| dc.description.abstract | Malaria, caused by Plasmodium falciparum (Pf), is one of the most important infections in African children and a leading cause of morbidity and mortality among refugees in sub-Saharan Africa. Uganda is one of the largest refugee hosting countries in the world, and the largest in sub-Saharan Africa, with over 1.4 million refugees. Serious threats to malaria control in sub-Saharan Africa include recent reports that there’s resistance to artemisinins (Tukwasibwe et al., 2017); the backbones of first line combination therapies to treat malaria, and P. falciparum Histidine Rich Protein 2 (PfHRP) gene deletions mediating false negative rapid diagnostic tests for malaria (mRDTs), have emerged in East Africa (Nsobya et al., 2021). A retrospective study involving utilization of 211 Blood Slide (BS) positive stored Dried Blood Spots (DBS) samples and 10 mRDT negative samples from newly arriving children aged 6 months to 10 years was conducted at 2 refugee camps in Kyangwali (from eastern Congo) and Adjumani (from Southern Sudan) in 2022. Samples were then packaged appropriately and transported to the IDRC-National Malaria Reference Laboratory. Molecular Inversion Probe (MIPs) was then prepared, samples sequenced and analyzed for malaria drug resistance markers and HRP2/3 deletions The positivity rate for RDT was 36.5% (Adjumani) and 67.2% (Kyangwali) among the refugees. Prevalences of mutations associated with aminoquinoline resistance were much higher in Adjumani. Prevalences of mutations associated with high level sulfadoxine-pyrimethamine and dihydroartemisinin-piperaquine resistance were much higher in Kyangwali (61.0% and 48.1% for PfDHFR I164L and PfDHPS A581G, p-values <0.001 for both mutations). The prevalence of PfK13 mutations associated with artemisinin partial resistance was higher (8% and 15.4% for A675V and C469Y, p-values 0.05 and 0.030 respectively) in Adjumani compared to Kyangwali. The prevalence of mutations associated with with high level aminoquinoline resistance was much higher in Adjumani with 48.7% for PfCRT K76T p-value <0.001 and 33.3% for PfMDR1 N86Y, p-value <0.001. Discordant diagnostic results were uncommon and not explained by PfHRP2 deletions. This study required to be run on a national level to get a clear picture of transmission of resistance markers in Uganda. The PfHRP2 assay required a parasitemia of >100 p/uL to be able to get meaningful results for analysis. | en_US |
