Trends in sexual behaviour and risk factors for HIV infection among homosexual men, 1984-7.

To assess whether the spread of infection with HIV can be reduced by changes in behaviour among groups most at risk because of their sexual practices sexual behaviour was monitored among 1050 homosexual men tested for HIV infection at a genitourinary medicine clinic in west London from November 1984 to September 1987. Four cohorts, defined by date of presentation, were studied by questionnaire at their presentation, and blood samples were analysed. Between the first and last cohorts there was a considerable fall in the proportion reporting casual relationships (291/329 (88%) v 107/213 (50%] and high risk activities, such as anoreceptive intercourse with casual partners (262/291 (90%) v 74/106 (70%], with the greatest changes occurring before the government information campaign began in 1986. Nevertheless, half of the men in the last cohort studied reported having casual partners. Multiple logistic regression showed that behavioural risk factors for HIV infection most closely resembled those for hepatitis B and that previous sexually transmitted diseases (syphilis, hepatitis B, and anogenital herpes) were themselves independent risk factors. A history of syphilis ranked above anoreceptive intercourse as the strongest predictor of HIV infection. Actively bisexual men showed a much lower prevalence of HIV infection (3/57, 5%) than exclusively homosexual men (113/375, 30%). Sexual behaviour among homosexual men changed during the period studied, and the incidence of HIV infection fell, although more education programmes directed at homosexual men are needed to re-emphasise the dangers of infection.     

Changes in sexual behaviour and the fall in incidence of HIV infection among homosexual men.

To investigate the epidemiology and normal course of infection with HIV the prevalence and incidence of the infection were studied among two cohorts of homosexual men in Amsterdam in 1980-7. The cumulative incidence of infection increased from a weighted 2.2% in 1980 to 39.0% in 1987. The estimated yearly incidence of HIV was 3.0% in 1981, rose to 8.8% in 1984, and fell gradually to 0% in 1987. During the study the sexual behaviour of the cohorts was examined. The number of men with whom anopenetrative intercourse was practised fell from a mean of 10.6 to 1.4 for those positive for HIV antibody, whereas the number with whom anoreceptive intercourse was practised fell from a mean of 3.7 to 0.5 for those negative for the antibody. In addition, there was a reduction in the number of cases of hepatitis B and syphilis among men in general. The decline in infection with HIV was assumed to be linked to changes in sexual behaviour. Such changes practised early in the course of the epidemic probably had a strong effect on the number of cases of AIDS among homosexual men in Amsterdam.     

Attitudes and sexual behaviours of unmarried people with HIV/AIDS living in the Niger Delta region of Nigeria

Background Increasing morbidity and mortality associated with HIV/AIDS may be attributable to the lifestyle of individuals. Appropriate sexual behaviour and lifestyle modification may be helpful strategies for prevention and control of HIV/AIDS in many countries.Aim The study was designed to assess the impact of attitudes and sexual behaviour on control of HIV/AIDS among unmarried people living with HIV/AIDS in Uyo, a community in the Niger Delta region of Nigeria.Method A total of 365 unmarried individuals living with HIV/AIDS were assessed at the HIV clinic of the University of Uyo Teaching Hospital. Attitudes and sexual behaviour were evaluated using the Attitude and Sexual Behaviour Questionnaire adapted from previous studies.Results Of the 365 individuals living with HIV/AIDS, 142 (38.9%) were male and 223 (61.1%) were female. The majority of the subjects were below 50 years of age. The mean ages (± SD) of men and women were 36.8 ± 3.9 and 29.2 ± 1.7 years, respectively. Sexual attitudes and behaviours were variable. There was no change in the partner''s reaction to sex for 28.9% of men and 27.8% of women, abstinence in 7.7% of men and 8.1% of women, and breakdown of the relationship with the partner for 4.9% of men and 7.2% of women. More women than men agreed to undergo testing after their partners had tested positive for HIV. Sexual activity was higher in women than men, with 4.9% of men and 10.3% of women reporting daily sexual intercourse, 16.2% of men and 15.7% of women reporting weekly intercourse, and occasional sexual intercourse being reported by 44.4% of both men and women. After testing positive, 58.4% of male partners and 56.9% of female partners were persuaded to use condoms during sexual intercourse.Conclusion This study has demonstrated unhealthy attitudes and sexual behaviour among individuals living with HIV/AIDS in the Niger Delta region of Nigeria. This can potentially limit efforts and investment in controlling HIV/AIDS in this region. Therefore there is a need to initiate concrete policies and programmes that would encourage people living with HIV/AIDS in the Niger Delta region to adopt a healthy lifestyle.     

