18.3.10

A. Estimating the spread of HIV/AIDS among MSM.

In 1994 Erik Goldman, reporting for the Clinical Psychiatry News, wrote that:

"HIV/AIDS is rampant in the homosexual community. Epidemiologists estimate that 30 percent of all 20-year-old homosexually-active men will be HIV positive or dead of AIDS by the time they are 30."

Goldman, “Psychological Factors Generate HIV Resurgence in Young Gay Men,” Clinical Psychiatry News, Oct. 1994.
He was referring to a paper written by a San Francisco clinical pychiatrist who presented it to a meeting comprised of international scientists who were studying HIV and clinicians who were treating people with HIV. That event eventually grew into the Conference on Retroviruses and Opportunistic Infections which has become the most important annual conference on HIV/AIDS. The researchers were among the leading pioneers in the fight against HIV/AIDS.

The researcher had based his projection on data from the Centers for Disease Control's surveillance of the HIV/ADS epidemics across the US.



Early data and early trends.

In 1991, about a decade after the start of the HIV/AIDS epidemic, the American Journal of Epidemiology published the research of Hoover and colleagues.

Based on their analysis of the historical spread of HIV infection in homosexual and bisexual men, the team of researchers projected the growth of the epidemic among that subpopulation.
Future seroconversion among homosexual men was predicted assuming that the "stabilized" 1986-1990 hazards (stratified by age) observed here will be representative of future rates. [...] [A] seronegative 20-year-old [...] has a 20.2% chance of serocon-verting before reaching the age of 25 years (a 4.4% yearly hazard). The annual hazard drops to 2.5% between 25 and 30 years, to about 1.5% between 30 and 45 years, and to 1.0% between 45 and 55 years. The overall probability of seroconversion prior to age 55 years is about 50%, with seroconversion still continuing at and after age 55. Given that this cohort consists of volunteers receiving extensive anti-HIV-1 transmission education, the future seroconversion rates of the general homosexual population may be even higher than those observed here.
In other words, a twenty year old MSM had about 30% chance of being HIV-infected by age 30 and about a 50% chance by age 55.

See: Donald R. Hoover (1991) Estimating the 1978-1990 and future spread of human immunodeficiency virus type 1 in subgroups of homosexual men. American Journal of Epidemiology. 134, 10: 1190-205.



Morris and Dean are Epidemiologists at Columbia University. In 1994 their research on HIV/AIDS appeared in The American Journal of Epidemiology, which is published by Johns Hopkins University School of Hygiene and Public Health.

The current levels of unsafe sex reported in the Longitudinal AIDS Impact Project are shown to be almost exactly on the epidemic threshold. If this behavior were maintained, HIV prevalence would slowty decline in the population, but with just one additional unsafe sexual partner per year HIV would instead become endemic, with seroprevalence of about 65% in the oldest group and about 25% in the youngest.

[...]

Cohort studies continue to document annual seroconversion rates of 1-2 percent per year or higher in some groups [...] this leads to lifetime individual risks of seroconversion of over 50 percent, with the highest annual hazard (4.4 percent per year) occurring before age 25 years.
See: Morris, M., Dean, L. (1994) Effects of Sexual Behavior Change on Long-Term Human Immunodeficiency Virus Prevalence among Homosexual Men. American Journal of Epidemiology. 140, 3: 217 - 32.



Lifelong risk of infection.

Walter Odets is a clinical psychologist in San Francisco. According to his website, Odets has "written extensively about the psychological and social issues of gay men and gay communities, HIV prevention, and the US AIDS epidemic."

In 1994 he wrote about the available evidence on HIV prevalence, incidence, and risk for homosexualy-active men: "Reinventing HIV Prevention for Gay Men".

