Impact of highly active antiretroviral treatment on HIV seroincidence among men who have sex with men: San Francisco

Trends in HIV testing, serial HIV prevalence and HIV incidence among people attending a Center for AIDS Prevention from 1988 to 2003

AIM

To analyse trends in HIV testing, serial HIV prevalence and HIV incidence among people who underwent voluntary testing in a Center for AIDS Prevention in Valencia, Spain.

METHODS

Open cohort study including all subjects who went to the Center for AIDS Prevention from 1988 to 2003. Information on sociodemographic variables and HIV test results was collected. Serial prevalence and incidence rates were calculated, and joinpoint regression was used to identify changes in trends over time.

RESULTS

21,241 subjects were analysed; 67% men, 27% injecting drug users (IDUs), 43% heterosexuals and 13% men who have sex with men (MSM). From 1988 to 1990, IDUs accounted for 57% of clinic attenders, decreasing to 14% by 1997-2003, accompanied by an increase in heterosexuals. Overall, HIV prevalence for the whole period was 15%, dropping from 35% to <10% after 1999 and to 3% by 2003, when HIV prevalence was 26% in IDUs, 6% in MSM and 2% in heterosexuals. Total HIV incidence was 2.5%. From 1988 to 1990, HIV incidence ranged from 6% to 8%, and a gradual and progressive decline observed from 1990 onwards. From 1995 onwards, HIV incidence was <2%. The highest incidence rate is seen in IDUs, 7-12% in the first period and 4-5% at the end. Among MSM, a change in the decreasing trend is seen by 1998, and increases in incidence are detected by 2002-3.

CONCLUSIONS

Serial HIV prevalence has markedly decreased from 1988 in all transmission categories, although it is still high. With regard to HIV incidence, the drop has been marked too, although a worrying increase, that requires further follow-up, has been detected in MSM in the past 2 years.

Factors associated with unprotected sexual intercourse with steady male, casual male, and female partners among men who have sex with men in Barcelona, Spain

To increase understanding of the HIV epidemic among MSM in Barcelona, anonymous questionnaires were completed by 640 MSM recruited in the city in 2002. The prevalence of unprotected anal intercourse (UAI) with casual male partners in the prior 12 months was higher among self-reported HIV-positive men (confirmed through saliva testing) than among men who were HIV-negative or of unknown serostatus (35% vs. 20%, p < .01). The prevalence of UAI with steady male partners was substantially lower among HIV-positive men than other men (28% vs. 60%, p < .01). In multivariate analyses, UAI with casual partners was more likely among HIV-positive individuals; those who used drugs before sex; perceived less acceptance of their sexual orientation by family, friends, or coworkers; and were less concerned about HIV prevention because of antiretroviral therapy (ART). UAI with steady partners was more likely among HIV-negative men with seroconcordant partners, those living with a partner, and men less concerned about HIV prevention because of ART. Findings indicate a need for prevention programs targeting HIV-positive MSM in Barcelona. Attention to substance use and attitudes about HIV prevention are needed for MSM in general.

Unsafe sexual behavior and correlates of risk in a probability sample of men who have sex with men in the era of highly active antiretroviral therapy

OBJECTIVE

To assess the levels and correlates of potential exposure to and transmission of HIV in a contemporary, community-based probability sample of men who have sex with men (MSM).

METHODS

In 2003, 311 sexually active MSM participated in a random-digit dial telephone survey in Seattle neighborhoods with a high prevalence of MSM. The primary outcomes were potential exposure to and transmission of HIV, defined as unprotected anal intercourse with a man of opposite or unknown HIV status in the preceding 12 months.

RESULTS

Fourteen percent of respondents reported being HIV-positive, 77% reported being HIV-negative, and 8% had not been tested. Of 241 HIV-negative MSM, 25 (10%; 95% confidence interval [CI], 7-15%) were potentially exposed to HIV; among 45 HIV-positive MSM, 14 (31%; 95% CI, 20-46%) were potential HIV-transmitters. Among HIV-negative men, the strongest bivariate correlates of potential exposure to HIV were recent bacterial sexually transmitted disease (odds ratio [OR], 5.8), number of recent male sexual partners (OR, 1.01 per partner), recent sex at a bathhouse (OR, 9.1), and recent use of sildenafil (OR, 4.4), amyl nitrite (OR, 6.2), and methamphetamine (OR, 8.0). Among HIV-infected men, the strongest correlates of potential HIV transmission were recent use of amyl nitrite (OR, 3.1), number of recent male sex partners (OR, 1.07 per partner), and having a male spouse or domestic partner (OR, 0.3).

CONCLUSIONS

Most MSM knew their HIV status and adopted safer sexual behaviors to reduce their risk of HIV acquisition or transmission. However, 10% of HIV-negative MSM and 31% of HIV-positive MSM recently engaged in behaviors that placed them at high risk for acquiring or transmitting HIV.

Number of risk acts by relationship status and partner serostatus: Findings from the HIM cohort of homosexually active men in Sydney, Australia

In recent years, increases in both risk behavior and in seroconversion among homosexually active men have been noted in a number of parts of the world. Data were available from 903 HIV negative homosexual men regarding number of acts of unprotected anal intercourse (UAI), separated into receptive and insertive UAI, with and without ejaculation, with steady and with casual partners. Partners were classified according to serostatus as reported by respondents. Men (N = 325) reported 13,692 UAI acts, most of which were with steady partners, of whom most were reported to be HIV-negative. With HIV-positive partners, both steady and casual, and with casual partners of unknown serostatus, receptive UAI with ejaculation was relatively rare. Insertive UAI without ejaculation was relatively common with casual partners of unknown serostatus. Patterns of UAI suggest that risk of transmission may be greater with steady partners. Men appear to modify practice according to both the nature of the relationship (steady or casual) and (assumed) serostatus of partner.

Incidence of sexually transmitted diseases and HIV infection in men who have sex with men related to knowledge, perceived susceptibility, and perceived severity of sexually transmitted diseases and HIV infection: Dutch MSM-Cohort Study

BACKGROUND

This longitudinal study was conducted to investigate whether knowledge, perceived susceptibility, and perceived severity of HIV infection and sexually transmitted diseases (STDs) are associated with the incidence of STDs and new HIV infections among men who have sex with men (MSM).

