вЂњAll other regionsвЂќ include those with no assigned travel destination. Because of small case numbers, a more simplified regional classification was sometimes used: sub-Saharan Africa, south-central America (South and Central America), Asia (south-central, southeast, east, and north Asia), and eastern Europe. More than 1 chief complaint per patient was possible.Д¬ountries were assigned to 1 of 15 regional classifications ( 13). The percentage of вЂњchief complaintsвЂќ was expressed as the number of primary symptoms that led to a clinic visit per total patients in each group. The rate of illness was calculated as the number of patients with a specific or a summary diagnosis as a proportion of all VFR or traditional travelers, respectively, expressed as number per 1,000 patients. Different patient classifications were possible (i.e., immigrant-VFR, traveler-VFR). When the purpose of recent travel was visiting friends and relatives, a traveler was termed VFR. Traveler (or traditional traveler) was defined as a resident of Switzerland who crossed an international border and did not previously immigrate to Switzerland. Working and final diagnoses were assigned by a physician.ДЄn immigrant/refugee was defined as a foreign-born person who had obtained permanent resident status or immigrant/refugee status in Switzerland. Patients were classified as immigrants/refugees, foreign visitors, urban expatriates, nonurban expatriates, students, military personnel, or travelers. Reasons for most recent travel were immigration, tourism, business, research/education, missionary/volunteer work, visit to friends or relatives, and expatriation. The questionnaire asked for demographic data (age, sex, country of birth, country of residence, current citizenship), travel history during the previous 5 years, inpatient or outpatient status, major clinical symptoms (>1 per patient possible), pretravel visit information, reason for most recent travel, and patient classification. Data were collected according to a standardized, anonymous questionnaire. Only final diagnoses were considered, and >1 diagnosis per patient was possible. Relevant travel details focused only on data from the 6 months before the onset of illness. To be eligible, patients must have crossed an international border в‰¤10 years before seeking treatment and must have sought medical advice for a presumed travel-related illness. We evaluated the epidemiology of imported infectious disease of patients seeking treatment for travel-associated illness at the University Hospital of ZГјrich from January 2004 through May 2005. The outpatient departments treat в‰€120,000 patients each year, and the inpatient departments treat >35,000. The University Hospital of ZГјrich serves a large proportion of the cityвЂ™s population, which includes a multiethnic range of patients and immigrants. Compared with the health of the native population of Switzerland, the health status of the immigrant population is poor ( 8) because of the high prevalence of infectious diseases in the home countries ( 9), a difficult psychosocial environment in the new country, inappropriate risk-taking behavior ( 10), and social inequalities ( 11). In Switzerland, в‰€21% (1.6 million) residents are foreign born ( 7). One third were born in a country outside of Europe ( 6). The population of western Europe includes в‰€20 million persons living in nonnative countries most are settled immigrants. Travelers visiting friends and relatives (VFR travelers)-predominantly immigrants and their children returning to their home countries for vacations, to maintain family ties, or to visit sick relatives-are at particularly high risk for preventable infectious diseases, such as malaria, typhoid fever, hepatitis A, hepatitis B, and tuberculosis ( 3вЂ“ 5).ДЄ recent review of a global surveillance networkвЂ™s data set showed different demographic characteristics and different types of travel-related illnesses among immigrant-VFR, traveler-VFR, and tourist travelers ( 5). Approximately 80 million people from resource-rich areas worldwide travel to resource-poor countries every year ( 2) and are exposed to many infections that are no longer prevalent in the countries where they live.

Importation of infectious diseases to new countries is likely to increase among both travelers and immigrants. More than 800 million tourist arrivals were registered worldwide in 2005, and an estimated 2% of the worldвЂ™s population lives outside the country of birth ( 1).

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