Dr
Moses Ocan
Project Title
Predictors of local emergence and spread of Artemisinin resistance among Ugandan Plasmodium falciparum parasites (Pfkelch13 emergence)
EDCTP Project
TMA2019CDF-2662
EDCTP Program
EDCTP2
EDCTP Project Call
Career Development Fellowship (CDF)
Host Organisation
| Department | Institution | Country |
|---|---|---|
| Makerere University | Uganda |
Current Organisation
Makerere University, College of Health Sciences
Current Job Title
Lecturer
Biography
Publications
Background: In the absence of an effective vaccine, malaria treatment and eradication is still a challenge in most
endemic areas globally. This is especially the case with the current reported emergence of resistance to artemisinin
agents in Southeast Asia. This study therefore explored the prevalence of K13-propeller gene polymorphisms among
Plasmodium falciparum parasites in northern Uganda.
Methods: Adult patients (≥18 years) presenting to out-patients department of Lira and Gulu regional referral hospitals
in northern Uganda were randomly recruited. Laboratory investigation for presence of plasmodium infection among
patients was done using Plasmodium falciparum exclusive rapid diagnostic test, histidine rich protein-2 (HRP2) (Pf).
Finger prick capillary blood from patients with a positive malaria test was spotted on a filter paper Whatman no. 903.
The parasite DNA was extracted using chelex resin method and sequenced for mutations in K13-propeller gene using
Sanger sequencing. PCR DNA sequence products were analyzed using in DNAsp 5.10.01software, data was further
processed in Excel spreadsheet 2007.
Results: A total of 60 parasite DNA samples were sequenced. Polymorphisms in the K13-propeller gene were detected
in four (4) of the 60 parasite DNA samples sequenced. A non-synonymous polymorphism at codon 533 previously
detected in Cambodia was found in the parasite DNA samples analyzed. Polymorphisms at codon 522 (non-synonymous)
and codon 509 (synonymous) were also found in the samples analyzed. The study found evidence of positive selection in
the Plasmodium falciparum population in northern Uganda (Tajima’s D=−1.83205; Fu and Li’s D=−1.82458).
Conclusions: Polymorphism in the K13-propeller gene previously reported in Cambodia has been found in the Ugandan
Plasmodium falciparum parasites. There is need for continuous surveillance for artemisinin resistance gene markers in
the country.
Background Substandard anti-malarial agents pose a significant challenge to effective malaria control and elimina- tion efforts especially in sub-Saharan Africa. The quality of anti-malarials in most low-and-middle income countries (LMICs) is affected by several factors including inadequate regulation and limited resources. In this study, the phar- macopeial quality of artemether–lumefantrine (AL) in low and high malaria transmission settings in Uganda was assessed.
Methods This was a cross-sectional study conducted among randomly selected private drug outlets. The AL anti- malarials available in drug outlets were purchased using overt method. The samples were screened for quality using visual inspection, weight uniformity, content assay and dissolution tests. The assay test was done using liquid chro- matography–mass spectrometry (LC–MS). The samples were considered substandard if the active pharmaceutical ingredient (API) content was outside 90–110% range of the label claim. Dissolution test was conducted following United States Pharmacopoeia (USP) method. Data was analysed using descriptive statistics and presented as means with standard deviations, frequencies, and proportions. Correlation between medicine quality and independent vari- ables was determined using Fisher’s exact test of independence at 95% level of significance.
Results A total of 74 AL anti-malarial samples were purchased from high (49/74; 66.2%) and low (25/74; 33.8%) malaria transmission settings. The most common batch of AL was LONART, 32.4% (24/74), with 33.8% (25/74) being ‘Green leaf’. Overall prevalence of substandard quality artemether–lumefantrine was 18.9% (14/74; 95% CI: 11.4–29.7). Substandard quality AL was significantly associated with setting (p = 0.002). A total of 10 samples (13.5%) failed artemether content assay test while, 4 samples (5.4%, 4/74) failed the lumefantrine assay test. One sample from a high malaria transmission setting failed both artemether and lumefantrine assay content test. Of the samples that failed artemether assay test, 90% had low (< 90%) artemether content. All the samples passed visual inspection and dissolu- tion tests.
Conclusion Artemether–lumefantrine agents, the recommended first-line treatment for uncomplicated malaria with APIs outside the recommended pharmacopeial content assay limit is common especially in high malaria transmission settings. There is need for continuous surveillance and monitoring of the quality of artemisinin-based anti-malarials across the country by the drug regulatory agency.