Giardiasis.
D000208:Acute Disease; D002908:Chronic Disease; D004196:Disease Outbreaks / Q000453:epidemiology; D005243:Feces / Q000469:parasitology; D005872:Giardia / Q000302:isolation & purification; D005873:Giardiasis / Q000188:drug therapy / Q000453:epidemiology / Q000635:transmission; D006801:Humans; D014481:United States; D014876:Water Pollution