Effect of pre-exposure prophylaxis and combination HIV prevention for men who have sex with men in the UK: a mathematical modelling study.

BACKGROUND: HIV transmission in men who have sex with men (MSM) in the UK has shown no sign of decreasing in the past decade. Additional prevention measures are needed. We aimed to estimate the effect of various potential interventions implemented individually and in combination on prevention of HIV infection. METHODS: We extended a deterministic partnership-based mathematical model for HIV transmission, informed by detailed behavioural and surveillance data, to assess the effect of seven different HIV interventions implemented in MSM (aged 15-64 years) in the UK during 2014-20, including increasing rates of HIV testing, test-and-treat programmes, pre-exposure prophylaxis (PrEP), and sexual behavioural changes. We did sensitivity analyses on risk compensation. FINDINGS: We predicted a baseline of 16 955 new infections (IQR 13 156-21 669) in MSM in the UK during 2014-20. At a coverage of ≤50%, testing twice a year outperformed all other interventions. Of all intervention combinations, only the combined effect of test and treat and annual HIV testing (61·8%, IQR 47·2-81·8, of total incidence) was greater than the sum of effects of the two interventions individually (32·6%, 23·7-46·0, and 23·9%, 16·5-33·3, respectively). Simultaneous PrEP, expansion of HIV testing, and initiation of test-and-treat programme in 25% of high-activity MSM could save 7399 (IQR 5587-9813) UK MSM from HIV infection (43·6%, IQR 32·9-57·9, of total incidence). An increase in unsafe sex or sexual partners to 50% or more could substantially reduce the effect of interventions, but is unlikely to negate the prevention benefit completely. INTERPRETATION: PrEP could prevent a large number of new HIV infections if other key strategies including HIV testing and treatment are simultaneously expanded and improved. Without PrEP, HIV incidence in MSM in the UK is unlikely to decrease substantially by the end of this decade. FUNDING: Health Protection Agency (now Public Health England).

Recreational drug use, polydrug use, and sexual behaviour in HIV-diagnosed men who have sex with men in the UK: results from the cross-sectional ASTRA study.

BACKGROUND: Recreational drug use in men who have sex with men (MSM) is of concern because it might be linked to the transmission of HIV and other sexually transmitted infections. Evidence about drug use in HIV-diagnosed MSM in the UK is limited by representativeness of the study populations. We describe patterns of drug use and associations with sexual behaviours in HIV-diagnosed MSM in the UK. METHODS: We used data from the cross-sectional ASTRA study, which recruited participants aged 18 years or older with HIV from eight HIV outpatient clinics in the UK between Feb 1, 2011, and Dec 31, 2012. We examined data for MSM, assessing the prevalence of recreational drug use and polydrug use in the previous 3 months and associations with sociodemographic and HIV-related factors. We examined the association of polydrug use with measures of condomless sex in the previous 3 months and with other sexual behaviours. FINDINGS: Our analysis included data for 2248 MSM: 2136 (95%) were gay, 1973 (89%) were white, 1904 (85%) were on antiretroviral treatment (ART), and 1682 (76%) had a viral load of 50 copies per mL or lower. 1138 (51%) used recreational drugs in the previous 3 months; 608 (27%) used nitrites, 477 (21%) used cannabis, 460 (21%) used erectile dysfunction drugs, 453 (20%) used cocaine, 280 (13%) used ketamine, 258 (12%) used 3,4-methylenedioxy-N-methylamphetamine (MDMA), 221 (10%) used gamma-hydroxybutyrate or gamma-butyrolactone, 175 (8%) used methamphetamine, and 162 (7%) used mephedrone. In the 1138 individuals who used drugs, 529 (47%) used three or more drugs and 241 (21%) used five or more. Prevalence of injection drug use was 3% (n = 68). Drug use was independently associated with younger age (p < 0·0001), not being religious (p = 0·001), having an HIV-positive stable partner (p = 0·0008), HIV-serostatus disclosure (p = 0·009), smoking (p < 0·0001), evidence of harmful alcohol drinking (p = 0·0001), and ART non-adherence (p < 0·0001). Increasing polydrug use was associated with increasing prevalence of condomless sex (prevalence range from no drug use to use of five or more drugs was 24% to 78%), condomless sex with HIV-seroconcordant partners (17% to 69%), condomless sex with HIV-serodiscordant partners (10% to 25%), and higher-HIV-risk condomless sex after taking viral load into account (4% to 16%; p ≤ 0·005 for all). Associations were similar after adjustment for sociodemographic and HIV-related factors. Methamphetamine was more strongly associated with higher-HIV-risk condomless sex than were other commonly used drugs. INTERPRETATION: Polydrug use is prevalent in HIV-diagnosed MSM and is strongly associated with condomless sex. Specialist support services for MSM with HIV who use recreational drugs might be beneficial in the reduction of harm and prevention of ongoing transmission of HIV and other sexually transmitted infections. FUNDING: National Institute for Health Research.