METHODS

A 3-year cohort study was conducted among 190 HIV-negative MSM. Data were collected on the incidence of STDs and new HIV infections, as well as on knowledge and perceived susceptibility to and perceived severity of HIV infection and STDs. Knowledge and perceptions were assessed in self-administered questionnaires.

RESULTS

In the course of the 3-year study, six MSM (3.2%) HIV-seroconverted and 78 (41.1%) participants were diagnosed with at least one STD. MSM seemed to be better informed about HIV infection compared with STDs, and HIV infection was perceived as more severe than other STDs. In multivariable analyses, low perceived severity of HIV infection significantly (P = 0.025) predicted increased likelihood of infection with STDs or HIV, and the practice of anal intercourse was (marginally) associated with an increased risk of acquiring STDs or HIV (P = 0.052).

CONCLUSIONS

A high perceived severity of HIV infection seems to induce sexual behavior that protects against STDs and HIV infection. More research is needed to establish the specific behaviors by which perceived severity of STDs/HIV influences the incidence of STDs and HIV.

Profile of male Brazilian injecting drug users who have sex with men

This study aims to characterize the profile of male injecting drug users who have sex with other men (MSM IDUs) recruited through a cross-sectional multi-city survey (AjUDE-Brasil II Project) in six Brazilian cities, in 2000-2001. MSM IDUs were compared to other male IDUs using bivariate and multivariate procedures (logistic regression and answer tree analysis with the CHAID algorithm). Among the 709 male IDUs, 187 (26.4%) reported ever having had sex with other men, while only 37 reported sex with other men in the previous six months. MSM IDUs were more likely to be unemployed (OR = 2.3), to have injected tranquilizers (OR = 3.6), and to be HIV-seropositive (OR = 2.1), compared to other male IDUs. Male same-sex relations in this subgroup appear to be associated with strategies to finance drug consuming habits, including sex for drugs with occasional female partners or obtaining injection paraphernalia from occasional sex partners. Further studies should focus on this especially vulnerable subgroup of IDUs, due to the bidirectional and complex interrelationships between their drug injecting habits and sexual risk behaviors.

WHAT WORKS, AND WHAT REMAINS TO BE DONE, IN HIV PREVENTION IN THE UNITED STATES

Since the beginning of the HIV epidemic in the United States, HIV prevention programs have prevented hundreds of thousands of HIV infections, and the investment in these programs has actually been cost-saving to society in terms of medical costs averted. A substantial body of evidence exists (including randomized controlled trials and careful meta-analyses) which demonstrates that various HIV prevention services are effective; an increasingly large body of data also demonstrates the cost-effectiveness of these interventions. However, the efforts to utilize these interventions in a comprehensive HIV prevention program are hampered by insufficient funding, imperfect targeting strategies, and a problematic policy environment that creates barriers to the use of some of these life-saving interventions. Progress toward reducing new HIV infections will likely be as much a function of improvements in funding and policies as it will in the development of new tools for HIV prevention.

Access to highly active antiretroviral therapy for injection drug users: adherence, resistance, and death

Injection drug users (IDUs) continue to comprise a major risk group for HIV infection throughout the world and represent the focal population for HIV epidemics in Asia and Eastern Europe/Russia. HIV prevention programs have ranged from HIV testing and counseling, education, behavioral and network interventions, drug abuse treatment, bleach disinfection of needles, needle exchange and expanded syringe access, as well as reducing transition to injection and primary substance abuse prevention. With the advent of highly active antiretroviral therapy (HAART) in 1996, dramatic clinical improvements have been seen. In addition, the treatment's impact on reducing HIV viral load (and therefore transmission by all routes) provides a stronger rationale for an expansion of the focus on prevention to emphasize early identification and treatment of HIV infected individuals. However, treatment of IDUs has many challenges including adherence, resistance and relapse to high risk behaviors, all of which impact issues of access and ultimately effectiveness of potent antiretroviral treatment. A major current challenge in addressing the HIV epidemic revolves around an appropriate approach to HIV treatment for IDUs.

HIV prevalence and sexual risk behaviors among men who have sex with men: results from a statewide population-based survey in California

OBJECTIVES

To investigate HIV prevalence, sexual risk behaviors, and HIV testing among men who have sex with men (MSM) between 18 and 64 years old living in California.

DESIGN

Cross-sectional study of a statewide population-based sample of MSM.

METHODS

Using data from the 2001 California Health Interview Survey (CHIS 2001), 398 men who self-identified as gay or bisexual were recontacted and interviewed by telephone for a follow-up study in 2002. Study participants were interviewed regarding their demographic characteristics and sexual behavior, HIV testing history, and HIV infection status. Those who self-reported as HIV-negative or of unknown status were offered an HIV test using a home urine specimen collection kit.

RESULTS

HIV prevalence among MSM in California was 19.1% (95% confidence interval [CI]: 12.8% to 25.3%) with higher rates seen among the following subgroups: high school or less education (40.4%), annual income less than dollar 20,000 (35.0%), or history of ever injecting recreational drugs (40.3%). Young age and Hispanic or African-American race/ethnicity were associated with higher proportions of risky sexual behavior and lower HIV testing rates.

CONCLUSIONS

HIV prevalence among MSM living in California continues to be high across the whole state, and population-based studies are needed periodically to complement findings from surveys using other sampling designs.

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.

Changing patterns of sexual behaviour in the era of highly active antiretroviral therapy

PURPOSE OF REVIEW

To describe changing patterns of sexual behaviour in the era of highly active antiretroviral therapy among gay/bisexual men in Europe, Canada, USA and Australia.

RECENT FINDINGS

While there has been a substantial increase in high-risk sexual behaviour among gay men since 1996, this now appears to be levelling off in some cities. Overall the empirical evidence does not support the suggestion that taking highly active antiretroviral therapy or having an undetectable viral load leads to risky sexual behaviour among people with HIV. Nor can HIV treatment optimism alone explain the recent increase in high-risk sexual behaviour. Since 1996, an increasing number of gay men have begun to use the Internet to look for sexual partners. By serosorting on the Internet, HIV-positive men are more likely to meet online, rather than off-line, other HIV-positive men for unprotected sex. While serosorting does not present a risk of HIV transmission to an uninfected person, it does present a risk of other sexually transmitted infections and co-infection with resistant virus for HIV-positive men themselves. This review also explores emerging behaviours such as barebacking and strategic positioning as well as the role of crystal meth and Viagra.

