Grant Colfax

Decreases in Community Viral Load Are Accompanied by Reductions in New HIV Infections in San Francisco

Background At the individual level, higher HIV viral load predicts sexual transmission risk. We evaluated San Franciscos community viral load (CVL) as a population level marker of HIV transmission risk. We hypothesized that the decrease in CVL in San Francisco from 2004–2008, corresponding with increased rates of HIV testing, antiretroviral therapy (ART) coverage and effectiveness, and population-level virologic suppression, would be associated with a reduction in new HIV infections. Methodology/Principal Findings We used San Franciscos HIV/AIDS surveillance system to examine the trends in CVL. Mean CVL was calculated as the mean of the most recent viral load of all reported HIV-positive individuals in a particular community. Total CVL was defined as the sum of the most recent viral loads of all HIV-positive individuals in a particular community. We used Poisson models with robust standard errors to assess the relationships between the mean and total CVL and the primary outcome: annual numbers of newly diagnosed HIV cases. Both mean and total CVL decreased from 2004–2008 and were accompanied by decreases in new HIV diagnoses from 798 (2004) to 434 (2008). The mean (p = 0.003) and total CVL (p = 0.002) were significantly associated with new HIV cases from 2004–2008. Conclusions/Significance Reductions in CVL are associated with decreased HIV infections. Results suggest that wide-scale ART could reduce HIV transmission at the population level. Because CVL is temporally upstream of new HIV infections, jurisdictions should consider adding CVL to routine HIV surveillance to track the epidemic, allocate resources, and to evaluate the effectiveness of HIV prevention and treatment efforts.

Risk factors for HIV infection among men who have sex with men.

Objectives:Risk factors for HIV acquisition were examined in a recent cohort of men who have sex with men (MSM). Design:A longitudinal analysis of 4295 HIV-negative MSM enrolled in a randomized behavioral intervention trial conducted in six US cities. Methods:MSM were enrolled and assessed for HIV infection and risk behaviors semi-annually, up to 48 months. Results:In multivariate analysis, men reporting four or more male sex partners, unprotected receptive anal intercourse with any HIV serostatus partners and unprotected insertive anal intercourse with HIV-positive partners were at increased risk of HIV infection, as were those reporting amphetamine or heavy alcohol use and alcohol or drug use before sex. Some depression symptoms and occurrence of gonorrhea also were independently associated with HIV infection. The attributable fractions of high number of male partners, use of alcohol or drugs before sex, and unprotected receptive anal intercourse with unknown status partners and the same with presumed negative partners accounted for 32.3, 29.0, 28.4 and 21.6% of infections, respectively. Conclusions:The challenge is to develop strategies to identify men in need. Interventions are needed to help men reduce their number of sexual partners, occurrences of unprotected anal intercourse, alcohol or drug use before sex and address other mental health issues.

Combination Antiretroviral Therapy and Recent Declines in AIDS Incidence and Mortality

The reasons for recent declines in AIDS incidence and mortality may include advances in treatment, but these may be confounded by earlier declines in the incidence of human immunodeficiency virus (HIV) infection. To determine whether the declines in AIDS and mortality may, in part, stem from wider use of combination antiretroviral therapy, 622 HIV-positive men with well-characterized dates of seroconversion were followed. In this group, combination therapy came into widespread use in only 1996. In a Cox proportional hazards model, the 1996 calendar period was significantly associated with slower progression to AIDS (relative hazard [RH]=0. 19, 95% confidence interval [CI], 0.05-0.69, P=.01) and death (RH=0. 45, 95% CI, 0.21-0.95, P=.04). Declines in incidence of HIV infection, changes in HIV virulence, and end-point underreporting cannot fully explain the decline in AIDS and death in 1996. The introduction of combination antiretroviral therapy as the standard of care may already have had measurable effects.

Age-Specific Prevalence of Anal Human Papillomavirus Infection in HIV-Negative Sexually Active Men Who Have Sex with Men: The EXPLORE Study

BACKGROUND In the United States, anal cancer in men who have sex with men (MSM) is more common than cervical cancer in women. Human papillomavirus (HPV) is causally linked to the development of anal and cervical cancer. In women, cervical HPV infection peaks early and decreases after the age of 30. Little is known about the age-specific prevalence of anal HPV infection in human immunodeficiency virus (HIV)-negative MSM. METHODS We studied the prevalence and determinants of anal HPV infection in 1218 HIV-negative MSM, 18-89 years old, who were recruited from 4 US cities. We assessed anal HPV infection status by polymerase chain reaction. RESULTS HPV DNA was found in the anal canal of 57% of study participants. The prevalence of anal HPV infection did not change with age or geographic location. Anal HPV infection was independently associated with receptive anal intercourse (odds ratio [OR], 2.0; P<.0001) during the preceding 6 months and with >5 sex partners during the preceding 6 months (OR, 1.5; P<.0001). CONCLUSIONS Urban, HIV-negative MSM have a stable, high prevalence of anal HPV infection across all age groups. These results differ substantially from the epidemiologic profile of cervical HPV infection in women. This may reflect differences between these populations with respect to the number of new sex partners after the age of 30 and may explain the high incidence of anal cancer in MSM.

