Ecology of respiratory virus transmission: a comparison of three communities in West Bengal.

Respiratory virus transmission in children was studied comparatively in three ecologically different low-income communities in West Bengal: an isolated village, a suburban village, and a crowded urban community. Continued use of contaminated pond water for bathing, irrigation of nasal passages, post-defecation washing of the anus, and washing of food vessels was common to all, as was intense crowding of indoor sleeping quarters during cold and wet seasons. Intensity of infection was highest (26%) in the most crowded urban area, the variety of virus types least in the most isolated village. Sources of drinking water differed but seemed unrelated to virus transmission. Toxigenic diphtheria organisms were found in nonspecific skin lesions in children in each area.