently associated with (all aspects of) stigma. These results indicate the potential utility of addressing stigma associated with the MDE as an important step in improving health-seeking behavior to promote adherence and retention in care.

Date:
2020-09-28

Authors:

Journal:
Clinical Infectious Diseases

Content:

Background: Medication adherence is known to challenge treatment of HIV/AIDS and multidrug-resistant tuberculosis (MDR-TB). We hypothesized that electronic dose adherence monitoring (EDM) would identify an ART adherence threshold for emergent ART resistance and predict treatment outcomes in patients with MDR-TB and HIV on ART and bedaquiline-containing TB regimens.

Methods: A prospective cohort of adults with MDR-TB and HIV, on ART and initiating MDR-TB treatment with bedaquiline, were enrolled at a public TB referral hospital in KwaZulu-Natal, South Africa (PRAXIS Study, Clinicaltrials.gov NCT03162107). Participants received separate EDM devices measuring adherence to bedaquiline and ART (nevirapine or lopinavir/ritonavir). Adherence was calculated cumulatively over six months. Participants were followed through completion of MDR-TB treatment. HIV genome sequencing was performed at baseline, 2 and 6 months on samples with HIV RNA ≥1000 copies/mL.

Findings: From November 2016 through February 2018, 198 MDR-TB and HIV co-infected participants were enrolled and followed (median 17.2 months, IQR 12.2 - 19.6). Eleven percent had baseline ART resistance mutations, and 7.5% developed emergent ART resistance at 6 months. ART adherence was independently associated with both emergent ART resistance and mortality. Modeling identified a significant (p<0.001), but linear association between ART adherence and emergent resistance, suggesting a strong association without a specific threshold.

Interpretation: Our findings highlight the need for ART resistance testing, especially in MDR-TB HIV co-infected patients, which is currently not standard of care in resource-limited settings. Despite short follow-up duration, reduced ART adherence was significantly associated with emergent resistance and increased mortality.

Date:
2022-03-30

Authors:

Journal:
Clinical Infectious Diseases

Content:

No abstract available

Keywords: COVID-19; Tuberculosis.

Date:
2022-02-11

Authors:

Journal:
South African Medical Journal

Content:

Background: Optimal drug levels and minimal toxicity are critical factors in improving treatment outcomes for patients' prescribed new and repurposed medicine for drug-resistant (DR) tuberculosis (TB). The optimal dose of clofazimine (CFZ), a repurposed medicine for DR-TB, that is safe and effective in the South African (SA) population is unknown.

Objectives: To report on dose-related final treatment outcomes in patients receiving CFZ plus a background regimen for DR-TB.

Methods: In a retrospective review of patient folders from 2012 to 2014, treatment outcomes documented for patients receiving high- (≥200 mg) and low-dose (100 mg) CFZ in a centralised DR-TB hospital in KwaZulu-Natal Province, SA, were investigated for an association between dose-weight interactions and outcomes.

Results: A total of 600 patients were included, of whom 169 (28.2%) received 100 mg. Of these, 87 (51.5%) weighed &lt;50 kg and 82 (48.5%) ≥50 kg. Four hundred and thirty-one (71.8%) received ≥200 mg, of whom 41 (9.5%) were &lt;50 kg and 390 (90.5%) ≥50 kg. Overall 77.2% were HIV-positive, with 93.95% on antiretroviral medicine. The majority of patients presented with extremely drug-resistant TB (55.3%). Forty-seven and a half percent of patients received a standardised background regimen, and 52.5% received an individualised regimen containing a new or repurposed medicine including CFZ. On multivariate analysis, adjusting for age, gender, HIV status and concomitant antiretrovirals, previous TB history, type of TB and background regimen, patients ≥50 kg prescribed 100 mg CFZ were 60% less likely to have a successful outcome (adjusted odds ratio (OR) 0.4; 95% confidence interval (CI) 0.2 - 0.8; p=0.009) compared with patients &lt;50 kg receiving 100 mg CFZ. Patients &lt;50 kg who received ≥200 mg were 40% less likely to have a successful treatment outcome (adjusted OR 0.6, p=0.3), and were found to have a higher risk of adverse events than patients &lt;50 kg receiving 100 mg CFZ (82.9% v. 65.5%).

Conclusions: Dose-weight interaction plays a role in the odds of a successful outcome. There is an association between dose-weight interactions, outcomes and adverse events. Weight-based dosing in patients &lt;50 kg and ≥50 kg must be considered to achieve optimal treatment outcomes and reduce adverse events. Active drug safety monitoring must be implemented as a package of care for patients receiving CFZ as part of a DR-TB treatment regimen.

Date:
2020-12-14

Authors:

Journal:
Clinical Infectious Diseases

Content:

Using an open-access spatiotemporal analytics program, we mapped spatiotemporal heterogeneity loci in tuberculosis (TB) cases (clusters) and dynamic changes, and characterized the drug-resistant TB clustering risk using routine microbiological data from KwaZulu-Natal, South Africa. The data may provide insight into transmission dynamics and support efficient deployment of public health resources.

Date:
2020-05-06

Authors:
Naidoo A Chirehwa M McIlleron H Naidoo K Essack S Yende-Zuma N Kimba-Phongi E Adamson J Govender K Padayatchi N Denti P

Journal:
Journal of Antimicrobial Chemotherapy 2017 May; 72(5):1441-49. doi: 10.1093/jac/dkx004. PMC5890691

Content:

Objectives: We compared the pharmacokinetics of moxifloxacin during rifampicin co-treatment or when dosed alone in African patients with drug-susceptible recurrent TB.

Methods: Patients in the intervention arm of the Improving Retreatment Success (IMPRESS) randomized controlled TB trial received 400 mg of moxifloxacin, with rifampicin, isoniazid and pyrazinamide in the treatment regimen. Moxifloxacin concentrations were measured in plasma during rifampicin-based TB treatment and again 4 weeks after treatment completion, when given alone as a single dose. Moxifloxacin concentration-time data were analysed using non-linear mixed-effects models.

Results: We included 58 patients; 42 (72.4%) were HIV co-infected and 40 (95%) of these were on efavirenz-based ART. Moxifloxacin pharmacokinetics was best described using a two-compartment disposition model with first-order lagged absorption and elimination using a semi-mechanistic model describing hepatic extraction. Oral clearance (CL/F) of moxifloxacin during rifampicin-based TB treatment was 24.3 L/h for a typical patient (fat-free mass of 47 kg), resulting in an AUC of 16.5 mg·h/L. This exposure was 7.8% lower than the AUC following the single dose of moxifloxacin given alone after TB treatment completion. In HIV-co-infected patients taking efavirenz-based ART, CL/F of moxifloxacin was increased by 42.4%, resulting in a further 30% reduction in moxifloxacin AUC.

Conclusions: Moxifloxacin clearance was high and plasma concentrations low in our patients overall. Moxifloxacin AUC was further decreased by co-administration of efavirenz-based ART and, to a lesser extent, rifampicin. The clinical relevance of the low moxifloxacin concentrations for TB treatment outcomes and the need for moxifloxacin dose adjustment in the presence of rifampicin and efavirenz co-treatment need further investigation.

Date:
2017-05-01

Authors:

Journal:
Implementation Science

Content:

Background: A quality improvement (QI) collaborative approach to enhancing integrated HIV-Tuberculosis (TB) services may be effective in scaling up and improving the quality of service delivery. Little is known of the role of organizational contextual factors (OCFs) in influencing the success of QI collaboratives. This study aims to determine which OCFs were associated with improvement in a QI collaborative intervention to enhance integrated HIV-TB services delivery.

Methods: This is a nested sub-study embedded in a cluster-randomized controlled trial. Sixteen nurse supervisors (clusters) overseeing 40 clinics were randomized (1:1) to receive QI training and mentorship, or standard of care support (SOC). In the QI arm, eight nurse supervisors and 20 clinics formed a "collaborative" which aimed to improve HIV-TB process indicators, namely HIV testing, TB screening, isoniazid preventive therapy (IPT) initiations, viral load testing, and antiretroviral therapy for TB patients. OCFs measured at baseline were physical infrastructure, key staff, flexibility of clinic hours, monitoring data for improvement (MDI), and leadership support. Surveys were administered to clinic staff at baseline and month 12 to assess perceptions of supportiveness of contexts for change, and clinic organization for delivering integrated HIV-TB services. Linear mixed modelling was used to test for associations between OCFs and HIV-TB process indicators.

Results: A total of 209 clinic staff participated in the study; 97 (46.4%) and 112 (53.6%) from QI and SOC arms, respectively. There were no differences between the QI and SOC arms scores achieved for physical infrastructure (78.9% vs 64.7%; p = 0.058), key staff (95.8 vs 92; p = 0.270), clinic hours (66.9 vs 65.5; p = 0.900), MDI (63.3 vs 65; p = 0.875, leadership support (46.0 vs 57.4; p = 0.265), and perceptions of supportiveness of contexts for change (76.2 vs 79.7; p = 0.128 and clinic organization for delivering integrated HIV-TB services (74.1 vs 80.1; p = 0.916). IPT initiation was the only indicator that was significantly improved in the parent study. MDI was a significantly associated with increasing IPT initiation rates [beta coefficient (β) = 0.004; p = 0.004].

