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Dr
Michael Frimpong

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Current Organisation

Kumasi Centre for Collaborative Research in Tropical Medicine

Current Job Title

Research Fellow

Biography

Publications

Authors:
Phillips RO, Robert J, Abass KM, Thompson W, Sarfo FS, Wilson T, Sarpong G, Gateau T, Chauty A, Omollo R, Ochieng Otieno M, Egondi TW, Ampadu EO, Agossadou D, Marion E, Ganlonon L, Wansbrough-Jones M, Grosset J, Macdonald JM, Treadwell T, Saunderson P, Paintsil A, Lehman L, Frimpong M, Sarpong NF, Saizonou R, Tiendrebeogo A, Ohene SA, Stienstra Y, Asiedu KB, van der Werf TS

Journal:
Lancet

Content:

Background

Buruli ulcer is a neglected tropical disease caused by Mycobacterium ulcerans infection that damages the skin and subcutis. It is most prevalent in western and central Africa and Australia. Standard antimicrobial treatment with oral rifampicin 10 mg/kg plus intramuscular streptomycin 15 mg/kg once daily for 8 weeks (RS8) is highly effective, but streptomycin injections are painful and potentially harmful. We aimed to compare the efficacy and tolerability of fully oral rifampicin 10 mg/kg plus clarithromycin 15 mg/kg extended release once daily for 8 weeks (RC8) with that of RS8 for treatment of early Buruli ulcer lesions.

Methods

We did an open-label, non-inferiority, randomised (1:1 with blocks of six), multicentre, phase 3 clinical trial comparing fully oral RC8 with RS8 in patients with early, limited Buruli ulcer lesions. There were four trial sites in hospitals in Ghana (Agogo, Tepa, Nkawie, Dunkwa) and one in Benin (Pobè). Participants were included if they were aged 5 years or older and had typical Buruli ulcer with no more than one lesion (caterories I and II) no larger than 10 cm in diameter. The trial was open label, and neither the investigators who took measurements of the lesions nor the attending doctors were masked to treatment assignment. The primary clinical endpoint was lesion healing (ie, full epithelialisation or stable scar) without recurrence at 52 weeks after start of antimicrobial therapy. The primary endpoint and safety were assessed in the intention-to-treat population. A sample size of 332 participants was calculated to detect inferiority of RC8 by a margin of 12%. This study was registered with ClinicalTrials.gov, NCT01659437.

Findings

Between Jan 1, 2013, and Dec 31, 2017, participants were recruited to the trial. We stopped recruitment after 310 participants. Median age of participants was 14 years (IQR 10–29) and 153 (52%) were female. 297 patients had PCR-confirmed Buruli ulcer; 151 (51%) were assigned to RS8 treatment, and 146 (49%) received oral RC8 treatment. In the RS8 group, lesions healed in 144 (95%, 95% CI 91 to 98) of 151 patients, whereas lesions healed in 140 (96%, 91 to 99) of 146 patients in the RC8 group. The difference in proportion, −0·5% (–5·2 to 4·2), was not significantly greater than zero (p=0·59), showing that RC8 treatment is non-inferior to RS8 treatment for lesion healing at 52 weeks. Treatment-related adverse events were recorded in 20 (13%) patients receiving RS8 and in nine (7%) patients receiving RC8. Most adverse events were grade 1–2, but one (1%) patient receiving RS8 developed serious ototoxicity and ended treatment after 6 weeks. No patients needed surgical resection. Four patients (two in each study group) had skin grafts.

Interpretation

Fully oral RC8 regimen was non-inferior to RS8 for treatment of early, limited Buruli ulcer and was associated with fewer adverse events. Therefore, we propose that fully oral RC8 should be the preferred therapy for early, limited lesions of Buruli ulcer.