SUMMARY

The review reminds us of the complexity of human and sexual behaviour. Among gay men, sexual behaviour in the era of highly active antiretroviral therapy has been characterized by risk reduction and stabilization as well as increasing risk. These changing patterns provide a new challenge as well as new opportunities for HIV prevention.

Revisiting the ABC strategy: HIV prevention in Uganda in the era of antiretroviral therapy

The ABC strategy is credited for bringing the HIV/AIDS epidemic under control in Uganda. By promoting abstinence, being faithful, and condom use, safe(r) behaviours have been identified that are applicable to people in different circumstances. However, scaling-up of antiretroviral therapy in the country raised concerns that HIV prevention messages targeting the uninfected population are not taking sufficient account of inherent complexities. Furthermore, there is debate in the country over relative importance of abstinence in reduction of HIV incidence as well as over the morality and effectiveness of condoms. The purpose of this paper is to examine each component of ABC in light of current developments. It is argued that there is still a strong justification for condom use to complement abstinence and being faithful. There is an urgent need to update and relaunch Uganda's ABC strategy--its three elements are complementary, synergistic, and inseparable in the national HIV prevention programme.

Overlooked, misunderstood and at-risk: exploring the lives and HIV risk of ethnic minority male-to-female transgender youth

PURPOSE

To describe the real life challenges and HIV-risk behaviors of male-to-female (MTF) transgender youth from communities of color.

METHODS

A convenience sample (n = 51) of ethnic-minority MTF transgender youth aged 16-25 years completed an anonymous questionnaire including demographics, psychosocial measures, and participation in substance use and sexual risk behaviors. Descriptive analyses and analyses of association were used to interpret the data.

RESULTS

The median age of participants was 22 years, and 57% were African-American. Twenty-two percent reported being human immunodeficiency virus positive (HIV+). Prevalence of life stressors among the sample included history of incarceration (37%), homelessness (18%), sex in exchange for resources (59%), forced sexual activity (52%), difficulty finding a job (63%), and difficulty accessing health care (41%). Within the past year, 98% had sex with men, 49% had unprotected receptive anal intercourse, and 53% had sex under the influence of drugs or alcohol. Substance use within the past year was common, with marijuana (71%) and alcohol (65%) most frequently reported. Twenty-nine percent of participants had used injection liquid silicone in their lifetime. Other injection drug use and needle-sharing behaviors were rare. Compared with other racial/ethnic groups, HIV was found in higher rates among African-American youth (p < .05). HIV status was not associated with any other demographic characteristic, psychosocial measure, sexual or substance use behavior.

CONCLUSIONS

These findings suggest that MTF transgender youth of color have many unmet needs and are at extreme risk of acquiring HIV. Future research is needed to better understand this adolescent subgroup and to develop targeted broad-based interventions that reduce risky behaviors.

The urban environment and sexual risk behavior among men who have sex with men

Increasingly, studies show that characteristics of the urban environment influence a wide variety of health behaviors and disease outcomes, yet few studies have focused on the sexual risk behaviors of men who have sex with men (MSM). This focus is important as many gay men reside in or move to urban areas, and sexual risk behaviors and associated outcomes have increased among some urban MSM in recent years. As interventions aimed at changing individual-level risk behaviors have shown mainly short-term effects, consideration of broader environmental influences is needed. Previous efforts to assess the influence of environmental characteristics on sexual behaviors and related health outcomes among the general population have generally applied three theories as explanatory models: physical disorder, social disorganization and social norms theories. In these models, the intervening mechanisms specified to link environmental characteristics to individual-level outcomes include stress, collective efficacy, and social influence processes, respectively. Whether these models can be empirically supported in generating inferences about the sexual behavior of urban MSM is underdeveloped. Conceptualizing sexual risk among MSM to include social and physical environmental characteristics provides a basis for generating novel and holistic disease prevention and health promotion interventions.

Highly active antiretroviral therapy (HAART) among HIV-infected drug users: a prospective cohort study of sexual risk and injecting behaviour

AIMS

To study sexual risk and injecting behaviour among HIV-infected drug users (DU) receiving highly active antiretroviral therapy (HAART).

DESIGN AND SETTING

As part of an ongoing prospective cohort study, HIV-infected DU who commenced HAART (n=67) were matched with those not starting HAART (n=130) on CD4 cell counts, duration of cohort participation, age and calendar year of visit. Immunological and virological responses of the HAART-treated DU were compared with the HAART-treated homosexual men from the same cohort (n=212).

MEASUREMENTS

Trends in behaviour and therapeutic response were tested with a logistic regression model adjusted for repeated measurements and a piecewise random effects model, respectively.

FINDINGS

Non-HAART users reported more episodes of injecting than HAART users. In both groups injecting declined over time with no effect of HAART initiation. Before HAART initiation an increase in sexual risk behaviour was observed among those who had been assigned to receive HAART; their sexual risk behaviour declined thereafter. No change in sexual risk behaviour was found among non-HAART users. Relative to homosexual men, DU had a similar initial therapeutic response, but DU started HAART at lower CD4 cell counts and higher viral load levels. Conclusion DU who are treated with HAART are not increasing their risk behaviour, and their early response to HAART is similar to homosexual men. However, before the treated DU received HAART they were seen to inject less often than those not treated with HAART. This suggests that selection of potential HAART starters is based on limited drug use. Although the DU who commence HAART are a selected group, our results show that HIV-infected DU can be treated effectively.

