Assessment of current malaria transmission levels and potential beha vioural changes of people and adult mosquitoes in Emutete Western Kenya after increased use of insecticide treated nets (ITNs).

Abstract

A longitudinal study was conducted in ten houses involving the collection of indoor resting vector densitiesmonthly for eight months from September 2009 to Apri12010. Species were identified both morphologically and by the (PCR) technique to determine the dominant malaria yector in the area. Infectivity rates were carried out by use of the Enzyme Linked Immunosorbent Assay (ELISA) methodto enable the generation of an entomological inoculation rate. Bed net coverage, utilization and ownership were monitored through a questionnaire approach administered among the school childrenand shifts in man-biting rates were determined by use of CDC light trapsbi- weekly for four months. Atotal of 142 adult malaria mosquito vectors were collected with An. gambiae s. s. as the principal malariavector. The mean human biting rate for eight months was 0.12, with an infectivity proportion rate for circumsporozoite for Plasmodium falciparium being 2.5%. These measurements yielded a transmission intensity of 1.1 infectious bites per person per year. An overall 71%: 95% CI 66-76% ofhouseholds owned nets, of this proportion parents had a proportion of 59.2%, children below 5 years 42.8% and above five years 35.8%. Of this proportion 87.3% were from the hospital and 12.7% from the shops. There was a significant difference between the proportion of parents who owned nets to that of children below and above 5 years (p« 0.001) and the proportions that obtained their bed nets from hospital to those from the shop (p «O.OOl).PropOliions that slept under thebed net the night before the study was 48.6%, those who slept under bed nets always was 39.6%, 35.4% sometimes sleep under a bed net and 23.1% never sleep under a bed net.