To T or not to T: Differences in Testosterone Use and Discontinuation by HIV Serostatus among Men who Have Sex with Men.

OBJECTIVES: The aim of the study was to characterize contemporary patterns and correlates of testosterone therapy (TTh) use and discontinuation by HIV serostatus among men in the Multicenter AIDS Cohort Study (MACS). METHODS: Self-reported testosterone use data were collected semiannually from 2400 (1286 HIV-infected and 1114 HIV-uninfected) men who have sex with men. Multivariable Poisson regression was used to estimate prevalence ratios for TTh use and predictors of TTh discontinuation (2012-2015). RESULTS: Use was higher among HIV-infected compared with HIV-uninfected men in all age strata, with an age-adjusted prevalence of 17% vs. 5%, respectively (adjusted prevalence ratio 3.7; P < 0.001). Correlates of use in the multivariable model were similar by HIV serostatus: white race, the Los Angeles (LA) site, more than one recent sexual partner, non-smoking status, and higher American Heart Association/American College of Cardiology (AHA/ACC) cardiovascular disease (CVD) risk score category (approximately 70% of testosterone users were in the high-risk category). Compared with HIV-uninfected men, HIV-infected men more frequently reported building muscle mass as a motivation for testosterone use. The TTh discontinuation rate was 20.9/100 person-years [95% confidence interval (CI) 17.3, 25.0/100 person-years]. Relative to HIV-uninfected men, HIV-infected men were half as likely to discontinue (adjusted incidence rate ratio 0.4; P < 0.001). Discontinuation was 40% higher in the period after the US Food and Drug Administration (FDA) safety communication for testosterone in 2014, independent of co-factors (P = 0.06). CONCLUSIONS: Given the high prevalence of both TTh use and CVD risk among HIV-infected men, the benefits and risks of TTh should be examined in future studies of aging HIV-infected men and monitored routinely in clinical practice.

Anti-retroviral Therapy Based HIV Prevention Among a Sample of Men Who Have Sex with Men in Cape Town, South Africa: Use of Post-exposure Prophylaxis and Knowledge on Pre-exposure Prophylaxis.

Men who have Sex with Men (MSM) have been affected disproportionately by the global HIV pandemic. Rates of consistent condom-use are low and there is a need for further biomedical prevention interventions to prevent new HIV infections. Post exposure prophylaxis (PEP) can reduce the risk of HIV, but uptake among MSM is low. Pre-exposure prophylaxis (PrEP), an innovative anti-retroviral-based HIV prevention tool might be an appropriate intervention for MSM who have recently accessed PEP that involves HIV negative individuals taking daily tenofovir+emtricitabine for HIV prevention. 44 MSM, attending a primary health-care level MSM-focused sexual health clinic in Cape Town, South Africa, who had initiated PEP were enrolled in this study. Participants were followed up after 2, 4 and 12 weeks. Self-administered electronic surveys were completed at the initial, 4 and 12 week visit. Barriers and facilitators to accessing PEP and remaining adherent were examined, as was knowledge about PrEP. Thirty-two participants (80 %) were <40 years of age (range 20-65 years). 35 % of the participants reported their reason for requiring PEP as condomless receptive anal intercourse. A further 20 % required PEP following condomless penetrative anal intercourse; 27.5 % required PEP due to a broken condom during receptive anal sex and 2 participants during insertive anal sex. Three participants did not complete 28 days of PEP or were lost to follow up. Over half (58.5 %) of the participants reported being completely adherent to their regime; under a third (31.7 %) reported missing one PEP dose; and 9.8 % reported missing more than one dose. 36/40 (90 %) had heard of PrEP and 30/40 (75 %) indicated that they would use PrEP if it were accessible to them. That we enrolled 44 MSM who accessed PEP from a Department of Health affiliated clinic over 12 months, speaks to the low uptake by MSM of PEP services in South Africa. Adherence was high and demonstrates that adherence support is feasible from a state health clinic. Reported risk behaviors in some high-risk participants did not change over time, demonstrating the need for additional longer-term HIV preventions such as PrEP. PEP users could conceivably be transitioned from PEP to PrEP.

