Does mass chloroquine treatment have any role in the elimination of Plasmodium vivax ?

Abstract

Countries in the Greater Mekong sub-region (GMS) have been encouraged to deploy mass chloroquine treatments given monthly for four months to reduce the burden of vivax malaria. This paper summarizes briefly current knowledge on Plasmodium vivax epidemiology, the biology of vivax relapse and previous experience using dihydroartemisinin-piperaquine mass treatments in the GMS to show why this approach would be extremely cost-ineffective. Around 800 full treatment courses in 200 people would be needed to prevent one symptomatic case. Mass chloroquine treatment will contribute little or nothing to the elimination of vivax malaria in this area.

Keywords: Plasmodium vivax; Chloroquine; Elimination; Mass drug administration.

Fig. 1

Changes in the prevalence of P. vivax infection during 12-month follow-up in control and dihydroartemisinin–piperaquine MDA intervention villages in a study conducted in Eastern Myanmar (reproduced from [11]). The prevalence of vivax malaria in one village with a low initial prevalence remained lower after MDA intervention when compared to baseline values (2% vs 14%). This suggested that under some epidemiological conditions mass blood stage treatment could have a more lasting effect, but concluding causality is not possible

Fig. 2

Hypnozoite burdens, summed over a village of 500 people, before and after successive rounds of chloroquine MDA based on [15]. Panels correspond to the population-average EIR, whereby 50% of bites are concentrated in 20% of individuals. Model assumptions and derivations are detailed in the Supplementary material