Date:
2020-04-01

Authors:

Journal:
Emerging Infectious Diseases

Content:

Date:
2014-06-01

Authors:
Frimpong M, Ahor HS, Sakyi SA, Agbavor B, Akowuah E, Phillips RO

Journal:
Diagnostics (Basel)

Content:

Isothermal amplification techniques such as recombinase polymerase amplification (RPA) and loop-mediated isothermal amplification (LAMP) for diagnosing Buruli ulcer, a necrotic skin disease caused by Mycobacterium ulcerans, have renewed hope for the molecular diagnosis of clinically suspected Buruli ulcer cases in endemic districts. If these techniques are applied at district-level hospitals or clinics, they will help facilitate early case detection with prompt treatment, thereby reducing disability and associated costs of disease management. The accuracy as well as the application of these molecular techniques at point of need is dependent on simple and fast DNA extraction. We have modified and tested a rapid extraction protocol for use with an already developed recombinase polymerase amplification assay. The entire procedure from "sample in, extraction and DNA amplification" was conducted in a mobile suitcase laboratory within 40 min. The DNA extraction procedure was performed within 15 min, with only two manipulation/pipetting steps needed. The diagnostic sensitivity and specificity of this extraction protocol together with M. ulcerans RPA in comparison with standard DNA extraction with real-time PCR was 87% (n = 26) and 100% (n = 13), respectively. We have established a simple, fast and efficient protocol for the extraction and detection of M. ulcerans DNA in clinical samples that is adaptable to field conditions.

Date:
2019-11-26

Authors:
Asare, R. Opoku-Okrah, C. Danquah, K.O. Opare-Sem, O. Addai-Mensah, O. Gyamfi, D. Amponsah, F.A. Afriyie, E.Y. Duneeh, R.V. Ofosu, D.N. Frimpong, M.

Journal:
Leukemia Research

Content:

Date:
2019-01-01

Authors:
Michael Frimpong Hubert Senanu Ahor Samuel Asamoah Sakyi Bernadette Agbavor Emmanuel Akowuah Richard Odame Phillips

Journal:
Diagnostics

Content:

Date:
2019-11-26

Authors:
Michael Frimpong Hubert Senanu Ahor Samuel Asamoah Sakyi Bernadette Agbavor Emmanuel Akowuah Richard Odame Phillips

Journal:

Content:

Date:
2019-01-01

Authors:

Journal:
CHRONIC WOUND CARE MANAGEMENT AND RESEARCH

Content:

Date:
2016-01-01

Authors:

Journal:
Journal of Tropical Diseases and Public Health

Content:

Date:
2015-05-18

Authors:

Journal:
BMC infectious diseases

Content:
Non-typhoidal Salmonella (NTS) cause the majority of bloodstream infections in Ghana, however the mode of transmission and source of invasive NTS in Africa are poorly understood. This study compares NTS from water sources and invasive bloodstream infections in rural Ghana. Blood from hospitalised, febrile children and samples from drinking water sources were analysed for Salmonella spp. Strains were serotyped to trace possible epidemiological links between human and water-derived isolates.. Antibiotic susceptibility testing was performed, In 2720 blood culture samples, 165 (6%) NTS were isolated. S. Typhimurium (70%) was the most common serovar followed by S. Enteritidis (8%) and S. Dublin (8%). Multidrug resistance (MDR) was found in 95 (58%) NTS isolates, including five S. Enteritidis.

Date:
2018-01-19

Authors:

Journal:
PLOS Neglected Tropical Diseases

Content:

Date:
2015-01-08

Authors:
Michael Frimpong Shirley Victoria Simpson Hubert Senanu Ahor Abigail Agbanyo Solomon Gyabaah Bernadette Agbavor Ivy Brago Amanor Kennedy Kwasi Addo Susanne Böhlken-Fascher Jonas Kissenkötter Ahmed Abd El Wahed Richard Odame Phillips

Journal:

Content:

Date:
2020-08-26

Authors:
Michael Frimpong Katharina Roeltgen Hubert Senanu Ahor Ahmed Abd El Wahed Bernadette Agbavor Francisca Naana Sarpong Kenneth Laing Mark Wansbrough-Jones Richard Odame Phillips

Journal:
PLOS Neglected Tropical Diseases

Content:

Date:
2019-02-01

Authors:
Michael Frimpong Katharina Roeltgen Bernadette Agbavor Mabel Sarpong Duah Aloysius Loglo Francisca N. Sarpong Justice Boakye-Appiah Kabiru M. Abass Mathias Dongyele George Amofa Wilson Tuah Margaret Frempong Yaw A. Amoako Mark Wansbrough-Jones Richard O. Phillips

