The more people move, the faster AIDS and other STDs, like other diseases, can spread. Mobility itself has been considered an independent risk factor for HIV infection (88). While little research has been conducted on the prevalence of STDs among migrant groups (91), studies show that the spread of HIV often coincides with migration patterns.

Usually, HIV appears first in urban areas and then diffuses to rural areas along major road networks. In Côte d'Ivoire, for example, HIV/AIDS has spread outward from the capital city, Abidjan, where almost half the population are immigrants from surrounding countries (4). AIDS has spread along transportation routes from Zambia, Zimbabwe, Malawi, and Mozambique to South Africa (267) and along the Mombassa highway from the Indian Ocean to the former Zaire (4).

A study in Kenya found that men who migrated between urban areas were more than twice as likely as nonmigrants to engage in high-risk sexual behavior—that is, to have more than one sex partner while not using condoms. It was not clear whether their behavior was more risky because they moved or whether those who moved were prone to more risky sexual behavior than others (46).

Other factors may increase risk for migrants and refugees. Communicable diseases, including STDs, spread most quickly in conditions of poverty, powerlessness, and social instability. Such conditions often are found in refugee emergencies (292, 308). Also, migrants often settle in areas with high prevalence of HIV infection, are exposed to intravenous drug use, and may be in poor health (127). The disruption of social ties and family life that occurs during moves, especially in situations of poverty and crisis, also increases risk of disease, as migrants find new sex partners. Sometimes women have no choice but to sell sex for protection, money, food, and other goods (32, 103, 142, 269, 292).

HIV high-risk groups and mobility. Many people who move frequently have a high risk of HIV infection, including truck drivers and other transportation workers, sex workers, and seasonal agricultural workers and other temporary migrants (4, 21, 101, 127, 220, 303).

Although not considered temporary migrants, long-distance truck drivers are of particular concern to disease control programs because they often are at high risk and can spread STDs long distances. They travel frequently, often to areas with high levels of HIV, and, because they are away from home for long periods of time, they may have many different sex partners (267).

For example, among 400 West Bengal long-distance truck drivers surveyed, more than 60% reported having visited sex workers, 36% had never heard of AIDS, and only 22% were regular users of condoms (127). About one-half of truck drivers arriving in Kigali, Rwanda, from Mombassa and Nairobi, Kenya, were HIV-positive, according to a 1994 study (205). In a study of 200 adolescents who frequented truck stops in Kenya, half the boys and almost one-third of the girls reported having had at least one STD (127).

Many sex workers move from place to place, whether voluntarily or involuntarily. For example, women from Cambodia, Laos, Myanmar, and Vietnam work in brothels in Thailand. Sex workers from Thailand and the Philippines work in Japan. Thai women become sex workers in Singapore, and Nepalese women work in India, where 35% or more of sex workers are infected with HIV (142, 180). Sex workers may spread HIV from cities to rural areas when they return home. In Ghana many rural women who left for Côte d'Ivoire and became sex workers brought HIV home with them to their villages, which now have a high prevalence of HIV (5, 87).

Often, boom towns and tourist centers that attract temporary migrants and visitors also attract many sex workers, to whom men away from their spouses or usual partners may turn (20, 91, 142, 172, 269, 341). Male migrants who go to sex workers infected with HIV can transmit the virus to other sex workers and also give the virus to their wives or other female partners at home when they do not use condoms (46, 240). In 1990 a study in KwaZulu/Natal province, which is a major source of migrant workers to the mines of South Africa, found that migrant men had twice the HIV rates of nonmigrants, while women who attended prenatal clinics in the province had twice the national level of HIV infection (20).

AIDS has spread even to remote countries with conservative norms about sex (255). For example, in the Pacific island nation of Kiribati some men who leave the country to work on foreign ships have become infected with HIV and have spread the virus upon returning home (39).

Border controls. Some countries have charged international migrants and foreign visitors with introducing HIV (102, 276). China has held foreign tourists responsible for the appearance of the AIDS virus in that country, although many HIV cases in China have involved returning migrants who had contact with sex workers elsewhere (154). In Ethiopia refugees, along with sailors and sex workers, have been blamed both for the introduction of HIV into the country (282) and for spreading the virus within the country (142). Mexico's Health Minister recently pointed to Mexicans returning home from the United States as the reason that the incidence of AIDS was increasing in rural areas of Mexico, especially where there is substantial migration to the US (243). An estimated 25 percent of AIDS cases in Mexico occur to individuals who have been temporary migrant workers in the United States (127).

A few countries have tried to stop the spread of AIDS by preventing people suspected of being infected with HIV from entering the country. In 1992 the US would not admit HIV-positive participants to the World AIDS Conference in San Francisco. Countries that have instituted border controls of various sorts include India (151), the Gulf States (186), South Africa (20, 67), Cuba, and Iraq (276).

Border controls are ineffective, however, and only create a false sense of security and detract attention from the need to reduce high-risk sexual behavior within the country. The World Health Organization (WHO) also has taken a stand against mandatory HIV testing in refugee situations, arguing that the tests can be inaccurate and do not prevent the spread of the disease (299). Mandatory testing may even increase the spread of HIV, if unsterile needles are used for drawing blood for tests, by infecting the people being tested (60).

Refugee movements and AIDS. Refugee movements have contributed to the spread of HIV/AIDS and other STDs. When nearly 2 million refugees who had fled in the 1980s to Malawi, which has a high HIV rate, returned home to Mozambique, the incidence of HIV began rising in Mozambique, where it was previously rare (29, 142). Liberian refugees in Côte d'Ivoire and Guinea, Rwandan and Ugandan refugees in the former Zaire, Laotian and Cambodian refugees in Thailand, Sudanese refugees in Uganda, and Ethiopian refugees in Sudan have carried HIV home with them, after having been infected during their flight (320).

Relatively little attention has been paid among humanitarian agencies to treatment of STDs in refugee situations. Among eight refugee camps in the Great Lakes Region of East Africa, only the two oldest camps provided comprehensive treatment at separate STD clinics; these served mostly men, who were reluctant to bring in their wives or other partners for treatment (222). When attention is paid to STDs and HIV/AIDS in refugee situations, it is often on a case by case basis—for example, after being identified during pregnancy or childbirth—rather than as part of a health education effort, and little attention is given to treatment of partners and to follow-up (255). There is little attention to counseling (222).

The situation is changing. Recently, the Joint United Nations Programme on HIV/AIDS published Guidelines for HIV Interventions in Emergency Situations (292). This publication discusses why HIV/AIDS should be given high priority and describes the services that are required to cope with the problem, including provision of condoms, education about HIV/AIDS prevention, and STD treatment.