Partner-specific sexual behavioral differences between phase 3 HIV vaccine efficacy trial participants and controls: Project VISION

OBJECTIVE: To assess and compare sexual behaviors using partner-specific data between HIV-negative men who have sex with men (MSM) recruited for an HIV vaccine efficacy trial and a control group. METHODS: HIV-negative MSM from an HIV vaccine trial (n = 525) and controls (n = 732) were recruited by similar strategies and interviewed about behaviors with the 3 most recent partners in the past 6 months, obtained by audio computer-assisted self-interview (A-CASI). RESULTS: Vaccine trial participants were more likely than controls to report an HIV-positive partner (24.7% and 14.1%, respectively) or an HIV-positive primary partner (16.1% and 6.8%, respectively) and were less likely to report occasional or single-time partners of unknown HIV status (51.6% and 63.2%, respectively; P < 0.05 for each comparison). Vaccine trial participants more often reported receptive unprotected anal intercourse (UAI) during their last sexual encounter with an HIV-positive partner (adjusted odds ratio [OR] = 2.7, 95% confidence interval [CI]: 1.0 to 7.9). Most believed their HIV-positive partners were receiving antiretroviral treatment (ART), however, and after adjustment for perceived ART use, the association between vaccine study participation and receptive UAI with an HIV-positive partner was not significant. CONCLUSIONS: High-risk sexual behavior was reported by many VAX004 participants and controls. Differences between vaccine trial and control participants in the highest risk per contact behavior, receptive UAI with HIV-positive partners, was partly accounted for by perceived ART use. Partner level data are useful in refining risk assessment, which is important in the evaluation of HIV vaccine and other prevention trials.     

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.     

Longitudinal patterns of sexual behavior and condom use in a cohort of HIV-negative gay and bisexual men in Vancouver, British Columbia, Canada, 1995-2000

OBJECTIVE: To characterize longitudinal patterns of sexual behavior in a cohort of young gay and bisexual men and determine their reasons for not using condoms. METHODS: Prospective data from a cohort of young gay and bisexual men aged 18 to 30 years were studied. Study participants had completed a baseline questionnaire and HIV test between May 1995 and April 1996 and four annual follow-up questionnaires. RESULTS: A total of 130 HIV-negative Vanguard participants met the eligibility criteria for this analysis. The median age at baseline was 26 years (range, 24-28). Most were white (79%), had completed high school (85%), were currently employed (82%), lived in stable housing (95%), and reported annual incomes of > or =$10,000 (82%). (All dollar amounts are given in Canadian dollars.) Consistently over the 5-year study period, > 70% of study subjects reported having > or =1 regular male sexual partners in the previous year. During each of the five successive 1-year periods, between 34% and 40% of respondents reported having had unprotected receptive anal intercourse with regular partners. Slightly fewer individuals (between 29%-39%) reported having had unprotected insertive anal intercourse with regular partners. Between 13% and 25% of participants reported having had insertive unprotected anal intercourse with casual sexual partners; and between 9% and 18% reported having had unprotected receptive anal intercourse with casual sexual partners. Reasons for engaging in unprotected anal intercourse varied depending on type of sexual partnership. CONCLUSION: High-risk sexual behaviors remained fairly consistent over a 5-year period in this study. This suggests that it is critically important to understand the motivations for unprotected sex when designing and implementing programs aimed at reducing HIV risk among young gay and bisexual men.     