Alcohol Use and Associated Sexual and Substance Use Behaviors Among Men Who Have Sex with Men in Moscow, Russia.

Alcohol use is a public health problem in the Russian Federation. This study explored relationships between alcohol use and behavioral risks for HIV transmission among men who have sex with men (MSM) in Moscow, Russia. Alcohol use disorder identification test (AUDIT) scores for 1367 MSM participating in a cross-sectional survey and HIV testing were categorized to: "abstinence/low use", "hazardous use", "harmful use/dependency". Multiple logistic regression models compared dependent variables for sexual and drug use behaviors across alcohol use strata. Hazardous and harmful/dependent alcohol use were significantly associated with high-risk sexual behaviors and drug use. Harmful use/dependency was associated with an increased odds of having more than five male sex partners (last 12 months; adjusted odds ratios-AOR 1.69; 95 % CI 1.25-2.27), inconsistent condom use during anal intercourse (AOR 2.19; 95 % CI 1.61-2.96) and, among those using recreational drugs, injection drug use (last month; AOR 4.38: 95 % CI 1.13-17.07) compared to abstinent/low-level users. Harmful/dependent use was marginally associated with HIV infection (AOR 1.48; 95 % CI 0.97-2.25). HIV prevention efforts for MSM in Moscow may benefit from addressing problem alcohol use to mitigate high-risk behaviors.

Knowledge, Attitudes and Beliefs regarding Post Exposure Prophylaxis among South African Men who have Sex with Men.

The Soweto Men's Study (2008), demonstrated an overall HIV prevalence rate of 13.2 %, with 10.1 % among straight-identified Men-who-have-sex-with-men (MSM), 6.4 % among bisexual-identified MSM and 33.9 % among gay-identified MSM. Behavioral interventions are imperative, but insufficient to prevent new HIV infections. Biomedical prevention of HIV offers a variety of combination prevention tools, including Post-exposure prophylaxis (PEP). PEP studies amongst MSM have been conducted in Amsterdam, Brazil and San Francisco, but never before in Africa. A cross-sectional, Internet-based survey was initiated to measure knowledge, attitudes and beliefs regarding PEP among South African MSM. Recruitment commenced in June 2014 and ran until October 2015. Participants were recruited through banner advertisements on Facebook.com and mambaonline.com, advertisements in the local gay media and at Health4Men (H4M) MSM-targeted clinics. Outreach workers distributed flyers advertising the study in their local communities. The survey was also made available on a computer at the H4M clinics in Cape Town and Johannesburg to reach MSM who may not have Internet access. A total of 408 men completed the survey. The majority of these men were under the age of 40, identified as gay/homosexual and were employed; 51 % (208/408) self-identified as black or of mixed race. In multivariate analysis participants who identified as gay had greater odds of having previously heard of PEP (AOR 1.91, 95 % CI 1.04, 3.51; p = 0.036), as did those who reported their HIV status as positive (AOR 2.59, 95 % CI 1.47, 4.45; p = 0.001). Participants with medical insurance had greater odds of having used PEP previously (AOR 2.67, 95 % CI 1.11, 6.43; p = 0.029). Bivariate analysis showed that condomless sex in the past 6 months was not significantly associated with PEP knowledge (p = 0.75) or uptake (p = 0.56) of PEP. Our findings suggest a lack of PEP knowledge and uptake among non-gay identified, HIV negative and un-insured MSM. Focusing PEP programs on these men may potentially increase uptake. Increased knowledge needs to be provided to MSM who engage in risky sexual behaviors.

Psychosocial health conditions and HIV prevalence and incidence in a cohort of men who have sex with men in Bangkok, Thailand: evidence of a syndemic effect.

