Background: The use of artemisinin derivative-based combination therapy (ACT) such as artesunate plus amodiaquine is currently recommended for the treatment of uncomplicated Plasmodium falciparum malaria. Fixed-dose combinations are more adapted to patients than regimens involving multiple tablets and improve treatment compliance. A fixed-dose combination of artesunate + amodiaquine (ASAQ) was recently developed. To assess the efficacy and safety of this new combination and to define its optimum dosage regimen (once or twice daily) in the treatment of uncomplicated P. falciparum malaria, a multicentre clinical study was conducted.

Background: Artesunate and amodiaquine (AS&AQ) is at present the world's second most widely used artemisinin-based combination therapy (ACT). It was necessary to evaluate the efficacy of ACT, recently adopted by the World Health Organization (WHO) and deployed over 80 countries, in order to make an evidence-based drug policy.

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 Chloroquine is no longer a viable option and has been withdrawn from the official drug outlets in Cameroon.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.

Background: Indoor residual spraying and insecticide-treated nets (ITN) are essential components of malaria vector control in Africa. Pyrethroids are the only recommended compounds for nets treatment because they are fast-acting insecticides with low mammalian toxicity. However, there is growing concern that pyrethroid resistance may threaten the sustainability of ITN scaling-up programmes. Here, insecticide susceptibility was investigated in Anopheles gambiae sensu lato from an area of large scale ITN distribution programme in southwestern Chad.

Abstract. In support of ongoing immunologic studies on immunity to Plasmodium falciparum, demographic, entomologic, parasitologic, and clinical studies were conducted in two Cameroonian villages located 3 km apart. Simbok (population ϭ 907) has pools of water present year round that provide breeding sites for Anopheles gambiae, whereas Etoa (population ϭ 485) has swampy areas that dry up annually in which A. funestus breed. Results showed that individuals in Simbok receive an estimated 1.9 and 1.2 infectious bites per night in the wet and dry season, respectively, whereas individuals in Etoa receive 2.4 and 0.4 infectious bites per night, respectively. Although transmission patterns differ, the rate of acquisition of immunity to malaria appears to be similar in both villages. A prevalence of 50-75% was found in children Ͻ 10 years old, variable levels in children 11-15 years old, and 31% in adults. Thus, as reported in other parts of Africa, individuals exposed to continuous transmission of P. falciparum slowly acquired significant, but not complete, immunity.