BangladeshArsenic PoisoningArsenicWater WellsCholeraRural PopulationWater Pollutants, ChemicalDrinking WaterWater SupplyVibrio cholerae O139Henipavirus InfectionsDiarrheaRural HealthMedicine, TraditionalVibrio cholerae O1Nipah VirusMaternal Health ServicesVibrio choleraeDeveloping CountriesHome ChildbirthInfant, NewbornDysentery, BacillaryFloodsChild Nutrition Disorders