Prevalence of gastrointestinal infection among international travellers returning to Canada

To describe the prevalence of parasitic and bacterial gastrointestinal infection (excluding enterotoxigenic Escherichia coli) among international travellers attending the International Travel Clinic at The University of Calgary.

Data were abstracted from the records of the first visit after travel of all persons making a post travel visit between January 1, 1986 and March 31, 1990.

Data were available for 886 first visits (840 persons). Stools were submitted by 692 travellers. The frequency of stool submission varied by the duration of travel abroad, and the frequency of diarrhea either during or after the trip was greater among those who had submitted a stool specimen. The prevalence of stools positive for ova, parasites or pathogenic bacteria was 41.2%. When only pathogenic organisms were considered, the prevalence of infection was 19.4%. The most commonly isolated pathogenic parasites were Dientamoeba fragilis, Giardia lamblia, and Entamoeba histolytica. The most commonly isolated bacteria were Campylobacter species and Salmonella species.

Although the prevalence of positive stool screens among returned travellers in this population was high, only about one-fifth of persons tested were positive for pathogens.