Syphilis epidemics and human immunodeficiency virus (HIV) incidence among men who have sex with men in the United States: implications for HIV prevention

Recent outbreaks of syphilis among men who have sex with men (MSM) in major cities in the United States and reported increases in sexual risk behavior have raised concerns about potential increases in human immunodeficiency virus (HIV) transmission. The majority of MSM who have early syphilis are HIV infected; in preliminary studies, rates of recent HIV infection among them are also high. Data from San Francisco, Los Angeles, and Seattle-King County, however, suggest no temporal increases in HIV incidence among MSM seeking HIV testing at select large public sites during the syphilis outbreaks. Because most HIV incidence and behavioral data are from large metropolitan areas with large gay populations and well-established HIV epidemics, we do not know whether, nationally, incidence of HIV infection among MSM has been increasing, decreasing, or stable during syphilis outbreaks. Further studies of HIV incidence in larger and smaller cities with different maturities of HIV epidemic are warranted. Comprehensive and integrated HIV/STD prevention and control efforts are also needed to halt the spread of syphilis and reduce HIV transmission among gay and bisexual men.

Immunotherapy for the treatment of drug abuse

Antibody therapy (as either active or passive immunization) is designed primarily to prevent drugs of abuse from entering the central nervous system (CNS). Antidrug antibodies reduce rush, euphoria, and drug distribution to the brain at doses that exceed the apparent binding capacity of the antibody. This is accomplished through a pharmacokinetic antagonism, which reduces the amount of drug in the brain, the rate of clearance across the blood-brain barrier, and the volume of drug distribution. Because the antibodies remain primarily in the circulatory system, they have no apparent central nervous system side effects. Active immunization with drug-protein conjugate vaccines has been tested for cocaine, heroin, methamphetamine, and nicotine in animal, with 1 cocaine and 3 nicotine vaccines in Phase 2 human trials. Passive immunization with high affinity monoclonal antibodies has been tested for cocaine, methamphetamine, nicotine, and phencyclidine (PCP) in preclinical animal models. Antibodies have 2 immediate clinical applications in drug abuse treatment: to treat drug overdose and to reduce relapse to drug use in addicted patients. The specificity of the therapies, the lack of addiction liability, minimal side effects, and long-lasting protection against drug use offer major therapeutic benefit over conventional small molecule agonists and antagonists. Immunotherapies can also be combined with other antiaddiction medications and enhance behavioral therapies. Current immunotherapies already show efficacy, but improved antigen design and antibody engineering promise highly specific and rapidly developed treatments for both existing and future addictions.

Changes in sexual behavior and risk of HIV transmission after antiretroviral therapy and prevention interventions in rural Uganda

BACKGROUND

The impact of antiretroviral therapy (ART) on sexual risk behavior and HIV transmission among HIV-infected persons in Africa is unknown.

OBJECTIVE

To assess changes in risky sexual behavior and estimated HIV transmission from HIV-infected adults after 6 months of ART.

DESIGN AND METHODS

A prospective cohort study was performed in rural Uganda. Between May 2003 and December 2004 a total of 926 HIV-infected adults were enrolled and followed in a home-based ART program that included prevention counselling, voluntary counseling and testing (VCT) for cohabitating partners and condom provision. At baseline and follow-up, participants' HIV plasma viral load and partner-specific sexual behaviors were assessed. Risky sex was defined as inconsistent or no condom use with partners of HIV-negative or unknown serostatus in the previous 3 months. The rates of risky sex were compared using a Poisson regression model and transmission risk per partner was estimated, based on established viral load-specific transmission rates.

RESULTS

Six months after initiating ART, risky sexual behavior reduced by 70% [adjusted risk ratio, 0.3; 95% confidence interval (CI), 0.2-0.7; P = 0.0017]. Over 85% of risky sexual acts occurred within married couples. At baseline, median viral load among those reporting risky sex was 122 500 copies/ml, and at follow-up, < 50 copies/ml. Estimated risk of HIV transmission from cohort members declined by 98%, from 45.7 to 0.9 per 1000 person years.

CONCLUSIONS

Providing ART, prevention counseling, and partner VCT was associated with reduced sexual risk behavior and estimated risk of HIV transmission among HIV-infected Ugandan adults during the first 6 months of therapy. Integrated ART and prevention programs may reduce HIV transmission in Africa.

Club drugs as causal risk factors for HIV acquisition among men who have sex with men: a review

We reviewed medical and psychology databases for articles published between January 1980 and August 2005 demonstrating associations between HIV/Sexually Transmitted Infection risk and club drug use. Seventy-four articles were reviewed, of which 30 provided adjusted risk ratios for associations between HIV/sexually transmitted infection risk and club drug use among men who have sex with men. Definitions and lists of club drugs were broad and inconsistent. We constructed a conceptual framework of biologically plausible pathways for causation. Using Hill's criteria to examine club drugs as causal risk factors for HIV, we found the most evidence for methamphetamine and volatile nitrites; however, more studies are needed.

Provider fatalism reduces the likelihood of HIV-prevention counseling in primary care settings

We examined the relationship between provider fatalism, a belief that behavior change among HIV-infected patients is unlikely, and HIV-prevention counseling in 16 publicly funded clinics. HIV-seropositive patients (N = 618) completed surveys assessing prevention counseling in the past 6 months. Additionally, 144 interviews were conducted with providers, administrators, and patients to examine beliefs about prevention counseling. We summed the number of fatalistic comments made by providers and administrators in each clinic, and assigned these counts as clinic-level fatalism scores to survey participants. Patients in high fatalism clinics were less likely to report prevention counseling than patients in low fatalism clinics. This difference remained significant even after controlling for clinic characteristics or patients' sexual risk and health status. However, clients in high fatalism clinics were more likely to be White, gay, educated, and older. Provider fatalism is a barrier that must be addressed when implementing HIV-prevention counseling in primary care settings.

HIV seroconversion among the homeless and marginally housed in San Francisco: a ten-year study

HIV seroprevalence was previously found to be 9-11% among the urban homeless in San Francisco, with most infections among injection drug users, men who have sex with men, and those who exchange sex for money or drugs. In this study, HIV incidence and risk factors for seroconversion were estimated among persons who repeatedly participated in cross-sectional serosurveys over a period of 10 years. There were 6 seroconversions among 799 HIV-negative persons, for an incidence rate of 0.30% per person-year (95% CI: 0.12-0.61% per person-year). The seroconversion rate among men who had had recent sex with men was 1.22% per person-year (95% CI: 0.29-3.18) and was 0.52% per person-year (95% CI: 0.19-1.13% per person-year) among those who ever injected drugs. The seroconversion rate among those who were aged <30 years at baseline was 1.67% per person-year (95% CI: 0.40-4.36% per person-year), which was significantly higher than for those age > or =30 years. Policy implications are that HIV resources aimed at the more stable, older homeless population should probably focus on treatment, while prevention efforts, conversely, should probably be targeted to younger homeless persons.