Discussion: MDI is a practice that should be fostered in public health facilities to increase the likelihood of success of future QI collaboratives to improve HIV-TB service delivery.

Trial registration: Clinicaltrials.gov , NCT02654613 . Registered 01 June 2015.

Date:
2021-09-17

Authors:

Journal:
Global Health: Science and Practice

Content:

Introduction: In South Africa, mortality rates among HIV-TB coinfected patients are among the highest in the world. The key to reducing mortality is integrating HIV-TB services, however, a generalizable implementation method and package of tested change ideas to guide the scale-up of integrated HIV-TB services are unavailable. We describe the implementation of a quality improvement (QI) intervention, health systems' weaknesses, change ideas, and lessons learned in improving integrated HIV-TB services.

Methods: Between December 1, 2016, and December 31, 2018, 8 nurse supervisors overseeing 20 primary health care (PHC) clinics formed a learning collaborative to improve a set of HIV-TB process indicators. HIV-TB process indicators comprised: HIV testing services (HTS), TB screening among PHC clinic attendees, isoniazid preventive therapy (IPT) for eligible HIV patients, antiretroviral therapy (ART) for HIV-TB coinfected patients, and viral load (VL) testing at month 12. Routine HIV-TB process data were collected and analyzed.

Results: Key change interventions, generated by health care workers, included: patient-flow redesign, daily data quality checks; prior identification of patients eligible for IPT and VL testing. Between baseline and post-QI intervention, IPT initiation rates increased from 15.9% to 76.4% (P=.019), HTS increased from 84.8% to 94.5% (P=.110), TB screening increased from 76.2% to 85.2% (P=.040), and VL testing increased from 61.4% to 74.0% (P=.045). ART initiation decreased from 95.8% to 94.1% (P=.481).

Discussion: Although integrating HIV-TB services is standard guidance, existing process gaps to achieve integration can be closed using QI methods. QI interventions can rapidly improve the performance of processes, particularly if baseline performance is low. Improving data quality enhances the success of QI initiatives.

Date:
2021-12-21

Authors:

Journal:
Journal of Nervous and Mental Disease

Content:

Although neurocognitive impairment (NCI) is a well-recognized challenge in human immunodeficiency virus (HIV), there is little evidence regarding it among individuals with multiple drug-resistant tuberculosis (MDR-TB) within HIV endemic sub-Saharan Africa. The extent of NCI risk, particularly HIV-associated neurocognitive disorders (HAND) risk, was investigated in 200 microbiologically confirmed inpatients with MDR-TB at a TB-specialist hospital in KwaZulu-Natal Province, South Africa. Within this population, the prevalence of HIV coinfection, major depressive episode, and substance use disorder was 89.50%, 10.50%, and 7.00%, respectively. After excluding individuals with major depressive episode/substance use disorder and monoinfection (i.e., MDR-TB without HIV), the prevalence of HAND risk was 43.5%. Older and low-income individuals had significantly greater odds of HAND risk, whereas those with family members/relatives who work(ed) in the health services had lower odds. The role of timely linkage to and retention of care in TB/HIV treatment to offset cognitive decline in MDR-TB/HIV coinfected individuals needs to be investigated further.

Date:
2019-04-28

Authors:

Journal:
South African Medical Journal

Content:

An HIV-positive mother infected her daughter with extensively drug-resistant Mycobacterium tuberculosis. Despite adhering to the then current guidelines for prevention, the infant was diagnosed with extensively drug-resistant pulmonary tuberculosis at the age of 4 months and developed tuberculous meningitis. After a short delay, appropriate treatment was initiated, followed by an inhospital stay at a specialised hospital. The infant became generally well, but had delayed neurological development. Secondary hydrocephalus due to tuberculous meningitis required a ventriculoperitoneal shunt. After 2 years of microbiologically and clinically effective tuberculosis treatment and several shunt complications, the HIV-negative child died at the age of 28 months ‒ with radiological signs of a shunt infection. The reason for the fatal outcome was probably related to inadequate risk reduction of airborne mother-to-child transmission, inappropriate chemoprophylaxis and delayed initiation of adequate treatment.

Date:
2020-08-31

Authors:

Journal:
Mem Inst Oswaldo Cruz

Content:

Background: The five BRICS (Brazil, Russian, Indian, China, and South Africa) countries bear 49% of the world's tuberculosis (TB) burden and they are committed to ending tuberculosis.

Objectives: The aim of this paper is to map the scientific landscape related to TB research in BRICS countries.

Methods: Were combined bibliometrics and social network analysis techniques to map the scientific publications related to TB produced by the BRICS. Was made a descriptive statistical data covering the full period of analysis (1993-2016) and the research networks were made for 2007-2016 (8,366 records). The bubble charts were generated by VantagePoint and the networks by the Gephi 0.9.1 software (Gephi Consortium 2010) from co-occurrence matrices produced in VantagePoint. The Fruchterman-Reingold algorithm provided the networks' layout.

Findings: During the period 1993-2016, there were 38,315 peer-reviewed, among them, there were 11,018 (28.7%) articles related by one or more authors in a BRICS: India 38.7%; China 23.8%; South Africa 21.1%; Brazil 13.0%; and Russia 4.5% (The total was greater than 100% because our criterion was all papers with at least one author in a BRICS). Among the BRICS, there was greater interaction between India and South Africa and organisations in India and China had the highest productivity; however, South African organisations had more interaction with countries outside the BRICS. Publications by and about BRICS generally covered all research areas, especially those in India and China covered all research areas, although Brazil and South Africa prioritised infectious diseases, microbiology, and the respiratory system.

Main conclusions: An overview of BRICS scientific publications and interactions highlighted the necessity to develop a BRICS TB research plan to increase efforts and funding to ensure that basic science research successfully translates into products and policies to help end the TB epidemic.

Date:
2020-03-16

Authors:

Journal:
Clinical Infectious Diseases

Content:

Background: In generalized drug-resistant tuberculosis (DR-TB) human immunodeficiency virus (HIV) epidemics, identifying subpopulations at high risk for treatment failure and loss to care is critically important to improve treatment outcomes and prevent amplification of drug resistance. We hypothesized that an electronic dose-monitoring (EDM) device could empirically identify adherence-challenged patients and that a mixed-methods approach would characterize treatment challenges.

Methods: A prospective study of patients with DR-TB HIV on antiretroviral therapy (ART) initiating bedaquiline-containing regimens in KwaZulu-Natal, South Africa. Separate EDM devices measured adherence for bedaquiline and ART. Patients with low adherence (<85%) to both bedaquiline and ART were identified as high risk for poor outcomes. Baseline survey, study visit notes, and focus group discussions characterized treatment challenges.

Results: From December 2016-February 2018, 32 of 198 (16%) enrolled patients with DR-TB HIV were identified as dual-adherence challenged. In a multivariate model including baseline characteristics, only receiving a disability grant was significantly associated with dual nonadherence at 6 months. Mixed-methods identified treatment barriers including alcohol abuse, family conflicts, and mental health issues. Compared with adherent patients, dual-adherence-challenged patients struggled to prioritize treatment and lacked support, and dual-adherence-challenged patients experienced higher rates of detectable HIV viral load and mortality than more adherent patients.

Conclusions: EDM empirically identified a subpopulation of patients with DR-TB HIV with dual-adherence challenges early in treatment. Mixed-methods revealed intense psychosocial, behavioral, and structural barriers to care in this subpopulation. Our data support developing differential, patient-centered, adherence support interventions focused on psychosocial and structural challenges for subpopulations of at-risk DR-TB HIV patients.

Date:
2022-10-05

Authors:

Journal:
Frontiers in Microbiology

Content:

HIV-infected individuals are at high risk of tuberculosis disease and those with prior tuberculosis episodes are at even higher risk of disease recurrence. A non-sputum biomarker that identifies individuals at highest tuberculosis risk would allow targeted microbiological testing and appropriate treatment and also guide need for prolonged therapy. We determined the utility of a previously developed whole blood transcriptomic correlate of risk (COR) signature for (1) predicting incident recurrent tuberculosis, (2) tuberculosis diagnosis and (3) its potential utility for tuberculosis treatment monitoring in HIV-infected individuals. We retrieved cryopreserved blood specimens from three previously completed clinical studies and measured the COR signature by quantitative microfluidic real-time-PCR. The signature differentiated recurrent tuberculosis progressors from non-progressors within 3 months of diagnosis with an area under the Receiver-operating characteristic (ROC) curve (AUC) of 0.72 (95% confidence interval (CI), 0.58-0.85) amongst HIV-infected individuals on antiretroviral therapy (ART). Twenty-five of 43 progressors (58%) were asymptomatic at microbiological diagnosis and thus had subclinical disease. The signature showed excellent diagnostic discrimination between HIV-uninfected tuberculosis cases and controls (AUC 0.97; 95%CI 0.94-1). Performance was lower in HIV-infected individuals (AUC 0.83; 95%CI 0.81-0.96) and signature scores were directly associated with HIV viral loads. Tuberculosis treatment response in HIV-infected individuals on ART with a new recurrent tuberculosis diagnosis was also assessed. Signature scores decreased significantly during treatment. However, pre-treatment scores could not differentiate between those who became sputum negative before and after 2 months. Direct application of the unmodified blood transcriptomic COR signature detected subclinical and active tuberculosis by blind validation in HIV-infected individuals. However, prognostic performance for recurrent tuberculosis, and performance as diagnostic and as treatment monitoring tool in HIV-infected persons was inferior to published results from HIV-negative cohorts. Our results suggest that performance of transcriptomic signatures comprising interferon stimulated genes are negatively affected in HIV-infected individuals, especially in those with incompletely suppressed viral loads.

