gms | German Medical Science

Background: Insecticide-treated mosquito nets (ITNs) have been shown to be very effective against malaria and are now a key tool of the global Roll Back Malaria initiative. There remain, however, concerns regarding possible higher mortality in children protected during early infancy due to interference with immunity development. Moreover, the long-term effects on malaria prevalence and morbidity are not well described.

Methods: Between 2000 and 2002, a birth cohort was enrolled in 41 villages of a malaria holoendemic area in north-western Burkina Faso. All neonates (n=3387) were individually randomised to ITN protection from birth (group A) versus ITN protection from age 6 months (group B). Primary outcome was all-cause mortality. In 2009, a survey took place in 6 sentinel study villages, and in 2010, a census was conducted in all study villages.

Results: After a mean follow-up time of 7.3 years, 443/3387 (13.1%) children had migrated out of the area and 436/3230 (13%) had died, mostly at home. There were no differences in mortality between study groups (248 deaths in group A, 236 deaths in group B; rate ratio 1.05, 95% CI: 0.889-1.237). Long-term compliance with ITN protection was rather good. The survey conducted briefly after the rainy season showed that more than 80% of study children (mean age 8.6 years) carried asexual malaria parasites and up to 20% had clinical malaria.

Conclusions: ITN protection in early infancy is not a risk factor for mortality at older ages. Individual ITN protection does not sufficiently reduce malaria prevalence in high-transmission areas. Achieving high ITN coverage remains a major challenge in Africa.