High-Risk Sexual Behavior in Adults With Genotypically Proven Antiretroviral-Resistant HIV Infection

BACKGROUND

The substantial frequency of drug resistance in persons recently infected with HIV implies exposure among HIV-uninfected individuals to HIV-infected persons with drug-resistant virus. Although there is an increasing emphasis on understanding high-risk behavior among HIV-infected patients, little work has focused on those with drug-resistant virus.

METHODS

We examined antiretroviral-treated patients with drug resistance in the Study of the Consequences of the Protease Inhibitor Era, a clinic-based cohort of HIV-infected adults. Sexual behavior was ascertained by self-administered questionnaire. Genotypic antiretroviral resistance testing was performed on isolates from participants with a plasma HIV RNA level > or =100 copies/mL.

RESULTS

Among 279 participants on antiretroviral therapy, 168 (60%) had genotypic resistance to at least 1 drug. In those with drug resistance, 27% of men who have sex with men (MSM) and 11% of heterosexual men and women reported at least 1 episode of unprotected penile-anal or penile-vaginal intercourse in the previous 4 months; 17% of MSM and 6% of heterosexual participants reported unprotected intercourse with an HIV-uninfected or status unknown partner. In a multivariable model of predictors of unprotected anal or vaginal intercourse with an HIV-uninfected or status unknown partner, there was strong evidence for an effect of younger age, depression, and sildenafil use and moderate evidence for frequent alcohol use.

CONCLUSIONS

Among HIV-infected patients with drug-resistant viremia, there is a substantial prevalence of high-risk sex with HIV-uninfected partners. The presence of definable risk factors for unsafe sex suggests a role for targeted rather than broad intervention, particularly when resources are limited.

Increase in HIV sexual risk behaviour in homosexual men in Scotland, 1996-2002: prevention failure?

OBJECTIVE

To investigate trends in homosexual men's sexual risk behaviour for HIV infection in Scotland.

METHODS

Cross sectional surveys in 1996, 1999, and 2002 were carried out in "gay" bars in Glasgow and Edinburgh, Scotland. 6508 men-2276 (79% response rate) in 1996, 2498 (78%) in 1999, and 1734 (62%) in 2002.

RESULTS

In 1996, 10.7% of men surveyed and in 1999, 11.2% reported unprotected anal intercourse (UAI) with casual partners, compared with 18.6% in 2002 (p < 0.001). There was also a significant increase in men reporting that they "knew" their casual partners' HIV status, despite no increase in HIV testing among men who reported UAI with casual partners. In 2002, increases in UAI with more than one partner, in UAI with casual partners and in reporting seroconcordance remained significant after adjusting for confounding factors including HIV testing status and demographic characteristics.

CONCLUSIONS

High risk sexual behaviour among homosexual men in Scotland increased between 1999 and 2002. Men showed increased confidence of shared antibody status, despite no increase in HIV testing, or evidence of discussion of HIV status. Explanations for this must include consideration of a cultural shift in the perception of HIV and "prevention failure" on the part of governments and health agencies.

Antiretroviral therapy and sexual behavior: a comparative study between antiretroviral- naive and -experienced patients at an urban HIV/AIDS care and research center in Kampala, Uganda

We examined whether use of antiretroviral (ARV) therapy is associated with increased sexual risk behavior in a cross-sectional study of patients undergoing ARV therapy (ARV experienced) compared to patients not undergoing ARV therapy (ARV-naïve) attending an urban HIV clinic in Kampala, Uganda. Sexual behavior during the prior 6 months and sexually transmitted disease (STD) treatment was determined by face-to-face structured interviews. Multiple logistic regression was used to identify independent correlates of sexual activity, multiple sexual partners, inconsistent condom use, and STD treatment during the prior 6 months. Three hundred forty-seven (48%) of the 723 respondents reported a history of sexual intercourse in the 6 months prior to the interview (sexually active). Receipt of ARV therapy was not associated with a significantly higher likelihood of being sexually active (adjusted odds ratio [AOR], 2.0 95% confidence interval [CI], 0.3-9.9). Among both ARV-experienced and ARV-naïve persons who were sexually active, 35% (120) reported one or more casual sexual partners in addition to a main partner (no difference by ARV status). Consistent condom use with spouse, regular, casual, and commercial partners was reported by 57%, 65%, 85%, and 85% of the sexually active respondents, respectively. The ARV-experienced respondents were more likely to report consistent condom use with their spouses than were ARV-naïve respondents (OR 2.82 95% CI 1.74-4.6). ARV-experienced respondents were more likely than ARV-naïve respondents to have disclosed their HIV status to their spouses (OR 1.57 95% CI 1.07-2.30).The ARV-experienced group was more likely to report STD treatment in the prior 6 months (AOR 2.62 95% CI 1.8-3.83) than the ARV-naïve group. The findings suggest that in this population, use of ARV therapy was not associated with risky sexual behavior in the prior 6 months. Still, recall and social desirability biases remain important limitations in interpreting these conclusions.

The Public Health Response to Epidemic Syphilis, San Francisco, 1999–2004

In 1999, the Centers for Disease Control and Prevention launched the National Plan to Eliminate Syphilis. From 1999 to 2003 in San Francisco, early syphilis was epidemic, increasing from 44 cases to 522 cases a year. Syphilis cases were more likely to be in gay or bisexual men, those with human immunodeficiency virus (HIV) infection, those who had anonymous partners, and those who met sex partners on the Internet. Increases in sexual activity and sexual risk behavior in men who have sex with men during this period have been attributed to the improved physical health of HIV-infected men on highly active antiretroviral therapy, HIV treatment optimism, increases in methamphetamine use, and the use of Viagra. The San Francisco Department of Public Health's response to the epidemic included enhanced surveillance, expanded clinical and testing services, provider and community mobilization and sexual health education, and risk factor identification and abatement through investigations, public health advocacy, and treatment. Collaborations with community-based organizations and local businesses were key to the successful implementation of disease-control efforts. A multitude of converging risk factors and new environments contributed to the syphilis epidemic, requiring a comprehensive, innovative, and flexible disease-control strategy.

