US researchers have reported that gay men in the US are more likely to get HIV from their main sexual partner than casual sex. What are the implications for HIV prevention messages there? askGus Cairns, and Michael Carter.
In a country where sex between men and women is the main route of transmission to HIV, the highest increase in a woman's HIV risk occurs when she is married. This is one reason why sexual abstinence campaigns do not work: most women with HIVThey wereAbstainers - until their wedding night.
But in countries where most of the transmission is between homosexual men, there was an underlying assumption that everything is fueled by casual sex. This idea was recently tested by a North American study,,Which estimated that two-thirds of gay men get HIV from their regular partner.
- The study did not analyze the actual episodes of HIV transmission in a group of men. Instead, it analyzed data from the National HIV Behavioral Surveillance System (NHBS) in a study of 3652 HIV-negative and positive homosexual men in five cities Between 2003 and 2005.
- Taking a look at the number of male sexual partners with whom they had at least one sexual contact in a year, noting the main partner and / or casual partners;
- The perception of the HIV serostatus of its partners
- The proportion of unprotected anal sex the last time they had sex;
- Whether they were insertive or receptive.
The NHBS study also took anonymous saliva samples for HIV screening of half the men who were studied. He could, therefore, know whether the perception of gay men about their own serology was accurate.
Because the study only collected data on the latest sexual episode, one thing that was missing was knowing how many times men actually had sex with senior and casual partners during the year. They therefore added in data from an earlier study, the Vaccine Preparedness Study, which recruited 3617 gay men in six US cities between 1995 and 1997.
Encouraging couples to test, or retest, HIV the moment they engage with someone emotionally has several benefits.
With all these data, the researchers were able to find out what proportion of HIV infections should have come from regular partners, and the response was about two-thirds - 68%. Even when they tested their study model for inaccuracy, putting the lowest possible estimated rate of unsafe sex with key partners and as much as possible for casual partners, even more than half of all HIV infections had come from major partners.
There were several reasons for this. Firstly, the men had more real occasions of sex with the main partner. In gross numbers there were about 195,000 occasions of sex between the main partners and about 173,000 episodes of casual sex. So gay men do not behave exactly like Indian brides, but they still have more sex (about 80 times a year on average) with their regular partner than with casual partners when there are casual ones. Translator's Note: It was not a great quest, as it may seem. Most of the time studies are easily localizable after two or three searches with the crossing of two four variables. Any search after that turns out to be useless and this was the case. We will still seek ...
Second, they were more likely to have anal sex with major partners, not more casual ones, and were more likely to have the receptive role as well. Forty percent had been receptive the last time they had sex with their boyfriend (although they were also active) but only a quarter of them the last time they had casual sex.
Third, they were considerably less likely to use condoms with major partners than couples. Men used condoms for anal sex (in both roles) 72% of the time with casual partners, but only 43% of the time with major partners. Measuring all this leads to much more cases of unsafe sex with senior partners each year than with casual partners.
HIV prevalence was about 25% in casual and major partners. Men were very bad, either by knowing or "guessing" their own serological status or their partners. When researchers looked at actual HIV transmission, they found that only 16% of men who took HIV knew their partner had HIV.
In contrast, 46% of men who contracted HIV took it from someone they believed to be HIV negative and 55% of the major partner transmissions were from men who thought they were negative. In casual sex, 63% of the transmissions occurred in situations where partner status was unknown.
Men with HIV infection were diagnosed, therefore, thelessLikely to be responsible for the transmission of HIV. This was because, when a partner was known to have HIV, couples were no less likely to use condoms with their main partner than during casual sex.
There were some other outstanding findings from the study. First, despite being the receptive partner accounting for almost 70% of infections, 28% of infections were acquired by the insertion partner. This is more than anticipated in previous studies, although some HIV activists commented that some men might lie about being a "receptive", Because it is still very stigmatized. It should also be noted that the study found that 2 to 3% of infections come from oral sex - a figure who calls for previous studies.
Second, the annual incidence of HIV - the proportion of this group that gets HIV each year - has been calculated for 2,2%. Given that this is ten times the observed mortality rate among homosexual men in the Vaccine Preparation Study,threeThe number of homosexual men in the US with HIV will continue to grow, at least until significant numbers begin to die of old age, unless the incidence of HIV is cut dramatically.
This study obviously has major implications for HIV prevention messages. It is well known that people use condoms much less with their main partner and for many couples because condoms are viewed as a sign of mistrust. Trying to get regular partners who do not use condoms is already difficult ... finding those who are willing to use them can be a challenge.
Encouraging couples to test, or retest, HIV the moment they engage with someone emotionally has several benefits. If a partner tests positive for HIV, this does not only mean that they are in a much better position to take care of their own health, but successful treatment will also reduce their infectiveness. And regardless of test results, testing for HIV is a powerful prevention tool, putting people in touch with sexual health services and, most importantly, opening a discussion between partners about sexual health and safe sex.
Exactly which prevention message is most appropriate, however, depends on a question not asked by the search. In the words of Roger Tatoud, senior program manager at the International Institute for Clinical Trials for HIV at Imperial College London, "If most people contracted HIV from their main partner, where did he get it?" A dilemma faced by researchers in heterosexual transmission. There are two theories:
The theory of "serial monogamy" is based on the idea that committed relationships between homosexual men and especially young homosexuals will not last long, which is borne out by the finding that men seek 1,4 on average "major partners" per year. If the average interval between HIV tests or, for those who have never tested, between the first sex and the most recent, is higher than the average length of committed relationships, then there will be many men entering into new relationships they do not know they have HIV.
Message: Test yourself as soon as you get involved.
The "simultaneity" theory, on the other hand, assumes that there is a lot more sex going on outside of many major relationships than the researchers captured, both because the respondents did not talk about it (we know that people lie about sex even in more Confidential), or because the researchers made assumptions about what "core relationships" mean to gay men, for example, that emotional commitment means monogamy and therefore did not ask clearly enough about it.
Message: Have an agreement to keep safe sex out of your primary relationship.
Whatever the theory, this study challenges the assumptions that offering gay marriage and the chance to establish a family can mean less HIV transmission and will cause some rethink in the world of HIV prevention.
Translated by Cláudio Souza from the original written by Gus Cairns and Michael Carter published in Love is a DangerPublished in 1 of June of 2009.
- Sullivan PS et al.Estimating the proportion of HIV transmissions from main sex partners among men who have sex with men in five US cities.AIDS 23(9):1153-1162, 2009.
- Centers for Disease Control and Prevention.HIV prevalence, undiagnosed infection, and HIV testing among men who have sex with men: five US cities, June 2004-April 2005.MMWR 52: 597-601, 2005.
- Seage GR et al.Are US appropriate populations for human immunodeficiency virus Vaccine? The HIVNET Vaccine Preparedness Study. American Journal of Epidemiology 153 (7): 619-627, 2001.