Men who have sex with men (MSM) in Bangkok may experience multiple psychosocial health conditions, such as substance use, suicidality, and a history of sexual abuse. These factors may contribute to HIV vulnerability in a syndemic way. A syndemic is defined as a number of synergistically interacting health conditions producing excess disease in a population. The objective of this study is to examine whether psychosocial health conditions among MSM have a syndemic association with HIV prevalence and HIV incidence. To do this, we evaluated psychosocial health conditions and their associations with unprotected sex, HIV prevalence and HIV incidence in a cohort of Thai MSM (N = 1,292). There was a positive and significant association between the number of psychosocial health conditions and increased levels of unprotected sex and HIV prevalence at study baseline. The number of psychosocial health conditions at baseline was also associated with increased HIV incidence during follow-up (no conditions, HIV incidence = 15.3 %; one to three conditions, 23.7 %; four to five conditions, 33.2 %). The number of psychosocial health conditions was positively associated with HIV risk behavior and HIV prevalence and incidence. Prevention efforts among MSM need to address the existence of multiple psychosocial health conditions and their synergy to effectively decrease the spread of HIV infection.

Prevalence of AIDS-related risk factors and condom use in the United States.

A national probability survey of human immunodeficiency virus (HIV)-related risk factors among the general heterosexual population, the National AIDS (acquired immunodeficiency syndrome) Behavioral Surveys, has obtained data from 10,630 respondents. Data are presented on the prevalence of HIV-related risks in the general heterosexual population, on the distribution of the three largest risk groups across social strata, and on the prevalence and distribution of condom use among heterosexuals reporting a risk factor. Between 15 and 31 percent of heterosexuals nationally and 20 and 41 percent in cities with a high prevalence of AIDS reported an HIV risk factor. Condom use was relatively low. Only 17 percent of those with multiple sexual partners, 12.6 percent of those with risky sexual partners, and 10.8 percent of untested transfusion recipients used condoms all the time. Overall, the results suggest that current HIV prevention programs have, to a very limited extent, reached those heterosexuals with multiple sexual partners but have failed to reach many other groups of the heterosexual population at risk for HIV. New public health strategies may be needed for these specific risk groups.

Control of Citrus Canker and Citrus Bacterial Spot with Bacteriophages.

Bacteriophages, alone or in combination with copper bactericides, were evaluated for managing Asiatic citrus canker and citrus bacterial spot incited by Xanthomonas axonopodis pathovars citri and citrumelo, respectively. In a set of five greenhouse experiments, phage treatment provided consistent control of citrus canker, causing an average of 59% reduction in disease severity. However, treatment with phage was ineffective if applied with skim milk, a protective formulation, which increases phage residual activity. In nursery settings, phage treatment also reduced disease but was less effective than copper-mancozeb, a chemical bactericide. The integration of phage and copper-mancozeb resulted in equal or less control than copper-mancozeb application alone. Phage treatments were evaluated in a commercial citrus nursery for reducing citrus bacterial spot caused by natural inoculum. Phage treatment provided significant disease reduction on moderately sensitive Valencia oranges in two trials (48 and 35%); however, on the highly susceptible grapefruit host it was ineffective. In an experimental citrus nursery, phage treatment provided significant control of citrus bacterial spot caused by a phage-sensitive strain, but was equally or less effective than copper-mancozeb. The combination of phage and copper-mancozeb did not increase control compared with copper-mancozeb alone.

Diversity among xanthomonads pathogenic on pepper and tomato.

Xanthomonas campestris pv. vesicatoria, causal agent of bacterial spot of tomato and pepper, had been considered for nearly 70 years to be a relatively homogeneous organism. However, in the past decade this bacterium was determined to be composed of two genetically and phenotypically distinct groups. The two groups, designated A and B, were distinguished based on amylolytic activity, expression of unique protein bands, reaction on differential hosts (tomato races T1 and T2), reaction patterns with monoclonal antibodies, DNA restriction profiles, and DNA:DNA hybridization. The A and B groups were placed into X. axonopodis pv. vesicatoria and X. vesicatoria, respectively. A third group, designated C, was pathogenically (race T3) and serologically distinct from A and B strains, and formed unique DNA restriction profiles. DNA:DNA hybridization data suggest that C is distinct but related to A strains and may represent a subspecies of A. A final group, designated D, consisted of X. gardneri, an organism identified in Yugoslavia in 1957, and also found in Costa Rica. Group D was determined to be genetically distinct from strains within the other two groups; it represents a third Xanthomonas species pathogenic on tomato and pepper.

