Ecology and control of Anopheles mosquitoes and human malaria in Guinea Bissau, West Africa

Sammanfattning: This thesis analyses the relationship between risk of exposure to infective Anophelesmosquitoes and different environmental factors, in particular house construction, presence ofdomestic animals and house location, in coastal Guinea Bissau, West Africa. The potentialeffect of permethrin-impregnated bed nets on mosquito abundance in bed rooms, and on thePlasmodium parasite prevalence in children was also analysed. In addition, measures frequentlyused traditionally against mosquitoes in the Oio region of Guinea Bissau were identified andexperimentally evaluated.The house construction, in particular presence of open eaves, and presence of animals (pigs)in the house and a well in the garden were factors associated with increased mosquitoabundance indoors.Permethrin-impregnated bed nets dramatically reduced mosquito abundance indoors. Also,the malaria (Plasmodium) parasite prevalence was significantly lower in children sleepingunder impregnated bed nets compared to that of children sleeping under unimpregnated bednets.The most commonly used natural mosquito repellents were based on the plants Hyptissuaveolens and Daniellia oliveri. Experiments, both indoors and outdoors, revealed that these and certain other plants traditionally used in Guinea Bissau possess significant mosquito repellent properties. Increased knowledge about traditionally used mosquito repellents may reveal that certain of these plant-derived products may have particular advantages over imported synthetic arthropod repellents and chemical pesticides.