Journal:
PLOS Neglected Tropical Diseases

Content:

Date:
2019-08-26

Authors:
Collinson S, Frimpong VNB, Agbavor B, Montgomery B, Oppong M, Frimpong M, Amoako YA, Marks M, Phillips RO

Journal:
PLOS Neglected Tropical Diseases

Content:

Author summary

Buruli ulcer (BU) is a chronic ulcerating tropical skin disease known to particularly affect vulnerable populations. Without early detection and effective treatment it can lead to disfigurement, disability and stigma. In order to improve outcomes, we need to understand what factors prevent patients from accessing and completing treatment, however these factors are often not well understood. Factors considered to potentially affect treatment completion include access to care and type of treatment. In this study we analysed data available from clinical records of patients treated in Ghana to identify whether type of treatment and common patient characteristics were associated with treatment completion. We found that treatment completion was higher in patients who took a newly introduced oral treatment compared to those who took the traditional injectable treatment. We did not find a difference in treatment completion between patients living close to the clinic and those living further away, however we found that those living further were more likely to present with more advanced disease. The results from this study suggest that management for patients living far from care needs to be improved. The newly recommended oral treatment makes it feasible to provide care away from health centres and the improved treatment completion seen in this study supports its use. However, further research should be conducted to determine how fully community based care can best be provided.

Date:
2020-05-26

Authors:
Sarpong-Duah, M. Frimpong, M. Beissner, M. Saar, M. Laing, K. Sarpong, F. Loglo, A.D. Abass, K.M. Frempong, M. Sarfo, F.S. Bretzel, G. Wansbrough-Jones, M. Phillips, R.O.

Journal:
PLoS Neglected Tropical Diseases

Content:

Date:
2017-01-01

Authors:
Yaw Ampem Amoako Claire Fuller Nancy Ackam John-Paul Omuojine Michael Ntiamoah Oppong Abena Gyawu Owusu-Ansah Mohammed Kabiru Abass George Amofa Elizabeth Ofori Michael Frimpong Freddie Bailey David Hurst Molyneux Richard Odame Phillips

Journal:
PLOS Neglected Tropical Diseases

Content:

Date:
2021-06-01

Authors:
Simpson H Deribe K Tabah EN Peters A Maman I Frimpong M Ampadu E Phillips R Saunderson P Pullan RL Cano J

Journal:

Content:

Date:
2019-01-01

Authors:
YA Amoako M Frimpong DO Awuah G Plange-Rhule E Boakye-Yiadom B Agbavor F Sarpong H Ahor E Adu KG Danso MK Abass K Asiedu M Wansbrough-Jones RO Phillips

Journal:

Content:

Date:
2019-01-01

Authors:
Simpson H Deribe K Tabah EN Peters A Maman I Frimpong M Ampadu E Phillips R Saunderson P Pullan RL Cano J

Journal:
Lancet Global Health

Content:

BACKGROUND: Buruli ulcer can cause disfigurement and long-term loss of function. It is underdiagnosed and under-reported, and its current distribution is unclear. We aimed to synthesise and evaluate data on Buruli ulcer prevalence and distribution.

METHODS: We did a systematic review of Buruli ulcer prevalence and used an evidence consensus framework to describe and evaluate evidence for Buruli ulcer distribution worldwide. We searched PubMed and Web of Science databases from inception to Aug 6, 2018, for records of Buruli ulcer and Mycobacterium ulcerans detection, with no limits on study type, publication date, participant population, or location. English, French, and Spanish language publications were included. We included population-based surveys presenting Buruli ulcer prevalence estimates, or data that allowed prevalence to be estimated, in the systematic review. We extracted geographical data on the occurrence of Buruli ulcer cases and M ulcerans detection from studies of any type for the evidence consensus framework; articles that did not report original data were excluded. For the main analysis, we extracted prevalence estimates from included surveys and calculated 95% CIs using Byar's method. We included occurrence records, reports to WHO and the Global Infectious Diseases and Epidemiology Network, and surveillance data from Buruli ulcer control programmes in the evidence consensus framework to grade the strength of evidence for Buruli ulcer endemicity. This study is registered with PROSPERO, number CRD42018116260.

