ABSTRACT
Gametocytes are the malaria parasite stages responsible for transmission from humans to mosquitoes. Gametocytemia often follows drug treatment, especially as therapies start to fail. We examined Plasmodium falciparum gametocyte carriage and drug resistance profiles among 824 persons with uncomplicated malaria in Cambodia to determine whether prevalent drug resistance and antimalarial use has led to a concentration of drug-resistant parasites among gametocyte carriers. Although report of prior antimalarial use increased from 2008 to 2014, the prevalence of study participants presenting with microscopic gametocyte carriage declined. Gametocytemia was more common in those reporting antimalarial use within the past year, and prior antimalarial use was correlated with higher IC50s to piperaquine and mefloquine, as well as to increased pfmdr1 copy number. However, there was no association between microscopic gametocyte carriage and parasite drug resistance. Thus, we found no evidence that the infectious reservoir, marked by those carrying gametocytes, is enriched with drug-resistant parasites.
Subject(s)
Antimalarials/pharmacology , Drug Resistance, Multiple , Malaria, Falciparum/blood , Malaria, Falciparum/drug therapy , Plasmodium falciparum/drug effects , Adult , Artemisinins/therapeutic use , Cambodia/epidemiology , Female , Humans , Inhibitory Concentration 50 , Malaria, Falciparum/epidemiology , Male , Mefloquine/therapeutic use , Multidrug Resistance-Associated Proteins/economics , Plasmodium falciparum/genetics , Young AdultABSTRACT
The mechanism of massive intravascular haemolysis occurring during the treatment of malaria infection resulting in haemoglobinuria, commonly known as blackwater fever (BWF), remains unknown. BWF is most often seen in those with severe malaria treated with amino-alcohol drugs, including quinine, mefloquine and halofantrine. The potential for drugs containing artemisinins, chloroquine or piperaquine to cause oxidant haemolysis is believed to be much lower, particularly during treatment of uncomplicated malaria. Here is an unusual case of BWF, which developed on day 2 of treatment for uncomplicated Plasmodium falciparum infection with dihydroartemisinin-piperaquine (DHA-PIP) with documented evidence of concomitant seropositivity for Chikungunya infection.
