Epidemiology of non-B clade forms of HIV-1 in men who have sex with men in the UK

Department of HIV, Guys and St Thomas' NHS Trust/ Kings College London, St Thomas' Hospital, London, UK.
AIDS (London, England) (Impact Factor: 5.55). 09/2010; 24(15):2397-401. DOI: 10.1097/QAD.0b013e32833cbb5b
Source: PubMed


To describe the frequency and risk factors of non-B HIV-1 subtypes in men who have sex with men (MSM) in the UK.
Observational study.
MSM diagnosed with HIV-1 infection from 1980-2007, with HIV genotype held in the UK HIV Drug Resistance Database were identified. Protease and reverse transcriptase sequences were collected and viral clade determined using the REGA algorithm. Associations between demographic variables and subtype were analysed using logistic regression.
The prevalence of non-B HIV-1 infection amongst MSM in the UK was 5.4% (437/8058). In the UK this increased with year of diagnosis from pre1996 to 2002, and has subsequently remained relatively stable at around 7-9% after 2002, with a recent increase in 2007 to 13%. Multivariate analysis showed that acquisition of non-B HIV-1 infection was independently associated with later year of HIV diagnosis (P < 0.001), black ethnicity (P < 0.001) and non-European country of birth (P = 0.01). Age was also associated with subtype with individuals aged 25-39 years being less likely to have non-B virus than those aged less than 25 years (P = 0.01). Restricting the analysis to white men born in the UK, the association between subtype and year of diagnosis remained statistically significant (P < 0.001), as did the association with age (P < 0.001).
The number of MSM in the UK infected with non-B clade HIV-1 is increasing, suggesting that the sociodemographic boundaries between HIV-1 viral subtypes globally are diminishing. Should viral subtypes be relevant to clinical disease progression or vaccine design, the changing pattern of distribution will need to be taken into account.

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    • "These patients were mostly from Greece (n=53), but also from Cyprus (n=3), Portugal (n=2), Spain (n=1), the Netherlands (n=1) and Ireland (n=1). The increase in proportion of subtypes A1 and C has also been described in the MSM population of the United Kingdom [27]. Subtype G was significantly less prevalent in MSM (0.32%) than in IDUs (10.05%) and heterosexuals (7.20%), while subtypes C, CRF02_AG and CRF01_AE were significantly more prevalent in heterosexuals (15.7%, 7.41% and 9.16% respectively) than in IDUs (1.44%, 3.35% and 0.48% respectively) and MSM(0.48%, "
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    • "Non-B subtypes were present but rare in the UK until 1995, after which a substantial increase in immigration from southern Africa, particularly Zimbabwe, led to a dramatic rise in subtypes C and A (Parry et al. 2001). By 2005, the prevalence of non-B clades taken together equaled the B clade, and recently, in both France and the United Kingdom, there has been noticeable, and nonreciprocal, crossover of non-B clades into MSM (de Oliveira et al. 2010; Fox et al. 2010). Similarly, Swiss investigators have confirmed changes in B clade viral transmission over time (Kouyos RD et al. 2010). "
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