Perspectives on expedited partner therapy for chlamydia: a survey of health care providers.

There is a lack of research on health care providers' use of and perspectives on expedited partner therapy in a state where expedited partner therapy is not prohibited or explicitly allowed. The aim of our study was to understand if and how health care providers use expedited partner therapy, if specific demographic factors and knowledge contribute to increased use of expedited partner therapy, and to describe barriers and facilitators to the use of expedited partner therapy in Pittsburgh, Pennsylvania. A convenience sample of 112 health care providers from diverse disciplines who treat young women at risk for chlamydia completed an online survey. About 11% of health care providers used expedited partner therapy consistently. Those who self-reported that they were knowledgeable about expedited partner therapy were more likely to use expedited partner therapy (73% vs. 49%, p = .009) as were those who said no or were unsure about their institution's guidelines for expedited partner therapy (35% vs. 22%, p = 0.01) (62% vs. 57%, p = 0.01). The most commonly reported facilitator of expedited partner therapy was having clear legal guidelines (86%). This study finds that in a setting where expedited partner therapy is not expressly permitted, health care providers still use the practice but also experience barriers that limit uptake. Legislation expressly endorsing expedited partner therapy in the state and in medical institutions is needed to increase expedited partner therapy use.

Functional analysis of the early chlorosis factor gene.

Chlorosis is one of the symptoms of bacterial spot disease caused by Xanthomonas campestris pv. vesicatoria, which induces chlorosis before any other symptoms appear on tomato. We report characterization of a 2.1-kb gene called early chlorosis factor (ecf). The gene ecf encodes a hydrophobic protein with similarity to four other proteins in plant pathogens, including HolPsyAE, and uncharacterized gene products from X. campestris pv. campestris and X. axonopodis pv. citri, and, at the tertiary structure level, to colicin Ia from Escherichia coli. We demonstrate that the associated phenotype is hrp dependent, and that the ecf gene product appears to be translocated to host cells. The gene ecf has no impact on electrolyte leakage or on bacterial growth in planta in response to infection. Concentrated culture filtrates do not produce chlorosis. Study of its role in Xanthomonas spp.-tomato interactions will forward our understanding of symptom production by plant pathogens and allows further investigation into the mechanisms of bacterial virulence and production of symptoms.

Genomic localization of tomato genes that control a hypersensitive reaction to Xanthomonas campestris pv. vesicatoria (Doidge) dye.

Xanthomonas campestris pv. vesicatoria causes bacterial spot, one of the most serious diseases of tomatoes. The lycopersicon esculentum accession 'Hawaii 7998' is the only reliable source of resistance to race 1 strains of the pathogen. This resistance is associated with a hypersensitive reaction controlled by multiple nondominant genes. The inoculated area becomes fully necrotic 24 hr after inoculation in 'Hawaii 7998,' whereas full necrosis is observed 5 and 4 days after inoculation in the susceptible species L. pennellii (LA 716) and their F1, respectively. An interspecific backcross population, using 'Hawaii 7998' as the recurrent parent, was analyzed to determine the linkage relationships between the resistance genes and 135 molecular marker loci. The range of responses of the BC1 population included those of the parents. Linkage to a hypersensitive response factor was assessed by comparing the rates of necrosis development between homozygous and heterozygous plants at 8 hr-intervals. Three factors that affect the hypersensitive response of 'Hawaii 7998' were detected. One factor is on the short arm of chromosome I, another on the long arm of chromosome I, and a third on the long arm of chromosome 5. These factors appeared to act independently and to have additive effects.

AIDS risk behaviors among late middle-aged and elderly Americans. The National AIDS Behavioral Surveys.

