Diagnostic value of specific Giardia fecal antigen tests

: Two commercial faecal antigen tests, based on Giardia specific antigens, were compared with traditional microscopical examination of faeces in 40 clinical patients, including 14 patients with a confirmed Giardia infection as well as in a survey among 96 children in four day care centers. The results obtained with these faecal antigen tests were not much better than by using traditional microscopy by a well trained parasitologist. Specific Giardia antigen (GSA 65) has been still detected in faeces up to day 4th after treatment of giardiasis, when microscopical examination of faeces was already for a few days negative. The Giardia antigen detection test was not very useful in examining the unconcentrated duodenal content.