The Vancouver Lymphadenopathy-AIDS Study: 5. Antecedent behavioural,clinical and laboratory findings in patients with AIDS and HIV-seropositive controls.

In a group of homosexual men in Vancouver studied prospectively since November 1982, 26 cases of acquired immune deficiency syndrome (AIDS) have arisen. To identify behavioural, clinical and laboratory findings that might predict the development of AIDS in people with antibody to human immunodeficiency virus (HIV), we compared data for 25 patients with AIDS with corresponding data for 80 controls serologically positive for HIV selected from the cohort. The clinical and laboratory data for the patients with AIDS preceded the diagnosis of the syndrome by a mean of 17.5 months. The controls had been both seropositive and AIDS-free for a mean of 16.7 months after acquisition of their data. We detected significant differences between the patients with AIDS and the controls in IgG and IgA levels, absolute number of helper T cells and ratio of helper to suppressor T cells but not in lifetime number of male sexual partners, frequency of receptive anal intercourse or receptive fisting, illicit drug use or history of infectious disease. We also detected an increased risk of AIDS among those who had an elevated number of sexual contacts in AIDS-endemic areas in the 5 years before enrollment. A history of increased early sexual contact in AIDS-endemic areas is likely to be associated with early infection and with an increased risk of AIDS among men with HIV infection of unknown duration. Thus, although our analysis had limited statistical power, we conclude that most lifestyle variables appear to act as exposure factors in HIV infection but not as cofactors in the development of AIDS.     

Sexual transmission of hepatitis C virus and its relation with hepatitis B virus and HIV.

OBJECTIVE--To determine the extent of transmission of hepatitis C virus in sexual partners of intravenous drug misusers and to examine the relation between the prevalences of HIV, hepatitis B virus, and hepatitis C virus infections in homosexual men and intravenous drug misusers and their sexual partners. DESIGN--Serum samples collected between 1984 and 1988 were tested for hepatitis B virus markers and antibodies against hepatitis C virus by enzyme linked immunosorbent assay (ELISA) and for HIV antibody by enzyme immune analysis and western blotting. SETTING--Large referral university hospital with an external AIDS clinic in the metropolitan area of Barcelona, Spain. SUBJECTS--243 Intravenous drug misusers, 143 of their regular heterosexual partners, and 105 homosexual men. MAIN OUTCOME MEASURES--Prevalences of hepatitis C virus, hepatitis B virus, and HIV infections. RESULTS--In all, 178 of the 243 (73%) intravenous drug misusers, 16 out of 143 (11%) of their partners, and 17 of the 105 (16%) homosexual men had antibodies against hepatitis C virus. The presence of hepatitis C virus infection was unrelated to sex, age, the presence of HIV or hepatitis B virus infections, or the Centers for Disease Control stage of HIV. In sexual partners of intravenous drug misusers there were strong correlations between the presence of hepatitis C virus infection and that of HIV (p = 0.001) and hepatitis B virus (p = 0.013) infections. CONCLUSIONS--Intravenous drug misusers have a high risk of acquiring hepatitis C virus, hepatitis B virus, and HIV infections, but the presence of hepatitis C virus infection seems to be unrelated to the presence of the other two viruses. Homosexual men have a high prevalence of HIV and hepatitis B virus infections with a low prevalence of hepatitis C virus infection, the presence of which is not related to that of the other two infections. Conversely, heterosexual partners of intravenous drug misusers have low prevalences of the three virus infections, but the presence of hepatitis C virus infection correlates significantly with the presence of HIV and hepatitis B infections. The rate of sexual transmission of hepatitis C virus seems to be low, even in partners of people known to be seropositive for this virus.     

