Molecular Epidemiology of Malaria in Cameroon. Xxi. Baseline Therapeutic Efficacy of Chloroquine, Amodiaquine, and Sulfadoxine-Pyrimethamine Monotherapies in Children Before National Drug Policy Change

Abstract

The availability of epidemiologic data on drug-resistant malaria based on a standardized clinical and parasitological protocol is a prerequisite for a rational therapeutic strategy to control malaria. As part of the surveillance program on the therapeutic efficacy of the first-line (chloroquine and amodiaquine) and second-line (sulfadoxine-pyrimethamine) drugs for the management of uncomplicated Plasmodium falciparum infections, non-randomized studies were conducted in symptomatic children aged less than 10 years according to the World Health Organization protocol (14-day follow-up period) at 12 sentinel sites in Cameroon between 1999 and 2004. Of 1,407 children enrolled in the studies, 460, 444, and 503 were treated with chloroquine, amodiaquine, or sulfadoxine-pyrimethamine, respectively. Chloroquine treatment resulted in high failure rates (proportion of early and late failures, 48.6%). Amodiaquine was effective at all study sites (proportion of failures, 7.3%). Sulfadoxine-pyrimethamine therapy was less effective than amodiaquine (P < 0.05), with failures observed in 9.9% of patients. Chloroquine is no longer a viable option and has been withdrawn from the official drug outlets in Cameroon. Amodiaquine and, to a lesser extent, sulfadoxine-pyrimethamine monotherapies are still effective in Cameroon, but further development of resistance to these drugs should be delayed by the novel strategy using artemisinin-based combination therapy. Our findings indicate that amodiaquine is the most rational partner for artesunate. Studies on the efficacy of artesunate-amodiaquine combination are currently being undertaken at several sites in the country.

Molecular typing reveals substantial Plasmodium vivax infection in asymptomatic adults in a rural area of Cameroon

“…Although malaria is endemic throughout Cameroon [23], the country has very different geographical and epidemiologic levels [24]. The epidemiology of malaria in Bolifamba has been well described [22].…”

Longitudinal Studies of Plasmodium falciparum Malaria in Pregnant Women Living in a Rural Cameroonian Village with High Perennial Transmission

“…However, between 1999 and 2004 CQ resistance reached 48.6% in children < 10 years of age and between 2000 and 2004 64% of parasite isolates tested in vitro were CQ resistant. 14,15 Because of increasing drug resistance, amodiaquine (AQ) became the official drug of choice (2002)(2003)(2004). Since 2004, artemisinin plus AQ is the recommended first-line drug.…”

“…Since 2004, artemisinin plus AQ is the recommended first-line drug. 14,15 Women contacted the village health worker if they became ill to receive treatment of malaria or other conditions.…”

Association of candidate gene polymorphisms and TGF-beta/IL-10 levels with malaria in three regions of Cameroon: a case–control study

“…Although malaria is endemic throughout Cameroon, the country has very different geographical and epidemiologic strata that may alter the course of the infection. In general, malaria transmission is intense and perennial in the Centre, Littoral (Coastal), and South Western regions, with peak periods corresponding to the rainy seasons [28]. …”

“…The Centre region (Yaoundé) is located within the rainforest belt of central Africa [29] and has the Guinea-type equatorial climate [28]. This is characterized by fairly constant temperatures [ranging from 17°C to 30°C (mean = 23.1°C)] [30], abundant rainfall (1,500–2,000 mm), with the average relative humidity index ranging from 85% to 90%, and four distinct seasons: two rainy seasons (March – May/June, September – November) and two dry seasons (December – February, June/July – August).…”