OBJECTIVES: Although 10% of all acquired immunodeficiency syndrome (AIDS) cases diagnosed in the United States have been among Americans aged 50 years of age or older, little attention has been devoted to understanding AIDS risk-taking behaviors among middle-aged or older Americans. This study describes the prevalence of AIDS risk among Americans aged 50 years of age or older. DESIGN AND STUDY POPULATION: We present data from the National AIDS Behavioral Surveys, two large cross-sectional national surveys taken in 1990-1991. MAIN OUTCOME VARIABLE: Prevalence of risk behaviors for human immunodeficiency virus (HIV) transmission and of HIV testing. RESULTS: Findings from both surveys provide replication of several important points. First, the prevalence of having at least one risk factor for HIV infection was about 10% among Americans aged 50 years or older in both samples. Very small proportions of Americans past the age of 50 years with a known behavioral risk for HIV infection used condoms during sex or had undergone HIV testing. At-risk Americans past the age of 50 years were one sixth as likely to use condoms during sex and one fifth as likely to have been tested for HIV as a comparison group of at-risk individuals in their 20s. CONCLUSIONS: Despite the fact that HIV infection is clearly present among those past the age of 50 years, a small proportion of individuals in this age group take behavioral risks for HIV infection. High-risk individuals older than 50 years are much less likely to have adopted AIDS prevention strategies than are younger individuals who engage in the same behavioral risks.

Is offering post-exposure prevention for sexual exposures to HIV related to sexual risk behavior in gay men?

OBJECTIVE: To examine the impact of the availability of postexposure prevention (PEP) for sexual exposures to HIV on sexual risk behavior among gay men. METHODS: Two cross-sectional samples of 529 gay men in San Francisco (June 1998, January 1999) completed face-to-face street interviews assessing sexual risk behavior and whether they had heard of PEP in general as well as whether they knew that PEP was available in San Francisco. The second sample was collected after a community-wide outreach campaign had been conducted to increase people's knowledge that PEP was available in San Francisco. RESULTS: Of those who had heard of PEP at Time 1, 24% had recently had unprotected anal intercourse, versus 26% of those who had not heard of PEP. At Time 2, 37% of those who had heard of PEP had recently engaged in unprotected anal intercourse versus 26% of those who had not heard of PEP (chi2, 4.06; P = 0.03). At both time points, however, men who actually knew that PEP was available in San Francisco did not report more risk behavior than men who did not know PEP was available in San Francisco. In addition, only a small percentage at both time points self-reported that PEP had the effect of increasing their sexual risk behavior. CONCLUSIONS: There is little evidence that the availability of PEP for sexual exposures may be related to increased sexual risk-taking among gay men in San Francisco. The potential impact of PEP on risk behavior must, however, still be considered as part of the larger context of HIV/AIDS treatment optimism and possibly escalating levels of risk behavior among gay men.

Safer sex among gay men: what is the ultimate goal?

PIP: Sex between homosexual partners in anything other than a mutually monogamous relationship between 2 HIV-negative people involves some risk of virus transmission; a condom must be used during anal intercourse to be considered safe. People, however, have the right to take risks and harm reduction is a long-term, stepwise process. Gay men receive multiple messages which either advocate risk-taking or preach that their sexual needs are bad. Instead of blaming people who occasionally engage in unprotected anal intercourse, people should be trained in skills to reduce their risk; safe sex should be eroticized; and attention should be given to interpersonal or social conditions which may lead to unsafe sex. Society must be challenged to support the messages of risk reduction and the sexual needs of all members of society. The authors further call for the recognition of various risk reduction strategies such as negotiated safety taken by gay men despite the potential problem of this strategy which relies upon the ability of sex partners to reveal their serostatus. The authors also stress that while the goal of eliminating unsafe sex and new HIV infections must be upheld, it is untenable. The understanding that this goal will never be realized, however, does not mean that efforts should not continue to educate and convince people to take better care of themselves. While no infringing upon individual rights, researchers should help prevent all future HIV infections.^ieng

Predictors of repeat HIV testing among gay and bisexual men.