Risk factors for infection with human immmunodeficiency virus among European expatriates in Africa.

The pattern of cases of AIDS in Belgium suggests that Europeans infected with human immunodeficiency virus (HIV) acquired the infection in Africa. The prevalence of infection was assessed in Belgian advisers and European expatriates and risk factors for infection defined in a case-control study of expatriate men. Fifteen (1.1%) of 1401 Belgian advisers working in Africa and 41 (0.9%) of 4564 European expatriates living in Africa, were positive for antibody to HIV in a voluntary screening programme in Belgium. Among subjects with antibody to HIV the ratio of men to women was 3:1. These subjects did not have a history of intravenous drug abuse or blood transfusion and only one was homosexual. In a case-control study of 33 expatriate men who had antibody to HIV and 119 controls the men with antibody reported significantly more female sexual partners, who were more commonly local; and significantly more sexual contact with prostitutes in Africa. They had a significantly higher prevalence of history of sexually transmitted disease and had received significantly more injections by unqualified staff in Africa during the previous five years. No specific sexual practices were associated with having antibody to HIV. After multivariate analysis sexual contact with local women (adjusted odds ratio 14.7; 95% confidence interval 2.81 to 76.9), sexual contact with prostitutes (adjusted odds ratio 10.8 (1.6 to 71.9), and injections by unqualified staff (adjusted odds ratio 13.5 (3.7 to 49.8) remained independent risk factors for infection. European expatriates in Africa were at increased risk from infection with HIV and were a means of introducing HIV into the heterosexual population in Europe. Transmission from women to men by vaginal intercourse seemed to be the most probable route of infection.     

HIV infection in patients attending clinics for sexually transmitted diseases in England and Wales. Collaborative Study by Consultants in Genitourinary Medicine and the Public Health Laboratory Service.

A national study of the prevalence of HIV antibody designed to monitor sexual spread of HIV infection in England and Wales was made of homosexual and heterosexual patients attending sexually transmitted disease clinics in four districts in 1985, seven in 1986, and 14 in 1987. Patients were invited to participate and were counselled. Among homosexual men in two clinics in south east England, HIV antibody was found in 92 (12.9%) of 711 in 1985, 65 (15.2%) of 428 in 1986, and 81 (14.6%) of 556 in 1987: corresponding findings in the other regions were 16 (5.0%) of 321, 41 (6.3%) of 654, and 21 (3.1%) of 678. The prevalence of HIV antibody was higher in homosexual than bisexual men, in patients aged 25 years or more, or with one or more specified minor complaints. Among heterosexual patients in the south east in 1986, HIV antibody was found in seven (3.0%) of 230 men and three (1.3%) of 233 women and in 1987 in 10 (1.0%) of 962 men and seven (0.7%) of 949 women. In other areas corresponding findings in 1986 were two (0.2%) of 950 men and three (0.4%) of 752 women and in 1987 were three (0.06%) of 5312 men and one (0.02%) of 4778 women. All but one of the heterosexual patients with the antibody were intravenous drug abusers or had had sexual contacts in or were from an area abroad with a high prevalence of AIDS. Failure to identify a heterosexual patient with HIV antibody not in a risk group (other than that of being an attender at the clinic) or who did not have a sexual partner in a risk group suggests that their prevalence in the patient population of the clinics in the south east is less than one in 700 and in the other regions less than one in 3000. Refusals to participate increased during the study but comparisons of patients who agreed and refused in terms of age, the presence of symptoms suggesting AIDS, travel abroad, and number of sexual partners a month showed little evidence of selective bias.     

