Fig. 1From: Impact of single annual treatment and four-monthly treatment for hookworm and Ascaris lumbricoides, and factors associated with residual infection among Kenyan school childrenAnalytical framework. Overall distribution and occurrence of STHs are influenced by environmental factors that ensure the survival of infectious stages. Factors in the immediate environment where children live (both at the household and school levels) also influence rate of STH infection and reinfection. Intrinsic factors such as nutritional status, age, and sex-related behaviours play a role in infections. Having an initial STH infection predisposes a child to having another infectionBack to article page