FINDINGS: 2763 titles met the search criteria. We extracted prevalence estimates from ten studies and occurrence data from 208 studies and five unpublished surveillance datasets. Prevalence estimates within study areas ranged from 3·2 (95% CI 3·1-3·3) cases per 10 000 population in Côte d'Ivoire to 26·9 (23·5-30·7) cases per 10 000 population in Benin. There was evidence of Buruli ulcer in 32 countries and consensus on presence in 12.

INTERPRETATION: The global distribution of Buruli ulcer is uncertain and potentially wider than currently recognised. Our findings represent the strongest available evidence on Buruli ulcer distribution so far and have many potential applications, from directing surveillance activities to informing burden estimates

Date:
2019-07-01

Authors:
Frimpong M Ahor HS Wahed AAE Agbavor B Sarpong FN Laing K Wansbrough-Jones M Phillips RO

Journal:
PLoS Neglected Tropical Diseases

Content:

BACKGROUND: Access to an accurate diagnostic test for Buruli ulcer (BU) is a research priority according to the World Health Organization. Nucleic acid amplification of insertion sequence IS2404 by polymerase chain reaction (PCR) is the most sensitive and specific method to detect Mycobacterium ulcerans (M. ulcerans), the causative agent of BU. However, PCR is not always available in endemic communities in Africa due to its cost and technological sophistication. Isothermal DNA amplification systems such as the recombinase polymerase amplification (RPA) have emerged as a molecular diagnostic tool with similar accuracy to PCR but having the advantage of amplifying a template DNA at a constant lower temperature in a shorter time. The aim of this study was to develop RPA for the detection of M. ulcerans and evaluate its use in Buruli ulcer disease.

METHODOLOGY AND PRINCIPAL FINDINGS: A specific fragment of IS2404 of M. ulcerans was amplified within 15 minutes at a constant 42°C using RPA method. The detection limit was 45 copies of IS2404 molecular DNA standard per reaction. The assay was highly specific as all 7 strains of M. ulcerans tested were detected, and no cross reactivity was observed to other mycobacteria or clinically relevant bacteria species. The clinical performance of the M. ulcerans (Mu-RPA) assay was evaluated using DNA extracted from fine needle aspirates or swabs taken from 67 patients in whom BU was suspected and 12 patients with clinically confirmed non-BU lesions. All results were compared to a highly sensitive real-time PCR. The clinical specificity of the Mu-RPA assay was 100% (95% CI, 84-100), whiles the sensitivity was 88% (95% CI, 77-95).

CONCLUSION: The Mu-RPA assay represents an alternative to PCR, especially in areas with limited infrastructure.

Date:
2019-02-01

Authors:

Journal:
The Lancet Global Health

Content:

Date:
2019-07-01

Authors:
Kwarteng, A. Dissou-Arthur, Y. Sylverken, A. Frimpong, M. Terkper, S.A. Owusu-Dabo, E.

Journal:
Cogent Education

Content:

Date:
2018-01-01

Authors:
Amoako YA, Frimpong M, Awuah DO, Plange-Rhule G, Boakye-Yiadom E, Agbavor B, Sarpong F, Ahor H, Adu E, Danso KG, Abass MK, Asiedu K, Wansbrough-Jones M, Phillips RO

Journal:
Journal of Medical Case Reports

Content:

Background: Buruli ulcer caused by Mycobacterium ulcerans is endemic in parts of West Africa and is most prevalent among the 5-15 years age group; Buruli ulcer is uncommon among neonates. The mode of transmission and incubation period of Buruli ulcer are unknown. We report two cases of confirmed Buruli ulcer in human immunodeficiency virus-unexposed, vaginally delivered term neonates in Ghana.

