Giardiasis

An infection of the small intestine caused by the protozoan parasite. Giardiasis is spread by eating or drinking food or water that is contaminated or by way of direct contact with someone who is infected. Most of those infected do not have symptoms. If, however, symptoms do occur, they begin 1–3 days after infection and include diarrhoea and wind. The faeces of those infected tend to be highly foul-smelling, greasy, and float. Abdominal discomfort, cramps, and swelling, loss of appetite, and nausea may also occur. In some cases, giardiasis becomes chronic. Infection is diagnosed from examination of a faecal sample or by a jejunal biopsy. Acute giardiasis usually clears up without treatment, but the drug metronidazole quickly relieves symptoms and prevents the spread of infection.