Effect of large-scale social marketing of insecticide-treated nets on child survival in rural Tanzania Joanna R M Armstrong Schellenberg, Salim Abdulla, Rose Nathan, Oscar Mukasa, Tanya J Marchant, Nassor Kikumbih, Adiel K Mushi, Haji Mponda, Happiness Minja, Hassan Mshinda, Marcel Tanner, Christian Lengeler
Background Insecticide-treated nets have proven efficacy as a malaria-control tool in Africa. However, the transition from efficacy to effectiveness cannot be taken for granted. We assessed coverage and the effect on child survival of a largescale social marketing programme for insecticide-treated nets in two rural districts of southern Tanzania with high perennial malaria transmission. Methods Socially marketed insecticide-treated nets were introduced step-wise over a 2-year period from May, 1997, in a population of 480 000 people. Cross-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, the effect of insecticide-treated nets on child survival was assessed by a case-control approach. Cases were deaths in children aged between 1 month and 4 years. Four controls for each case were chosen from the DSS database. Use of insecticide-treated nets and potential confounding factors were assessed by questionnaire. Individual effectiveness estimates from the case-control study were combined with coverage to estimate community effectiveness. Findings Insecticide-treated net coverage of infants in the DSS area rose from less than 10% at baseline to more than 50% 3 years later. Insecticide-treated nets were associated with a 27% increase in survival in children aged 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 achieved by 1999 in the two districts (18% in children younger than 5 years) suggests that insecticidetreated nets prevented 1 in 20 child deaths at that time. Interpretation Social marketing of insecticide-treated nets has great potential for effective malaria control in rural African settings. Lancet 2001; 357: 1241–47 See Commentary page 1219
Malaria remains the greatest threat to survival for young African children, causing at least 750 000 deaths each year.1 In endemic areas, people of all ages have regular attacks throughout their lives, yet young children and pregnant women are most at risk of severe malaria and death. Malaria also contributes to other child deaths by affecting immunity to other diseases. Successful malaria control measures could therefore result in a larger reduction of deaths than that due to malaria alone.2 African leaders and the international community have made a major commitment to prevention and treatment of malaria as part of the Roll Back Malaria (RBM) movement.3 Despite the huge malaria burden in Africa, there are alarmingly few control tools. Current policy options include prompt treatment of patients with an effective antimalarial drug, and malaria prevention through reduction of human–vector contact. Insecticide-treated nets are a practical malaria control tool with proven efficacy, but some fear a detrimental effect on immunity in long-term users.4,5 In a meta-analysis of randomised controlled trials, insecticide-treated nets reduced overall child mortality by 19%.6 Despite this evidence of efficacy, the effectiveness of insecticide-treated nets on mortality in a programme setting has yet to be shown, especially in hightransmission areas.7 Efficient delivery mechanisms are urgently needed, since the goal of RBM is to protect 50 million African children by 2005,3 but the public sector alone is unlikely to be able to provide nets on a large scale. In an assessment of the only national programme of net treatment in Africa to date, d’Alessandro and colleagues8 reported from The Gambia...