Increased HIV incidence in men who have sex with men despite high levels of ART-induced viral suppression: analysis of an extensively documented epidemic.

BACKGROUND: There is interest in expanding ART to prevent HIV transmission, but in the group with the highest levels of ART use, men-who-have-sex-with-men (MSM), numbers of new infections diagnosed each year have not decreased as ARTcoverage has increased for reasons which remain unclear. METHODS: We analysed data on the HIV-epidemic in MSM in the UK from a range of sources using an individual-based simulation model. Model runs using parameter sets found to result in good model fit were used to infer changes in HIV-incidence and risk behaviour. RESULTS: HIV-incidence has increased (estimated mean incidence 0.30/100 person-years 1990-1997, 0.45/100 py 1998-2010), associated with a modest (26%) rise in condomless sex. We also explored counter-factual scenarios: had ART not been introduced, but the rise in condomless sex had still occurred, then incidence 2006-2010 was 68% higher; a policy of ART initiation in all diagnosed with HIV from 2001 resulted in 32% lower incidence; had levels of HIV testing been higher (68% tested/year instead of 25%) incidence was 25% lower; a combination of higher testing and ART at diagnosis resulted in 62% lower incidence; cessation of all condom use in 2000 resulted in a 424% increase in incidence. In 2010, we estimate that undiagnosed men, the majority in primary infection, accounted for 82% of new infections. CONCLUSION: A rise in HIV-incidence has occurred in MSM in the UK despite an only modest increase in levels of condomless sex and high coverage of ART. ART has almost certainly exerted a limiting effect on incidence. Much higher rates of HIV testing combined with initiation of ART at diagnosis would be likely to lead to substantial reductions in HIV incidence. Increased condom use should be promoted to avoid the erosion of the benefits of ART and to prevent other serious sexually transmitted infections.

Decreasing incidence of tuberculosis among heterosexuals living with diagnosed HIV in England and Wales.

OBJECTIVES: To calculate annual tuberculosis incidence rates, and investigate risk factors for tuberculosis, among heterosexual adults living with diagnosed HIV in England and Wales. DESIGN: Analyses of comprehensive national records of persons seen for HIV care between 2002 and 2010 linked to the national tuberculosis database (1999-2010) for England and Wales. METHODS: Annual incidence rates of tuberculosis among heterosexual adults living with diagnosed HIV were calculated on the basis of the number of heterosexual adults seen for HIV care in a given year and the number, in that same year, with a first episode of tuberculosis at the time of, or subsequent to, their HIV diagnosis. RESULTS: Between 2002 and 2010, almost one in 10 (4266/45,322) heterosexual adults living with HIV were diagnosed with tuberculosis, of whom the majority (92%) were diagnosed at the time of, or after, their HIV diagnosis; 84% (3307) were black African. The annual tuberculosis incidence rate decreased from 30 per 1000 in 2002 to 8.8 per 1000 in 2010 (P < 0.01). The annual tuberculosis incidence rate among those not on antiretroviral therapy (ART) was significantly higher than among those using ART (2010: 36 versus 3 per 1000; P < 0.01). CONCLUSIONS: The annual tuberculosis incidence rate among heterosexual adults living with diagnosed HIV in England and Wales has declined significantly over the past decade. However, the 2010 rate remains significantly higher than in the general population. Our findings support routine HIV testing in tuberculosis clinics, screening for latent tuberculosis in HIV diagnosed persons, and the prompt initiation of ART where appropriate.

HIV infection among ethnic minority and migrant men who have sex with men in Britain.

