Parasites and Biliary stones

Giardiasis ٦٠
diagnosis must be considered (Babb, 1995). Extraintestinal
manifestations of giardiasis are rare but include maculopapular rash,
urticaria, dermatitis, arthritis, and biliary tract disease. Acute giardiasis
must be differentiated from other acute diarrheal illnesses, such as viral or
bacterial gastroenteritis and food poisoning. Similarly, the differential
diagnosis of chronic giardiasis includes inflammatory bowel disease,
irritable bowel syndrome and celiac disease (Tessier and Davies, 1999).
Diagnosis:
Diagnosis of giardiasis should be considered in patients with a
typical clinical history and epidemiological risk factors. In most cases,
history, physical examination, and stool evaluation are sufficient to
establish the diagnosis (Heresi and Cleary, 1997).
Microscopic identification:
Stool examination by light microscopy of stool for cysts,
trophozoites, or both is the current standard procedure for diagnosis. Two
problems for microscopic identification are that it requires a skilled
technician and that G. lamblia cysts and trophozoites are excreted
intermittently. At least 3 stool specimens collected on non consecutive
days or during a 10-days period should be examined. A single stool
examination will miss one-half of infected patients. If 3 stools are
examined, the frequency of identification of the parasite increases to 97%
(Wolfe, 1979). Stool culture for G. lamblia can be done (Meyer, 1976).
Studies of duodenal fluids: A duodenal sample can be obtained by
endoscopy or by absorption to a swallowed coiled nylon string
(Enterotest); the latter procedure is safe and inexpensive. The sensitivity
of this test may be higher than that of stool examination, (Kamath and
Murugasu, 1974) but this observation has not been confirmed. Presently,