Increasing rates of sexually transmitted diseases in homosexual men in Western europe and the United States: why?

The recent increases in acute STDs among MSM must be viewed in the context of a post-AIDS era that is characterized by demographic shifts,changing sexual attitudes, and rapidly changing social contexts. A key driver seems to be the growing prevalent pool of HIV-positive MSM for whom the crucial motivator for safer sex (primary HIV prevention) no longer exists and where, given the prevalence of seroconcordant sexual mixing, consider-able uncertainty and conflicting advice regarding the rationale and benefits for continued safer-sex practice are unclear [105,106]. Although it is tempting to ascribe these changes to increases in risk behavior, it is essential that the contexts in which the changes are occurring are also considered. It may also be appropriate to contemplate whether further changes to the social environment (eg, structural interventions) are a suitable adjunct to our traditional prevention activities that operate largely in isolation from each other. It seems natural to advocate that interventions that adopt holistic approaches to the sexual health of MSM and that address upstream factors such as mental health, drug use, discrimination, and internalized homophobia should be included in the efforts to create more healthy environments for MSM. However, there is still some way to go in identifying which of these upstream interventions are effective, how they may be implemented within or alongside existing health care systems, and what impact, if any, they are likely to have on STD transmission. Such interventions are also likely to belong on implementation time, require consider political will, and be extremely hard to evaluate, and the benefits may not be seen within the same generation in which they are implemented. Therefore, there must be confidence that this is the appropriate route of travel. The consistency of findings from across industrialized countries confirms an increasing connectivity within the global MSM community;a community that is decreasingly defined by geographic boundaries and, in the era of the Internet and easier foreign travel, increasingly linked by shared interests and social and sexual networks. This is powerfully demonstrated in the near-simultaneous syphilis and LGV outbreaks among MSM in Europe and the United States [29]. In this regard, greater collaboration between researchers and providers working with MSM indifferent countries is now required. More specifically, consideration should be given to creating closer partnerships between sentinel cities, such as London, New York, San Francisco, Berlin, Paris, and Amsterdam, that have large MSM populations and are likely to be emerging, or rapid diffusion sites for new social and sexual trends that may impact on disease transmission. There are many benefits to such cross-national working,including earlier recognition and improved response to emerging threats,sharing innovative practice, avoiding duplication of effort, and creating a united front for dealing with what must be considered a cause for concern domestically and globally.

Effectiveness of Highly Active Antiretroviral Therapy in Reducing Heterosexual Transmission of HIV

Highly active antiretroviral therapy (HAART) has been shown to be highly effective in reducing plasma levels of HIV RNA; therefore, these treatments could diminish the risk of transmission. We analyzed 393 steady heterosexual couples, of which one partner had been previously diagnosed with HIV infection (index case) and where the nonindex partner reported his or her sexual relationship with the index case as the unique risk exposure. These couples were consecutively enrolled in the period 1991 through 2003 when the nonindex partners took their first HIV test. HIV prevalence among partners of index cases who had not received antiretroviral therapy was 8.6%, whereas no partner was infected in couples in which the index case had been treated with HAART (P = 0.0123). HIV prevalence among nonindex partners declined from 10.3% during the pre-HAART period (1991-1995) to 1.9% during the late HAART period (1999-2003; P = 0.0061). In the multivariate analysis, this decline held (odds ratio = 0.14, 95% confidence interval: 0.03-0.66) after adjusting for length of partnership, unprotected coitus, and pregnancies as well as gender, CD4 lymphocyte count, AIDS-defining diseases, and sexually transmitted infections in the index case. When HAART became widely available, a reduction of approximately 80% in heterosexual transmission of HIV was observed, irrespective of changes in other factors that affect transmission.

Sexually transmitted disease testing protocols, sexually transmitted disease testing, and discussion of sexual behaviors in HIV clinics in Los Angeles County

OBJECTIVE/GOAL

The objective of this study was to evaluate the use of written protocols for sexually transmitted disease (STD) screening, the frequency and types of STD tests performed, and the occurrence and frequency of obtaining sexual risk assessments among HIV clinics.

STUDY

A survey was administered to 36 medical directors, clinic directors, and HIV providers representing 48 HIV healthcare clinics in Los Angeles.

RESULTS

The use of a written or electronic protocol for STD testing was reported by 50% of clinics. Clinics with written or electronic STD protocols were significantly more likely to report questioning patients at each visit regarding their sexual practices (prevalence ratio, 2.2; 95% confidence interval, 1.4-3.4). Clinics with written or electronic protocols were not more likely to report more frequent STD testing.

CONCLUSIONS

Written or electronic protocols for STD testing may promote sexual risk assessment questioning among HIV healthcare providers and may help to ensure STD testing per Centers for Disease Control and Prevention/IDSA guidelines for HIV-positive persons at sexual risk.

Social Marketing Campaign Significantly Associated With Increases in Syphilis Testing Among Gay and Bisexual Men in San Francisco

BACKGROUND

Between 1999 and 2002, San Francisco experienced a sharp increase in early syphilis among gay and bisexual men. In response, the San Francisco Department of Public Health launched a social marketing campaign to increase testing for syphilis, and awareness and knowledge about syphilis among gay and bisexual men.

METHODS

A convenience sample of 244 gay and bisexual men (18-60 years of age) were surveyed to evaluate the effectiveness of the campaign. Respondents were interviewed to elicit unaided and aided awareness about the campaign, knowledge about syphilis, recent sexual behaviors, and syphilis testing behavior.

RESULTS

After controlling for other potential confounders, unaided campaign awareness was a significant correlate of having a syphilis test in the last 6 months (odds ratio, 3.21; 95% confidence interval, 1.30-7.97) compared with no awareness of the campaign. A comparison of respondents aware of the campaign with those not aware also revealed significant increases in awareness and knowledge about syphilis.

CONCLUSIONS

The Healthy Penis 2002 campaign achieved its primary objective of increasing syphilis testing, and awareness and knowledge about syphilis among gay and bisexual men in San Francisco.