OBJECTIVE: To examine the prevalence and predictors of repeat HIV testing. DESIGN, SETTING AND PARTICIPANTS: Cross-sectional data from two random household-based and bar-based samples of gay/bisexual men in two medium-size cities (Tucson, Arizona and Portland, Oregon) with substantial numbers of AIDS cases, in 1992 (n = 2602). MAIN OUTCOME MEASURE: The prevalence and predictors of repeat testing among men who reported being HIV-tested at least once but not being HIV-positive (n = 1583). RESULTS: In total, 51% of the sample had been tested three or more times, and 15% were tested more than once every 6 months. Men with higher risk were more likely to be repeatedly tested, although oral but not anal risk was a significant predictor of repeat testing in regression analyses. Men who did not know the HIV status of their primary partner were less likely to be repeatedly tested. Men who perceived that social norms favored secondary prevention, specifically adherence to medical recommendations for the treatment of HIV infection, and who communicated more often about testing were more likely to be repeatedly tested. CONCLUSIONS: Policy and clinical recommendations for repeat testing must be based on consideration of the complexity and multi-faceted nature of repeat testing. For some individuals, repeat testing may play a legitimate role in HIV prevention by reinforcing safe behavior and providing confirmation of HIV-negative status. However, for others repeat testing may indicate a need for different or more intensive interventions to encourage safe sex.

Behavioral factors in the spread of HIV infection.

PIP: Evidence that behavioral factors affect the spread of HIV infection, both direct and by implication from high-risk behavior in general, and a model for further research and intervention are reviewed. Measurement of prevalence of high-risk behaviors over time is essential to see whether risk is increasing or decreasing in populations. There is good evidence that AIDS education programs have controlled HIV spread among homosexual and bisexual men in San Francisco, judging by both HIV seroprevalence and that of gonococcal proctitis. These educational interventions virtually saturated the area. Other populations have failed to respond to AIDS education, particularly teens, young adults, poor, non-white, less educated, and people from other areas. 39% of AIDS cases in the U.S. are from minority groups; 50% are Black and 24% are Hispanic. Currently homosexual men living outside a gay community, those without social ties and bisexual men are still showing increasing HIV infections, while homosexual men in open, active communities have decreasing rates. Other risk-behaviors associated with HIV infection include use of drugs, alcohol, tobacco, and having sex outside of "relationships." Conditions correlated with safe behaviors included knowing of one's positive HIV status, possessing skills of safe sex, perceiving one's risk accurately, and having peer support. Peer support is extremely influential, and includes general social support, peer expectations and support for behavior change, and capability to seek help when needed. A detailed AIDS risk reduction model is proposed and described.^ieng

AIDS risk-taking behavior during carnival in São Paulo, Brazil.

OBJECTIVE: The Brazilian Carnival is thought to be a time when the risk of HIV infection is likely to be high. We therefore compared the risk during Carnival to risk in the past month among male samba school participants in São Paulo, Brazil. SUBJECTS AND METHODS: A cross-sectional study was conducted among 380 male samba school drummers randomly sampled during rehearsal for the 1993 Carnival in São Paulo by means of a 20-min interviewer-administered questionnaire. The main outcome variable was condom use with non-steady partners. RESULTS: The sexual behavior of 36.1% of subjects risked HIV infection, but only 9.7% of all subjects were at risk only during Carnival. Subjects with a sexual risk of HIV differed from those without risk in substance use, attitudes towards condoms and expectations about Carnival; those who were at risk only during Carnival did not differ from those who were at risk at other times. About half of the subjects had been given free condoms during Carnival, although few of the men at risk had actually used them. CONCLUSIONS: Though more than a third of the drummers were at risk of HIV infection, only a small per cent were at risk only during Carnival. The level of sexual risk of HIV infection is probably better explained by factors in the men's daily lives, rather than through information on risks taken during Carnival. These results raise questions concerning the efficacy of universal condom distribution during Carnival, since about half of the men were given condoms but few of those at risk actually used them. A targeted distribution of condoms to populations with a high demonstrated risk may be more effective in preventing new HIV infection.

Actual versus perceived HIV status, sexual behaviors and predictors of unprotected sex among young gay and bisexual men who identify as HIV-negative, HIV-positive and untested.

