Giardia is present in the western world but infection is much more common in countries of low hygienic standards. It is the commonest cause of diarrhoea and may persist for weeks upon return home. It is caused by a small parasite which lives in the small intestine and may cause damage to the lining. Infective cysts are passed in the stools and infection is caused by swallowing these cysts via food or water.
Some people have no effects from the cyst but excrete infected stools. Other people may have slight diarrhoea with excess wind and a distended stomach. This may occur for up to six months. In its worst case the symptoms may include severe diarrhoea, marked weight loss, weakness and anaemia due to the inability of the intestine to absorb food.
Giardia is diagnosed by examination of stool specimens and is treated by metroniazole or similar drugs.
© K.Vans-Colina 1992-99