Epidemiological observation of non-parenteral infection of hepatitis type B--a possible mechanism.
D000328:Adult; D000818:Animals; D002648:Child; D009033:Culicidae; D005759:Gastroenteritis / Q000453:epidemiology*; D006509:Hepatitis B / Q000453:epidemiology*; D006801:Humans; D007194:India; D011156:Population Density; D012621:Seasons