OBJECTIVES: To compare the prevalence and predictors of HIV sexual risk behavior among young gay and bisexual men who perceived themselves to be HIV-negative, HIV-positive, or who were untested. DESIGN: Population-based sample of young gay and bisexual men. METHODS: Using multi-stage probability sampling, 408 gay and bisexual men aged 18-29 years in San Francisco were recruited and interviewed, and blood samples for HIV-testing from 364 participants were obtained. RESULTS: HIV prevalence was 18.7%, although 25% of the men who were HIV-positive did not know it. Thirty-seven per cent reported engaging in unprotected anal intercourse during the past year, including 59% of the men who knew they were HIV-positive, 35% of the men who perceived themselves HIV-negative and 28% of the untested men. Logistic regressions found similar predictors of unprotected intercourse for HIV-negatives and HIV-positives, including sexual impulsivity, substance use, sexual enjoyment and communication problems. CONCLUSIONS: The high rates of unprotected intercourse, particularly among the HIV-positive men, attest to the urgent need for HIV-prevention interventions for young gay and bisexual men. The findings suggest that many of the important variables to target in interventions are similar for both HIV-positive and HIV-negative men.

Truck drivers in Brazil: prevalence of HIV and other sexually transmitted diseases, risk behavior and potential for spread of infection.

OBJECTIVES: To determine the prevalence of HIV and syphilis and related risk behavior in a sample of truck drivers in Santos, Brazil. SUBJECTS AND METHODS: A cross-sectional study was performed of 300 male truck drivers recruited in the port of Santos, Brazil, including a face-to-face interview and blood sampling for HIV and syphilis serology. RESULTS: Of 300 subjects, 4 (1.3%) were positive for HIV, 25 (8.3%) for syphilis by the Venereal Disease Research Laboratory (VDRL) test and 38 (13%) were positive for syphilis by the fluorescent treponemal antibody (absorbed) test (FTA-Abs). Seventy-one per cent had been employed as truck drivers for more than 10 years and 93% lived outside of Santos. Most participants were married (72%); 40% reported having more than one sex partner; 21% reported sex with commercial sex workers; 14% reported sex with girls that they met on the road; 16% had sex with other men's wives; and 3.3% reported sex with men during the past year. The use of rebite, an oral stimulant, was reported by 43% and was associated with being FTA-Abs-positive (P = 0.04). Being HIV-positive was associated with having sex with friends (P = 0.04), partners usually considered 'safe' by truck drivers. Being syphilis-positive (VDRL) was significantly associated with sex with partners also considered as 'safe', namely primary sex partners, steady partners and other men's wives. DISCUSSION: This is the first study to determine HIV and syphilis seroprevalence among truck drivers in South America. Findings confirm that this group has a high potential risk for HIV infection and other sexually transmitted diseases, and thus currently presents an opportunity for prevention.

Gay men report high rates of unprotected anal sex with partners of unknown or discordant HIV status.

OBJECTIVE: To examine patterns and factors that correlate with unprotected anal intercourse (UAI) practices among San Francisco gay men, including UAI with partners of unknown or different HIV antibody status. DESIGN: A longitudinal cohort recruited for the San Francisco Young Men's Health Study in 1992; re-assessed annually. PARTICIPANTS AND METHODS: A sample of 510 unmarried gay men who were 18 to 29 years at baseline were originally recruited as part of a larger population and referral-based sample. Subjects participated in four consecutive waves of data collection. RESULTS: The prevalence of reported unprotected anal intercourse (UAI) increased from 37% to 50% between 1993-1994 and 1996-1997. Almost half of all men who reported UAI in 1996-1997 indicated that it occurred with a partner of unknown or discordant HIV antibody status. This high-risk practice correlated with greater numbers of male sex partners, use of nitrite inhalants, sex in commercial sex environments, perceived difficulty controlling sexual risk-taking, and negative emotional reactions following UAI. CONCLUSIONS: These data on increasing rates of sexual risk-taking further confirm trends in sexual behavior previously suggested by rising rates of rectal gonorrhea in this population. Additional and sustained prevention efforts are urgently needed in light of the very high background rates of HIV infection found among gay men in San Francisco.