Is risk of Kaposi's sarcoma in AIDS patients in Britain increased if sexual partners came from United States or Africa?

OBJECTIVE--To determine whether the risk of Kaposi''s sarcoma in patients with AIDS is increased by sexual contact with groups from abroad with a high incidence of Kaposi''s sarcoma. DESIGN--Analysis of risk of Kaposi''s sarcoma in patients with AIDS, according to country of origin of their sexual partners. SETTING--United Kingdom. PATIENTS--2830 patients with AIDS reported to the Communicable Disease Surveillance Centre and the Communicable Disease (Scotland) Unit up to March 1990, of whom 566 had Kaposi''s sarcoma. MAIN OUTCOME MEASURES--Percentage of patients with AIDS who had Kaposi''s sarcoma. RESULTS--537 of 2291 homosexual or bisexual men (23%) with AIDS had Kaposi''s sarcoma; 10% (14/135) of the men and women who acquired HIV by heterosexual contact had Kaposi''s sarcoma. None of the 316 subjects who acquired HIV through non-sexual routes had Kaposi''s sarcoma. Kaposi''s sarcoma was more common among homosexual men whose likely source of infection included the United States (171/551, 31%) or Africa (9/34, 26%) than among those infected in the United Kingdom (119/625, 19%) (p less than 0.05). CONCLUSION--The data suggest that Kaposi''s sarcoma is caused by a sexually transmissible agent which was introduced into the British homosexual population mainly from the United States [corrected].     

The transmission dynamics of the human immunodeficiency virus type 1 in the male homosexual community in the United Kingdom: the influence of changes in sexual behaviour

This paper examines the transmission dynamics of human immune deficiency virus type 1 (HIV-1) in the male homosexual population in the U.K. via numerical studies employing a mathematical model representing the principal epidemiological process. The model is based on an assumption of proportionate mixing between different sexual-activity classes (defined by the rate of sexual partner change per unit of time) and incorporates heterogeneity in sexual activity, distributed infection and incubation periods and the recruitment of susceptibles to the sexually active population. The sensitivity of model predictions to various assumptions and parameter assignments is examined. Numerical studies of model behaviour focus on the influence of changes in the magnitudes of the transmission parameters, associated with three periods of infectiousness during the incubation period of acquired immune deficiency syndrome (AIDS), on the magnitude and duration of the epidemic and on the level of the endemic equilibrium state. Predicted temporal trends in the incidence of AIDS are shown to be particularly sensitive to changes in the intensities and durations of the stages of infectiousness. Most of the paper addresses the influence of changes in sexual behaviour on the magnitude and duration of the epidemic. Numerical simulations show that the manner in which behavioural changes occur and who is influenced by such changes (i.e. infecteds or susceptibles, the sexually active population or new recruits to this population) have a major impact on the future timecourse of the epidemic. The greatest reduction in the incidence of AIDS over the coming decades is induced by changes in the rate of sexual-partner change among the sexually active population, particularly those currently infected. The time periods at which changes in behaviour occur, in relation to the starting point of the epidemic (assumed to be 1979), are also of particular significance to the future pattern of the incidence of disease and infection. Changes in behaviour early on in the timecourse of the epidemic have a much greater impact than equivalent changes at latter time points. On the basis of limited data on the pattern of change in sexual behaviour among the male homosexual community in the U.K., numerical studies of model behaviour tentatively suggest that the epidemic is at, or near to, a period of peak incidence of the disease AIDS. Analyses suggest that, following the peak in incidence, there will be a period of slow decline over many decades provided recent changes in behaviour are maintained in the coming years.(ABSTRACT TRUNCATED AT 400 WORDS)     

Changes in Seroadaptive Practices from before to after Diagnosis of Recent HIV Infection among Men Who Have Sex with Men

Objective

We assessed changes in sexual behavior among men who have sex with men (MSM), before and for several years after HIV diagnosis, accounting for adoption of a variety of seroadaptive practices.