Date:
2019-06-26

Authors:
Perumal P Padayatchi N Yende-Zuma N Naidoo A Govender D Naidoo K

Journal:
Clinical Infectious Diseases 2019 February.pii: ciz152. https://doi.org/10.1093/cid/ciz152

Content:

BACKGROUND: The substitution of moxifloxacin for ethambutol produced promising results for improved tuberculosis (TB) treatment outcomes.

METHOD: We conducted an open-label randomized trial to test whether a moxifloxacin-containing treatment regimen was superior to the standard regimen for the treatment of recurrent TB. The primary and secondary outcomes were sputum culture conversion rate at the end of 8 weeks and the proportion of participants with a favourable outcome, respectively.

RESULTS: We enrolled 196 participants; 69.9% were male and 70.4% were co-infected with HIV. There was no significant difference between the study groups in the proportion of patients achieving culture conversion at the end of 8 weeks [83.0% (Moxifloxacin) vs 78.5% (Control), p=0.463], however the median time to culture conversion was significantly shorter (6.0 weeks, IQR 4.0 - 8.3) in the moxifloxacin group than the control group (7.9 weeks, IQR 4.0- 11.4) (p=0.018). A favourable end-of-treatment outcome was reported in 86 participants (87.8%) in the moxifloxacin group and 93 participants (94.9%) in the control group, for an adjusted absolute risk difference of -5.5 (95% CI -13.8 to 2.8, p=0.193) percentage points. There was a significantly higher proportion of participants with grade 3 or 4 adverse events [43.9% (43/98) vs 25.5% (25/98), p=0.011] and serious adverse events [27.6% (27/98) vs 12.2% (12/98), p=0.012] in the moxifloxacin group.

CONCLUSION: Replacement of ethambutol with moxifloxacin did not significantly improve culture conversion rates at the end of 8 weeks or treatment success, and was associated with a higher incidence of adverse events.

Date:
2020-01-01

Authors:

Journal:
Clinical Infectious Diseases

Content:

A case of multidrug-resistant tuberculosis is presented. It highlights the role of whole-genome sequencing, expanded phenotypic drug susceptibility testing, and enhanced case management, offering a more complete understanding of drug susceptibility to Mycobacterium tuberculosis. This approach guides an effective individualized treatment strategy that results in rapid sustained culture conversion.

Date:
2020-12-30

Authors:

Journal:
International Journal of Tuberculosis and Lung Disease

Content:

No abstract available

Date:
2020-12-01

Authors:

Journal:
Journal of Infection

Content:

Human genomic mapping has advanced molecular medicine health care and created a transformative paradigm shift towards Precision Medicine. In 2015, President Obama launched the PM initiative, encapsulated as "unique individualized data-driven treatments". Since then, this field is rapidly advancing both curative treatment and disease prevention by accounting for both individual and environmental variability. While a substantial evidence for accelerating adoption of Precision Medicine in other spheres of medicine exists, application of Precision Medicine in infectious diseases is far more complex. One of the most warranted applications of precision healthcare is in the management and treatment of Drug-resistant Tuberculosis. Application of Precision Medicine to Drug-resistant Tuberculosis could potentially change the landscape of treatment and prevention of a disease affecting vulnerable patients in impoverished communities. Poorly diagnosed and treated Drug-resistant Tuberculosis not only leads to increased mortality and morbidity but also increased transmission of DR-TB strains, fuelling ongoing high incidence rates and further infection. A Precision medicine model using individual clinical case histories used in conjunction with Mycobacterium Tuberculosis infection genomic data will better guide health care practitioners in more appropriate drug selection, and an individualized management approach. This viewpoint deliberates the intricacies of adopting a PM approach in the management of DR-TB. If applied correctly, we postulate that the research, application, and deployment of PM in DR-TB management may address the fundamental rule of PM in infectious disease: to treat the correct patient, at the correct time, with the correct drug.

Date:
2019-04-30

Authors:

Journal:
Lancet HIV

Content:

Bedaquiline, a potent new therapy for drug-resistant tuberculosis, results in improved survival including in HIV patients with multidrug and extensively drug-resistant tuberculosis. In line with WHO recommendations, in South Africa and other low-income and middle-income settings, antiretroviral therapy is switched from generic fixed-dose combination efavirenz-containing regimens to twice-daily nevirapine with separate companion pills because of interactions between efavirenz and bedaquiline. Early data suggest a signal for low antiretroviral therapy adherence after this antiretroviral therapy switch. Mortality and other tuberculosis-specific benefits noted with bedaquiline treatment in multidrug and extensively drug-resistant tuberculosis HIV might be compromised by HIV viral failure, and emergent antiretroviral resistance. Programmatic responses, such as adherence support and dual pharmacovigilance, should be instituted; antiretroviral therapy initiation with fixed-dose combinations without bedaquiline drug interactions should be strongly considered.

Date:
2019-03-28

Authors:

Journal:
Scientific Reports

Content:

Improved tuberculosis diagnostics and tools for monitoring treatment response are urgently needed. We developed a robust and simple, PCR-based host-blood transcriptomic signature, RISK6, for multiple applications: identifying individuals at risk of incident disease, as a screening test for subclinical or clinical tuberculosis, and for monitoring tuberculosis treatment. RISK6 utility was validated by blind prediction using quantitative real-time (qRT) PCR in seven independent cohorts. Prognostic performance significantly exceeded that of previous signatures discovered in the same cohort. Performance for diagnosing subclinical and clinical disease in HIV-uninfected and HIV-infected persons, assessed by area under the receiver-operating characteristic curve, exceeded 85%. As a screening test for tuberculosis, the sensitivity at 90% specificity met or approached the benchmarks set out in World Health Organization target product profiles for non-sputum-based tests. RISK6 scores correlated with lung immunopathology activity, measured by positron emission tomography, and tracked treatment response, demonstrating utility as treatment response biomarker, while predicting treatment failure prior to treatment initiation. Performance of the test in capillary blood samples collected by finger-prick was noninferior to venous blood collected in PAXgene tubes. These results support incorporation of RISK6 into rapid, capillary blood-based point-of-care PCR devices for prospective assessment in field studies.

Date:
2020-05-25

Authors:

Journal:
Journal of the International AIDS Society

Content:

Introduction: Tuberculosis (TB) remains the most common cause of death among people living with HIV. Integrating HIV and TB services reduces mortality but is sub-optimally implemented. Quality improvement (QI) methods offer a low-cost and easily implementable approach to strengthening healthcare delivery systems. This trial assessed a QI intervention on key process indicators for delivering integrated HIV-TB care in rural South African primary healthcare (PHC) clinics.

Methods: Sixteen nurse supervisors, (each with a cluster of clinics) overseeing 40 PHC clinics, were randomized 1:1 to the intervention or the standard of care (SOC) groups. The QI intervention comprised three key components: clinical and QI skills training, on-site mentorship of nurse supervisors and clinic staff, and data quality improvement activities to enhance accuracy and completeness of routine clinic data. The SOC comprised monthly supervision and data feedback meetings. From 01 December 2016 to 31 December 2018, data were collected monthly by a team of study-appointed data capturers from all study clinics. This study's outcomes were HIV testing services (HTS), TB screening, antiretroviral therapy (ART) initiation, isoniazid preventive therapy (IPT) initiation and viral load (VL) testing.

Results: The QI group (eight clusters) comprised 244 clinic staff who attended to 13,347 patients during the trial compared to the SOC group (eight clusters) with 217 clinic staff who attended to 8141 patients. QI mentors completed 85% (510/600) of expected QI mentorship visits to QI clinics. HTS was 19% higher [94.5% vs. 79.6%; relative risk (RR)=1.19; 95% CI: 1.02-1.38; p=0.029] and IPT initiation was 66% higher (61.2 vs. 36.8; RR=1.66; 95% CI: 1.02-2.72; p=0·044), in the QI group compared to SOC group. The percentage of patients screened for TB (83.4% vs. 79.3%; RR=1.05; p=0.448), initiated on ART (91.7 vs. 95.5; RR=0.96; p=0.172) and VL testing (72.2% vs. 72.8%; RR=0.99; p=0.879) was similar in both groups.

Conclusions: QI improved HIV testing and IPT initiation compared to SOC. TB screening, ART initiation and VL testing remained similar. Incorporating QI methods into routine supervision and support activities may strengthen integrated HIV-TB service delivery and increase the success of future QI scale-up activities.

Trial registration: ClinicalTrials.gov NCT02654613.