Unprotected sex among HIV-positive injection drug-using women and their serodiscordant male partners: role of personal and partnership influences

We investigated the characteristics of human immunodeficiency virus (HIV)-positive injection drug-using women who reported unprotected vaginal and/or anal sex with HIV-negative or unknown serostatus (serodiscordant) male partners. Of 426 female study participants, 370 were sexually active. Of these women, 39% (144/370) and 40% (148/370) reported vaginal and/or anal sex with serodiscordant main and casual partners, respectively. Sixty percent of women inconsistently used condoms with their serodiscordant main partners, whereas 53% did so with casual partners. In multivariate analysis, during sex with main partners, inconsistent condom users were less likely to feel confident about achieving safe sex (self-efficacy), personal responsibility for limiting HIV transmission, and that their partner supported safe sex. Inconsistent condom use was also more likely among women who held negative beliefs about condoms and in couplings without mutual disclosure of HIV status. Regarding sex with casual partners, inconsistent condom users were more likely to experience psychologic distress, engage in sex trading, but they were less likely to feel confident about achieving safe sex. These findings suggest that there are widespread opportunities for the sexual transmission of HIV from drug-using women to HIV-uninfected men, and that reasons vary by type of partnership. Multifaceted interventions that address personal, dyadic, and addiction problems are needed for HIV-positive injection drug-using women.     

Willingness to participate and enroll in a phase 3 preventive HIV-1 vaccine trial

OBJECTIVES: To assess the extent to which HIV-negative cohort study participants would be willing to participate (WTP) in future HIV vaccine trials, to explore enrollment into an ongoing phase 3 HIV vaccine trial, and to assess changing WTP in such trials over time. METHODS: The Vanguard Project is a prospective study of gay and bisexual men in the greater Vancouver region, British Columbia, Canada. Sociodemographic characteristics, sexual risk behavior, beliefs around HIV, and reasons for not participating in the AIDSVAX B/B trial were collected from self-administered questionnaires. Contingency table analysis compared subjects who were WTP with subjects who were not WTP. Logistic regression analyses identified possible predictors of WTP. A subset analysis was conducted to assess changes in WTP in 2001 versus 1997. RESULTS: Of 440 respondents, 214 (48.6%) were WTP, and 97 (22.0%) were not WTP. Those WTP were disadvantaged, sexually risky, and had a high-perceived HIV risk (all p <.05). Reasons for not participating in the AIDSVAX B/B trial included fear of health problems and having missed the deadline for enrollment (all p < 0.05). Multivariate analysis revealed that having had a regular sex partner (adjusted odds ratio, 0.48 [confidence interval, 0.25-0.92]) was a negative predictor whereas having a high-perceived HIV risk (adjusted odds ratio, 5.35 [confidence interval, 1.57-18.25]) was a positive predictor of WTP. Comparing WTP in 2001 with that in 1997, 24% of 100 participants who had been previously WTP were now not WTP. CONCLUSION: Improving community and participant knowledge about preventive HIV vaccine trials may help ensure informed consent. However, whether informing potential participants will reverse or contribute to the declining trend in WTP observed in this cohort warrants further investigation.     

HIV transmission risk behavior among men and women living with HIV in 4 cities in the United States

Determining rates of HIV transmission risk behavior among HIV-positive individuals is a public health priority, especially as infected persons live longer because of improved medical treatments. Few studies have assessed the potential for transmission to the partners of HIV-positive persons who engage in high-risk activities. A total of 3723 HIV-infected persons (1918 men who have sex with men [MSM], 978 women, and 827 heterosexual men) were interviewed in clinics and community-based agencies in Los Angeles, Milwaukee, New York City, and San Francisco from June 2000 to January 2002 regarding sexual and drug use behaviors that confer risk for transmitting HIV. Less than one quarter of women and heterosexual men had 2 or more sexual partners, whereas 59% of MSM reported having multiple partners. Most unprotected vaginal and anal sexual activity took place in the context of relationships with other HIV-positive individuals. Approximately 19% of women, 15.6% of MSM, and 13.1% of heterosexual men engaged in unprotected vaginal or anal intercourse with partners who were HIV-negative or whose serostatus was unknown. The majority of sexually active participants disclosed their serostatus to all partners with whom they engaged in unprotected intercourse. An estimated 30.4 new infections (79.7% as a result of sexual interactions with MSM) would be expected among the sex partners of study participants during the 3-month reporting period. Eighteen percent of 304 participants who injected drugs in the past 3 months reported lending their used injection equipment to others. In addition to the more traditional approaches of HIV test counseling and of focusing on persons not infected, intensive prevention programs for persons with HIV infection are needed to stem the future spread of the virus.     

