Study Investigates Protective Efficacy of Intermittent Preventive Treatment of Malaria in Infants

Intermittent preventive treatment of infants (IPTi) reduces malaria-related morbidity in early childhood. Although genotypic drug resistance markers have proven useful in predicting the efficacy of antimalarial drugs, only scant data is available on the protective efficacy of these drugs when used as IPTi. A new study coordinated by ISGlobal researcher Ivo Mueller and published in Antimicrobial Agents and Chemotherapy shows how these markers can predict the protective efficacy of IPTi against both Plasmodium falciparum and Plasmodium vivax.

The paper presents data from an IPTi study in Papua New Guinea that investigated whether the frequency of mutations associated with antimalarial drug resistance could explain differences in efficacy between IPTi regimens (amodiaquine plus sulfadoxine-pyrimethamine vs artesunate plus sulfadoxine-pyrimethamine). The study also explored the impact of different IPTi regimens on the prevalence of resistance markers.

The researchers demonstrated concordance between the prevalence of drug-resistant genotypes of P falciparum and P vivax and the protective efficacy of the two combination IPTi regimens. "Drug resistance genotyping is a valuable public health tool for monitoring antimalarial drug resistance and the early detection of compromised therapeutic efficacy in case management. Analysis of population prevalence of genotypic markers could similarly help predict the protective efficacy of IPTi drug regimens in a wide variety of malaria-endemic settings," explained Ivo Mueller, a researcher at ISGlobal and the Walter and Eliza Hall Institute of Medical Research.

Reference:

Barnadas C, Senn N, Iga J, Timinao L, Javati S, Malau E, Rarau P, Reeder JC, Siba P, Karunajeewa H, Zimmerman PA, Davis TM, Mueller I. Plasmodium falciparum and Plasmodium vivax genotypes and efficacy of intermittent preventive treatment in Papua New Guinea. Antimicrob Agents Chemother. 2014 Aug 25.