Predictors of treatment failures of Plasmodium falciparum malaria in Vietnam: a 4-year single-center retrospective study

Abstract

BackgroundDrug-resistant falciparum malaria is an increasing public health burden. We examined the magnitude of Plasmodium falciparum infection and the patterns and predictors of treatment failure in Vietnam. MethodsMedical records of all 443 patients with malaria infection admitted to the Hospital for Tropical Diseases between January 2015 and December 2018 were used to extract information on demographics, risk factors, symptoms, laboratory tests, treatment, and outcomes. ResultsMore than half (59.8%, CI 55.1%-64.4%) of patient acquired P. falciparum infection of whom 21.9% (CI 17.1%-27.4%) had severe malaria, while 7.2% (CI 4.6%-10.9%) and 19.2% (CI 14.7%-24.5%) developed early treatment failure (ETF) and late treatment failure (LTF) respectively. ETF was 4.7% among patients referred from Binh Phuoc province and Central Highland, 12.9% from other areas in Vietnam, and 6.9% from Africa. LTF was 16.2% among patients from Binh Phuoc province and Central Highland, 22.6% from other areas in Vietnam, and 27.6% from Africa. Most patients (98.5%) recovered completely. Having severe malaria was a predictor of ETF (AOR 6.96, CI 2.55-19.02, P < 0.001). No predictor of LTF was identified.ConclusionP. falciparum remains the prevalent malaria parasite. Despite low mortality rate, severe malaria is not rare and is a significant predictor of ETF. To reduce the risk for ETF, studies are needed to examine the effectiveness of combination therapy including parenteral artesunate and a parenteral partner drug for severe malaria. The study alerts the possibility of drug-resistant malaria in Africa and other areas in Vietnam which are known as nonendemic areas of antimalarial drug resistance. A more comprehensive study using molecular technique in these regions is required to completely understand the magnitude of drug-resistant malaria and to design appropriate control strategies.