International travel and HIV infection.

This work summarizes the available epidemiological data on HIV infection in different countries analyzes the risk of contracting the virus during an international voyage and makes recommendations for prevention discusses problems involved in screening travellers for the virus and offers recommendations for seropositive individuals who travel. 222740 cases of AIDS from 153 countries were reported to the World Health Organization as of March 1990. HIV prevalence and patterns of transmission vary from 1 country to another and consequently so does the risk of becoming infected. Well-defined patterns of transmission resulting from the different times of introduction or full propagation of the virus and different characteristics of social behavior have been observed. In North America Western Europe Australia New Zealand South Africa and many urban zones of Latin America the virus spread widely in the late 1970s or early 1980s and most AIDS cases were acquired through sexual transmission among homosexuals and bisexuals. Nonsexual transmission resulted mainly from intravenous drug use. General prevalence in these countries is less than 1%. In parts of Africa and the Caribbean the virus began to spread in the 1970s and seroprevalence among adults exceeds 1% sometimes rising to 5-25%. Transmission is primarily heterosexual and nonsexual transmission results from the inability to screen blood and the use of unsterilized syringes and other instruments. In North Africa the Middle East Eastern Europe Asia and the Pacific and rural Latin America the virus was introduced somewhat later and prevalence rates are lower although rising. The risk of sexual transmission of HIV can be almost eliminated by avoiding sexual relations with intravenous drug users and prostitutes and others who have had many sexual partners. Condom use can reduce the risk. Seroprevalence rates among prostitutes vary widely in different countries and have been reported as high as 90%. The risk of nonsexual transmission can be reduced by avoiding drugs administered intravenously and by avoiding behavior that entails risk of injury and possible need for blood transfusion. Health services should screen their blood supplies and sterilize their instruments properly. HIV screening for international travellers would be prohibitively expensive and would divert scarce resources always from more effective modes of prevention. The logistical problems involved in screening record keeping and quality control would be enormous. Screening would be unable to detect some early cases with the tests in common use. Seropositive individuals planning international travel should review their proposed itineraries with a physician to determine whether specific vaccinations or prophylactic medications are needed. Those with symptomatic disease should be informed in advance of medical services available and possible restrictions on entrance of infected persons.