Methods

We collected self-reported sexual behavior data every 3 months from HIV-positive MSM at various stages of HIV infection. To establish population level trends in sexual behavior, we used negative binomial regression to model the relationship between time since diagnosis and several sexual behavior variables: numbers of (a) total partners, (b) potentially discordant partners (PDP; i.e., HIV-negative or unknown-status partners), (c) PDPs with whom unprotected anal intercourse (UAI) occurred, and (d) PDPs with whom unprotected insertive anal intercourse (uIAI) occurred.

Results

A total of 237 HIV-positive MSM contributed 502 interviews. UAI with PDPs occurred with a mean of 4.2 partners in the 3 months before diagnosis. This declined to 0.9 partners/3 months at 12 months after diagnosis, and subsequently rose to 1.7 partners/3 months at 48 months, before falling again to 1.0 partners/3 months at 60 months. The number of PDPs with whom uIAI occurred dropped from 2.4 in the pre-diagnosis period to 0.3 partners/3 months (an 87.5% reduction) by 12 months after enrollment, and continued to decline over time.

Conclusion

Within months after being diagnosed with HIV, MSM adopted seroadaptive practices, especially seropositioning, where the HIV-positive partner was not in the insertive position during UAI, resulting in a sustained decline in the sexual activity associated with the highest risk of HIV transmission.     

Sexually transmitted diseases and HIV-1 infection among homosexual men in England and Wales.

OBJECTIVE--To examine surveillance data for evidence of changing sexual behaviour and continuing transmission of HIV-1 among men who have sex with men. DESIGN--Analytic study of surveillance data on sexually transmitted diseases. SETTING--England and Wales. MAIN OUTCOME MEASURES--Number of cases of rectal gonorrhoea and newly diagnosed HIV infection in homosexual men. RESULTS--New cases of gonorrhoea among men attending genitourinary medicine clinics increased by 7.7% in 1989 and by 4.2% in 1990. Reports of rectal isolates of Neisseria gonorrhoeae also rose and the male to female ratio for patients with rectal gonorrhoea changed from 0.3:1 during 1988-9 to 2.6:1 in 1990-1. Although the overall number of cases of acute hepatitis B fell during 1988-91, 81 and 82 homosexual men were infected in 1990 and 1991 respectively compared with 50 and 42 in 1988 and 1989. 1526 men had HIV-1 infection diagnosed in 1991, the largest number since 1987. Twenty eight of the 97 (29%) men who seroconverted between January 1989 and December 1991 were aged less than 25. The proportion of men aged 15-19 who were found to be infected with HIV-1 at their first test increased from an average of 2.4% up to 1990 to 4.7% in the first nine months of 1991. The prevalence of HIV infection in men under 25 attending genitourinary medicine clinics in London was 17% compared with 7.8% outside London. CONCLUSION--Unsafe sexual behaviour and HIV transmissions have increased among homosexual men after a period of decline. Recent HIV transmissions may disproportionately affect younger men.     