Date:
2022-09-28

Authors:

Journal:
Frontiers in Immunology

Content:

Novel tuberculosis (TB) prevention and control strategies are urgently required. Utilising specimens from the Improving Retreatment Success (NCT02114684) trial we assessed the associations between inflammatory markers, measured during active TB, with treatment response and disease severity in HIV-infected and uninfected individuals. Multiplex immunoassays and ELISA were used to measure plasma expression of 24 cytokines/chemokines. Cytokines were log transformed to adjust for skewness. We conducted a nested, un-matched, case (n= 31) - control (n=101) study with cases defined as those participants who failed to sputum culture convert within 8-weeks of TB treatment initiation. Additionally, we examined the association between the measured cytokines and time to culture conversion and presence of lung cavitation using cox proportional hazards and logistic regression models, respectively. Multivariable analyses adjusted for a wide range of baseline clinical and demographic variables. IP-10 expression during active TB was associated with increased odds of sputum culture conversion by 8-weeks overall (aOR 4.255, 95% CI 1.025 - 17.544, p=0.046)) and among HIV-infected individuals (OR 10.204, 95% CI 1.247 - 83.333, p=0.030). Increased MCP-3 (aHR 1.723, 95% CI 1.040 - 2.855, p=0.035) and IL-6 (aHR 1.409, 95% CI 1.045 - 1.899, p=0.024) expression was associated with a shorter time to culture conversion in the total cohort. Higher plasma expression of IL-6 (aHR 1.783, 95% CI 1.128 - 2.820, p=0.013), IL-1RA (aHR 2.595, 95% CI 1.136 - 5.926, p=0.024), IP-10 (aHR 2.068, 95% CI 1.034 - 4.137, p=0.040) and IL-1α (aHR 2.008, 95% CI 1.053 - 3.831, p=0.035) were significantly associated with shorter time to culture conversion among HIV-infected individuals. Increased IL-6 and IL-1RA expression was significantly associated with the presence of lung cavitation during active TB in the total cohort (OR 2.543, 95% CI 1.254 - 5.160, p=0.010), (OR 4.639, 95% CI 1.203 - 21.031, p=0.047) and in HIV-infected individuals (OR 2.644, 95% CI 1.062 - 6.585, p=0.037), (OR 7.795, 95% CI 1.177 - 51.611, p=0.033) respectively. Our results indicate that inflammatory cytokines/chemokines play an important role in TB disease outcome. Importantly, the observed associations were stronger in multivariable models highlighting the impact of behavioural and clinical variables on the expression of immune markers as well as their potential effects on TB outcome.

Date:
2021-04-01

Authors:

Journal:
EClinicalMedicine

Content:

Background: HIV-TB treatment integration reduces mortality. Operational implementation of integrated services is challenging. This study assessed the impact of quality improvement (QI) for HIV-TB integration on mortality within primary healthcare (PHC) clinics in South Africa.

Methods: An open-label cluster randomized controlled study was conducted between 2016 and 2018 in 40 rural clinics in South Africa. The study statistician randomized PHC nurse-supervisors 1:1 into 16 clusters (eight nurse-supervisors supporting 20 clinics per arm) to receive QI, supported HIV-TB integration intervention or standard of care (control). Nurse supervisors and clinics under their supervision, based in the study health districts were eligible for inclusion in this study. Nurse supervisors were excluded if their clinics were managed by municipal health (different resource allocation), did not offer co-located antiretroviral therapy (ART) and TB services, services were performed by a single nurse, did not receive non-governmental organisation (NGO) support, patient data was not available for > 50% of attendees. The analysis population consists of all patients newly diagnosed with (i) both TB and HIV (ii) HIV only (among patients previously treated for TB or those who never had TB before) and (iii) TB only (among patients already diagnosed with HIV or those who were never diagnosed with HIV) after QI implementation in the intervention arm, or enrolment in the control arm. Mortality rates was assessed 12 months post enrolment, using unpaired t-tests and cox-proportional hazards model. (Clinicaltrials.gov, NCT02654613, registered 01 June 2015, trial closed).

Findings: Overall, 21 379 participants were enrolled between December 2016 and December 2018 in intervention and control arm clinics: 1329 and 841 HIV-TB co-infected (10·2%); 10 799 and 6 611 people living with Human Immunodeficiency Virus (HIV)/ acquired immunodeficiency syndrome (AIDS) (PLWHA) only (81·4%); 1 131 and 668 patients with TB only (8·4%), respectively. Average cluster sizes were 1657 (range 170-5782) and 1015 (range 33-2027) in intervention and control arms. By 12 months, 6529 (68·7%) and 4074 (70·4%) were alive and in care, 568 (6·0%) and 321 (5·6%) had completed TB treatment, 1078 (11·3%) and 694 (12·0%) were lost to follow-up, with 245 and 156 deaths occurring in intervention and control arms, respectively. Mortality rates overall [95% confidence interval (CI)] was 4·5 (3·4-5·9) in intervention arm, and 3·8 (2·6-5·4) per 100 person-years in control arm clusters [mortality rate ratio (MRR): 1·19 (95% CI 0·79-1·80)]. Mortality rates among HIV-TB co-infected patients was 10·1 (6·7-15·3) and 9·8 (5·0-18·9) per 100 person-years, [MRR: 1·04 (95% CI 0·51-2·10)], in intervention and control arm clusters, respectively.

Interpretation: HIV-TB integration supported by a QI intervention did not reduce mortality in HIV-TB co-infected patients. Demonstrating mortality benefit from health systems process improvements in real-world operational settings remains challenging. Despite the study being potentially underpowered to demonstrate the effect size, integration interventions were implemented using existing facility staff and infrastructure reflecting the real-world context where most patients in similar settings access care, thereby improving generalizability and scalability of study findings.

Funding: Research reported in this publication was supported by South African Medical Research Council (SAMRC), and UK Government's Newton Fund through United Kingdom Medical Research Council (UKMRC).

Keywords: Cluster randomized trial; HIV; Mortality; Primary healthcare; Quality improvement; TB/HIV integration.

Date:
2022-02-12

Authors:

Journal:
BMC Infectious Diseases

Content:

Background: Hepatitis B virus (HBV), Human Immunodeficiency virus (HIV) and Tuberculosis (TB) are common infections in South Africa. We utilized the opportunity of care provision for HIV-TB co-infected patients to better understand the relationship between these coinfections, determine the magnitude of the problem, and identify risk factors for HBV infection in HIV infected patients with and without TB in KwaZulu-Natal, South Africa.

Methods: This retrospective cohort analysis was undertaken in 2018. In-care HIV infected patients were included in the analysis. Results from clinical records were analysed to determine the prevalence, incidence, persistence and factors associated with HBsAg positivity in HIV-infected patients with or without TB co-infection.

Results: A total of 4292 HIV-infected patients with a mean age of 34.7 years (SD: 8.8) were included. Based on HBsAg positivity, the prevalence of HBV was 8.5% (363/4292) [95% confidence interval (CI): 7.7-9.3] at baseline and 9.4% (95%CI: 8.6-10.3%) at end of follow-up. The HBV incidence rate was 2.1/100 person-years (p-y). Risk of incident HBV infection was two-fold higher among male patients (HR 2.11; 95% CI: 1.14-3.92), while severe immunosuppression was associated with a greater than two-fold higher risk of persistent infection (adjusted risk ratio (RR) 2.54; 95% CI 1.06-6.14; p = 0.004. Additionally, active TB at enrolment was associated with a two-fold higher risk of incident HBV infection (aHR 2.38; 95% CI: 0.77-7.35).

Conclusion: The provision of HIV care and treatment in high HBV burden settings provide a missed opportunity for HBV screening, immunization and care provision.

Date:
2020-11-16

Authors:

Journal:
Frontiers in Cellular and Infection Microbiology

Content:

Several studies described the presence of non-replicating, drug-tolerant differentially culturable tubercle bacteria (DCTB) in sputum from patients with active tuberculosis (TB). These organisms are unable to form colonies on agar but can be recovered in liquid media supplemented with culture filtrate as a source of growth factors. Herein, we undertook to investigate the response of DCTB during the treatment of individuals with drug-resistant TB. A cohort of 100 participants diagnosed with rifampicin-resistant TB were enrolled and prospectively followed to monitor response to therapy using routine culture and limiting dilution assays, supplemented with culture filtrate (CF) to quantify DCTB. Fifteen participants were excluded due to contamination, and of the remaining 85 participants, 29, 49, and 7 were infected with rifampicin mono-resistant (RMR), multidrug-resistant (MDR), or extremely drug-resistant (XDR) TB, respectively. Analysis of baseline sputum demonstrated that CF supplementation of limiting dilution assays detected notable amounts of DCTB. Prevalence of DCTB was not influenced by smear status or mycobacterial growth indicator tube time to positivity. CF devoid of resuscitation promoting factors (Rpfs) yielded a greater amount of DCTB in sputum from participants with MDR-TB compared with those with RMR-TB. A similar effect was noted in DCTB assays without CF supplementation, suggesting that CF is dispensable for the detection of DCTB from drug-resistant strains. The HIV status of participants, and CD4 count, did not affect the amount of DCTB recovered. During treatment with second-line drug regimens, the probability of detecting DCTB from sputum specimens in liquid media with or without CF was higher compared with colony forming units, with DCTB detected up to 16 weeks post treatment. Collectively, these data point to differences in the ability of drug-resistant strains to respond to CF and Rpfs. Our findings demonstrate the possible utility of DCTB assays to diagnose and monitor treatment response for drug-resistant TB, particularly in immune compromised individuals with low CD4 counts.

