Maloprim® malaria prophylaxis in children living in a holoendemic village in north-eastern Tanzania

Abstract

A randomized, double-'blind', placebo-controlled trial of weekly Maloprim (dapsone-pyrimethamine, D-P) for malaria prophylaxis was conducted at Magoda village in north-eastern Tanzania. The effect of D-P on the incidence of clinical malaria, Plasmodium falciparum prevalence and density, splenomegaly, and packed cell volume (PCV) was investigated in a cohort of 249 children (126 receiving D-P and 123 receiving placebo) aged 1-9 years. The case definition of clinical malaria (malaria fever) was measured axillary temperature > or = 37.5 degrees C and/or reported fever, and P. falciparum asexual parasitaemia > or = 5000/microL. Children aged 1-4 years given D-P experienced 1.56 episodes of clinical malaria per year, whereas children on placebo experienced 2.55 episodes (relative rate [RR] = 0.61, 95% confidence interval [CI] 0.47, 0.80). Thus, D-P protective efficacy against clinical malaria, in this age group, was 39% (95% CI 20%, 53%; P = 0.0002). The annual incidence of clinical malaria among children aged 5-9 years was 0.16 episodes in the D-P group and 0.26 episodes in those receiving placebo (RR = 0.58, 95% CI 0.26, 1.28; P = 0.17). Increased malaria transmission and drug resistance, during the course of the trial, resulted in a reduction in the protective efficacy of D-P. Overall, D-P was able to reduce parasite densities and splenomegaly. D-P prophylaxis also resulted in an increase in PCV but this effect diminished towards the end of the trial. D-P exerted a suppressive effect on asexual parasitaemia throughout the trial.

Declining burden of malaria over two decades in a rural community of Muheza district, north-eastern Tanzania

“…The villages were involved in malaria and filariasis studies as described elsewhere [38-40]. Currently, the two villages have a population of 2,934 individuals in 678 households and under-fives account for 13.2% of the entire population.…”

“…After an initial screening of parasite prevalence of the entire population of Magoda village in 1992, and based on the promising results from the Gambia [41], a Maloprim ® (3.125 mg pyrimethamine and 25 mg dapsone, GlaxoSmithKline, UK) trial was the first study to be implemented in Magoda in 1993–94 to test the prophylactic effects of weekly administration of the drug on parasite infections, anaemia and splenomegaly [40]. Children aged <10 years old were given either one or two tablet(s) of Maloprim ® to under-fives and those aged 5–9 years, respectively and followed-up weekly to determine their general condition and malaria infection status [40].…”

Distinguishing Plasmodium falciparum treatment failures from re-infections by using polymerase chain reaction genotyping in a holoendemic area in northeastern Tanzania.

“…The area is holoendemic for malaria and has been described in detail elsewhere. 8 Study population. The present drug efficacy trial was carried out during the long rainy season in April 1996 at the beginning of a malaria transmission peak.…”

In Vivo Selection for a Specific Genotype of Dihydropteroate Synthetase ofPlasmodium falciparumby Pyrimethamine‐Sulfadoxine but Not Chlorproguanil‐Dapsone Treatment

“…These studies their survival within their human host. In Kenya, studies of S. mansoni -infected persons have indicated that parasite-specific have also indicated that antigen-specific IgE and eosinophilia are associated with resistance to reinfection [2,3], implying IFN-g and IL-5 production is higher after clearance of infection [7]. Moreover, in Schistosoma haematobium -infected persons, that a bias toward Th2 might provide protection to invading parasites.…”