Case presentation: Patient 1: Two weeks after hospital delivery, a baby born to natives of the Ashanti ethnic group of Ghana was noticed by her mother to have a papule with associated edema on the right anterior chest wall and neck that later ulcerated. There was no restriction of neck movements. The diagnosis of Buruli ulcer was confirmed on the basis of a swab sample that had a positive polymerase chain reaction result for the IS2404 repeat sequence of M. ulcerans. Patient 2: This patient, from the Ashanti ethnic group in Ghana, had the mother noticing a swelling in the baby's left gluteal region 4 days after birth. The lesion progressively increased in size to involve almost the entire left gluteal region. Around the same time, the mother noticed a second, smaller lesion on the forehead and left side of neck. The diagnosis of Buruli ulcer was confirmed by polymerase chain reaction when the child was aged 4 weeks. Both patients 1 and 2 were treated with oral rifampicin and clarithromycin at recommended doses for 8 weeks in addition to appropriate daily wound dressing, leading to complete healing. Our report details two cases of polymerase chain reaction-confirmed Buruli ulcer in children whose lesions appeared at ages 14 and 4 days, respectively. The mode of transmission of M. ulcerans infection is unknown, so the incubation period is difficult to estimate and is probably dependent on the infective dose and the age of exposure. In our study, lesions appeared 4 days after birth in patient 2. Unless the infection was acquired in utero, this would be the shortest incubation period ever recorded.

Conclusions: Buruli ulcer should be included in the differential diagnosis of neonates who present with characteristic lesions. The incubation period of Buruli ulcer in neonates is probably shorter than is reported for adults.

Date:
2019-07-18

Authors:

Journal:
PLoS Neglected Tropical Diseases

Content:

Date:
2015-11-01

Authors:
Dekker D1,2, Krumkamp R3,4, Eibach D3,4, Sarpong N5, Boahen KG5, Frimpong M5, Fechtner E3, Poppert S3, Hagen RM6, Schwarz NG3, Adu-Sarkodie Y7, Owusu-Dabo E5, Im J8, Marks F8,9, Frickmann H6,10, May J3,4

Journal:
BMC Infect Dis

Content:

BACKGROUND: Non-typhoidal Salmonella (NTS) cause the majority of bloodstream infections in Ghana, however the mode of transmission and source of invasive NTS in Africa are poorly understood. This study compares NTS from water sources and invasive bloodstream infections in rural Ghana.

METHODS: Blood from hospitalised, febrile children and samples from drinking water sources were analysed for Salmonella spp. Strains were serotyped to trace possible epidemiological links between human and water-derived isolates.. Antibiotic susceptibility testing was performed, RESULTS: In 2720 blood culture samples, 165 (6%) NTS were isolated. S. Typhimurium (70%) was the most common serovar followed by S. Enteritidis (8%) and S. Dublin (8%). Multidrug resistance (MDR) was found in 95 (58%) NTS isolates, including five S. Enteritidis. One S. Typhimurium showed reduced fluroquinolone susceptibility. In 511 water samples, 19 (4%) tested positive for S. enterica with two isolates being resistant to ampicillin and one isolate being resistant to cotrimoxazole. Serovars from water samples were not encountered in any of the clinical specimens.

CONCLUSION: Water analyses demonstrated that common drinking water sources were contaminated with S. enterica posing a potential risk for transmission. However, a link between S. enterica from water sources and patients could not be established, questioning the ability of water-derived serovars to cause invasive bloodstream infections

Date:
2018-01-19

Authors:
Kwarteng, A. Frimpong, M. Sylverken, A.A. Arthur, Y.D. Ahuno, S.T. Owusu-Dabo, E.

Journal:
Cogent Education

Content:

Date:
2017-01-01

Authors:
Michael Frimpong Shirley Victoria Simpson Hubert Senanu Ahor Abigail Agbanyo Solomon Gyabaah Bernadette Agbavor Ivy Brago Amanor Kennedy Kwasi Addo Susanne Böhlken-Fascher Jonas Kissenkötter Ahmed Abd El Wahed Richard Odame Phillips

Journal:
Tropical Medicine and Infectious Disease

Content:

Date:
2020-10-06

Authors:

Journal:
Antimicrobial Agents and Chemotherapy

Content:

Date:
2014-10-01

Authors:
Augustina Angelina Sylverken Philip El-Duah Michael Owusu Julia Schneider Richmond Yeboah Ayisi-Boateng Ayisi-Boateng Richmond Gorman Eric Adu Alexander Kwarteng Michael Frimpong Sherihane Aryeetey Jesse Addo Asamoah Yaw Ampem Amoako John Humphrey Amuasi Jörn Beheim-Schwarzbach Ellis Owusu-Dabo Yaw Adu-Sarkodie Kwasi Obiri-Danso Victor Max Corman Christian Drosten Richard Phillips