 

Date:
2022-09-09

Authors:
Naidoo A McIlleron H Naidoo K Yende-Zuma N Singh R Ncgapu S Adamson J Govender K Denti P Padayatchi N

Journal:
Pharmacogenomics

Content:

AIM: We report the prevalence and effect of genetic variability on pharmacokinetic parameters of isoniazid and rifampicin.

MATERIALS & METHODS: Genotypes for SLCO1B1, NAT2, PXR, ABCB1 and UGT1A genes were determined using a TaqMan® Genotyping OpenArray™. Nonlinear mixed-effects models were used to describe drug pharmacokinetics.

RESULTS: Among 172 patients, 18, 43 and 34% were classified as rapid, intermediate and slow NAT2 acetylators, respectively. Of the 58 patients contributing drug concentrations, rapid and intermediate acetylators had 2.3- and 1.6-times faster isoniazid clearance than slow acetylators. No association was observed between rifampicin pharmacokinetics and SLCO1B1, ABCB1, UGT1A or PXR genotypes.

CONCLUSION: Clinical relevance of the effects of genetic variation on isoniazid concentrations and low first-line tuberculosis drug exposures observed require further investigation.

Date:
2019-02-15

Authors:

Journal:
International Journal of Tuberculosis and Lung Disease

Content:

BACKGROUND: Pharmacokinetic variability arising from drug-drug interactions and pharmacogenetics may influence the effectiveness of treatment regimens for TB. The Improving Treatment Success Trial compared the WHO-recommended standard treatment in TB patients with an experimental regimen substituting ethambutol with moxifloxacin (MFX) in Durban, South Africa.

METHODS: Non-linear mixed-effects modelling was used to investigate the population pharmacokinetics of rifampicin (RIF), isoniazid (INH) and pyrazinamide (PZA). A total of 25 single-nucleotide polymorphisms, including pregnane-X-receptor, were selected for analysis.

RESULTS: TB drug concentrations were available in a subset of 101 patients: 58 in the MFX arm and 43 in the control arm. Baseline characteristics were well-balanced between study arms: median age and weight were respectively 36 years and 57.7 kg; 75.2% of the patients were living with HIV. Although weight-based drug dosing was the same in the two arms, we found that RIF exposure was increased by 19.3%, INH decreased by 19% and PZA decreased by 19.2% when administered as part of the MFX-containing regimen. Genetic variation in pregnane-X-receptor (rs2472677) was associated with a 25.3% reduction in RIF exposure.

CONCLUSION: Optimised weight-based TB treatment dosing is essential when RIF, INH and PZA are co-administered with fluoroquinolones. The reduction in RIF exposure associated with pharmacogenetic variation is worrying.

Date:
2022-08-01

Authors:

Journal:
Frontiers in Immunology

Content:

There is an urgent need to identify immunological markers of tuberculosis (TB) risk in HIV co-infected individuals. Previously we have shown that TB recurrence in HIV co-infected individuals on ART was associated with markers of systemic inflammation (IL-6, IL1β and IL-1Rα). Here we examined the effect of additional acute inflammation and microbial translocation marker expression on risk of TB recurrence. Stored plasma samples were drawn from the TB Recurrence upon Treatment with HAART (TRuTH) study, in which individuals with previously treated pulmonary TB were screened for recurrence quarterly for up to 4 years. Recurrent TB cases (n = 37) were matched to controls (n = 102) by original trial study arm assignment and ART start date. Additional subsets of HIV infected (n = 41) and HIV uninfected (n = 37) individuals from Improving Recurrence Success (IMPRESS) study were sampled at active TB and post successful treatment completion. Plasma concentrations of soluble adhesion molecules (sMAdCAM, sICAM and sVCAM), lipopolysaccharide binding protein (LBP) and transforming growth factor-beta (TGF-β1, TGF-β2, TGF-β3) were measured by multiplex immunoassays and ELISA. Cytokine data was square root transformed in order to reduce variability. Multivariable analysis adjusted for a number of potential confounders measured at sample time-point: age, BMI, CD4 count, viral load (VL) and measured at baseline: presence or absence of lung cavities, previous history of TB, and WHO disease stage (4 vs 3). The following analytes were associated with increased risk of TB recurrence in the multivariable model: sICAM (aOR 1.06, 95% CI: 1.02-1.12, p = 0.009), LBP (aOR 8.78, 95% CI: 1.23-62.66, p = 0.030) and TGF-β3 (aOR 1.44, 95% CI 1.01-2.05, p = 0.044). Additionally, we observed a positive correlation between LBP and sICAM (r= 0.347, p<0.0001), and LBP and IL-6, identified to be one of the strongest predictors of TB risk in our previous study (r=0.623, p=0.03). These data show that increased risk of TB recurrence in HIV infected individuals on ART is likely associated with HIV mediated translocation of microbial products and the resulting chronic immune activation.

Date:
2021-03-25

Authors:

Journal:
International Journal Tuberculosis and Lung Disease

Content:

Low serum concentrations of first-line tuberculosis (TB) drugs have been widely reported. However, the impact of low serum concentrations on treatment outcome is less well studied. A systematic search of MEDLINE/Pubmed and the Cochrane Central Register of Controlled Trials up to 31 March 2018 was conducted for articles describing drug concentrations of first-line TB drugs and treatment outcome in adult patients with drug-susceptible TB. The search identified 3073 unique publication abstracts, which were reviewed for suitability: 21 articles were acceptable for inclusion in the qualitative analysis comprising 13 prospective observational cohorts, 4 retrospective observational cohorts, 1 case-control study and 3 randomised controlled trials. Data for meta-analysis were available for 15 studies, 13 studies of rifampicin (RMP), 10 of isoniazid (INH), 8 of pyrazinamide (PZA) and 4 of ethambutol (EMB). This meta-analysis revealed that low PZA concentration appears to increase the risk of poor outcomes (8 studies, n = 2727; RR 1.73, 95%CI 1.10-2.72), low RMP concentrations may slightly increase the risk of poor outcomes (13 studies, n = 2753; RR 1.40, 95%CI 0.91-2.16), whereas low concentrations of INH (10 studies, n = 2640; RR 1.32, 95%CI 0.66-2.63) and EMB (4 studies, n = 551; RR 1.12, 95%CI 0.41-3.05) appear to make no difference to treatment outcome. There was no significant publication bias or between-study heterogeneity in any of the analyses. The potential clinical impact of low concentrations of PZA and RMP warrants further evaluation. Also, comprehensive assessments of the complex pharmacokinetic-pharmacodynamic relationships in the treatment of TB are urgently needed.

Date:
2020-01-01

Authors:
Naidoo A Ramsuran V Chirehwa M Denti P McIlleron H Naidoo K Yende-Zuma N Singh R Ngcapu S Chaudhry M Pepper MS Padayatchi N

Journal:
Pharmacogenomics 2018 January; 19(1):17-29. doi: 10.2217/pgs-2017-0144. PMC5753622

Content:

AIM: We assessed the effect of genetic variability in UGT1A and ABCB1 genes on moxifloxacin pharmacokinetics.

METHODS: Genotypes for selected UGT1A and ABCB1 SNPs were determined using a TaqMan® Genotyping OpenArray and high-resolution melt analysis for rs8175347. A nonlinear mixed-effects model was used to describe moxifloxacin pharmacokinetics.

RESULTS:Genotypes of UGT1A SNPs, rs8175347 and rs3755319 (20.6% lower and 11.6% increased clearance, respectively) and ABCB1 SNP rs2032582 (40% reduced bioavailability in one individual) were significantly associated with changes in moxifloxacin pharmacokinetic parameters.

CONCLUSION:Genetic variation in UGT1A as represented by rs8175347 to a lesser extent rs3755319 and the ABCB1 rs2032582 SNP is modestly associated with the interindividual variability reported in moxifloxacin pharmacokinetics and exposure. Clinical relevance of the effects of genetic variation on moxifloxacin pharmacokinetic requires further investigation.

Date:
2018-01-30

Authors:

Journal:
Lancet Global Health

Content:

Background: There is little evidence of patient acceptability for drug-resistant tuberculosis (DRTB) care in the context of new treatment regimens and HIV co-infection. We aim to describe experiences of DRTB-HIV care among patients in KwaZulu-Natal province, South Africa.

Methods: In this qualitative study using Bury's framework for chronic illness, we conducted 13 focus groups at a tertiary hospital with 55 patients co-infected with DRTB and HIV (28 women, 27 men) who were receiving new bedaquiline-based treatment for DRTB, concurrent with antiretroviral therapy. Eligible patients were consenting adults (aged >18 years) with confirmed DRTB and HIV who were enrolled into the PRAXIS study within 2 weeks of initiating bedaquiline-based treatment for DRTB. Participants were recruited from the PRAXIS cohort to participate in a focus group based on their time in DRTB treatment: early (2-6 weeks after treatment initiation), middle (2-6 months after discharge or treatment initiation if never hospitalised), and late (>6 months after treatment initiation). Focus groups were carried out in isiZulu language, audio recorded, and translated to English within 4 weeks. Participants were asked about their experiences of DRTB and HIV care and treatment, and qualitative data were coded and thematically analysed.

