Impact of the HIV Epidemic in Sub-Saharan Africa on the Pattern of HIV in the UK

The current study describes the epidemiology of HIV infection acquired in Africa and among African communities in the United Kingdom. The authors produced a descriptive analysis using national HIV and AIDS surveillance data, routine voluntary confidential HIV reporting, and unlinked anonymous seroprevalence surveys in the United Kingdom to the end of December 2001.

Researchers found that of all reported HIV infections diagnosed in the United Kingdom by the end of 2001, 21 percent (9,993 of 48,226) were probably acquired in Africa, and 90 percent of those were transmitted heterosexually. Diagnoses of HIV infection acquired in Africa have been rapidly increasing, with infections from southeastern and southern Africa predominating recently.

Of the 28.5 million people with HIV/AIDS in sub-Saharan Africa at the end of 2001, according to a UNAIDS estimate, 74 percent of them lived in commonwealth countries. "The focus of the global epidemic in these countries with close links to the United Kingdom has led in recent years to large rises in the numbers of new UK diagnoses of HIV infections that were probably acquired in sub-Saharan Africa," they wrote. Most of the people affected are of black African ethnicity.

In the United Kingdom, routine surveillance reports the probable route of HIV infection for all new diagnoses using five broad categories: sex between men, heterosexual sex, injection drug use, mother-to-child transmission, and treatment with blood or blood products. Until 2000, country of infection was recorded only for infections transmitted through heterosexual sex. Now, such information is reported for all new diagnoses. Ethnicity data are recorded in broad categories based on the 1991 census classification.

New diagnoses of heterosexually transmitted HIV have grown steadily throughout the course of the United Kingdom's epidemic, overtaking HIV transmitted by sex between men in 1999. Since 1990, 85 percent of all AIDS cases diagnosed annually have been in people of black African or white ethnicity, but the ratio has been changing. In 1990, 12 times as many cases were diagnosed in people of white ethnicity as in black Africans. By 1995, the ration had fallen to 5 times white to black, and by 2000, to 1.5. Part of the trend is attributable to rising numbers of late diagnoses in black Africans and the falling numbers of late diagnoses among whites.

The study noted that a high number of African women are pregnant at diagnosis, thus increasing the need for intervention strategies to prevent mother-to-child transmission. The researchers also pointed out that self-help projects and funding earmarked for prevention efforts since 1995 have had some success in spreading prevention and education messages among African communities in the United Kingdom.

"Infections acquired in Africa and among Africans are making an increasing contribution to HIV infection in the United Kingdom," the authors concluded. "Migration, diagnosis of long-standing infection and incident cases are all potential influences, but they are difficult to measure. Improvement in early diagnosis of HIV continues to be an important component of intervention to prevent onward vertical and sexual transmission and to promote access to treatment and care."