Journal:

Content:

Date:
2020-09-15

Authors:
Hope Simpson Gerd Pluschke Earnest Njih Tabah Richard O. Phillips Michael Frimpong Issaka Maman Edwin Ampadu Joseph Timothy Paul Saunderson Rachel L. Pullan Jorge Cano

Journal:
PLOS Neglected Tropical Diseases

Content:

Date:
2021-03-03

Authors:
Sarpong-Duah M, Frimpong M, Beissner M, Saar M, Laing K, Sarpong F, Loglo AD, Abass KM, Frempong M, Sarfo FS, Bretzel G, Wansbrough-Jones M, Phillips RO

Journal:
PLoS Neglected Tropical Diseases

Content:

Introduction: Buruli ulcer (BU) caused by Mycobacterium ulcerans is effectively treated with rifampicin and streptomycin for 8 weeks but some lesions take several months to heal. We have shown previously that some slowly healing lesions contain mycolactone suggesting continuing infection after antibiotic therapy. Now we have determined how rapidly combined M. ulcerans 16S rRNA reverse transcriptase / IS2404 qPCR assay (16S rRNA) became negative during antibiotic treatment and investigated its influence on healing.

Methods: Fine needle aspirates and swab samples were obtained for culture, acid fast bacilli (AFB) and detection of M. ulcerans 16S rRNA and IS2404 by qPCR (16S rRNA) from patients with IS2404 PCR confirmed BU at baseline, during antibiotic and after treatment. Patients were followed up at 2 weekly intervals to determine the rate of healing. The Kaplan-Meier survival analysis was used to analyse the time to clearance of M. ulcerans 16S rRNA and the influence of persistent M ulcerans 16S rRNA on time to healing. The Mann Whitney test was used to compare the bacillary load at baseline in patients with or without viable organisms at week 4, and to analyse rate of healing at week 4 in relation to detection of viable organisms.

Results: Out of 129 patients, 16S rRNA was detected in 65% of lesions at baseline. The M. ulcerans 16S rRNA remained positive in 78% of patients with unhealed lesions at 4 weeks, 52% at 8 weeks, 23% at 12 weeks and 10% at week 16. The median time to clearance of M. ulcerans 16S rRNA was 12 weeks. BU lesions with positive 16S rRNA after antibiotic treatment had significantly higher bacterial load at baseline, longer healing time and lower healing rate at week 4 compared with those in which 16S rRNA was not detected at baseline or had become undetectable by week 4.

Conclusions: Current antibiotic therapy for BU is highly successful in most patients but it may be possible to abbreviate treatment to 4 weeks in patients with a low initial bacterial load. On the other hand persistent infection contributes to slow healing in patients with a high bacterial load at baseline, some of whom may need antibiotic treatment extended beyond 8 weeks. Bacterial load was estimated from a single sample taken at baseline. A better estimate could be made by taking multiple samples or biopsies but this was not ethically acceptable.

Date:
2017-07-03

Authors:

Journal:
PLOS Neglected Tropical Diseases

Content:

Date:
2014-06-19

Authors:
Frimpong M, Agbavor B, Duah MS, Loglo A, Sarpong FN, Boakye-Appiah J, Abass KM, Dongyele M, Amofa G, Tuah W, Frempong M, Amoako YA, Wansbrough-Jones M, Phillips RO

Journal:
PLoS Neglected Tropical Diseases

Content:

Background: We investigated the relationship between bacterial load in Buruli ulcer (BU) lesions and the development of paradoxical reaction following initiation of antibiotic treatment.

Methods: This was a longitudinal study involving BU patients from June 2013 to June 2017. Fine needle aspirates (FNA) and swab samples were obtained to establish the diagnosis of BU by PCR. Additional samples were obtained at baseline, during and after treatment (if the lesion had not healed) for microscopy, culture and combined 16S rRNA reverse transcriptase/ IS2404 qPCR assay. Patients were followed up at regular intervals until complete healing.