Findings: From March, 2017, to June, 2018, distinctive patient challenges were identified at four critical stages of DRTB care: diagnosis, marked by centralised hospitalisation, renunciation from routine life, systemic stigmatisation and, for patients with longstanding HIV, renewed destabilisation; treatment initiation, marked by side-effects, isolation, and social disconnectedness; discharge, marked by brief respite and resurgent therapeutic and social disruption; and continuity, marked by deepening socioeconomic challenges despite clinical recovery. The periods of diagnosis and discharge into the community were particularly difficult. Treatment information and agency in decision making was a persistent gap. Sources of stigmatisation shifted with movement between the hospital and community. Resilience was built by connecting to peers, self-isolating, financial and material security, and a focus on recovery.

Interpretation: People with DRTB and HIV undergo disruptive, life-altering experiences. The lack of information, agency, and social protections in DRTB care and treatment causes wider-reaching challenges for patients compared with HIV. Decentralised, community, peer-support, and differentiated care models for DRTB might be ameliorative and help to maximise the promise of new regimens.

Date:
2021-04-28

Authors:

Journal:
South African medical journal

Content:

Background: Optimal drug levels and minimal toxicity are critical factors in improving treatment outcomes for patients prescribed new and repurposed medicine for drug-resistant (DR) tuberculosis (TB). The optimal dose and dose-related safety of clofazimine (CFZ), a repurposed medicine for DR TB, in the South African (SA) population are unknown.

Objectives: To report on dose-related adverse events in patients receiving CFZ plus a background regimen for DR TB.

Methods: In a retrospective review of patient folders from 2012 to 2014, adverse events documented for patients receiving high- (≥200 mg) and low-dose (100 mg) CFZ in a centralised DR TB hospital in KwaZulu-Natal Province, SA, were investigated for an association between dose-weight interactions and adverse events.

Results: Of 600 patients included, 78.7% (n=472) weighed ≥50 kg. Of these, 17.4% (n=82) received 100 mg CFZ and 82.6% (n=390) received &gt;200 mg. Of 128 patients (21.3%) who weighed &lt;50 kg, 68.0% (n=87) received 100 mg CFZ and 32.0% (n=41) received ≥200 mg. Of 463 patients (77.2%) who were HIV-positive, 94.0% were on antiretrovirals. There was no difference between the dose-weight cohorts in the background regimen given in addition to high- or low-dose CFZ. The frequency and types of adverse events observed were similar to the published literature. When analysed per dose-weight cohort, patients weighing &lt;50 kg and receiving high-dose CFZ (≥200 mg) had a 2.6 times higher risk of any adverse event (adjusted odds ratio (aOR) 2.57; 95% confidence interval (CI) 1.02 - 6.05; p=0.05: reference category &lt;50 kg and 100 mg). Patients weighing &lt;50 kg and receiving high-dose CFZ had a 3.3 times higher risk of gastrointestinal adverse events than patients weighing &lt;50 kg and receiving 100 mg CFZ (aOR 3.30; 95% CI 1.51 - 7.19; p=0.003). A high risk of chest pain was observed in patients receiving high- and low-dose CFZ, irrespective of weight. Patients weighing &lt;50 kg receiving high-dose CFZ had a slightly higher risk of adverse events related to the skin (aOR 1.2; 95% CI 0.55 - 2.62; p=0.7) There were no documented reports of the CFZ dose being reduced or the drug being stopped due to adverse events in the sample population.

Conclusions: There is an association between dose-weight interaction and adverse events. The odds of any adverse event occurring were higher when low-weight patients (&lt;50 kg) received high-dose CFZ (≥200 mg). Gastrointestinal and skin-related adverse events were more common when high-dose CFZ was used in patients weighing &lt;50 kg. Chest pain was reported in patients receiving high- and low-dose CFZ, irrespective of weight, and may be a symptom of cardiac toxicity. Plasma concentrations of CFZ may be affected by drug-drug interactions, so active drug safety monitoring including electrocardiograms is recommended routinely when CFZ is part of the regimen.

Date:
2019-12-12

Authors:

Journal:
JAIDS

Content:

Background: Novel regimens have revolutionized multidrug-resistant tuberculosis (MDR-TB) treatment; however, medication adherence remains challenging and poorly characterized. We hypothesized that bedaquiline adherence, measured using electronic dose monitoring, would predict MDR-TB treatment outcomes.

Setting: This is a prospective cohort study conducted in KwaZulu-Natal, South Africa.

Methods: Adults with MDR-TB and HIV initiating bedaquiline and on antiretroviral therapy (ART) were eligible. Separate electronic dose monitoring devices measured bedaquiline and ART adherence through 6 months, calculated as observed versus expected doses. Whole-genome sequencing was performed to identify bedaquiline resistance-associated variants.

Results: From November 2016 through February 2018, 199 participants with MDR-TB and HIV were enrolled and followed up through treatment completion (median 17.2 months interquartile range 12.2-19.6). The median bedaquiline adherence was higher than ART adherence (97 vs. 89%, P < 0.001) but correlated (r2 = 0.68, P < 0.001). High bedaquiline adherence (≥90%) compared with lower adherence was associated with improved end of treatment successful outcome (83.4% vs. 46.3%, P < 0.001), decreased mortality (11.0% vs. 29.6% P = 0.004), and improved retention in care through end of treatment (94.5% vs. 79.6% P = 0.002). Modeling identified a highly significant but linear association between bedaquiline adherence and outcome. On multivariable analysis, bedaquiline adherence was independently associated with mortality and outcome. Bedaquiline resistance-associated variants were seen in 12% (7/57) of sequenced isolates (7% baseline, 5% emergent) with only 28.6% experiencing successful treatment outcome.

Conclusions: Bedaquiline adherence through 6 months independently predicted end of MDR-TB treatment outcome, but a specific bedaquiline adherence threshold was not identified. Interventions to optimize bedaquiline adherence are urgently needed to improve MDR-TB HIV treatment outcomes.

Date:
2022-07-01

Authors:

Journal:
Social psychiatry and psychiatric epidemiology

Content:

Purpose: Household food insecurity in South Africa is a pervasive public health challenge. Although its link to chronic health conditions is well established, its relationship to mental illness, particularly major depression, is not well-understood. Despite KwaZulu-Natal Province being the epicenter of the drug-resistant tuberculosis (MDR-TB) epidemic, and having the largest share of poverty in South Africa, this relationship remains unexamined. This study investigated the association between major depressive episode (MDE) and household food insecurity among individuals with MDR-TB.

Methods: We enrolled and interviewed 141 newly admitted microbiologically confirmed MDR-TB inpatients at a specialized TB hospital in KwaZulu-Natal Province, South Africa. Logistic regression models were fitted to assess the relationship between MDE and household food insecurity, while accounting for socio-demographic status (e.g., age, gender, education, marital status, social grant status, income, and preference for living in one's community).

Results: The prevalence of MDE and household food insecurity was 11.35% and 21.01%, respectively. MDE was significantly associated with household food insecurity (aOR 4.63, 95% CI 1.17-18.38). Individuals who are female (aOR 6.29, 95% CI 1.13-35.03), young (aOR 8.86, 95% CI 1.69-46.34), have low educational attainment (aOR 6.19, 95% CI 1.70-22.59) and receive social grants (aOR 7.60, 95% CI 2.36-24.48) were most at risk of household food insecurity.

Conclusions: MDE in individuals with MDR-TB was significantly associated with household food insecurity, independent of socio-economic status. Although MDR-TB is not exclusively a disease of the poor, individuals from socio-economically disadvantaged backgrounds (e.g., female, young adults, low education, and social grant recipients) were more likely to experience household food insecurity. Our study underscores the need to address the co-occurring cycles of food insecurity and untreated MDE in South Africa.

Date:
2019-03-28

Authors:

Journal:
BMC Infectious Diseases

Content:

ackground: There is a need for innovative strategies to improve TB testing uptake and patient retention along the continuum of TB care early-on in treatment without burdening under-resourced health systems. We used a mixed methods approach to develop and pilot test a tuberculosis literacy and counselling intervention at an urban clinic in KwaZulu Natal, South Africa, to improve TB testing uptake and retention in tuberculosis care.

Methods: We engaged in discussions with clinic staff to plan and develop the intervention, which was delivered by senior social work students who received one-week training. The intervention included: 1) group health talks with all patients attending the primary clinic; and 2) individual counselling sessions, using motivational interviewing techniques, with newly diagnosed tuberculosis patients. We compared social work students' tuberculosis knowledge, attitudes, and practices before and after their training. We assessed the change in number of tuberculosis diagnostic tests performed after implementation via an interrupted time series analysis with a quasi-Poisson regression model. We compared pre- and post-intervention probabilities of treatment initiation and completion using regression analyses, adjusting for potential baseline confounders. We conducted focus groups with the students, as well as brief surveys and one-on-one interviews with patients, to assess acceptability, feasibility, and implementation.

