Evidence for Onward Transmission of HIV-1 Non-B Subtype Strains in the United Kingdom
March 15, 2006
In the United Kingdom and other European countries, an increasing proportion of new HIV diagnoses involve non-B subtype infections. These are found chiefly among black Africans infected through heterosexual sex in sub-Saharan Africa. In the current study, the researchers looked for evidence of onward transmission of non-B subtypes in an ethnically diverse cohort of HIV-1-infected patients in South London.
In-house enzyme-linked immunoassay and env sequencing were used to subtype 384 HIV-1-infected patients at Kings College Hospital. Epidemiological data from physicians and medical charts were used to determine the most likely source and country of infection. An identifiable subtype was found in 344 patients (154 black African, 148 white UK-born, and 42 black Caribbean). The prevalence of non-B subtypes was found to be 96.8 percent among the black Africans, 14.2 percent among the whites, and 31 percent among the black Caribbeans.
Most non-B subtypes were found among the black Africans (149 of 183 cases); these were mainly acquired in sub-Saharan Africa, although 22.9 percent (42 of 183 cases) were probably acquired in the United Kingdom. Fifteen of the 21 white, UK-born patients with a non-B subtype were probably infected in the United Kingdom; only six of these patients reported a source sexual partner from an HIV endemic area. Of the 13 black Caribbean patients with a non-B infection, all likely were infected in the United Kingdom; eight of the 13 were probably infected by a partner from an HIV endemic area.
"Potential acquisition of HIV infection in the United Kingdom was lowest among black African patients with a non-B infection, and most of these infections were probably acquired from a partner originating from an HIV endemic area," the researchers concluded. "This study provides the first evidence for onward transmission of non-B subtypes in the United Kingdom, particularly among the black Caribbean population."
Journal of Acquired Immune Deficiency Syndromes
02.01.06; Vol. 41; No. 2: P. 201-209; Ila Aggarwal, M.D.; Melvyn Smith, M.D.; Iain D. Tatt, Ph.D.; Shahed Murad, M.Sc.; Natasha Osner, M.Sc.; Anna Maria Geretti, M.D., Ph.D.; Philippa J. Easterbrook, M.D., M.P.H.
This article was provided by CDC National Prevention Information Network. It is a part of the publication CDC HIV/Hepatitis/STD/TB Prevention News Update.