Results: Forty-seven of 354 patients (13%) with PCR confirmed BU had a PR, occurring between 2 and 42 (median 6) weeks after treatment initiation. The bacterial load, the proportion of patients with positive M. ulcerans culture (15/34 (44%) vs 29/119 (24%), p = 0.025) and the proportion with positive microscopy results (19/31 (61%) vs 28/90 (31%), p = 0.003) before initiation of treatment were significantly higher in the PR compared to the no PR group. Plaques (OR 5.12; 95% CI 2.26-11.61; p<0.001), oedematous (OR 4.23; 95% CI 1.43-12.5; p = 0.009) and category II lesions (OR 2.26; 95% CI 1.14-4.48; p = 0.02) were strongly associated with the occurrence of PR. The median time to complete healing (28 vs 13 weeks, p <0.001) was significantly longer in the PR group.

Conclusions: Buruli ulcer patients who develop PR are characterized by high bacterial load in lesion samples taken at baseline and a higher rate of positive M. ulcerans culture. Occurrence of a PR was associated with delayed healing.

Date:
2019-08-26

Authors:
Aloysius D. Loglo Michael Frimpong Mabel Sarpong Duah Fred Sarfo Francisca N. Sarpong Bernadette Agbavor Justice K. Boakye-Appiah Kabiru M. Abass Mathias Dongyele Margaret Frempong Sacha Pidot Mark Wansbrough-Jones Timothy P. Stinear Virginie Roupie Kris Huygen Richard O. Phillips

Journal:
PeerJ

Content:

Date:
2018-07-31

Authors:

Journal:

Content:

Date:
2015-03-23

Authors:

Journal:
International Journal of Environmental Research and Public Health

Content:

Date:
2015-03-27

Authors:
Niang, F. Sarfo, F.S. Frimpong, M. Guenin-Macé, L. Wansbrough-Jones, M. Stinear, T. Phillips, R.O. Demangel, C.

Journal:
Scientific Reports

Content:

Date:
2015-01-01

Authors:

Journal:
International Journal of Mycobacteriology

Content:

Date:
2016-03-01

Authors:
Amoako, Y.A. Frimpong, M. Awuah, D.O. Plange-Rhule, G. Boakye-Yiadom, E. Agbavor, B. Sarpong, F. Ahor, H. Adu, E. Danso, K.G. Abass, M.K. Asiedu, K. Wansbrough-Jones, M. Phillips, R.O.

Journal:
Journal of Medical Case Reports

Content:

Date:
2019-01-01

Authors:
Wadagni AC, Steinhorst J, Barogui YT, Catraye PM, Gnimavo R, Abass KM, Amofa G, Frimpong M, Sarpong FN, van der Werf TS, Phillips R, Sopoh GE, Johnson CR, Stienstra Y

Journal:
PLoS Neglected Tropical Diseases

Content:

Background: Antibiotic treatment proved itself as the mainstay of treatment for Buruli ulcer disease. This neglected tropical disease is caused by Mycobacterium ulcerans. Surgery persists as an adjunct therapy intended to reduce the mycobacterial load. In an earlier clinical trial, patients benefited from delaying the decision to operate. Nevertheless, the rate of surgical interventions differs highly per clinic.Methods: A retrospective study was conducted in six different Buruli ulcer (BU) treatment centers in Benin and Ghana. BU patients clinically diagnosed between January 2012 and December 2016 were included and surgical interventions during the follow-up period, at least one year after diagnosis, were recorded. Logistic regression analysis was carried out to estimate the effect of the treatment center on the decision to perform surgery, while controlling for interaction and confounders.Results: A total of 1193 patients, 612 from Benin and 581 from Ghana, were included. In Benin, lesions were most frequently (42%) categorized as the most severe lesions (WHO criteria, category III), whereas in Ghana lesions were most frequently (44%) categorized as small lesions (WHO criteria, category I). In total 344 (29%) patients received surgical intervention. The percentage of patients receiving surgical intervention varied between hospitals from 1.5% to 72%. Patients treated in one of the centers in Benin were much more likely to have surgery compared to the clinic in Ghana with the lowest rate of surgical intervention (RR = 46.7 CI 95% [17.5-124.8]). Even after adjusting for confounders (severity of disease, age, sex, limitation of movement at joint at time of diagnosis, ulcer and critical sites), rates of surgical interventions varied highly. Conclusion: The decision to perform surgery to reduce the mycobacterial load in BU varies highly per clinic. Evidence based guidelines are needed to guide the role of surgery in the treatment of BU.

