Bacteria are the most common pathogens isolated in acute travelers' diarrhea. Some patients returning from tropical and subtropical areas suffer from prolonged diarrhea lasting more than 14 days. Instestinal protozoan parasites such as Cryptosporidium, parvum, Giardia lamblia, Entamoeba histolytica, Blastocystis homonis, and Cyclospora cayentanensis seem to be relevant pathogens.
Limited data are available about the role of microsporidia in travelers' diarrhea.
This investigation tested whether microsporidia are possibly relevant pathogens in returned travelers. We examined stool specimens of 120 patients with persistent diarrhea after travel to tropical countries attending an outpatient clinic for tropical disease between January and March 1998. Two different methods were used for the examinations. In light microscopy microsporidian spores of different sizes were found in 5 cases, but species differentiation could not be performed by light microscopy. Microsporidian DNA was found in the stool specimens of 8 patients, including all patients with positive light microscopy.