Ascaris lumbricoides Infection Following School-Based Deworming in Western Kenya: Assessing the Role of Pupils' School and Home Water, Sanitation, and Hygiene Exposures.

Water, sanitation, and hygiene (WaSH) technologies and behaviors can prevent infection by soil-transmitted helminth species independently, but may also interact in complex ways. However, these interactions are poorly understood. The purpose of this study was to characterize how school and home WaSH exposures were associated with Ascaris lumbricoides infection and to identify relevant interactions between separate WaSH technologies and behaviors. A study was conducted among 4,404 children attending 51 primary schools in western Kenya. We used multivariable mixed effects logistic regression to characterize how various WaSH exposures were associated with A. lumbricoides infection after annual school-based deworming. Few WaSH behaviors and technologies were independently associated with A. lumbricoides infection. However, by considering relevant interdependencies between variables, important associations were elucidated. The association between handwashing and A. lumbricoides depended largely upon the pupils' access to an improved water source. Among pupils who had access to improved water sources, A. lumbricoides prevalence was lower for those who handwashed both at school and home compared with neither place (odds ratio: 0.38, 95% confidence interval: 0.18-0.83; P = 0.01). This study contributes to a further understanding of the impact of WaSH on A. lumbricoides infection and shows the importance of accounting for interactions between WaSH technologies and behaviors.

Association between CD4+ T-lymphocyte counts and fecal excretion of Schistosoma mansoni eggs in patients coinfected with S. mansoni and human immunodeficiency virus before and after initiation of antiretroviral therapy.

Previously, we have shown that persons with human immunodeficiency virus 1 (HIV-1) infection and reduced CD4(+) T-lymphocyte counts excrete significantly fewer Schistosoma mansoni eggs than HIV-1-negative persons with similar intensities of schistosome infections. To determine how antiretroviral therapy (ART) might affect egg excretion, we conducted a study of HIV+ adults living in an area highly endemic for S. mansoni as they began an ART program. Fecal egg excretion and CD4(+) T-lymphocyte counts were evaluated at enrollment as well as 2 and 4 weeks after initiation of ART. Fourteen individuals who were Kato-Katz-negative at enrollment subsequently started excreting S. mansoni eggs accompanied by a significant increase in CD4(+) T lymphocytes (P = 0.004). Study participants who were S. mansoni egg-positive at enrollment and received both praziquantel and ART also showed significantly increased CD4(+) T-lymphocyte counts compared with baseline (P < 0.0001). Our data support a role for CD4(+) T lymphocytes in S. mansoni egg excretion.