OBJECTIVE: To examine human immunodeficiency virus (HIV) infection among men who have sex with men (MSM) from different ethnic and migrant groups living in Britain. METHODS: In 2007-2008, a diverse national sample of MSM living in Britain was recruited through Web sites, in sexual health clinics, bars, clubs, and other venues. Men completed an online survey that included questions on HIV testing, HIV status, and sexual behavior. RESULTS: Nine hundred and ninety-one ethnic minority MSM, 207 men born in Central or Eastern Europe (CEE), 136 men born in South or Central America, and 11,944 white British men were included in the analysis. Self-reported HIV seropositivity was low for men of South Asian, Chinese, and "other Asian" ethnicity (range, 0.0%-5.8%) and for men born in CEE (4.5%) but elevated for men born in South or Central America (18.7%), compared with white British men (13.1%) (P < 0.001). There were no significant differences between these groups in high-risk sexual behavior (P = 0.8). After adjusting for confounding factors in a multivariable model, substantial differences in the odds of HIV infection remained for South Asian and Chinese MSM as well as for migrants from CEE, but not for other groups, compared with white British men; for example, South Asian men, adjusted odds ratio 0.43, 95% confidence interval 0.23, 0.79, P = 0.007. CONCLUSION: There were marked differences in self-reported HIV seropositivity between ethnic minority, key migrant, and white British MSM in this study but not in high-risk sexual behavior. This highlights the importance of health promotion targeting MSM from all ethnic and migrant groups in Britain.

Loss to follow-up among adults attending human immunodeficiency virus services in England, Wales, and Northern Ireland.

AIM: To assess the extent to which human immunodeficiency virus (HIV)-diagnosed adults attending HIV-services in England, Wales, and Northern Ireland are lost to follow-up or attend services intermittently. METHODS: A cohort of HIV-diagnosed adults was created by linking records across the 1998 to 2007 national annual Survey of Prevalent HIV Infections Diagnosed. The records were also linked to the national HIV and acquired immune deficiency syndrome New Diagnoses Database (n = 61,495) and to Office for National Statistics death records. Patterns of HIV-service attendance were analyzed. RESULTS: On average, 90% of adults attending HIV-services in any one year attended the following year. Nearly 5% of adults attending services in any one year were lost to follow-up, a further 4% subsequently attended services intermittently, whereas less than 2% died. Cumulatively, 19% of adults seen for HIV care between 1998 and 2006 were lost to follow-up by the end of 2007. Factors associated with loss to follow-up included being the following: female; aged 15 to 34 years; black-African or "other" ethnicity; not on antiretroviral therapy; recently diagnosed; and infected outside the United Kingdom. CONCLUSIONS: Although the majority of HIV-diagnosed adults in England, Wales, and Northern Ireland attended HIV-services regularly, cumulatively nearly 1 in 5 adults were lost to follow-up between 1998 and 2007. Innovative strategies focusing on those most likely to drop out of regular care should be developed to maintain regular service engagement and to ensure optimal care.

Barebacking among HIV-positive gay men in London.

OBJECTIVES: The objectives of this study were to examine the extent to which HIV-positive gay men in London intentionally seek unprotected anal intercourse ("barebacking") and the contribution this makes to total sexual risk. STUDY DESIGN: In 2002 to 2003, HIV-positive gay men surveyed in an HIV outpatient clinic or on the Internet were asked whether they had intentionally looked for anal sex without a condom in the previous 12 months. RESULTS: Of 481 men in the clinic, 59 (12.3%) said they had intentionally looked for anal sex without a condom, 34 (7.1%) only with another HIV-positive man and 25 (5.2%) with a man of unknown or discordant HIV status. Overall, 85 men reported unprotected anal intercourse (UAI) with a casual partner of unknown or discordant HIV status; 20 (23.5%) had intentionally looked for UAI with such a partner, whereas the remaining 65 (76.5%) had not. Of 66 men surveyed on the Internet, 32 (48.5%) said they had intentionally looked for anal sex without a condom. CONCLUSION: Although barebackers made a disproportionate contribution to sexual risk, three-fourths of high-risk sex reported by HIV-positive gay men in London was not intentional. The Internet sample overestimated the prevalence of barebacking among HIV-positive gay men because of sampling bias.