Some simple epidemiology helps answer these questions: To date, more San Franciscans have died of AIDS - 90% of them gay men - than all the San Franciscans dead from the four wars of the 20th century, combined and quadrupled. Nationally, 30 percent of 20 year-old gay men will be infected with HIV or dead of AIDS by age 30. A majority of gay 20 year-olds will contract HIV during their lifetimes. In San Francisco, our current rates of seroconversion will much more than maintain a 50% prevalence of HIV infection indefinitely.
Clinical psychiatrist, Walt Odets wrote and presented a paper for the Dallas Prevention Summit of the Gay and Lesbian Medical Association: "Young Gay and Bisexual Men".
Younger men thus engaged our hopes that they would not have to suffer with AIDS, and they have been burdened with our expectations that the epidemic could be brought to an end in the gay and bisexual communities. By 1990 it had become clear that very young men would suffer with AIDS. In 1992 the San Francisco Department of Health estimated (by means of a voluntary enlistment study) that 15 percent of 20 to 24 year old gay-identified men were already HIV infected, and young gay and bisexual men seeking services at San Francisco city STD clinics have shown an astonishing 40 percent infection rate. Because the young, in general, seek fewer medical services than older individuals, the level of ELISA testing among young men is unknown. It is thus possible that infection rates are higher than those seen in the self-selected study groups that generate our current figures. The projections we do have suggest that 30 percent of 20 year old gay men will be infected with HIV or dead of AIDS by age 30, and that a majority will become HIV infected during their lifetimes. [Odets' emphasis.]
See: Odets, Ph.D., "Psychosexual and Educational Challenges for the Gay and Bisexual Male Communities," a report to the American Association of Physicians for Human Rights, AIDS Prevention Summit, Dallas, Texas, July 15-17, 1994.

Also: Odets, (1994) AIDS Education and Harm Reduction for Gay Men: Psychological Approaches for the 21st Century. AIDS & Public Policy Journal. 9, 1: 1 - 15.



Resurgence among homosexually-active men.

Odets was cited by Wolitski and collegues in their 2001 research paper, "Are We Headed for a Resurgence of the HIV Epidemic Among Men Who Have Sex With Men?"

It was published in American Journal of Public Health Vol. 91, No. 6, pg 883-888. They are with the National Center for HIV, STD, and TB Prevention, Centers for Disease Control and Prevention.
The HIV prevalence rate for MSM is substantially higher than that for the general population. In a population-based study of MSM in 4 major metropolitan areas conducted from 1996 through 1998, 18% of participants, compared with less than 1% of the overall population, reported that they were HIV-seropositive. Compared with older MSM, younger MSM have lower HIV prevalence rates, but they are at substantial risk for infection over time. According to a 7-city study of MSM aged 15 to 22 years conducted from 1994 through 1998, 7% were infected with HIV. Although none of the 15-year-olds in this study were infected, the rates of infection rose steadily with increasing age, to nearly 10% among 22-year-olds.

[...]

The emerging data presented here suggest that we may be headed toward a resurgence in HIV infections among MSM, unless we act decisively to reevaluate, refocus, and reinvigorate our prevention efforts.

The researchers cited a leading CDC researcher, R. Stall, who wrote in 1994 that the best way to lose the fight against HIV among MSM is to declare victory and leave the field.



In 2005, at the 16th International AIDS Conference, R. Stall, a leading CDC researcher presented his paper, "Emerging HIV Epidemics among Gay and non-Gay Identified MSM".

He calculated the lifelong risk for twenty-year-old homosexually-active men (i.e. men who have sex with men, aka MSM) of becoming infected with HIV. By age 30 -- some ten years hence -- about 25% would be infected; 40% by age 40; and 50% by age 50.

A young black twentysomething is at higher risk: 50% infected by age 40 and about 75% by age 50. He estimated that 1 in 3 would not know that they had been infected.

This is not a test of faith -- of blindly believing -- but epidemiologists do substantiate their work and they expect that as the epidemic continues to unfold their assumptions, analyses, modelling, and projections will be tested by surveillance of HIV/AIDS.


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