Among young Thai men who have sex with men, 6 in 100 acquire HIV each year. With the average age at infection being 26, this explosive epidemic is affecting a far younger group of men than the gay epidemics in Western countries. These are the headline findings of the first three years of a study to monitor HIV incidence, reported by Frits van Griensven to the Eighteenth International AIDS Conference in Vienna on Tuesday.
Thailand is often seen as a lesson in early and effective HIV control. However, until recently, efforts have largely concentrated on commercial sex workers, their clients and injecting drug users. The ongoing spread of HIV among men who have sex with men (MSM) was largely ignored until a much overdue study of Bangkok MSM in 2005 found an HIV prevalence of 17%.
In the incidence study, a cohort of 1292 Bangkok MSM was recruited, which is being followed at four-monthly intervals. Recruitment began in April 2006 and was completed by January 2008. Participants are all Thai nationals, male at birth, resident in the Bangkok area, aged 18 or over, and have had anal or oral sex with a man in the six months before recruitment. Participants were recruited from the sexual health clinic where follow-up visits were conducted, through a website, from a range of bars, saunas and parks used by MSM, and through community organisations.
Men recruited were relatively young (73% aged 29 and under), and were frequently born outside of Bangkok (64%). A majority were employed, well educated and identified as homosexual or gay.
In this sample, 22% of men were HIV-positive at baseline but were generally unaware of their infection. After three years of study, another 135 men had acquired HIV. In a 12-month period, the annual rate of HIV acquisition (incidence) was 5.9 per 100 person years. This did not vary between years 1, 2 or 3 of the study.
The mean age at seroconversion was 26.4, and the median was 26. “This means that 50% of the men who became infected during follow-up were younger than 26 years, and we have seen quite a large number of cases where men got infected when they were 18 or 19 years of age,” van Griensven commented. He noted that in cohort studies in other parts of the world, men are typically in their thirties when they seroconvert.
Among those men who were initially HIV-negative, it was the youngest men who were actually most likely to have acquired HIV by the end of the study. Using the Kaplan-Meier method to estimate the chances of remaining HIV-negative after four years, 89% of those aged 30 or over would be negative, in contrast to 71% of those aged 18 to 21 at recruitment.
This suggests that men are most vulnerable to infection when they are younger – men who did not acquire HIV at a young age are less likely to acquire it when they are older. van Griensven said that behavioural surveys showed that on average younger men had more drug use, unprotected sex and sexual partners.
The age difference is also illustrated by the odds ratios for having either prevalent or incident HIV infection. Prevalence relates to an infection acquired at any time in the past, so older men were more likely to have prevalent HIV. A man aged 30 or over was three times more likely to have prevalent HIV than a man aged 18 to 21 (odds ratio 3.2)..
On the other hand, incidence refers only to newly acquired infections. A man aged 18 to 21 was also almost three times more likely to have incident HIV than a man aged over 30 (odds ratio 2.7).
As well as age, other factors associated with incident (new) infections in the multivariate analysis were using drugs for sexual pleasure (primarily crystal meth, odds ratio 2.9); using taking the receptive position (odds ratio 1.9); inconsistent condom use (odds ratio 5.3 but with wide 95% confidence intervals, 1.3 to 21.8); past herpes infection (odds ratio 1.6) and past syphilis infection (odds ratio 2.5).
In response to a question, van Griensven stated that his study could not indicate whether incidence is rising or falling in Bangkok. However, a separate study of HIV prevalence among Bangkok men who have sex with men may suggest that prevalence is in fact falling.
Nonetheless, the survey method (a series of cross-sectional surveys, conducted at two-year intervals) is not the most reliable way of measuring these changes. Slightly different recruitment methods used for each survey could result in a different profile of men being recruited to different surveys, with the result that apparent changes in HIV prevalence may not be genuine.
The surveys have been conducted over an eight-year period, in 2003, 2005, 2007 and 2009. Men aged 15 and over, who report anal or oral sex with another man in the past six months, are recruited at entertainment venues, saunas and parks.
Overall HIV prevalence rates were 17% in 2003; 28% in 2005; 31% in 2007; and 25% in 2009. The increase from 2003 to 2005 was statistically significant, whereas the apparent decrease from 2007 to 2009 was not (p=0.22).
For those under the age of 22, HIV prevalence was 13% in 2003; 22% in 2005; 22% in 2007; and 13% in 2009.
Regarding risk behaviours, almost all 2003 survey respondents reported that they had engaged in anal sex at some point in their life, but only about two-thirds of respondents did so in 2009 (98 vs 62%; p<0.001).
On the other hand, almost no men in 2003 reported using drugs in the three months preceding the survey, but in 2009, one in five had done so (4 vs 20%; p< 0.001). Drug use during last sex also increased, from 0.7 to 4.2% (p< 0.001).
Consistent condom use in the past three months remained steady at around 64% – 68% across survey rounds.
References
Van Griensven F et al. Three years of follow-up in the Bangkok MSM cohort : evidence of an explosive epidemic of HIV infection. Eighteenth International AIDS Conference, Vienna, abstract TUAC0301, 2010.
Kladsawas K et al. Trends in HIV prevalence and risk behaviour among men who have sex with men (MSM) in Bangkok, Thailand, 2003 to 2009. Eighteenth International AIDS Conference, Vienna, abstract TUAC0203, 2010.
This article was first published by NAM/Aidsmap.com and is republished with permission.
讀者回應
The less society judges MSM the less emotional the issue, the more objective the interventions.
Please share this version of the song to encourage HIV testing and safer sex among those who read Thai (and/or understand the English lyrics).
Sincerely,
Nicholas Snow
romance and slow food and slow sex are back in vogue and its actually quite fun and far more interesting
Having read all these comments. Sure what what you say people have said is part of the picture. I have been here for more than 10 years and have many Thai friends who do not have sex with westerners only with Thai me . What you see in the around the bars is only a fraction of the gay life in Thailand. Among my friends , they all know the risks, but still bareback as they call it. One of the big problems is lack of real understanding about the problems associated with the medications available for treatment. There seems to be a prevalent attitude among young Thai gay men that it's treatable so the risk isn't life threatening. It's difficult trying to get the message across, but I try.
Thailand is a wake up to all of us. While the rate of contraction might be higher in Thailand, I have known people in Australia who have had HIV. One young kid committed suicide as a result. The whole attitude as a whole needs to change. This idea of random drunk hook ups which is promoted alot in 'the scene' is really quite stupid. Know someone who has been affected by HIV and you will know why.
But one thing I will completely fail to understand is how in Hong Kong on the chat sites so many people openly solicit for BB (Bareback) sex? From individual tops to btms to BB group sex, it seems these people have completely thrown caution to the wind....they might as well play russian roulette. Why is it in this age of information and knowledge are there this group of people determined to be infected with STD and HIV.? I beg the question, can anybody give me a guide line as to their pyschological well being and their state of mind towards this ' deliberate ' attempt to be infected.?
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