Population-based HIV testing and counseling in rural Uganda: participation and risk characteristics.

OBJECTIVES: To assess self-selection in a population-based voluntary HIV testing and counseling (VTC) program by comparing the HIV risk characteristics of users and nonusers of VTC in rural Uganda. DESIGN: A 1994 to 1995 community-randomized trial in the Rakai District of Uganda enrolled adults aged 15 to 59 years and ascertained their HIV status, sociodemographic characteristics, risk behaviors, and AIDS-associated symptoms. All subjects were offered confidential individual VTC at no cost. METHODS: We compared users and nonusers of VTC among 10,950 participants (4764 male and 6186 female) enrolled at baseline using multivariate logistic regression. RESULTS: Women were significantly less likely to receive VTC than men (31.5% vs. 34.8%, p <.001). In multivariate analysis, younger age, HIV-positive status, and having no sexual partners in the past 5 years (and, significant for women only, having 2 or more sexual partners) were associated with lower VTC participation for both men and women. Among women, higher VTC participation was associated with symptoms suggestive of AIDS and other illnesses and shopkeeper occupations. CONCLUSIONS: During the initial phase of a population-based free VTC program in rural Uganda, certain high-risk groups were underrepresented among VTC recipients. There is a need to target VTC to ensure participation by high-risk individuals most in need of services.     

Correlates of risky behaviors among young and older men having sexual relations with men in Montréal, Québec, Canada. Omega Study Group

OBJECTIVE: To assess characteristics associated with 1) age and 2) recent unprotected anal sex with casual partners among men having sexual relations with men (MSM) participating in the Omega Cohort, Montréal, Québec, Canada. METHODS: The Omega Cohort is a study of the incidence and psychosocial determinants of HIV infection among MSM living in Montréal. MSM complete a questionnaire and are tested for HIV every 6 months. RESULTS: Thirteen percent of young MSM (< 30 years of age, n = 355) and 12% of older MSM (> or = 30 years of age, n = 455) reported recent unprotected anal sex with casual partners. The predictors of this latter behavior were: not living with a male sexual partner, unprotected anal sex with regular partner, > 5 casual partners, alcohol/drug use before anal sex, and having difficulties with procedures needed for safe sex. Among young MSM, additional predictors were: to have been living in Montreal for less than 1 year and to have exchanged money for sex. Among older MSM, additional predictors were: female sexual partners, unprotected anal sex with an HIV-infected partner, and feeling invulnerable to AIDS. CONCLUSION: Young Omega participants do not have more risky behaviors than older participants. Some predictors of recent risk behaviors with casual partners were different between the two groups. Prevention programs should be adapted consequently.     

Willingness to participate in HIV vaccine trials among men who have sex with men in Rio de Janeiro, Brazil. Projeto Praça Onze Study Group

Evaluation of HIV vaccines requires high-risk individuals willing to participate in a vaccine trial. We investigated the willingness to participate in HIV vaccine trials of initially HIV-seronegative homosexual men enrolled in an HIV seroincidence cohort study. Of 815 initially HIV-seronegative participants, 569 (69.8%) reported willingness to participate in an HIV vaccine trial. Altruism was the primary reason given for wanting to participate. Fear of HIV infection from the study's immunizations and a vaccine-induced positive HIV test result were the main reasons for not wanting to participate. Of the 34 study subjects who eventually had HIV seroconversion, 29 (85%) had indicated a willingness to participate. In a univariate analysis, factors associated with willingness to participate included HIV seroconversion during follow-up (odds ratio [OR]. 2.6; p =.04), low educational level (OR, 1.6; p =.005), low family income (p =.02), and exchanging sex for housing, food, or clothing (OR 6.1; p =.005). Students were less likely to be willing to participate in a trial (OR, 0.7; p = .03), as well as those who reported sex at the first encounter (OR, 0.7; p = .05). In a multivariate analysis, low education level, infection with Condyloma, and exchanging sex for housing, food, or clothing were positively associated with willingness to participate, whereas being a student and reporting sex at first encounter were negatively associated. In general, factors indicative of high-risk of HIV infection were associated with a higher willingness. These data demonstrate that this high-risk homosexual male cohort has a high willingness to participate in HIV vaccine trials.     

