[Underestimation of intestinal protozoa as a cause of diarrhea in family practice]. / Onderschatting van darmprotozoa als oorzaak van diarree in de huisartspraktijk.

ABSTRACT

OBJECTIVE: To assess the frequency of intestinal protozoa in stool samples of patients with diarrhoea in general practice. SETTING: General practitioners' laboratory in Haarlem, Netherlands. DESIGN: Descriptive study. METHOD: During one year (1 February 1992 to 31 January 1993) all stool samples from patients with diarrhoea visiting a general practitioner were examined according to a standard protocol consisting of bacterial and protozoal examination. RESULTS: Among 1703 stool examinations requested by general practitioners and performed according to the protocol, pathogenic protozoa were found in 10.8% and pathogenic bacteria in 8.6%. Of the 184 patients who tested positive for pathogenic protozoa 156 harboured Giardia lamblia, 22 Entamoeba histolytica and 6 Cryptosporidium spp. Pathogenic protozoa were predominantly found in patients with diarrhoea persisting for longer than 1 week and in cases with intermittent diarrhoea. In patients with acute diarrhoea (duration < 1 week) we predominantly found pathogenic bacteria (Campylobacyter jejuni). If the search for protozoa in the stool samples would not have been performed routinely, 34% of the pathogenic protozoa (Giardia lamblia) would not have been found. CONCLUSION: Intestinal infections with protozoa are not rare in general practice. It seems worthwhile to perform protozoal examination of the stool samples in case of persistent diarrhoea.