Answer 2
Giardia lamblia
False a. is usually acquired by ingestion of food or water contaminated by the trophozoites
False b. trophozoites have four flagella
True c. can effectively be treated by mepacrine
False d. cysts are killed by standard chlorination of water
False e. cysts survive in water boiled for ten minutes
Giardia lamblia is a protozoon. During the trophozoite phase it lives in the proximal small bowel where it adheres to the mucosa. Each trophozoite has four pairs of flagella. Infection is acquired though water contaminated with giardial cysts.
Infection is not confined to the tropics; although common in India and Africa, attacks are notoriously common in various Russian cities.
Clinical features: diarrhoea, flatulence, abdominal pain, malabsorption.
Treatment: usually metronidazole. Mepacrine and furazolidone are also effective.
Prevention: standard chlorination of water does not kill cysts but drinking water can be made safe by boiling for 10 minutes.
