Viral infections during pregnancy and in early life.

There is evidence that fetal antigenic stimulation and intrauterine infection is much more frequent in developing rural populations than in industrialized societies. A similar contrast is observed for postnatal intestinal infection that is significantly greater in the less developed areas. The differences are explained by the divergence in environmental sanitation and personal hygiene. Intestinal infection is important in that diarrheal disease is one of the main factors leading to malnutrition. It is apparent that for developing nations to attain better nutrition, much of the present burden of intestinal infection needs to be controlled.