Socioeconomic and environmental factors important for acquiring non-severe malaria in children in Yemen: a case-control study.

Little is known about the relative importance of environmental and socioeconomic factors for acquiring malaria in Yemen. A case-control study was conducted to determine the importance of these factors for acquiring malaria among children in Yemen. Cases of non-severe malaria were recruited from health centres; community controls were from the neighbourhood of the cases. Data were collected by personal interview and direct inspection during home visits. In total, 320 cases and 308 controls were recruited. In the multivariate analysis, environmental factors (living near streams and freshwater marshes), earth roofs of houses and history of travel were all significantly and positively associated with the occurrence of malaria, whilst regular spraying with insecticides at home was a protective factor. There was no association with socioeconomic factors, including crowding, education and occupation of parents, and ownership of house assets. An index created based on a number of indicators of wealth showed a significant association with malaria in the univariate analysis but was not significant in the multivariate analysis. Control activities can be targeted on identifiable environmental factors such as stream and freshwater marshes, although this needs further investigation. Extra protective measures may be needed by all those who travel in Yemen.