HIV is hyperendemic among men who have sex with men in San Francisco: 10-year trends in HIV incidence, HIV prevalence, sexually transmitted infections and sexual risk behaviour.

OBJECTIVES: To evaluate trends in the HIV epidemic among men who have sex with men (MSM) in San Francisco and the implications for HIV prevention. METHODS: An ecological approach assessed temporal trends in sexual risk behaviour, sexually transmitted infections (STI), HIV incidence and prevalence from multiple data sources between 1998 and 2007. RESULTS: By 2007, there were over 13 000 HIV-infected MSM living in San Francisco. No consistent upward or downward temporal trends were found in HIV incidence, newly reported HIV cases, AIDS deaths, proportion of AIDS cases using antiretroviral therapy, rectal gonorrhoea or primary and secondary syphilis cases among MSM during the study period. Trends in indicators of sexual risk behaviour among MSM were mixed. Overall, unprotected anal intercourse (UAI) increased in community-based surveys. Among HIV-positive MSM, no significant trends were noted for UAI. Among HIV-negative MSM, UAI with unknown serostatus partners decreased but increased with potentially discordant serostatus partners. Among MSM seeking HIV testing, increases were noted in insertive UAI at anonymous testing sites and at the STI clinic, in receptive UAI at anonymous test sites and in receptive UAI with a known HIV-positive partner at the STI clinic. CONCLUSIONS: Temporal trends in multiple biological and behavioural indicators over the past decade describe a hyperendemic state of HIV infection among MSM in San Francisco, whereby prevalence has stabilised at a very high level. In the absence of new, effective prevention strategies this state will persist.

Alcohol and drug use in the context of anal sex and other factors associated with sexually transmitted infections: results from a multi-city study of high-risk men who have sex with men in the USA.

Men who have sex with men (MSM) who use alcohol and drugs are at especially high risk for sexually transmitted infections (STIs); more information is needed about associated factors to improve risk reduction. We assessed reported STIs and demographic and event-level alcohol and drug use characteristics associated with STIs in a diverse, multi-city study in the USA of MSM who use substances. Improved risk reduction efforts are needed for this group as well as some initiatives tailored to men who are HIV positive, younger and use drugs (not alcohol) in the context of anal sex.

Communication of HIV viral load to guide sexual risk decisions with serodiscordant partners among San Francisco men who have sex with men.

The objective of this study was to estimate frequency and correlates of discussing HIV viral load (VL) with serodiscordant sex partners to guide decisions about sexual activities among men who have sex with men (MSM). We conducted a cross-sectional survey of 573 San Francisco MSM. Among 507 who knew their HIV status, 397 (78%) were familiar with the term 'viral load', and half (n=199) had a serodiscordant partner in the prior year. These 199 respondents (n=130 [65%] HIV-positive; n=69 [35%] HIV-negative) were the focus of this analysis. A majority (n=111, 56%) discussed VL in the prior year with serodiscordant partners specifically to guide decisions about sexual risk behaviour. Discussion was more common among HIV-positive than HIV-negative participants (adjusted odds ratio [AOR], 3.5; 95% confidence interval [CI], 1.6-7.6), and African Americans compared to whites (AOR, 3.7; 95% CI, 1.5-9.5). HIV-negative men who discussed VL were more concerned about becoming infected, but also more willing to engage in risky behaviour with a partner whose VL is undetectable, than men not discussing VL. Some HIV-negative men may be discussing VL to engage in higher risk behaviour upon learning of an HIV-positive partner's undetectable VL. Interventions targeting MSM should explain that while risk of transmission is likely reduced with a low blood plasma VL, it is not necessarily eliminated.

Case management is associated with improved antiretroviral adherence and CD4+ cell counts in homeless and marginally housed individuals with HIV infection.

BACKGROUND: Case management (CM) coordinates care for persons with complex health care needs. It is not known whether CM is effective at improving biological outcomes among homeless and marginally housed persons with human immunodeficiency virus (HIV) infection. Our goal was to determine whether CM is associated with reduced acute medical care use and improved biological outcomes in homeless and marginally housed persons with HIV infection. METHODS: We conducted a prospective observational cohort study in a probability-based community sample of HIV-infected homeless and marginally housed adults in San Francisco, California. The primary independent variable was CM, defined as none or rare (any CM in 25% but 75%). The dependent variables were 3 self-reported health service use measures (receipt of primary care, emergency department visits and hospitalizations, and antiretroviral therapy adherence) and 2 biological measures (increase in CD4(+) cell count of >or=50% and geometric mean HIV load of or=50% improvements in CD4(+) cell count. CM was not associated with geometric HIV load <400 copies/mL when antiretroviral therapy adherence was included in the model. Study limitations include a lack of randomization. CONCLUSION: CM may be a successful method to improve adherence to antiretroviral therapy and biological outcomes among HIV-infected homeless and marginally housed adults.

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.

What happened to home HIV test collection kits? Intent to use kits, actual use, and barriers to use among persons at risk for HIV infection.

