Correlation between malaria epidemic incidence and some natural and social factors in high incidence areas of Shandong Province

OBJECTIVE: To explore the association between malaria epidemic situation and some natural and social factors in high-incidence areas of Shandong Province, so as to provide evidences for malaria elimination in these areas. METHODS: Twenty towns of 10 counties (cities, districts,) in the high incidence areas of malaria in Shandong Province were selected as the study sites, and the residents in the study sites were investigated by questionnaires with one household as a unit, so as to understand the related natural and social factors. In addition, the malaria epidemic data in the study sites from 2006 to 2010 were collected, and the correlation between these factors and the epidemic situation of malaria was analyzed by Spearman rank correlation and multiple stepwise regression. RESULTS: The square root of malaria incidence rate (Y) was negatively related to the rate of households using insecticide (X3), and the rate of households using screen doors and windows (X4) (both P < 0.05), but was positively related to the rate of housing surrounding water environment and exposure ratio (X6) (both P < 0.05). The regression equation established was Y = 0.032X5 + 0.048X6-0.495, R2 = 0.973. CONCLUSIONS: Malaria incidence is obviously associated with some natural and social factors. The measures such as clearing the breeding place of mosquito, protecting the exposure population at nightfall, as well as using door-window screen and repellents correctly, can effectively control malaria.