A bridge over troubled waters: factors associated with non-injection drug users having injection drug-using sex partners

OBJECTIVES: To examine factors associated with noninjectors having 1 or more injection drug users as sex partners. METHODS: We collected data as a part of the Self-Help in Eliminating Life Threatening Diseases study, a network-oriented experimental HIV prevention intervention. All eligible participants were administered a detailed face-to-face interview on their sociodemographic background, patterns of drug use, HIV prevention and risk behaviors, and social networks. The sample for these analyses consisted of 863 noninjectors, 97 of whom had 1 or more injection drug-using sex partners. RESULTS: Among the factors associated with an increased odds of having 1 or more injecting sex partners were long-term unemployment, increasing proportion of women in network (among male noninjectors), increasing number of recent sex partners (among former injectors), increasing number of injecting non-sex partners in the network, and increasing network size above 15. CONCLUSIONS: There are specific network characteristics associated with noninjectors having injecting sex partners.     

The influence of social and sexual networks in the spread of HIV and syphilis among men who have sex with men in Shanghai, China

OBJECTIVES: To analyze characteristics of social and sexual networks and their role as risk factors for HIV and syphilis among men who have sex with men (MSM) in Shanghai, China. DESIGN:: A cross-sectional study. METHODS: We recruited 477 participants using a snowball sampling method. We administered a face-to-face questionnaire and provided testing and counseling for HIV and syphilis. RESULTS: The prevalences of HIV and markers for syphilis were 1.47% (95% confidence interval [CI]: 0.59 to 3.01) and 13.47% (95% CI: 10.53 to 16.88), respectively. The independent factors associated with lower risk for syphilis infection were having a contact network, overlap of social and sexual networks, meeting other MSM at the gym or through the Internet, having 3 to 5 lifetime male anal sex partners, and having a female steady sex partner. A larger male sexual network size, having been married, being more knowledgeable about HIV, having 6 or more lifetime male anal sex partners, and having steady male or female sex partners were independently associated with having unprotected anal or vaginal intercourse. CONCLUSIONS: Significant associations were found between network characteristics and syphilis infection and unprotected sex. Network-based interventions should be developed to reduce this HIV risk among MSM in China.     

Recruitment and baseline epidemiologic profile of participants in the first phase 3 HIV vaccine efficacy trial

OBJECTIVE: To describe recruitment and baseline epidemiologic characteristics of volunteers in the first phase 3 placebo-controlled trial of a recombinant gp120 HIV vaccine (AIDSVAX B/B). METHODS: Volunteers were gay/bisexual men or women at risk for sexually transmitted HIV infection. Recruitment strategies, demographics, and risk factors were assessed. HIV status was determined by standard HIV-1 antibody assays. Seronegative/viremic HIV infection at enrollment was determined using the HIV-1 nucleic acid test. RESULTS: From June 1998 through October 1999, 5417 of 7185 volunteers screened were enrolled at 61 sites in the United States, Canada, and The Netherlands. Successful recruitment methods included distribution of study information at gay venues, advertising and media coverage, and referrals from volunteers. Most volunteers were altruistically motivated, men (98%), young (median, 36 years), white (83%), well educated (61% college education or more), and at high risk for HIV during the 6 months before enrollment. At baseline, 14 were HIV infected (12 were seronegative but viremic; 2 were seropositive and viremic). CONCLUSION: Men and women at high risk for sexually transmitted HIV infection were successfully recruited for the first phase 3 HIV vaccine efficacy trial. Knowledge of recruitment and baseline epidemiologic characteristics of participants in this trial will provide valuable guidance for designing and conducting future trials.     