Date:
2019-10-28

Authors:

Journal:
PLoS Neglected Tropical Diseases

Content:

Date:
2015-11-01

Authors:
Frimpong M Ahor HS Wahed AAE Agbavor B Sarpong FN Laing K Wansbrough-Jones M Phillips RO

Journal:

Content:

Date:
2019-01-01

Authors:
Loglo AD Frimpong M Sarpong Duah M Sarfo F Sarpong FN Agbavor B Boakye-Appiah JK Abass KM Dongyele M Frempong M Pidot S Wansbrough-Jones M Stinear TP Roupie V Huygen K Phillips RO

Journal:
PeerJ

Content:

Background: Buruli ulcer is a disease of the skin and soft tissues caused by infection with a slow growing pathogen, Mycobacterium ulcerans. A vaccine for this disease is not available but M. ulcerans possesses a giant plasmid pMUM001 that harbours the polyketide synthase (PKS) genes encoding a multi-enzyme complex needed for the production of its unique lipid toxin called mycolactone, which is central to the pathogenesis of Buruli ulcer. We have studied the immunogenicity of enzymatic domains in humans with M. ulcerans disease, their contacts, as well as non-endemic areas controls.

Methods: Between March 2013 and August 2015, heparinized whole blood was obtained from patients confirmed with Buruli ulcer. The blood samples were diluted 1 in 10 in Roswell Park Memorial Institute (RPMI) medium and incubated for 5 days with recombinant mycolactone PKS domains and mycolyltransferase antigen 85A (Ag85A). Blood samples were obtained before and at completion of antibiotic treatment for 8 weeks and again 8 weeks after completion of treatment. Supernatants were assayed for interferon-γ (IFN-γ) and interleukin-5 (IL-5) by enzyme-linked immunosorbent assay. Responses were compared with those of contacts and non-endemic controls.

Results: More than 80% of patients and contacts from endemic areas produced IFN-γ in response to all the antigens except acyl carrier protein type 3 (ACP3) to which only 47% of active Buruli ulcer cases and 71% of contacts responded. The highest proportion of responders in cases and contacts was to load module ketosynthase domain (Ksalt) (100%) and enoylreductase (100%). Lower IL-5 responses were induced in a smaller proportion of patients ranging from 54% after ketoreductase type B stimulation to only 21% with ketosynthase type C (KS C). Among endemic area contacts, the, highest proportion was 73% responding to KS C and the lowest was 40% responding to acyltransferase with acetate specificity type 2. Contacts of Buruli ulcer patients produced significantly higher IFN-γ and IL-5 responses compared with those of patients to PKS domain antigens and to mycolyltransferase Ag85A of M. ulcerans. There was low or no response to all the antigens in non-endemic areas controls. IFN-γ and IL-5 responses of patients improved after treatment when compared to baseline results.

Discussion: The major response to PKS antigen stimulation was IFN-γ and the strongest responses were observed in healthy contacts of patients living in areas endemic for Buruli ulcer. Patients elicited lower responses than healthy contacts, possibly due to the immunosuppressive effect of mycolactone, but the responses were enhanced after antibiotic treatment. A vaccine made up of the most immunogenic PKS domains combined with the mycolyltransferase Ag85A warrants further investigation.

Date:
2018-07-31

Authors:

Journal:
PLOS Neglected Tropical Diseases

Content:

Date:
2014-04-10

Authors:
Paradoxical reactions in Buruli ulcer after initiation of antibiotic therapy: Relationship to bacterial load. Frimpong M Agbavor B Duah MS Loglo A Sarpong FN Boakye-Appiah J Abass KM Dongyele M Amofa G Tuah W Frempong M Amoako YA Wansbrough-Jones M Phillips RO

Journal:

Content:

Date:
2019-01-01