Epidemiology of giardiasis in German travelers.

BACKGROUND Giardiasis has been well characterized in individuals traveling from areas of low to high endemicity. METHODS Clinical features, travel and medical histories in 352 patients with giardiasis who presented to a German outpatient clinic for Infectious and Tropical Diseases were investigated in order to identify common epidemiological factors and potential strategies of prevention. RESULTS Compared to the total patient population of the outpatient clinic during the period of investigation (n=13, 566 patients), patients who presented with giardiasis traveled longer (median 28 days versus 19 days, p <.001). While only 19.2% of the total patient population had traveled to the Indian subcontinent prior to referral, 32.1% of the patients with giardiasis acquired the infection there (p <.0001). Similar results were obtained for West Africa: in contrast to 19% of patients with giardiasis (p <. 0001), only 5.4% of the total patient population traveled there. CONCLUSION The risk of infection appears to be highest when making an extended journey to the Indian subcontinent. Short-time visitors to other parts of Asia and Latin America are apparently at a markedly lower risk. Risk factors such as type, duration and destination of the journey should be considered in pretravel counseling.