Project Details

Malaria drug and diagnostic resistance in refugee children in Uganda

Stephen Tukwasibwe, PhD

Summary

BACKGROUND: Resistance to antimalarial drugs, especially artemisinins, and deletions in HRP-2 based rapid diagnostic tests that result in false negative tests are seen at varied and increasing prevalence in Africa, including countries where refugees to Uganda originate. Malaria testing at reception centers, which process refugees when they enter Uganda, is only done when refugees present with clinical signs suggesting malaria, posing a risk of importation of malaria parasites, with genetic polymorphisms mediating drug and diagnostic resistance, especially in refugees with asymptomatic malaria parasitemia, which is common in Africa. GAP: We do not know the prevalence of malaria parasitemia in refugee children entering Uganda or, for those who are parasitemic, the prevalences of key drug and diagnostic resistance mediating genetic polymorphisms. HYPOTHESIS: We tested the hypothesize that the prevalence of malaria parasitemia is high in newly arriving refugee children and that the prevalence of key markers of drug and diagnostic resistance will differ between refugee and non-refugee populations. METHODS: This was a cross-sectional surveillance study of refugee and non-refugee populations. We studied newly arrived refugee children and children in nearby non-refugee populations in Uganda. We used molecular invasion probe assays (MIPs) PRELIMINARY RESULTS: The prevalence of K13 mutations associated with resistance to artemisinin (469Y and 675V) have been observed to be high in refugees from South Sudan (at Adjumani reception centre). The prevalence of antifolate mutations (164 and 581) are high in refugees from Democratic Republic of Cong (DRC) (at Kyangwali reception center). The prevalence of asymptomatic parasitemia by microscopy and malaria rapid diagnostic tests (RDTs) was high in both refugees from South Sudan (28.5%, microscopy, 36.5%, RDT) and DRC 44.9%, microscopy, 67.2% RDT). We have also observed parasites with RDT negative but microscopy positive (2.4%, Kyangwali, and 2.3%, Adjumani). Analysis for plasmodium species, drug resistance markers (K13, pfmdr1, pfcrt, dhps and dhfr), HRP2/3 gene deletions, and parasite genetic relatedness (refugee vs. Uganda parasite isolates) is ongoing. IMPACT: Our results will be shared with policy makers and be of value in the prioritization of malaria control efforts in Uganda. Specifically, our data may suggest introduction of testing for malaria parasitemia and resistance markers in refugee screening. This project may be followed by a larger refugee surveillance program and/or clinical trials to test improved control policies in refugee populations.