epidemiology
Last reviewed 01/2018
Environmental factors include:
- poverty and overcrowding, in the absence of clean water supply, proper sewerage disposal and appropriate personal hygiene are important internationally
- malnutrition is a strong contributory factor
- bottle feeding, with incorrect sterilisation
The highest risk groups are children under six months old in the developed, or infants bottle fed or between weaning and the second year in the developing world.