From the UCLA Program in Global Health, UCLA David Geffen School of Medicine, Los Angeles, California, USA.
Correspondence to Dr Thomas Coates, PhD, Director, UCLA Program in Global Health, UCLA David Geffen School of Medicine, 10940 Wilshire Blvd, Suite 1220, Los Angeles, CA 90024, USA. E-mail: firstname.lastname@example.org
The article by Williamson et al.  presents a perfect storm for the spread of HIV. A total of 41.2% of the HIV-infected men had undiagnosed HIV infection; 81.1% had previously been tested and 92.2% of these were negative. Undiagnosed men were over twice as likely to engage in unprotected anal intercourse with two or more partners.
The first few examples of behavioral changes resulting in changes in HIV incidence and prevalence came from within the gay communities of the United States, Europe, and Australia. HIV incidence declined from the double digits to less than 1% per year in San Francisco between 1982 and 1986 [2,3], and this decline was preceded by important reductions in unprotected anal intercourse [4,5]. Similar reductions in HIV incidence and risk behavior occurred in gay communities in other cities in the US (e.g., Chicago, New York, Pittsburgh, and Baltimore), The Netherlands, The United Kingdom, and Australia.
It now appears that all of that has changed. The number of HIV infections among men who have sex with men is now increasing in many developed high-income countries  including the US, Europe, and Australia [7,8]. This correlates with the observed increases in unprotected intercourse, especially with individuals who are HIV-infected or whose serostatus is unknown.
Serosorting, reserving the highest risk activities for persons of similar serostatus, appears not to work. This could be a beneficial strategy if one knows or is able to report one's serostatus accurately. We found previously that the risk of acquiring HIV was equally high when one is engaged in unprotected receptive anal intercourse with declared negatives and serostatus unknown partners as with declared seropositive partners . Williamson et al.  provide one explanation of why this is the case. Undiagnosed men, compared with HIV-uninfected men, were twice as likely to engage in high-risk behavior.
Williamson et al.  also showed that HIV-infected men who were aware of their serostatus reported the highest risk behaviors, including unprotected anal intercourse with partners of unknown or discordant serostatus. They were also more likely to have more sexual partners and more unprotected anal intercourse partners than seronegative or HIV undiagnosed men.
What is to be done? The authors suggest a number of strategies – and all of their suggestions are important – but they do not necessarily hit the heart of the matter. The early response to the HIV epidemic in the gay community was certainly one of fear. People saw their friends succumbing to the disease, and naturally wanted to avoid that fate themselves. Reductions in the highest risk behaviors, increases in condom use, and fewer sexual partners became the norm, and HIV incidence and prevalence declined as a result.
HIV is not as immediately lethal as it once was, and attempts at fear messaging fall on deaf ears or, even worse, are ignored because they do not fit the reality of the HIV epidemic today. We know that counseling, even of an intensive nature, is not sufficient over the long term to prevent HIV transmission . We also know that certain factors related to high-risk sex, such as stimulant use, are highly resistant to change [11–14].
The truth is that individuals place other priorities over avoidance of HIV, and thus will engage in the highest risk activities – unprotected receptive anal intercourse – with individuals whose serostatus is declared negative, or unknown, or even positive. This is the toughest conundrum of health promotion, and HIV now faces the same difficulty as is faced when trying to prevent other health problems, especially the chronic ones caused by lifestyle. Motivating individuals to forego an immediate benefit for a long-term one is never easy. We need the best minds to engage on this task to see if other more clever strategies can be developed. It is also possible that technologies under test, such as preexposure prophylaxis and microbicides, might protect people from infection even when engaging in the highest risk activities . HIV infection might be prevented if these strategies prove efficacious in clinical trials, and can be deployed to those at highest risk for HIV.
But the gay community, early in the epidemic, wanted to avoid inflicting HIV on others. Dealing with the HIV epidemic was necessary, not only for the survival of individuals, but also for the survival of the community. Now it seems that it is each man for himself. Missing from all discussions of HIV transmission and prevention is any sense of concern for the collective or responsibility for the health of the community. We need leadership from within the community itself to encourage concern for the collective so that the community norm, once again, can be one of balancing what the individual might want against the desire to take care of others.
Major gains have been made since the turn of the century in diagnosing and treating HIV infection in developing countries, especially those with the highest burden of disease. Those in the forefront of this effort are still working hard to ramp up services, provide voluntary counseling and testing for HIV, and provide care for those infected and in need of it. It would behoove us to prepare, simultaneously, for what is to come down the road. There is no reason to doubt that the findings of Williamson et al.  will be replicated as diagnosis and treatment matures in developing countries. Perhaps we can begin to prepare now, and maybe avoid the same outcomes there.
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