Drug Use and Sexual Risk Behavior Among Gay and Bisexual Men Who Attend Circuit Parties: A Venue-Based Comparison

Context: HIV risk behavior among urban gay/bisexual men has recently increased. High‐risk sexual activity and drug use may be particularly high during circuit party (CP) weekends, during which gay/bisexual men congregate for social activities and dancing. Objectives: To compare prevalence of risk behaviors during CP weekends with those during non‐CP weekends. Design: Cross‐sectional study. Participants: 295 gay/bisexual men from the San Francisco Bay Area. Main Outcome Measures: Drug use and sexual risk behavior during a San Francisco CP weekend, a CP weekend held in another geographic area (distant weekends), and two non‐CP weekends. Results: During their most recent distant CP weekend, 80% of participants used methylenedioxymethamphetamine (ecstasy), 66% ketamine, 43% crystal methamphetamines, 29% gamma‐hydroxybutyrate or gamma‐butyrolactone (GHB/GBL), 14% sildenafil (Viagra), and 12% amyl nitrites (poppers); 53% used four or more drugs. Drug use prevalence was greater during CP than non‐CP weekends (p < .001). Unprotected anal sex with partners of unknown or opposite HIV serostatus was most prevalent during distant CP weekends, reported by 21% of HIV‐positive and 9% of HIV‐negative participants. In multivariate analysis, predictors of unprotected anal sex with opposite or unknown HIV serostatus partners included being HIV‐positive (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.4‐7.5), and weekend use of crystal methamphetamines (OR 2.4; 95% CI, 1.1 ‐4.9), sildenafil (OR, 3.8; 95% CI, 2.0‐7.3), and amyl nitrites (OR, 2.2; 95% CI, 1.3‐4.0). Conclusions: Prevalence of high‐risk activity during these weekends suggests significant potential for HIV transmission in this population. Public health programs in communities hosting CPs should aim to reduce rates of drug use and sexual risk behavior among CP participants, especially HIV‐positive men.

Longitudinal patterns of methamphetamine, popper (amyl nitrite), and cocaine use and high-risk sexual behavior among a cohort of san francisco men who have sex with men.

Most prior studies examining drug use among men who have sex with men (MSM) have been cross-sectional or retrospective and have not determined whether periods of increased drug use are associated with high-risk sexual behavior at the individual level. In this article, we describe patterns of use of methamphetamines, poppers, and sniffed cocaine and sexual risk behavior among 736 San Francisco MSM enrolled in the EXPLORE study and followed for up to 48 months. In longitudinal analysis, use of methamphetamines, poppers, and sniffed cocaine declined during follow-up. However, compared with older participants, younger participants were more likely to increase their drug use over time. Results of conditional logistic regression demonstrated that high-risk sexual behavior was more common during reporting periods characterized by increased methamphetamine, poppers, or sniffed cocaine use. This within-person analysis found that compared with periods of no drug use, periods of both light drug use (less than weekly use of drugs) and heavier drug use (at least weekly use of at least one drug) were significantly associated with increased risk of engaging in uprotected anal sex with an HIV-positive or unknown-status partner. These results suggest that even intermittent, recreational use of these drugs may lead to high-risk sexual behavior, and that, to reduce and prevent risks of HIV, no level of use of these drugs should be considered “safe.” HIV prevention interventions should target MSM who report either light or heavy use of methamphetamines, poppers, and sniffed cocaine.

Sexual risk behaviors and implications for secondary HIV transmission during and after HIV seroconversion

ObjectivesTo determine the potential for secondary HIV transmission among newly HIV-infected men who have sex with men (MSM) during their HIV antibody seroconversion period, and for the 12 months after seroconversion. DesignA cohort study. MethodsRisk assessment questionnaires administered before receipt of the first positive HIV antibody result, plasma and seminal viral load measurements, and risk assessments one month and quarterly after receipt of the first HIV-positive test, and generalized estimating equation modelling techniques to analyse behavioral trends. ResultsOf 66 seroconverters, more than half reported unprotected anal intercourse (UAI) with HIV-negative or unknown-serostatus partners during seroconversion, with 27% reporting insertive UAI with an HIV-negative partner. The initial median plasma viral load was 4.6 log/ml, the median seminal viral load was 2.7 log/ml, suggesting a high level of infectiousness. Compared with risk behavior during seroconversion, UAI with HIV-negative or unknown-serostatus partners was reduced after the receipt of positive antibody results; however, a substantial proportion of participants reported high-risk behaviors for transmission for 12 months of follow-up. After learning of their HIV infection, recent seroconverters did not reduce the risk of secondary transmission by engaging in proportionally more high-risk practices with HIV-infected partners (compared with HIV-negative or unknown-serostatus partners), or engaging in proportionally more receptive compared with insertive UAI. ConclusionSubstantial potential exists for secondary HIV transmission during and for one year after HIV seroconversion. Receipt of an HIV-positive test is associated with a significant reduction in risk behavior, reinforcing the need to identify and counsel recently HIV-infected MSM.