Reduced HIV risk-taking and low HIV incidence after enrollment and risk-reduction counseling in a sexually transmitted disease prevention trial in Nairobi,Kenya

There is an urgent need in sub-Saharan Africa to develop more effective methods of HIV prevention, including improved strategies of sexually transmitted infection (STI) prevention or an HIV vaccine. The efficacy of these strategies may be tested through clinical trials within cohorts at high risk for STI and HIV, such as female commercial sex workers. For ethical reasons, standard HIV prevention services, including access to free condoms, risk-reduction counseling, and STI therapy, will generally be offered to all study subjects. Because study subjects would often not otherwise have access to these prevention services, it is possible that enrollment in such clinical trials will itself reduce incidence rates of STI and HIV below expected levels, reducing the power to test the efficacy of the randomized intervention. We show that the provision of standard HIV prevention services as part of a randomized STI/HIV prevention trial is temporally associated with a dramatic reduction in sexual risk-taking, and that this reduction is directly associated with reduced STI incidence. This finding should be considered in the design of clinical trials with an endpoint of HIV incidence, in particular HIV preventive vaccine trials.     

Support among persons infected with HIV for routine health department contact for HIV partner notification

Public health partner notification (PN) services are provided inconsistently to persons diagnosed with HIV/AIDS in the United States, and some community groups representing persons with HIV/AIDS have opposed widespread application of PN. We surveyed persons with HIV recently reported to our health department and a random sample of HIV-infected persons attending an HIV/AIDS clinic. A total of 95 persons, of whom 76 (80%) were men who have sex with men, completed an anonymous self-administered questionnaire. Eighty-four percent of participants believed the health department should routinely offer everyone diagnosed with HIV help in notifying their partners; 79% indicated they would be somewhat or very likely to provide information to a doctor, case worker, or health department employee for purposes of PN; and 20% indicated they wanted help in notifying a recent sex partner. Seventy-eight percent of participants believed the health department should contact all HIV-infected persons after diagnosis to help them access medical care and social services, and 68% wanted the health department to contact them about the availability of medical or social services. In contrast to common public perceptions, these results suggest that most persons with HIV support health departments routinely contacting people after HIV diagnosis and that many want assistance with PN.     

Experiences in conducting multiple community-based HIV prevention trials among women in KwaZulu-Natal, South Africa

Background

South Africa, with its scientific capacity, good infrastructure and high HIV incidence rates, is ideally positioned to conduct large-scale HIV prevention trials. The HIV Prevention Research Unit of the South African Medical Research Council conducted four phase III and one phase IIb trials of women-initiated HIV prevention options in KwaZulu-Natal between 2003 and 2009. A total of 7046 women participated, with HIV prevalence between 25% and 45% and HIV incidence ranging from 4.5-9.1% per year. Unfortunately none of the interventions tested had any impact on reducing the risk of HIV acquisition; however, extremely valuable experience was gained, lessons learned and capacity built, while the communities gained associated benefits.

Experience

Our experience in conducting these trials ranged from setting up community partnerships to developing clinical research sites and dissemination of trial results. Community engagement included setting up community-based research sites with approval from both political and traditional leaders, and developing community advisory groups to assist with the research process. Community-wide education on HIV/sexually transmitted infection prevention, treatment and care was provided to over 90 000 individuals. Myths and misconceptions were addressed through methods such as anonymous suggestion boxes in clinic waiting areas and intensive education and counselling. Attempts were made to involve male partners to foster support and facilitate recruitment of women. Peer educator programmes were initiated to provide ongoing education and also to facilitate recruitment of women to the trials. Recruitment strategies such as door-to-door recruitment and community group meetings were initiated. Over 90% of women enrolled were retained. Community benefits from the trial included education on HIV prevention, treatment and care and provision of ancillary care (such as Pap smears, reproductive health care and referral for chronic illnesses). Social benefits included training of home-based caregivers and sustainable ongoing HIV prevention education through peer educator programmes.