Results: During the study period, 1226 individuals received tuberculosis diagnostic testing and 163 patients started tuberculosis treatment, of whom 84 (51.5%) received individual counselling. The number of diagnostic tuberculosis tests performed increased by 1.36 (95%CI 1.23-1.58) times post-intervention, adjusting for background calendar trend. Probabilities of TB treatment initiation and treatment completion increased by 10.1% (95%CI 1.5-21.3%) and 4.4% (95%CI -7.3-16.0%), respectively. Patients found the counselling sessions alleviated anxiety and increased treatment self-efficacy. Social work students felt the clinic staff were collaborative and highly supportive of the intervention, and that it improved patient engagement and adherence.

Conclusions: Engaging clinic staff in the development of an intervention ensures buy-in and collaboration. Education and counselling before and early-on in tuberculosis treatment can increase tuberculosis testing and treatment uptake. Training junior social workers can enable task-shifting in under-resourced settings, while addressing important service gaps in tuberculosis care.

Date:
2021-05-18

Authors:

Journal:
European Respiratory Journal

Content:

Abstract

The global loss to follow-up (LTFU) rate among drug-resistant tuberculosis (DR-TB) patients remains high at 15%. We conducted a systematic review to explore interventions to reduce LTFU during DR-TB treatment.We searched for studies published between January 2000 and December 2017 that provided any form of psychosocial or material support for patients with DR-TB. We estimated point estimates and 95% confidence intervals of the proportion LTFU. We performed subgroup analyses and pooled estimates using an exact binomial likelihood approach.We included 35 DR-TB cohorts from 25 studies, with a pooled proportion LTFU of 17 (12-23)%. Cohorts that received any form of psychosocial or material support had lower LTFU rates than those that received standard care. Psychosocial support throughout treatment, via counselling sessions or home visits, was associated with lower LTFU rates compared to when support was provided through a limited number of visits or not at all.Our review suggests that psychosocial support should be provided throughout DR-TB treatment in order to reduce treatment LTFU. Future studies should explore the potential of providing self-administered therapy complemented with psychosocial support during the continuation phase.

Date:
2019-01-10

Authors:

Journal:
International Journal Tuberculosis and Lung Disease

Content:

ACKGROUND: Bedaquiline (BDQ) has not been extensively studied among patients co-infected with HIV drug-resistant tuberculosis (DR-TB). We compared treatment outcomes in DR-TB patients treated with BDQ- and linezolid (LZD) containing regimens to historic controls treated with second-line injectable-containing regimens.METHODS: Retrospective cohort study of consecutive DR-TB patients initiated on BDQ- and LZD-containing regimens at a TB referral hospital in KwaZulu-Natal, South Africa. Participants were prospectively followed through 24 months for treatment outcome and adverse events. Outcomes were compared to a historic control cohort of DR-TB HIV patients enrolled at the same facility prior to BDQ introduction.RESULTS: Adult DR-TB patients initiating BDQ between January 2014 and November 2015 were enrolled (n = 151). The majority of patients were female (52%), HIV co-infected (77%) and on antiretroviral therapy (100%). End of treatment outcomes included cure (63%), TB culture conversion (83%), completion (0.7%), loss to follow-up (15%), treatment failure (5%), and death (17%). Compared to historic controls (n = 105), patients treated with BDQ experienced significantly higher TB culture conversion and cure, with significantly lower mortality. Adverse effects were common (92%), and most frequently attributed to LZD (24.1%). QT segment prolongation was common but without clinical sequelae.CONCLUSION: Treatment with BDQ- and LZD-containing regimens was associated with improved treatment outcomes and survival in DR-TB HIV patients.

Date:
2020-10-01

Authors:

Journal:
PLoS One

Content:

Background: Adverse events (AEs) during drug-resistant tuberculosis (DR-TB) treatment, especially with human immunodeficiency virus (HIV) co-infection, remains a major threat to poor DR-TB treatment adherence and outcomes. This meta-analysis aims to investigate the effect of HIV infection on the development of AEs during DR-TB treatment.

Methods: Eligible studies evaluating the association between HIV seropositivity and risks of AE occurrence in DR-TB patients were included in this systematic review. Interventional and observational studies were assessed for risk of bias using the Risk of Bias in Nonrandomized Studies of Intervention and Newcastle-Ottawa Scale tool, respectively. Random-effects meta-analysis was performed to estimate the pooled risk ratio (RR) along with their 95% confidence intervals (CIs).

Results: A total of 37 studies involving 8657 patients were included in this systematic review. We discovered that HIV infection independently increased the risk of developing AEs in DR-TB patients by 12% (RR 1.12 [95% CI: 1.02-1.22]; I2 = 0%, p = 0.75). In particular, the risks were more accentuated in the development of hearing loss (RR 1.44 [95% CI: 1.18-1.75]; I2 = 60%), nephrotoxicity (RR 2.45 [95% CI: 1.20-4.98], I2 = 0%), and depression (RR 3.53 [95% CI: 1.38-9.03]; I2 = 0%). Although our findings indicated that the augmented risk was primarily driven by antiretroviral drug usage rather than HIV-related immunosuppression, further studies investigating their independent effects are required to confirm our findings.

Conclusion: HIV co-infection independently increased the risk of developing AEs during DR-TB treatment. Increased pharmacovigilance through routine assessments of audiological, renal, and mental functions are strongly encouraged to enable prompt diagnosis and treatment in patients experiencing AEs during concomitant DR-TB and HIV treatment.

Date:
2021-03-04

Authors:

Journal:
Journal of Antimicrobial Chemotherapy

Content:

Objectives: To determine the impact of pretreatment low-abundance HIV-1 drug-resistant variants (LA-DRVs) on virological failure (VF) among HIV-1/TB-co-infected individuals treated with NNRTI first-line ART.

Methods: We conducted a case-control study of 170 adults with HIV-1/TB co-infection. Cases had at least one viral load (VL) ≥1000 RNA copies/mL after ≥6 months on NNRTI-based ART, and controls had sustained VLs <1000 copies/mL. We sequenced plasma viruses by Sanger and MiSeq next-generation sequencing (NGS). We assessed drug resistance mutations (DRMs) using the Stanford drug resistance database, and analysed NGS data for DRMs at ≥20%, 10%, 5% and 2% thresholds. We assessed the effect of pretreatment drug resistance (PDR) on VF.

Results: We analysed sequences from 45 cases and 125 controls. Overall prevalence of PDR detected at a ≥20% threshold was 4.7% (8/170) and was higher in cases than in controls (8.9% versus 3.2%), P = 0.210. Participants with PDR at ≥20% had almost 4-fold higher odds of VF (adjusted OR 3.7, 95% CI 0.8-18.3) compared with those without, P = 0.104. PDR prevalence increased to 18.2% (31/170) when LA-DRVs at ≥2% were included. Participants with pretreatment LA-DRVs only had 1.6-fold higher odds of VF (adjusted OR 1.6, 95% CI 0.6-4.3) compared with those without, P = 0.398.

Conclusions: Pretreatment DRMs and LA-DRVs increased the odds of developing VF on NNRTI-based ART, although without statistical significance. NGS increased detection of DRMs but provided no additional benefit in identifying participants at risk of VF at lower thresholds. More studies assessing mutation thresholds predictive of VF are required to inform use of NGS in treatment decisions.

Date:
2020-11-01

Authors:

Journal:
Lancet Infectious Disease

Content:

The emergence and expansion of the multidrug-resistant tuberculosis epidemic is a threat to the global control of tuberculosis. Multidrug-resistant tuberculosis is the result of the selection of resistance-conferring mutations during inadequate antituberculosis treatment. However, HIV has a profound effect on the natural history of tuberculosis, manifesting in an increased rate of disease progression, leading to increased transmission and amplification of multidrug-resistant tuberculosis. Interventions specific to HIV-endemic areas are urgently needed to block tuberculosis transmission. These interventions should include a combination of rapid molecular diagnostics and improved chemotherapy to shorten the duration of infectiousness, implementation of infection control measures, and active screening of multidrug-resistant tuberculosis contacts, with prophylactic regimens for individuals without evidence of disease. Development and improvement of the efficacy of interventions will require a greater understanding of the factors affecting the transmission of multidrug-resistant tuberculosis in HIV-endemic settings, including population-based molecular epidemiology studies. In this Series article, we review what we know about the transmission of multidrug-resistant tuberculosis in settings with high burdens of HIV and define the research priorities required to develop more effective interventions, to diminish ongoing transmission and the amplification of drug resistance.

Date:
2019-03-31

Authors:

Journal:
Journal of Clinical Tuberculosis and Other Mycobacterial Diseases

Content:

Tuberculosis (TB) is the leading infectious cause of death among people living with HIV, causing one third of AIDS-related deaths globally. The concerning number of missing TB cases, ongoing high TB mortality, slow reduction in TB incidence, and limited uptake of TB preventive treatment among people living with HIV, all indicate the urgent need to improve quality of TB services within HIV programs. In this mini-review we discuss major gaps in quality of TB care that impede achieving prevention and treatment targets within the TB-HIV care cascades, show approaches of assessing gaps in TB service provision, and describe outcomes from innovative quality improvement projects among HIV and TB programs. We also offer recommendations for measuring quality of TB care.