Methamphetamine and sildenafil (Viagra) use are linked to unprotected receptive and insertive anal sex, respectively, in a sample of men who have sex with men

Objectives: There is evidence that methamphetamine and sildenafil (Viagra) use are associated with sexual risk behaviour among men who have sex with men (MSM). We investigated the association of methamphetamine, sildenafil, and other substance use with unprotected receptive and insertive anal sex among MSM by conducting an encounter specific analysis. Methods: Data were from a cross sectional, community based survey of MSM in San Francisco regarding behaviour during their most recent anal sex encounter. Mulitvariate regression analysed independent associations of specific substance use and demographic variables with unprotected anal sex behaviours. Results: The sample (n = 388) was diverse in race/ethnicity, age, income, education, HIV status, and homosexual/bisexual identification. More than half (53%) reported unprotected anal sex, including insertive (29%) and receptive (37%) during their most recent anal sex encounter; 12% reported unprotected insertive and 17% reported unprotected receptive anal sex with an HIV discordant or unknown partner. Methamphetamine was used by 15% and sildenafil was used by 6% of the men before or during the encounter; 2% used both drugs. In multivariate analysis controlling for demographic factors and other substance use, methamphetamine use was associated with unprotected receptive (odds ratio (OR), 2.03; 95% confidence interval (CI), 1.09 to 3.76) and sildenafil use was associated with unprotected insertive (OR, 6.51; CI, 2.46 to 17.24) anal sex. Effects were stronger with HIV discordant or unknown sex partners specifically. Conclusion: Encounter specific associations of methamphetamine and sildenafil use with unprotected receptive and insertive anal sex, respectively, indicate the importance of assessment specificity and tailoring risk reduction efforts to address certain drugs and sexual behavioural roles among MSM.

Anal human papillomavirus infection is associated with HIV acquisition in men who have sex with men

Objective:Human papillomavirus (HPV) is a common sexually transmitted agent that causes anogenital cancer and precancer lesions that have an inflammatory infiltrate, may be friable and bleed. Our aim was to determine the association between anal HPV infection and HIV acquisition. Design:A prospective cohort study. Methods:We recruited 1409 HIV-negative men who have sex with men from a community-based setting in Boston, Denver, New York and San Francisco. We used Cox proportional hazards regression modeling and assessed the independent association of HPV infection with the rate of acquisition of HIV infection. Results:Of 1409 participants contributing 4375 person-years of follow-up, 51 HIV-seroconverted. The median number of HPV types in HPV-infected HIV-seroconverters was 2 (interquartile range 1–3) at the time of HIV seroconversion. After adjustment for sexual activity, substance use, occurrence of other sexually transmitted infections and demographic variables, there was evidence (P = 0.002) for the effect of infection with at least two HPV types (hazard ratio 3.5, 95% confidence interval 1.2–10.6) in HIV seroconversion. Conclusion:Anal HPV infection is independently associated with HIV acquisition. Studies that incorporate high-resolution anoscopy to more accurately identify HPV-associated disease are needed to determine the relationship between HPV-associated disease and HIV seroconversion.

Amphetamine-group substances and HIV.

Amphetamine-group substances are used worldwide and are more prevalent than either cocaine or opioids. We reviewed published reports about amphetamine-group substances and did a meta-analysis of randomised controlled trials of behavioural interventions for their use. Most research was done in developed countries. Many, but not all, studies show an association between amphetamine-group substance use and risk of HIV infection. Much use of amphetamine-group substances is non-injection and is associated with increased HIV risk, particularly in men who have sex with men. The structural, social, interpersonal, and personal factors that link to amphetamine-group substance use and HIV risk are poorly understood. 13 studies, with a cumulative sample size of 1997 individuals, qualified for the meta-analysis. Overall, high-intensity behavioural interventions were moderately effective in reducing use of amphetamine-group substances (effect size 0.28, 95% CI 0.13-0.44). We did not find conclusive evidence that behavioural interventions as a group are more effective than are passive or minium treatment for reduction of amphetamine-group substance use or sexual risk behaviours. The search for effective, scalable, and sustainable interventions for amphetamine-group substance use, including pharmacotherapies, should be supported and encouraged.