Epidemiological and statistical aspects of the AIDS epidemic: introduction

In 1988, a government working party studied estimates of incidence and prevalence of numbers of acquired immunodeficiency syndrome (AIDS) cases. They investigated a series of epidemiological, statistical and mathematical problems associated with predicting trends in incidences of AIDS. This paper introduces a series of papers that give a fuller and more technical exposition of the appendixes of that working party report. The papers provide a brief background to the current state of knowledge on the epidemiology of the infection and the disease; a deterministic model for human immunodeficiency virus (HIV) transmission in the male homosexual community in England and Wales is introduced. Back-projection methods are studied in two papers, following the distribution of the incubation period of the disease. The concept of minimum size of the epidemic is introduced. Mathematical functions to describe the spread of HIV infection are refined by using past trends in the incidence of AIDS to estimate values for some parameters. Survival times for AIDS patients from the point of diagnosis are considered and evidence for changes in male homosexual sexual behaviour is studied; lag-time from the point of diagnosis to the report of the case is also examined. There is a comparative analysis of the AIDS epidemic in various European countries. The incubation period of HIV in patients with haemophilia A and B infections and the problems associated with making predictions for different at-risk groups or small subgroups based on geographical area are discussed. Reasons for fluctuation between the number of reported cases from month to month are provided.     

The transmission dynamics of human immunodeficiency virus (HIV)

The paper first reviews data on HIV infections and AIDS disease among homosexual men, heterosexuals, intravenous (IV) drug abusers and children born to infected mothers, in both developed and developing countries. We survey such information as is currently available about the distribution of incubation times that elapse between HIV infection and the appearance of AIDS, about the fraction of those infected with HIV who eventually go on to develop AIDS, about time-dependent patterns of infectiousness and about distributions of rates of acquiring new sexual or needle-sharing partners. With this information, models for the transmission dynamics of HIV are developed, beginning with deliberately oversimplified models and progressing--on the basis of the understanding thus gained--to more complex ones. Where possible, estimates of the model's parameters are derived from the epidemiological data, and predictions are compared with observed trends. We also combine these epidemiological models with demographic considerations to assess the effects that heterosexually-transmitted HIV/AIDS may eventually have on rates of population growth, on age profiles and on associated economic and social indicators, in African and other countries. The degree to which sexual or other habits must change to bring the 'basic reproductive rate', R0, of HIV infections below unity is discussed. We conclude by outlining some research needs, both in the refinement and development of models and in the collection of epidemiological data.     

Perception of risk of HIV/AIDS and sexual behaviour in Kenya

The association between perception of risk of HIV infection and sexual behaviour remains poorly understood, although perception of risk is considered to be the first stage towards behavioural change from risk-taking to safer behaviour. Using data from the 1998 Kenya Demographic and Health Survey, logistic regression models were fitted to examine the direction and the strength of the association between perceived risk of HIV/AIDS and risky sexual behaviour in the last 12 months before the survey. The findings indicate a strong positive association between perceived risk of HIV/AIDS and risky sexual behaviour for both women and men. Controlling for sociodemographic, sexual exposure and knowledge factors such as age, marital status, education, work status, residence, ethnicity, source of AIDS information, specific knowledge of AIDS, and condom use to avoid AIDS did not change the direction of the association, but altered its strength slightly. Young and unmarried women and men were more likely than older and married ones to report risky sexual behaviour. Ethnicity was significantly associated with risky sexual behaviour, suggesting a need to identify the contextual and social factors that influence behaviour among Kenyan people.     

Five myths about AIDS that have misdirected research and treatment

A number of widely repeated and factually incorrect myths have pervaded the AIDS research literature, misdirecting research and treatment. Five of the most outstanding are: 1) that all risk groups develop AIDS at the same rate following HIV infection; 2) that there are no true seroreversions following HIV infection; 3) that antibody is protective against HIV infection; 4) that the only way to treat AIDS effectively is through retroviral therapies; and 5) that since HIV is so highly correlated with AIDS incidence, it must be the sole necessary and sufficient cause of AIDS. A huge body of research, reviewed in this paper, demonstrates the falsity of these myths. 1) The average number of years between HIV infection and AIDS is greater than 20 years for mild hemophiliacs, 14 years for transfussion severe hemophiliacs, 10 years for old severe hemophiliacs, 10 years for homosexual men, 6 years for transfusion patients of all ages, 2 years for transplant patients, and 6 months for perinatally infected infants. These differences can only be explained in terms of risk-group associated cofactors. 2) Seroreversions are common. Between 10 and 20 percent of HIV-seronegative people in high risk groups have T-cell immunity to HIV, and may have had one or more verified positive HIV antibody tests in the past. 3) Antibody, far from being protective against HIV, appears to be highly diagnostic of loss of immune regulation of HIV, and some evidence of antibody-enhancement of infection exists. 4) Non-retroviral treatments of HIV infection, including safer sex practices, elimination of drug use, high nutrient diets, and limited reexposure to HIV and its cofactors have proven to be effective means of preventing or delaying onset of AIDS. 5) Many immunosuppressive factors, including drug use, multiple concurrent infections, and exposure to alloantigens, are as highly correlated with AIDS risk groups as HIV. These data are more consistent with AIDS being a multifactorial or synergistic disease than a monofactorial one.     

