Data collection will take place at each school once every six to eight weeks for the duration of up to three school years. The investigators will conduct school observations and an interview with the school director about school conditions, handwashing behavior observations of children, and a review of aggregate school-wide academic record data including percentage of children obtaining a passing average, advancing to the next class, and drop-outs. None of these school activities collect personal data or identifiers. Data collection with pupils will be done with the same pupils every six to eight weeks and will entail a five-minute interview asking about recent absence, symptoms of diarrhea or respiratory illness, age, and grade. Select pupils in a subset of schools will undergo testing for cognition, attention, and hydration. Select pupils in a subset of school will provide a stool sample for analyses of helminth infection prior to school-wide de-worming. Data collection will also take place at the household of select pupils in a subset of schools. The investigators will conduct a household survey once at the beginning of each school year to assess the range of household WASH access among pupils in study selected schools.