Date:
2019-09-20

Authors:

Journal:
Health Hum Rights

Content:

No abstract available

Date:
2022-06-22

Authors:

Journal:
Tropical Medicine & International Health

Content:

Objectives: Optimising medication adherence is one of the essential factors in reversing the tide of a TB-HIV syndemic in sub-Saharan Africa, especially South Africa. Impairment in key neurocognitive domains may impair patients' ability to maintain adherence to treatment, but the level of cognition and its relationship to HIV status has not been examined in individuals with drug-resistant TB. We therefore investigated performance on several key neurocognitive domains in relationship to HIV status in a multidrug-resistant tuberculosis patients (MDR-TB) sample.

Methods: We enrolled microbiologically confirmed MDR-TB inpatients at a TB-specialist referral hospital in KwaZulu-Natal province, South Africa. We collected cross-sectional data on sociodemographic, clinical and neurocognitive function (e.g. attention, memory, executive functioning, language fluency, visual-spatial, eye-hand coordination). For the primary analysis, we excluded participants with major depressive episode/substance use disorder (MDE/SUD). We fitted adjusted Poisson regression models to explore the association between HIV and neurocognitive function.

Results: We enrolled 200 people with MDR-TB; 33 had MDE/SUD, and data of 167 were analysed (151 HIV+, 16 HIV-). The mean age of participants was 34.2 years; the majority were female (83%), and 53% had not completed secondary school. There was evidence of impaired neurocognitive functioning across all domains in both HIV+/- study participants. Based on the regression analyses, individuals with co-infection (MDR-TB/HIV+), as well as those who had longer duration of hospital stays experienced significantly lower cognitive performance in several domains. Poor cognitive performance was significantly related to older age and lower educational attainment. The presence of major depression or substance use disorders did not influence the significance of the findings.

Conclusions: Adults with MDR-TB have significant neurocognitive impairment, especially if HIV positive. An integrated approach is necessary in the management of MDR-TB as cognitive health influences the ability to adhere to chronic treatment, clinical outcomes and functionality.

Date:
2020-08-31

Authors:
Naidoo K Dookie N Naidoo K Yende-Zuma N Chimukangara B Bhushan A Govender D Gengiah S Padayatchi N

Journal:
Infection and Drug Resistance 2018 Sept; 11:1413-21. doi: 10.2147/IDR.S150644. PMC6130302

Content:

Background: Recurrent tuberculosis (TB) following TB treatment completion in HIV-infected individuals remains a major public health burden. We assessed the role of various risk factors in mediating the development of recurrent TB and subsequent resistance to antiretroviral therapy and anti-TB drugs.

Patients and methods: We analyzed secondary demographic, clinical, and laboratory data from medical records of five HIV-infected TB patients enrolled between 2009 and 2014 in a prospective observational study investigating TB recurrence. Paired clinical isolates of Myco-bacterium tuberculosis were typed by IS6110 restriction fragment length polymorphism analysis to determine the mechanism of TB recurrence. Plasma samples were genotyped to determine acquisition of HIV drug resistance mutations on antiretroviral treatment (ART).

Results: All five patients were HIV-coinfected, with a previous history of TB infection and prior exposure to anti-TB treatment, and residual lung damage, and demonstrated poor treatment adherence - significant risk factors linked to the development of recurrent TB disease. Furthermore, three of the five patients had multiple episodes of drug-susceptible TB infection with subsequent drug-resistant TB infection. Genotyping of the initial and recurrent M. tuberculosis isolates demonstrated three cases of recurrent TB because of relapse and two because of reinfection. All five patients had no mutations at ART initiation; however, by the end of the study follow-up, all patients developed dual class resistance.

Conclusion: This series demonstrates the complexity of recurrent TB in HIV coinfection. We highlight the challenges of managing coinfected patients and the increased propensity for the development of drug resistance. We report on the role of various risk factors mediating the development of resistance and subsequent clinical impact. This report underscores the need for structural clinical and adherence interventions for the management of complex treatment and dosing.

Date:
2018-09-05

Authors:

Journal:
European Respiratory Journal

Content:

Genetic mutations linked to bedaquiline resistance were found before starting treatment and acquired during treatment in patients with drug-resistant TB and HIV in KwaZulu-Natal, South Africa. Routine bedaquiline resistance testing needs to be accelerated. http://bit.ly/2vnL4VY

Date:
2020-06-04

Authors:

Journal:
Frontiers in Immunology

Content:

The World Health Organization's End TB Strategy prioritizes universal access to an early diagnosis and comprehensive drug susceptibility testing (DST) for all individuals with tuberculosis (TB) as a key component of integrated, patient-centered TB care. Next generation whole genome sequencing (WGS) and its associated technology has demonstrated exceptional potential for reliable and comprehensive resistance prediction for Mycobacterium tuberculosis isolates, allowing for accurate clinical decisions. This review presents a descriptive analysis of research describing the potential of WGS to accelerate delivery of individualized care, recent advances in sputum-based WGS technology and the role of targeted sequencing for resistance detection. We provide an update on recent research describing the mechanisms of resistance to new and repurposed drugs and the dynamics of mixed infections and its potential implication on TB diagnosis and treatment. Whilst the studies reviewed here have greatly improved our understanding of recent advances in this arena, it highlights significant challenges that remain. The wide-spread introduction of new drugs in the absence of standardized DST has led to rapid emergence of drug resistance. This review highlights apparent gaps in our knowledge of the mechanisms contributing to resistance for these new drugs and challenges that limit the clinical utility of next generation sequencing techniques. It is recommended that a combination of genotypic and phenotypic techniques is warranted to monitor treatment response, curb emerging resistance and further dissemination of drug resistance.

Keywords: drug-resistance; mixed infection; next-generation sequencing; resistance mechanisms; targeted sequencing; tuberculosis; whole genome sequencing.

Date:
2022-03-24

Authors:

Journal:
BMJ Global Health

Content:

Tuberculosis (TB) remains an enormous public health concern globally. India and South Africa rank among the top 10 high TB burden countries with the highest absolute burden of TB, and the second highest rate of TB incidence, respectively. Although the primary drivers of TB transmission vary considerably between these two countries, they do indeed share common themes. In 2017, only 64% of the global estimated incident cases of TB were reported, the remaining 36% of 'missing' cases were either undiagnosed, untreated or unreported. These 'missing TB cases' have generated much hype for the challenges they present in achieving the End TB Strategy. Although India and South Africa have indeed made significant strides in TB control, analysis of the patient cascade of care clearly suggests that these 'missed' patients are not really missing-most are actively engaging the health system-the system, however, is failing to appropriately manage them. In short, quality of TB care is suboptimal and must urgently be addressed, merely focusing on coverage of TB services is no longer sufficient. While the world awaits revolutionary vaccines, drugs and diagnostics, programmatic data indicate that much can be done to accelerate the decline of TB. In this perspective, we compare and contrast these two national epidemics, and explore barriers, with a particular focus on the role of health systems in finding the missing millions.

Date:
2019-01-30

Authors:

Journal:
AIDS Research and Therapy

Content:

Background: Introduction of tenofovir (TDF) plus lamivudine (3TC) and dolutegravir (DTG) in first- and second-line HIV treatment regimens in South Africa warrants characterization of acquired HIV-1 drug resistance (ADR) mutations that could impact DTG-based antiretroviral therapy (ART). In this study, we sought to determine prevalence of ADR mutations and their potential impact on susceptibility to drugs used in combination with DTG among HIV-positive adults (≥ 18 years) accessing routine care at a selected ART facility in KwaZulu-Natal, South Africa.

Methods: We enrolled adult participants in a cross-sectional study between May and September 2019. Eligible participants had a most recent documented viral load (VL) ≥ 1000 copies/mL after at least 6 months on ART. We genotyped HIV-1 reverse transcriptase and protease genes by Sanger sequencing and assessed ADR. We characterized the effect of ADR mutations on the predicted susceptibility to drugs used in combination with DTG.

Results: From 143 participants enrolled, we obtained sequence data for 115 (80%), and 92.2% (95% CI 85.7-96.4) had ADR. The proportion with ADR was similar for participants on first-line ART (65/70, 92.9%, 95% CI 84.1-97.6) and those on second-line ART (40/44, 90.9%, 95% CI 78.3-97.5), and was present for the single participant on third-line ART. Approximately 89% (62/70) of those on first-line ART had dual class NRTI and NNRTI resistance and only six (13.6%) of those on second-line ART had major PI mutations. Most participants (82%) with first-line viraemia maintained susceptibility to Zidovudine (AZT), and the majority of them had lost susceptibility to TDF (71%) and 3TC (84%). Approximately two in every five TDF-treated individuals had thymidine analogue mutations (TAMs).

Conclusions: Susceptibility to AZT among most participants with first-line viraemia suggests that a new second-line regimen of AZT + 3TC + DTG could be effective. However, atypical occurrence of TAMs in TDF-treated individuals suggests a less effective AZT + 3TC + DTG regimen in a subpopulation of patients. As most patients with first-line viraemia had at least low-level resistance to TDF and 3TC, identifying viraemia before switch to TDF + 3TC + DTG is important to avoid DTG functional monotherapy. These findings highlight a need for close monitoring of outcomes on new standardized treatment regimens.

Date:
2021-10-16