Substantial number of HIV infections in UK-born patients acquired abroad

A substantial number of HIV infections in UK-born individuals were acquired abroad, investigators report in HIV Medicine. Overall, 15% of HIV infections in UK nationals were probably acquired abroad, and “sex tourism” was a risk factor.

“We provide evidence of a substantial number of UK-born adults over the past decade acquiring HIV infection in countries with generalised epidemics, and in common holiday destinations,” write the authors. “Thailand…has become synonymous with ‘sex tourism’, [and] was by far the country most commonly reported. Of particular concern was the high proportion of men infected in Thailand who reported sex with a commercial sex worker.”

There is no sign that the UK’s HIV epidemic is abating. Between 2002 and 2010 a total of 15997 UK-born individuals were diagnosed with the infection in England and Wales. Investigators from the Health Protection Agency wished to determine how many of these infections were acquired abroad and the characteristics of these patients.

Information on the country of infection was available for 13891 individuals, of whom 15% (2066 people) probably acquired their infection outside the UK.

Compared with UK-born adults who were probably infected with HIV in the UK, the patients who were infected abroad were more likely to be female (19% vs. 15%), non-white (16% vs. 10%), and acquired HIV heterosexually (70% vs. 22%) (all p < 0.001). Individuals infected abroad were also older (median 42 v. 36 years) and had lower CD4 cell counts at the time of diagnosis (median 340 vs. 390 cells/mm³). A significantly higher proportion of individuals infected abroad were diagnosed late (CD4 cell count below 350 cells/mm³, 52% vs. 45%).

The characteristics of UK-born men and women infected abroad differed somewhat.

The majority of men infected abroad were white (90%) and heterosexual (64%; 33% gay and other men who have sex with men). The most commonly reported countries where HIV infection was probably acquired were Thailand (31%), USA (6%), and South Africa (5%).

Among the men acquiring HIV heterosexually, 41% of infections occurred in Thailand, 5% in Nigeria and 5% in South Africa. For gay men, the most commonly reported countries were the USA (16%), Thailand (11%) and Spain (10%).

Almost all the women infected abroad reported heterosexual sex as their risk factor. Over half (58%) were white, 21% were black African and 12% black Caribbean.

The most commonly reported countries were Zimbabwe (10%), Nigeria (9%) and Jamaica (9%). The findings suggest that infection abroad is often linked to travel for reasons of family ties - 99% of black African women acquired HIV in an African country.

Overall, 5% of UK-born adults infected abroad reported sex with a commercial sex worker compared to 1% of UK-born adults infected in the UK. Contact with a commercial sex worker was most frequently reported by men infected in Thailand (11%).

The investigators believe their findings have important implications for the design of HIV prevention initiatives.

“Limited funds for HIV prevention and testing have largely been focused on groups most at risk of acquiring HIV infection in the UK. Our findings call for the extension of these efforts to reduce HIV transmission and promote earlier diagnosis…among travellers abroad.

The authors conclude, “safer sex messages should include an awareness of the detrimental health and social impacts of the sex industry.”