Challenges

Several challenges were encountered, including manipulation by participants of their eligibility criteria in order to enroll in the trial. Women attempted to co-enroll in multiple trials to benefit from financial reimbursements and individualised care. The trials became ethically challenging when participants refused to take up referrals for care due to stigma, denial of their HIV status and inadequate health infrastructure. Lack of disclosure of HIV status to partners and family members was particularly challenging. Some of the ethical dilemmas put to the test our responsibility as researchers and our obligation to provide health care to research participants.

Conclusion

Conducting these five trials in a period of six years provided us with invaluable insights into trial implementation, community participation, recruitment and retention, provision of care and dissemination of trial results. The critical mass of scientists trained as clinical trialists will continue to address the relentless HIV epidemic in our setting and ensure our commitment to finding a biomedical HIV prevention option for women in the future.     

Participating in the United Kingdom Prospective Diabetes Study (UKPDS): a qualitative study of patients'' experiences.

The United Kingdom Prospective Diabetes Study (UKPDS) is one of the longest and largest clinical trials ever conducted. It explored the effects of intensive blood glucose and blood pressure control on the development of complications in patients with type 2 diabetes. Patients took part in this trial for up to 20 years and the drop-out rate was extremely low. The aim of this discussion paper is to explore patients' motivations for joining the UKPDS and for remaining in the trial, and to examine the implications of findings for good practice before, during, and after clinical trials. A qualitative, exploratory study was undertaken, involving former UKPDS patients (n = 10) at Northampton General Hospital, England. In-depth, semi-structured interviews were undertaken and the data analysed using grounded theory approaches. The results showed that patients were motivated to join the UKPDS because they believed this would give them the best clinical care and reduce the threat of the disease. However, all of the patients identified unanticipated benefits of trial participation, to which they attributed their strong commitment to the UKPDS. These included the reassurance provided by regular clinical examinations, the personal nature of clinical care, and the welcome discipline imposed by UKPDS professionals. Transition back to primary care at trial closure could be a lonely experience, despite follow-up being seen as competent. Practitioners involved in recruiting patients for clinical trials should be aware that participants may be motivated by the desire for better clinical care, irrespective of randomisation consequences. Those taking back the clinical care of trial participants with chronic disease may wish to consider a 're-entry' interview, to minimise trial bereavement.     

Unrecognized HIV infection, risk behaviors, and perceptions of risk among young men who have sex with men: opportunities for advancing HIV prevention in the third decade of HIV/AIDS

This study evaluated the magnitude and distribution of unrecognized HIV infection among young men who have sex with men (MSM) and of those with unrecognized infection, the prevalence and correlates of unprotected anal intercourse (UAI), perceived low risk for infection, and delayed HIV testing. MSM aged 15-29 years were approached, interviewed, counseled, and tested for HIV at 263 randomly sampled venues in 6 US cities from 1994-2000. Of 5649 MSM participants, 573 (10%) tested positive for HIV. Of these, 91% of black, 69% of Hispanic, and 60% of white MSM (77% overall) were unaware of their infection. The 439 MSM with unrecognized infection reported a total of 2253 male sex partners in the previous 6 months; 51% had UAI; 59% perceived that they were at low risk for being infected; and 55% had not tested in the previous year. The HIV epidemic among MSM in the United States continues unabated, in part, because many young HIV-infected MSM are unaware of their infection and unknowingly expose their partners to HIV. To advance HIV prevention in the third decade of HIV/AIDS, prevention programs must reduce unrecognized infection among young MSM by increasing the demand for and availability of HIV testing services.     

