AEGiS-15IAC: Evidence of onward transmission of HIV-1 non-B subtype strains in the UK.

15th International AIDS Conference

Bangkok, Thailand - July 11-16, 2004

Evidence of onward transmission of HIV-1 non-B subtype strains in the UK.

Int Conf AIDS 2004 Jul 11-16; 15:(abstract no. ThOrC1363)

Easterbrook PJ, Aggarwal I, Smith M, Tatt I, Murad S; King's College Hospital, London, United Kingdom

BACKGROUND: An increasing proportion of new HIV diagnoses in the UK, and other European countries are due to non-B subtype infection, mainly among black Africans with infections heterosexually acquired in sub-Saharan Africa. We examined whether there was evidence for ongoing transmission of non-B subtypes within an ethnically diverse HIV cohort in south London.

METHODS: A random sample of 384 HIV-1 infected patients attending Kings College Hospital were subtyped using an in-house ELISA and env sequencing. Epidemiological data was used to establish the most likely source and country of infection from medical chart review and the patients' physician.

RESULTS: 182 (47.4%) patients' were black African, 158 (41.1%) were white and 44 (11.5%) were black Caribbean. The prevalence of non-B versus B infection among those with identifiable subtype was 149 (96.7%) vs. 5 (3.3%) among 154 black Africans; 21 (14.2%) vs. 127 (85.8%) among 148 white; and 13 (30.9%) vs 29 (69.1%) among 42 black Caribbeans. 81.4% of the 183 non-B subtype infections in our study cohort were among black Africans and most were acquired in sub-Saharan Africa, but 14% of all other non-B infections were probably acquired in the UK and 2.7% from overseas travel. The majority (62%) of the 21 white patients with non-B infection acquired their infection in the UK (3/3 heterosexual women, 1/3 heterosexual men, 2/2 IDUs, and 7/13 homosexual men). All 13 black Caribbean patients with non-B infection probably acquired their infection in the UK; overall, 61.5% of black Caribbeans with non-B subtypes were probably infected by an African partner. Of the 5 black Africans with subtype B infection, 3 may have acquired their infection in the UK (1 heterosexual woman, 1 heterosexual man and 1 homosexual man). Conclusion This study provides the first evidence for ongoing low-level transmission of non-B subtypes in the UK among the white and black Caribbean populations.

Keywords: AEGIS, HIV-1, Heterosexuality, Genes, env, Acquired Immunodeficiency Syndrome, Africa South of the Sahara, Prevalence, Homosexuality, African Continental Ancestry Group, Communicable Diseases, HIV Seropositivity, London, Humans, Male, Female, transmission, genetics

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