Bed-nets Hour Density after a Usage of Three Years of Long-lasting Insecticide-treated Nets in Malaria re-elimination Areas in Ngadirejo Village, Purworejo District, Indonesia

Abstract

Background: Malaria, caused by the genus Plasmodium, is still a global health problem. Its transmission and spread are strongly influenced by the presence of the Anopheles vector. One of the efforts to reduce cases is the distribution of long-lasting insecticide-treated nets to the residents of malaria-endemic areas. This study aims to measure the density of mosquitoes perched on insecticide-treated bed nets after three years of usage. Method: A cross-sectional study was conducted to observe mosquitoes perching on insecticide-treated bed nets at night and calculation of mosquito density data in units of mosquitoes/LLINs/hour. Results: The number of mosquito bites before bedtime in respondents reached 72.5%, while the number of bed nets infested with mosquitoes reached 74.4%. The density of mosquitoes perched varied between 1 and 10 mosquitoes/LLINs/hour with the highest density proportion of 3 mosquitoes/LLINs/hour. Conclusion: LLINs that have been used for three years were found to be less effective at killing and preventing mosquitoes. It is advisable to re-dip with the insecticide doses to match the local vector susceptibility level by officer assistance so that the mosquito nets still function properly