Comparison of clients of a mobile health van and a traditional STD clinic

The objective of this study was to determine if there were any demographic, behavioral, and clinical differences between clients seen aboard a mobile sexually transmitted disease (STD)/HIV clinic compared with those seen in a traditional municipal STD/HIV health clinic for receipt of STD/HIV services. Clients seen in the two different settings were interviewed about demographic characteristics, reasons for their visit, STD history, their HIV/STD risk factors, and the risk factors of their sex partners. Clients in both settings were also offered testing for syphilis, gonorrhea, chlamydia, and HIV. Results suggested that clients seen at the mobile clinic were older, more likely to be injecting drug users themselves and/or to have sex partners who were, or had engaged in prostitution for money or drugs. Over half (54.4%) of the mobile clinic clients sought testing for HIV, and they were far less likely to be seeking care for symptoms of an STD. In contrast, only 7.1% of municipal clinic clients indicated HIV testing as the reason for their visit, whereas nearly two thirds (64.5%) reported symptoms of disease. Two percent of municipal clinic clients and 5.4% of mobile clinic clients had a positive HIV test ( p<.001), and 17.8% of STD clinic clients and 5.6% of mobile van clients had a positive gonorrhea and/or test ( p<.001). These data suggest that a mobile STD/HIV clinic may be an effective strategy to reach individuals at high risk for HIV who are not being served by traditional municipal STD/HIV health clinics.     

The impact of sex partners' HIV status on HIV seroconversion in a prospective cohort of injection drug users

OBJECTIVE AND DESIGN: The identification of individuals at highest risk of HIV infection is critical for targeting prevention strategies. We evaluated the HIV status of the sex partners of injection drug users (IDUs) and rates of subsequent HIV seroconversion among a prospective cohort study of IDUs. METHODS: We performed an analysis of the time to HIV infection among baseline HIV-negative IDUs enrolled in the Vancouver Injection Drug Users Study. IDUs were stratified based on whether or not they reported having an HIV-positive sex partner. Kaplan-Meier methods were used to estimate cumulative HIV incidence rates, and Cox regression was used to determine adjusted relative hazards (RHs) for HIV seroconversion. RESULTS: Of 1013 initially HIV-negative IDUs, 4.8% had an HIV-positive partner at baseline. After 18 months, the cumulative HIV incidence rate was significantly elevated among those who reported having an HIV-positive sex partner (23.4% vs. 8.1%; log-rank P < 0.001). In a Cox regression model adjusting for all variables that were associated with the time to HIV infection in univariate analyses, including drug use characteristics, having an HIV-positive sex partner (RH = 2.42 [95% confidence interval: 1.30 to 4.60]; P = 0.005) remained independently associated with time to HIV seroconversion. CONCLUSIONS: Having an HIV-positive sex partner was strongly and independently associated with seroconversion after adjustment for risk factors related to drug use. Our findings may aid public health workers in their efforts to identify IDUs who should be targeted with education and prevention efforts and indicate the need for ongoing development of prevention interventions for IDU sex partners who are HIV discordant.     

柳州市不同层次暗娼人群梅毒及艾滋病感染状况分析

目的了解柳州市不同层次商业性工作者人群特征、艾滋病相关知识、行为及梅毒、艾滋病病毒感染等现状。方法采用二阶段整群抽样方法抽取调查对象,使用健康问卷面对面调查并采集血样检测HIV和梅毒抗体。结果本次研究共调查403人,部分调查对象认为能够从表面区分艾滋病感染者,与客人发生性行为时安全套使用率较高,但与固定性伴安全套使用率很低。不同档次对象的年龄、婚姻和文化程度略有不同,安全套使用率也略有差别。调查者中1d接客最多20人,1周接客最多25人;首次性行为年龄最小12岁,首次商业性服务年龄最小14岁。58.50%的调查者最近1年患过性传播疾病。未发现HIV阳性者,但发现梅毒RPR初筛阳性者10人,阳性率为2.48%。结论在干预活动时应针对不同层次人群特点,对有配偶或固定性伴者应当加大干预力度和采取不同的策略促其使用安全套,以减少HIV进一步传播。