Patterns of chloroquine use and resistance in sub-Saharan Africa: a systematic review of household survey and molecular data

Anne Ep Frosch,Meera Venkatesan,Miriam K Laufer

doi:10.1186/1475-2875-10-116

Anne Ep Frosch, Meera Venkatesan + Show 1 more

Open Access

https://doi.org/10.1186/1475-2875-10-116

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Abstract

BackgroundAs a result of widespread chloroquine and sulphadoxine-pyrimethamine (SP) resistance, 90% of sub-Saharan African countries had adopted policies of artemisinin-based combination therapy (ACT) for treatment of uncomplicated malaria by 2007. In Malawi, cessation of chloroquine use was followed by the re-emergence of chloroquine-susceptible malaria. It was expected that introduction of ACT would lead to a return in chloroquine susceptibility throughout Africa, but this has not yet widely occurred. This observation suggests that there is continuing use of ineffective anti-malarials in Africa and that persistent chloroquine-resistant malaria is due to ongoing drug pressure despite national policy changes.MethodsTo estimate drug use on a national level, 2006-2007 Demographic Health Survey and Multiple Indicator Cluster Survey data from 21 African countries were analysed. Resistance data were compiled by systematic review of the published literature on the prevalence of the Plasmodium falciparum chloroquine resistance transporter polymorphism at codon 76, which causes chloroquine resistance.ResultsChloroquine was the most common anti-malarial used according to surveys from 14 of 21 countries analysed, predominantly in West Africa. SP was most commonly reported in two of 21 countries. Among eight countries with longitudinal molecular resistance data, the four countries where the highest proportion of children treated for fever received chloroquine (Uganda, Burkina Faso, Guinea Bissau, and Mali) also showed no significant declines in the prevalence of chloroquine-resistant infections. The three countries with low or decreasing chloroquine use among children who reported fever treatment (Malawi, Kenya, and Tanzania) had statistically significant declines in the prevalence of chloroquine resistance.ConclusionsThis study demonstrates that in 2006-2007, chloroquine and SP continued to be used at high rates in many African countries. In countries reporting sustained chloroquine use, chloroquine-resistant malaria persists. In contrast, a low level of estimated chloroquine use is associated with a declining prevalence of chloroquine resistance.

Highlights

As a result of widespread chloroquine and sulphadoxine-pyrimethamine (SP) resistance, 90% of subSaharan African countries had adopted policies of artemisinin-based combination therapy (ACT) for treatment of uncomplicated malaria by 2007
With emerging concerns of artemisinin resistance in Asia [50,51] and the possibility that drugs previously compromised by resistance can regain efficacy, it is important that we elucidate the effect of drug use on the dynamics of anti-malarial resistance
The results presented here suggest that the evolutionary effects of anti-malarial treatment pressure on malaria parasite populations can be reversed

Summary

Introduction

As a result of widespread chloroquine and sulphadoxine-pyrimethamine (SP) resistance, 90% of subSaharan African countries had adopted policies of artemisinin-based combination therapy (ACT) for treatment of uncomplicated malaria by 2007. It was expected that introduction of ACT would lead to a return in chloroquine susceptibility throughout Africa, but this has not yet widely occurred This observation suggests that there is continuing use of ineffective anti-malarials in Africa and that persistent chloroquine-resistant malaria is due to ongoing drug pressure despite national policy changes. In 1993, Malawi was the first African country to discontinue the policy of chloroquine use for uncomplicated malaria treatment. In Niger, where chloroquine use was not officially stopped until 2005, parasites carrying chloroquine-resistant genotypes have been increasing in recent years [8]. Other than these examples, little is known about longitudinal patterns of chloroquine resistance in African countries. This study tests the hypothesis that changes in the prevalence of chloroquine-resistant malaria will reflect changes in reported chloroquine use on a national level

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