HIV sexual risk behavior over 36 months of follow-up in the world's first HIV vaccine efficacy trial

Increased risk behavior among participants in HIV vaccine efficacy trials has been a concern. This study evaluated HIV sexual risk behavior among 5095 HIV-negative men who have sex with men (MSM) and 308 women enrolled in a randomized, double-blind, placebo-controlled efficacy trial of a bivalent rgp120 vaccine at 61 sites, primarily in North America. Sexual risk behavior data were collected at baseline and semiannually for 36 months. Overall, sexual risk behavior did not exceed baseline levels during the trial. Among MSM, younger age (< or =30 years), perceived assignment to vaccine, and nonblack race were associated with an increased probability of unprotected anal sex. Among women, unprotected vaginal sex initially decreased but was statistically equivalent to baseline by 24 months, whereas unprotected vaginal sex with HIV-infected partners decreased from baseline, where it remained throughout the trial. HIV sexual risk behavior did not increase among trial participants; however, it was substantial throughout the trial. Consistently high levels of risk behavior and the association of these behaviors to perceived assignment and demographic variables underscore the need for vigilant HIV risk reduction counseling, informed consent, and educational processes in the context of HIV vaccine efficacy trials.

Comparison of three methods to measure HIV incidence among persons seeking voluntary, anonymous counseling and testing

OBJECTIVES

The authors compared 3 practical methods to estimate human HIV incidence rates using existing data from persons seeking anonymous testing in San Francisco between 1996-2002. Each method was assessed for strengths and limitations.

METHODS

Three different approaches were used to determine HIV incidence: one based on self-reported dates of prior tests, one based on linking records of prior tests using an anonymous unique testing code, and one based on the Serologic Testing Algorithm for Recent HIV Seroconversion (STARHS).

RESULTS

The 3 methods found comparable rates of seroconversion overall (1.0, 1.2, and 1.3 per 100 person-years) and among men who have sex with men (1.4, 1.6, and 2.0 per 100 person-years). Incidence for all 3 methods saw a peak during 1999 followed by a decline. Greatest variability of incidence was observed among lower-risk populations, in whom few infections were expected.

CONCLUSIONS

The 3 methods had complementary strengths and limitations, which may prevent proper interpretation of HIV incidence if any one method is analyzed alone. HIV incidence rates among persons seeking HIV testing should be interpreted cautiously using corroborative data on risk behavior and sexually transmitted diseases and other contextual information.

Prevalence of rectal, urethral, and pharyngeal chlamydia and gonorrhea detected in 2 clinical settings among men who have sex with men: San Francisco, California, 2003

BACKGROUND

The Centers for Disease Control and Prevention developed screening and diagnostic testing guidelines for chlamydia and gonorrhea at urethral, rectal, and pharyngeal sites for men who have sex with men (MSM). However, in most clinical settings, rectal chlamydial testing is not performed for MSM, and primarily sexually transmitted disease (STD) clinics alone perform routine rectal and pharyngeal gonorrhea screening for asymptomatic men.

METHODS

We evaluated the prevalence of rectal, urethral, and pharyngeal chlamydial and gonococcal infections among MSM seen at the municipal STD clinic and the gay men's community health center. We also determined the proportion of asymptomatic rectal infections, described the patterns of single and multiple anatomic sites of infection, and evaluated the proportion of chlamydial infections that would be missed and not treated if MSM were not routinely tested for chlamydia. We tested specimens using previously validated nucleic acid amplification tests (NAATs).

RESULTS

The prevalence of infection varied by anatomic site (chlamydia: rectal, 7.9%; urethral, 5.2%; and pharyngeal, 1.4%; for gonorrhea, rectal, 6.9%; urethral, 6.0%; and pharyngeal, 9.2%). Approximately 85% of rectal infections were asymptomatic supporting the need for routine screening. Because 53% of chlamydial infections and 64% of gonococcal infections were at nonurethral sites, these infections would be missed and not treated if only urethral screening was performed. In addition, >70% of chlamydial infections would be missed and not treated if MSM were tested only for gonorrhea.

CONCLUSIONS

Because these infections enhance both HIV transmission and susceptibility, clinical settings serving MSM should evaluate the prevalence of chlamydial and gonococcal infections by anatomic site using validated NAATs.

Sexual Risk, Nitrite Inhalant Use, and Lack of Circumcision Associated With HIV Seroconversion in Men Who Have Sex With Men in the United States

Men who have sex with men (MSM) continue to account for the largest number of new HIV infections in the United States, but limited data exist on independent risk factors for infection beyond the early 1990s. The HIV Network for Prevention Trials Vaccine Preparedness Study enrolled 3257 MSM in 6 US cities from 1995 to 1997. HIV seroincidence was 1.55 per 100 person-years (95% confidence interval: 1.23-1.95) over 18 months of follow-up. On multi-variable analysis using time-dependent covariates, independent risk factors for HIV seroconversion were increased number of reported HIV-negative male sex partners (adjusted odds ratio (AOR) = 1.14 per partner, population attributable risk (PAR) = 28%), nitrite inhalant use (AOR = 2.2, PAR = 28%), unprotected receptive anal sex with an HIV unknown serostatus partner (AOR = 2.7, PAR = 15%) or HIV-positive partner (AOR = 3.4, PAR = 12%), protected receptive anal sex with an HIV-positive partner (AOR = 2.2, PAR = 11%), lack of circumcision (AOR = 2.0, PAR = 10%), and receptive oral sex to ejaculation with an HIV-positive partner (AOR = 3.8, PAR = 7%). Having a large number of male sex partners, nitrite inhalant use, and engaging in receptive anal sex explained the majority of infections in this cohort and should be targeted in prevention strategies for MSM.

Substance use and high-risk sex among men who have sex with men: a national online study in the USA

This paper describes drug and sexual risk behaviors during a six-month period in 2001 of 2,916 gay and bisexual men who were recruited online. Bivariate and multivariate analyses examined correlates of unprotected anal intercourse (UAI). Drug and alcohol use were also examined by US region. UAI was associated with using alcohol or drugs, including poppers, crystal methamphetamine, cocaine, marijuana and Viagra before or during sex. Meeting sex partners both online and offline and having multiple sex partners were also predictive of UAI. Significant regional differences were seen in the prevalence of drug use and alcohol use. Findings are discussed in relation to the need to integrate messages about the relationship between drug use and sexual behavior into HIV prevention programs.

