A CONTROLLED TRIAL OF LAMBDA-CYHALOTHRIN-IMPREGNATED BED NETS AND OR DAPSONE/PYRIMETHAMINE FOR MALARIA CONTROL IN SIERRA-LEONE/

A randomized controlled trial investigated the impact of community-wid e use of mosquito nets impregnated with lambda-cyhalothrin alone or wi th dapsone/pyrimethamine (d/p) prophylaxis on clinical malaria due to perennially transmitted Plasmodium falciparum in children in the Bo di strict of Sierra Leone. The 17 study communities were pair-matched and randomly allocated to receive treated mosquito nets or no nets and th e children (age range = 3 months-6 years) in each community were rando mly allocated to receive d/p or placebo individually every two weeks. This resulted in each of the approximately 2,000 children recruited be ing in one of four study groups (impregnated mosquito nets and d/p pro phylaxis, impregnated mosquito nets, d/p prophylaxis, and controls). T he intervention phase of the study lasted 12 months. A total of 1,800 children attended more than 25% of the 48 total weekly morbidity surve illance surveys and were included in the analysis. The effects of the exclusive use of either treated mosquito nets or d/p prophylaxis on pr otection against clinical malaria due to P. falciparum was significant ly similar (49% and 42%, respectively), while in combination this prot ective efficacy was significantly increased to 72% (95% confidence int erval = 67-76%). Children in the control group had an average of 1.3 c linical malaria episodes per child annually compared with 0.65 episode s or 0.78 episodes for those using treated mosquito nets and d/p, resp ectively. Children using both treated mosquito nets and d/p prophylaxi s had and average of 0.37 episodes per child. The interventions signif icantly reduced spleen rates and increased hematocrit values, and redu ced the duration of episodes of clinical malaria.