Developing national treatment policy for falciparum malaria in Africa: Malawi experience.

The emergence and spread across sub-Saharan Africa of Plasmodium falciparum resistant to the inexpensive antimalarials chloroquine and sulfadoxine-pyrimethamine has worsened the health and hampered the socio-economic development of affected countries, a situation that calls for urgent review of malaria treatment policies in these countries. The Roll Back Malaria (RBM) initiative promotes strong partnerships for implementing effective malaria control measures. The development of clear policies to guide such implementation at country level offers a way of assessing the achievement of set milestones in this collaborative venture. In this article we describe the policy development process for the treatment of falciparum malaria in Africa, based on experience in Malawi, where the first-line drug treatment was recently changed from sulfadoxine-pyrimethamine to an artemisinin combination therapy.

Effects of HIV-1 serostatus, HIV-1 RNA concentration, and CD4 cell count on the incidence of malaria infection in a cohort of adults in rural Malawi.

BACKGROUND: To assess the effects of human immunodeficiency virus (HIV) infection on susceptibility to malaria, we compared the incidence rates of malaria by HIV type 1 (HIV-1) serostatus, baseline blood HIV-1 RNA concentration, and baseline CD4 cell count, over the course of a malaria season. METHODS: We followed a cohort of 349 adults in Malawi. For the 224 HIV-1-seropositive adults (64% of the cohort), we measured HIV-1 RNA concentration (n=187) and CD4 cell count (n=184) at baseline. Parasitemia was defined as presence of asexual parasites on a thick film of blood and was treated with sulfadoxine/pyrimethamine (SP), in accordance with national policy. Hazard ratios (HRs) of parasitemia were estimated using Cox regression. Demographics were adjusted for. RESULTS: HIV-1 seropositivity was associated with parasitemia (adjusted HR, 1.8 [95% confidence interval {CI}, 1.2-2.7] for a first parasitemia episode; adjusted HR, 2.5 [95% CI, 1.5-4.2] for a second parasitemia episode [> 14 days after the first episode]; adjusted HR, 1.9 [95% CI, 1.4-2.6] for parasitemia overall). Treatment failure (parasitemia < or = 14 days after SP treatment) did not differ by HIV-1 serostatus (risk ratio, 1.3 [95% CI, 0.5-3.2]). HIV-1 RNA concentrations and CD4 cell counts were moderately but inconsistently associated with parasitemia. A high parasite density with fever was associated with HIV-1 seropositivity and low CD4 cell count. CONCLUSION: HIV-infected adults in malaria-endemic areas are at increased risk for malaria. Where possible, additional malaria prevention efforts should be targeted at this population.

Reemergence of chloroquine-sensitive Plasmodium falciparum malaria after cessation of chloroquine use in Malawi.

In 1993, Malawi became the first African country to replace chloroquine with sulfadoxine-pyrimethamine nationwide in response to high rates of chloroquine-resistant falciparum malaria. To determine whether withdrawal of chloroquine can lead to the reemergence of chloroquine sensitivity, the prevalence of the pfcrt 76T molecular marker for chloroquine-resistant Plasmodium falciparum malaria was retrospectively measured in Blantyre, Malawi. The prevalence of the chloroquine-resistant pfcrt genotype decreased from 85% in 1992 to 13% in 2000. In 2001, chloroquine cleared 100% of 63 asymptomatic P. falciparum infections, no isolates were resistant to chloroquine in vitro, and no infections with the chloroquine-resistant pfcrt genotype were detected. A concerted national effort to withdraw chloroquine from use has been followed by a return of chloroquine-sensitive falciparum malaria in Malawi. The reintroduction of chloroquine, ideally in combination with another antimalarial drug, should be considered in areas where chloroquine resistance has declined and safe and affordable alternatives remain unavailable.