Effect of large-scale social marketing of insecticide-treated nets on child survival in rural Tanzania

Background Insecticide-treated nets have proven efficacy as a malaria-contr ol tool in Africa. However, the transition from efficacy to effectiveness c annot be taken for granted. We assessed coverage and the effect on child su rvival of a large-scale social marketing programme for insecticide-treated nets in two rural districts of southern Tanzania with high perennial malari a transmission. Methods Socially marketed insecticide-treated nets were introduced stepwise over a 2-year period from May, 1997, in a population of 480 000 people. Cr oss-sectional coverage surveys were done at baseline and after 1, 2, and 3 years. A demographic surveillance system (DSS) was set up in an area of 60 000 people to record population, births, and deaths. Within the DSS area, t he effect of insecticide-treated nets on child survival was assessed by a c ase-control approach. Cases were deaths in children aged between 1 month an d 4 years. Four controls for each case were chosen from the DSS database. U se of insecticide-treated nets and potential confounding factors were asses sed by questionnaire. Individual effectiveness estimates from the case-cont rol study were combined with coverage to estimate community effectiveness. Findings Insecticide-treated net coverage of infants in the DSS area rose f rom less than 10% at baseline to more than 50% 3 years later. Insecticide-t reated nets were associated with a 27% increase in survival in children age d 1 month to 4 years (95% CI 3-45). Coverage in such children was higher in areas with longer access to the programme. The modest average coverage ach ieved by 1999 in the two districts (18% in children younger than 5 years) s uggests that insecticide-treated nets prevented 1 in 20 child deaths at tha t time. Interpretation Social marketing of insecticide-treated nets has great poten tial for effective malaria control in rural African settings.