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.