Comparison of coverage with insecticide-treated nets in a Tanzanian town and villages where nets and insecticide are either marketed or provided free of charge

Over several years questionnaires and surveys of usage and condition of nets were carried out throughout a town and 15 villages in north-east Tanzania, where nets and insecticide have to be purchased and in 24 other villages where over 15000 nets had been donated and annual re-treatment is provided free-of-charge.There was very high population coverage in the town but, in the villages where nets have to be purchased, only 9.3% of people used nets which were intact and/or had been insecticide-treated and could, therefore, provide protection. However, where nets had been provided free, over 90% of the nets were still present and were brought for re-treatment several years later.In this part of Tanzania, social marketing has performed well in a town but very poorly in villages. However, the study showed that people look after and bring for re-treatment nets which had been provided free-of-charge.Bednets provide no protection if torn and untreated but, if intact and/or insecticidal, nets provide good, but not perfect, personal protection to sleepers against night biting mosquitoes [1-3]. If used by almost all members of a community, insecticidal nets kill large numbers of the local malaria vectors, reducing the mean survival, sporozoite rate and population density of the vector population and hence substantially reducing its entomological inoculation rate (EIR) [4]. This "bonus" effect of community-wide coverage of insecticide treated nets (ITNs) can equal or exceed the personal protection effect [5,6].Especially in Tanzania, there has been much emphasis on scaling up coverage with ITNs via social marketing and, comparing households who were able and willing to purchase nets with those who were not, there was significantly less child mortality and malaria morbidity in the former [7,8]. The argument advanced in favour of social marketing is that sustained donor funding to provide ITNs free of charge cannot be relied upon. It is therefore considered preferable to use exis