Through sequential cross-sectional surveys, we examined intent to use home HIV test collection kits, actual use and barriers to use among persons at high risk for HIV infection. Interest in kits was assessed in the 1995-96 HIV Testing Survey (HITS, n=1683). Kit use, knowledge of kits and barriers to use were assessed in the 1998-99 HITS (n=1788), after kits had become widely available. When asked to choose among future testing options, 19% of 1995-96 participants intended to use kits. Untested participants were more likely than previously tested HIV-negative participants to choose kits for their next HIV test (p < 0.001). Among 1998-99 participants, only 24 (1%) had used kits; 46% had never heard of kits. Predictors of not knowing about kits included never having been HIV tested and black or Latino race. Common reasons for not using kits among participants aware of home test kits were concerns about accuracy, lack of in-person counselling and cost. Despite high rates of anticipated use, kits have had minimal impact on the testing behaviour of persons at high risk for HIV infection. Increasing awareness of kits, reducing price and addressing concerns about kit testing procedures may increase kit use, leading to more HIV testing by at-risk individuals.

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.

The Circuit Party Men's Health Survey: findings and implications for gay and bisexual men.

OBJECTIVES: This study examined characteristics of gay and bisexual men who attend circuit parties, frequency of and motivations for attending parties, drug use and sexual behavior during circuit party weekends, and use of risk reduction materials available at parties. METHODS: A cross-sectional survey was conducted among 295 gay and bisexual men from the San Francisco Bay Area who had attended a circuit party in the previous year. RESULTS: One fourth of the men reported a drug "overuse" incident in the previous year. Nearly all respondents reported use of drugs during circuit party weekends, including ecstasy (75%), ketamine (58%), crystal methamphetamine (36%), gamma hydroxybutyrate or gamma butyrolactone (25%), and Viagra (12%). Two thirds of the men reported having sex (oral or anal), 49% reported having anal sex, and 28% reported having unprotected anal sex during the 3-day period. An association was found between use of drugs and sexual risk behavior. Prevention materials were observed at party events by some men; however, relatively few men used the materials. Common motivations for attending the parties were "to listen to music and dance" and "to be with friends." CONCLUSIONS: Intensive, targeted health promotion efforts are needed for gay and bisexual men who attend circuit parties.

Combination antiretroviral therapy and incidence of AIDS-related malignancies.

We evaluated recent trends in the incidence of AIDS-related malignancies using Cox proportional hazards analysis in 622 men with well-characterized dates of HIV seroconversion in the San Francisco City Clinic cohort. By the end of 1996, 182 men had been diagnosed with Kaposi's sarcoma (KS), and 45 men had been diagnosed with lymphoma. The incidence of KS dropped from 3.5 to 0 per 100 person-years between 1993 through 1995 and 1996 (p = .07), whereas lymphoma incidence remained stable between these periods (1.4-1.8, p = .2). Combination antiretroviral therapy increased from 13% to 23% in 1993 through 1995 to 49% in 1996 and 79% in 1997. The decline in KS cannot be explained by earlier declines in HIV incidence, and concurrent increases in antiretroviral therapy suggests that control of viral replication may lead to a direct or indirect effect on KS pathogenesis. Failure to see such a trend for AIDS-related lymphoma may reflect inadequate follow-up time after widespread use of therapy or a need to treat earlier in the course of HIV infection to prevent HIV-associated lymphomagenesis.

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.

Health benefits and risks of reporting HIV-infected individuals by name.

With more treatment options emerging for human immunodeficiency virus (HIV) infection, the policy of reporting HIV-infected individuals by name merits reevaluation. This paper reviews the benefits and risks of name reporting of persons infected with HIV. Public health departments have linked name reporting with medical referrals, risk reduction counseling, and partner notification programs. Yet some studies indicate that people are less likely to be tested for HIV infection when name reporting is implemented. Whether name reporting actually improves individual or public health, therefore justifying the increased risk of loss of confidentiality and possibly reduced testing rates, remains unknown. The lack of health outcome data on name reporting allows beliefs rather than facts to dominate debate about this policy. Before this practice is more widely adopted, a determination should be made as to whether the potential benefits of name reporting outweigh the risks.

A circadian rhythm of population behavior in Gonyaulax polyedra.

Like other flagellates, Gonyaulax polyedra exhibits diurnal vertical migration and pattern formation. Shape and size of the aggregations depend on container type, light intensity, and cell density. In Petri dishes, cells form oval "swarms"; within these, cells move downward in the highly dense center and rise up at the periphery. We have investigated the daily rhythm of this swarming activity in Petri dishes illuminated from the side, using time-lapse video recordings. At night, a "lawn" of cells forms at the bottom of the dish toward the light source (independent of light intensity). Before dawn, cells rise toward the surface and aggregate in swarms. The daily vertical migration occurs independent of light direction and intensity. The diurnal swarms, however, form every day at the same location within the dish, at a distance from the light that depends on light intensity, indicating a self-selection of light intensity. In constant light and temperature and with negligible vertical nutrient differences, all aspects of the rhythm continue to oscillate for up to 3 weeks, when the rhythm of the population becomes desynchronized. Under cycles of bright white-dim red light (WR), cell entrain to WR 10:10 but free run in WR 8:8 and shorter cycles, showing relative coordination (von Holst, 1939) to the driving light cycle. They also entrain to the 24-hr multiple of WR 6:6. Under nonentrained conditions, swarming activity is still influenced by light changes, and in spite of the apparent free run, the phasing of the averaged activity varies systematically with different T-cycle frequencies.