Incidence of HIV-1 infection in a rural region of Uganda.

OBJECTIVE--To determine the incidence of infection with HIV-1 and the risk factors associated with seroconversion in three geographical strata of a rural Ugandan district. DESIGN--Serological, sociodemographic, and behavioural surveys of everyone aged 13 or more in 21 randomly selected communities at baseline and one year later. SETTING--Rural population of Rakai district, southwestern Uganda, residing in main road trading centres, secondary trading villages, and agricultural villages. SUBJECTS--In 1989, 1292 adults provided a blood sample and interview data; one year later, 778 survivors (77%) who had been seronegative at baseline provided follow up data. MAIN OUTCOME MEASURES--Incidence of HIV infection in relation to individual characteristics and risk factors, including place of residence. RESULTS--Incidence of HIV infection in all adults was 2.1/100 person years of observation (SE 0.5 (95% confidence interval 1.1 to 3.1)); in people aged 15-39 the incidence was 3.2/100 person years. Incidence was highest in men and women aged 20-24 (9.2/100 person years (3.9) and 6.8/100 person years (2.9) respectively). Risk factors significantly associated with seroconversion were age 24 and under and two or more sexual partners. Between the surveys the proportion of all respondents reporting high risk behaviour (two or more partners) significantly increased from 8.9% to 12.3%. CONCLUSIONS--Despite preventive programmes and substantial knowledge about AIDS the incidence of HIV infection remains high in this rural population. Prevention aimed at vulnerable rural communities is urgently needed to contain the HIV epidemic.     

Sexual behaviour of young and middle aged men in England and Wales.

Establishing patterns of sexual behaviour is essential in predicting the future spread of HIV. The sexual behaviour patterns of a randomly selected sample of 480 white men aged 15 to 49 were obtained by interview and analysed in relation to age, social class, and area of residence. Over half of the men had first had intercourse before the age of 18 and over three quarters had done so before the age of 20. Age at first intercourse tended to be lower in more recent birth cohorts and in social classes III, IV, and V. Men in earlier birth cohorts tended to have had fewer heterosexual partners, both regular and casual, than those born more recently, but there were no social class or regional differences in the number of partners. Eight of the 480 men (1.7%, 95% confidence interval 1.1 to 2.3%) stated that they had had homosexual intercourse, four of whom had had one casual homosexual partner. Only one man had had more than 25 homosexual partners. The number of men having had homosexual intercourse was lower than is widely thought. When possible, data were checked with national data or other surveys and thought to be accurate. The difficulties in collecting data of this nature are discussed.     