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 unprotected 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.

Potential effect of HIV type 1 antiretroviral and herpes simplex virus type 2 antiviral therapy on transmission and acquisition of HIV type 1 infection

Biological strategies for interrupting transmission of human immunodeficiency virus (HIV) type 1 should be directed at reducing infectiousness of and susceptibility to HIV-1. Potential antiretroviral interventions include reducing the likelihood of transmission of HIV-1 by reducing HIV-1 load in the blood and genital tract of HIV-1--infected person, prophylaxis after high-risk exposure, and pre-exposure prophylaxis for very high risk populations. Antiviral treatment of herpes simplex virus (HSV) type 2, the most common cause of genital ulcers, should be evaluated as a strategy for HIV-1 infection prevention by reducing infectiousness of and susceptibility to HIV-1, on the basis of biological and epidemiological data indicating that HSV-2 facilitates transmission and acquisition of HIV-1. The rationale for antiretroviral and HSV-2-specific interventions and studies to test these strategies are described.

Predictors of substance use frequency and reductions in seriousness of use among persons living with HIV

AIMS

To examine predictors of the current level of substance use and reductions in seriousness of substance use among adults living with HIV.

DESIGN

Cross-sectional survey.

SETTING

Four major metropolitan areas of the United States.

PARTICIPANTS

Three thousand eight hundred six adults living with HIV.

MEASUREMENT

Self-reported substance use, depression, and quality of life from audio computer assisted self-interviewing and computer assisted personal interviewing structured assessments.

FINDINGS

Recent substance use of persons living with HIV was classified as frequent (40%), occasional (32%), or abstinent (28%). Participants using drugs at a frequent level identified as heterosexual, had public insurance, and had higher levels of depression. Participants who reduced from a lifetime high seriousness in substance use were female, older, and knew their HIV status for a longer period of time.

CONCLUSIONS

Screening and identification of substance use should be included in all treatment settings and community-based organizations serving adults living with HIV.

Condom use and perceived risk of HIV transmission among sexually active HIV-positive men who have sex with men

This study examined the association between HIV transmission risk perception and the sexual risk behaviors of HIV-positive men who have sex with men. Respondents rated the degree of risk of transmitting HIV through insertive anal intercourse and insertive oral sex. We examined (a) the perceived level of HIV transmission risk assigned to each sexual behavior and (b) the association between perceived risk for HIV transmission and condom use during insertive anal intercourse and insertive oral sex. We found for behaviors that have achieved less risk consensus that as transmission risk perception increases, so too does the likelihood of condom use. This study highlights the need for more research in understanding how perceived health risk to others influences protective behaviors.

The Healthy Living Project: an individually tailored, multidimensional intervention for HIV-infected persons

The NIMH Healthy Living Project (HLP), a randomized behavioral intervention trial for people living with HIV, enrolled 943 individuals, including women, heterosexual men, injection drug users, and men who have sex with men from Los Angeles, Milwaukee, New York, and San Francisco. The intervention, which is based on qualitative formative research and Ewart's Social Action Theory, addresses three interrelated aspects of living with HIV: stress and coping, transmission risk behavior, and medication adherence. Fifteen 90-minute structured sessions, divided into 3 modules of five sessions each, are delivered to individuals. Sessions are tailored to individuals within a structure that uses role-plays, problem solving, and goal setting techniques. A 'Life Project'--or overarching goal related to personal striving-provides continuity throughout sessions. Because this is an ongoing project with efficacy yet to be established, we do not report intervention outcomes. However, the intervention was designed to be useful for prevention case management, settings where repeated one-on-one contact is possible, and where a structured but highly individualized intervention approach is desired.

Sexual risk behavior of men who have sex with men: comparison of behavior at home and at a gay resort

This study compared sexual behavior of gay and bisexual men (N = 551) while at their primary residence to their behavior while vacationing at a gay resort community. Participants reported behavior for the days they spent in the resort and for their last 60 days in their home residences. Overall, 11 times more non-main partners were reported for unprotected anal intercourse (UAI) per day while in the resort as for the "at home" period. Regression analysis identified negative attitudes toward condoms, less concern about AIDS, and daily number of non-main, male partners at home with whom UAI occurred as significant predictors of the daily number of non-main male partners with whom holidaymakers engaged in UAI while in the resort area. The results suggest that sexual risk taking by men who have sex with men (MSM) while on holiday may be elevated over that at home and that prevention efforts need to be promoted in gay resorts. Behavioral surveillance research would be helpful in better characterizing the current social contexts of sexual risk taking by MSM. Theory-based studies of the nature of risk-taking and sexual decision-making on "gay holiday" could inform the development of empirically proven and conceptually grounded interventions.

Transmission of HIV-1 during primary infection: relationship to sexual risk and sexually transmitted infections

OBJECTIVE

To study primary HIV-1 infections (PHI) using molecular and epidemiological approaches in order to assess correlates of transmission in this population.

METHODS

Individuals with PHI were recruited prospectively from a discrete cohort of 1235 individuals under follow-up in a well-defined geographical area between 1999 and 2003. PHI was diagnosed by one of the following: negative HIV antibody test within 18 months, evolving antibody response, or application of the serological testing algorithm for recent HIV seroconversion. The pol gene was sequenced to identify genotypic resistance and facilitate molecular epidemiological analysis. Clinical data were collected and linked in an irretrievable fashion when informed consent was obtained.

RESULTS

A total of 103 individuals with PHI diagnosed between 1999 and 2003 were included in the study; 99 (96%) were male and 90 (91%) were men who have sex with men. Viruses from 35 out of 103 (34%) appeared within 15 phylogenetically related clusters. Significant associations with clustering were: young age, high CD4 cell count, number of sexual contacts, and unprotected anal intercourse (UAI) in the 3 months before diagnosis (P < 0.05 for all). High rates of acute sexually transmitted infections (STI) were observed in both groups with a trend towards higher rates in those individuals with viruses within a cluster (42.9 versus 27.9%; P = 0.13).

CONCLUSION

High rates of partner change, UAI and STI are factors that facilitate onward transmission during PHI. More active identification of individuals during PHI, the management of STI and highly active antiretroviral therapy may all be useful methods to break transmission networks.