Fig. 1

Environmental and household factors affecting the abundance of malaria vectors indoors. Indoor malaria vector abundance is affected by environmental risk factors such as weather conditions, proximity and productivity of natural and human-made larval habitats, presence of livestock and animals that may divert or attract malaria vectors, outdoor activities such as cooking, sleeping or playing which may increase biting (especially where outdoor early evening biting is a problem). Indoor malaria vector density can be reduced by features of the house construction (e.g. screening, closed eaves) and by use of personal protective measures such as ITNs and household insecticides. Increased human density indoors increases the odour plume of carbon dioxide and other attractants which can attract malaria vectors towards an inhabited house