Malaria
- Intensive epidemiological studies and a trial of mass drug administration (MDA) have been completed in rural southern Lao villages, with the Centre for Malariology, Parasitology and Entomology (CMPE) and coordinated by MORU-Bangkok. This included confirmation of the presence of foci of high levels of asymptomatic Plasmodium falciparum and P. vivax parasitaemia, a study of ACT + primaquine MDA as a tool for elimination, and social science studies of the acceptability of this approach. The preliminary results suggest that MDA with dihydroartemisinin-piperaquine plus a single low dose of primaquine is feasible, acceptable and safe but its impact on malaria transmission needs to be further investigated.
- Continued surveillance of antimalarial drug resistance, through both phenotypic studies and molecular markers has shown that piperaquine resistance has spread into southern Laos from neighbouring countries, even though the drug has never been used as treatment. Thus there are serious concerns as to what therapy will be recommended if artemether-lumefantrine (the first-line treatment) fails. We have participated in the multicentre TRAC ll study, with CMPE and coordinated by MORU-Bangkok, at Sekong Provincial Hospital.
- We conducted surveys of the prevalence of phenotypic and genotypic markers of G6PD deficiency in Laos to inform safer use of 8-aminoquinolines (e.g. primaquine) in vivax malaria. Estimated G6PD deficient or mutated hemizygous male prevalence was 8.1% in Laos and we also evaluated promising spot and rapid diagnostic tests for G6PD deficiency detection in Laos to decide on primaquine treatment.