Long Lasting Insecticidal Nets (LLINs) are among the most effective strategies in malaria vector control, halving the population at risk in sub-Saharan Africa since 2010. Despite this success, in some hyperendemic African countries, such as Burkina Faso, the annual incidence and the entomological infection rates are still very high. Evidence from a hyperendemic LLIN-protected village of Burkina Faso (Goden, Ouagadougou area) in 2011-2012 showed high Sporozoite Rates in major vector species (SR>7%), despite very low Human Blood Index (HBI<16%). We here report a similar picture from another LLIN-protected village in the same area (Koubri), where Anopheles funestus shows consistently high SR (8.6%) associated to a very low HBI (5.8%) associated to a strong exophilic behavior, suggesting again lack of community level protection despite massive LLIN implementation. We thus carried out a second entomological survey in Goden in 2015 by Human Landing Catches at three different time points during the night (21-22; 00-01; 03-04) and collected a total of 1,955 Anopheles gambiae complex specimens (A. coluzzii 55%, A. arabiensis 44%, A. gambiae 1%, without significant differences indoors vs outdoor, nor among time points). The median number of host-seeking mosquitoes/hour/person was 23.5 and the SR among the 692 specimens analysed so far was 6.2% (without significant differences in indoors vs. outdoors), corresponding to an entomological inoculation rate in equal to 1.46 infective bites/hour. Overall, these results highlight that, despite the large-scale usage of LLINs in the area since 2010, the mosquito population is still present at high densities and highly infected, probably as a consequence of shifting in biting behaviour of vector species. This leads to a non-negligible risk of malaria transmission to people either sleeping unprotected by a bednet indoors or exposed to mosquito bites outdoors and may explain the reduced effect of LLIN implementation in hyperendemic regions of sub-Saharan Africa.
Do the LLINs really protect from malaria at community level in areas of high transmission? / Pombi, M.; Guelbeogo, W. M.; Calzetta, M.; Perugini, E.; Fidati, S.; Pichler, V.; Ranson, H.; Sagnon, N.; Della Torre, A.. - (2018). ((Intervento presentato al convegno European Society for Vector Ecology 21st Conference tenutosi a Palermo, Italy.
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|Titolo:||Do the LLINs really protect from malaria at community level in areas of high transmission?|
|Data di pubblicazione:||2018|
|Citazione:||Do the LLINs really protect from malaria at community level in areas of high transmission? / Pombi, M.; Guelbeogo, W. M.; Calzetta, M.; Perugini, E.; Fidati, S.; Pichler, V.; Ranson, H.; Sagnon, N.; Della Torre, A.. - (2018). ((Intervento presentato al convegno European Society for Vector Ecology 21st Conference tenutosi a Palermo, Italy.|
|Appartiene alla tipologia:||04d Abstract in atti di convegno|