Determinants of human immunodeficiency virus (HIV) prevalence in homosexual and bisexual men screened for admission to a cohort study of HIV negatives in Belo Horizonte,Brazil: Project Horizonte

Project Horizonte, an open cohort of homosexual and bisexual human immunodeficiency virus (HIV-1) negative men, is a component of the AIDS Vaccine Program, in Belo Horizonte, Minas Gerais, Brazil. The objective of this study was to compare volunteers testing HIV positive at cohort entry with a sample of those who tested HIV negative in order to identify risk factors for prevalent HIV infection, in a population being screened for enrollment at Project Horizonte. A nested case-control study was conducted. HIV positive volunteers at entry (cases) were matched by age and admission date to three HIV negative controls each. Selected variables used for the current analysis included demographic factors, sexual behavior and other risk factors for HIV infection. During the study period (1994-2001), among the 621 volunteers screened, 61 tested positive for HIV. Cases were matched to 183 HIV negative control subjects. After adjustments, the main risk factors associated with HIV infection were unprotected sex with an occasional partners, OR = 3.7 (CI 95% 1.3-10.6), receptive anal intercourse with an occasional partner, OR = 2.8 (95% CI 0.9-8.9) and belonging to the negro racial group, OR = 3.4 (CI 95% 1.1-11.9). These variables were associated with an increase in the risk of HIV infection among men who have sex with men at the screening for admission to an open HIV negative cohort.     

Kunyenga, "real sex," and survival: assessing the risk of HIV infection among urban street boys in Tanzania

This article examines possible avenues of HIV infection among urban street boys in Tanzania. In doing so, it questions the ways that AIDS researchers have defined and approached the phenomenon of "survival sex" in East and Central Africa. The article specifically examines the boys' sexual networks, sexual practices, and attitudes regarding their own sexual behavior, including their perceived risk of HIV/AIDS infection. Seventy-five street boys aged eight to 20 from the city of Mwanza were interviewed. Results suggest that almost all street boys are involved in a sexual network in which homosexual and heterosexual behavior occurs. Homosexual practices are rooted in a complex set of behaviors and ideologies known as kunyenga, which is a situated aspect of life on the streets and helps maintain the boys' strong dependence on one another. A key aspect of the boys' sexual careers involves a decrease in kunyenga activity as they approach the age of 18 and an increase in heterosexual encounters after the age of 11. There appears to be a critical period between these ages in which heterosexual and kunyenga activities overlap. It is suggested that boys between these ages represent a potential bridge for HIV/AIDS infection between the general population and the relatively enclosed sexual network of street boys.     

Sexual Behaviours of Homosexual and Bisexual Men in France: A Generational Approach

Objective

In high-income countries, the social and epidemiological contexts surrounding homosexuality and AIDS have changed profoundly in recent decades. This work sought to examine key indicators of the long-term sexual trajectories of successive generations of men who have sex with men (MSM) in France.

Methods

We performed a longitudinal analysis of the French Gay Press surveys, which were self-administered socio-behavioural questionnaires, repeated from 1985 to 2011 in the gay press, and on the internet in 2004 and 2011. An age-cohort analysis using graphical representations and multivariate logistic regressions was conducted among participants aged 18-59 (N=38 821).

Results

First sexual intercourse occurred more often with a male partner in younger generations than in older ones: 76.0% in MSM who turned 18 in 1956-1959, 75.6% in 1980-1983, 83.7% in 2008-2011, p_overall=0.0002). Every generation showed the same pattern of sexual trajectory between 1985 and 2011: globally, the frequency of masturbation increased from the 1985 survey to the early 1990s and then decreased from the late 1990s to the end of the study period. Inversely, the frequency of oral and anal sex decreased in the mid-1980s and increased from 1990 to 2011. The frequency of both oral sex and anal intercourse is currently quite high, regardless of generation (>95% and around 80%, respectively). Compared to their predecessors, recent generations of young MSM reported more frequent oral and anal sex, but fewer male partners in the previous 12 months.

Discussion

While the increased frequency of first intercourse with a man over successive generations since the 1970s may be related to reduced social pressure for heterosexuality, there is evidence that sexual norms among MSM are widespread, with practices spreading across age groups and generations. Although AIDS profoundly affected sexual practices in the 1980s, further AIDS-related events (discovery of HIV antiretroviral drugs and their use in prevention) do not appear to have accentuated ongoing trends in sexual practices.