International Journal of Entomology Research

Authors
André Sominahouin, VirgileGnaguênon, Gil Padonou, Idelphonse Ahogni, Sahabi Bio Bangana, Damien Todjinou, Dina Gbénou, Christophe Houssou, Martin C Akogbéto

Abstract
The objectives of this study are to assess the geo-variability of the physical deterioration of LLINs and to map the risk of tearing them in two districts in southern Benin, Kessounou and Allada, and two others located further north at about 750 km, Kandi and Malanville, in order to analyse the spatial distribution of the physical deterioration of impregnated nets and their risk factors. In each of the 4 study sites, 500 nets were randomly selected. Only nets that are actually used in households and suspended in bed are selected. Each selected net was doubly marked with paint and a label with an identification number. The geographical coordinates of the household are then taken with a GPS. The integrity of nets has been assessed using the new methods described by WHO. The observed holes were counted and categorized according to their diameter and we are interested in data processing. It appears that one year after distribution, 62% to 87% of LLINs found in households are found at the different sites studied. And 24 months after distribution, 76% to 94% of LLINs found in households are found at the different sites studied. This situation is explained by factors that cause them to tear. The spatial distribution of PHI in Malanville is characterized by a trend towards a concentration of tear frequencies in the northeast and central parts of the site and that of Kessounou is characterized by a more or less homogeneous distribution of aggregates along the river. Since Moran's autocorrelation index is close to 0, there is spatial independence for this realization of the regionalised random variable. There are then spatial aggregates expressing the local existence of spatial autocorrelation. LLINs distributed and used in areas with high wash pressure are subject to a significantly higher risk of deterioration of their physical integrity than LLINs in areas with low wash pressure. The frequency of washing and appearance (dirty or clean), frequency of use of LLINs, number of net users, energy and location of the kitchen and distance of the area from a river are very important prognostic factors in the loss of physical integrity of LLINs.