Sex in Wales: tracking HIV through UK’s Wild West
In February 2007, a Welsh man was diagnosed with HIV at the Cardiff Royal Infirmary in Wales. So far, he was one amongst the 2500+ new HIV diagnoses in the UK that year. But he became the subject of scientific investigation when he reported 62 sexual encounters in the previous 6 months.
Of his first 9 sexual partners contacted by a team of researchers from the Cardiff Royal Infirmary interested in the transmission of HIV through sexual network, 5 turned out to be HIV positive. This did not mean that he had infected them, only that the number of HIV infections in his sexual network was high, which suggested onward transmission amongst the network members.
The researchers were able to track the contacts of the people were diagnosed HIV positive in this man network. Between February and June 2007 they identified 123 people of which 5 were women, 4 of which heterosexual (sic).
“The network is sparse and suggest a number of interlinked cliques with the highest risk of onward transmission in relatively few individuals” wrote the researchers in an article published in STI.
A closer look at this sexual network reveals some interesting associations.
- A is the“index case”, i.e. the initial patient in the population of an epidemiological investigation, a very sexually active man who reported 62 sexual encounters in the previous 6 months, of which 6 turned out to be HIV positive.
- B is an interesting case sharing 3 of his sexual partners with A and linking 4 different groups of people not related to each other with the exception of D who shares all his sexual partners with B, himself in the index case network.
- The C/D network suggests a couple sharing sexual partners, two of which have had at least one sexual encounter.
- E is in a network where half of the members are HIV positive, a very high proportion.
The network was bigger but only sexual partners with whom unsafe sex occured were tracked and investigated further. The only significant association with a new HIV diagnosis was a previous diagnosis of gonorrhoea. Remarkably, 11 out 11 of those newly diagnosed used the internet to meet sexual partners. Overall the HIV network was young (27 yrs old, range 19-41), well-educated, White, mostly British, with a high risk behaviour despite previous knowledge and awareness of HIV.
Reviewing cases-notes of the initial network, the researchers identified 65 new sexual contacts, belonging mostly to another sexually very active man. Three new cases of HIV as well as several new cases of Sexually Transmitted Infections (syphilis, Chlamydia, and gonorrhoea) were identified. One patient had seven separate cases of STIs.
Remarkably, the case study was diagnosed with more than 4 STIs and all the “connecting nodes” (network members connecting different groups of people) have been diagnosed with at least one STI at some point in time.
This study reveals a fascinating network of sexual relationships that illustrates how HIV can spread amongst a small population through unprotected sex. It also supports using contact tracking as a way to reach all those potentially infected in a network and supports intervention on an individual level to prevent further spread of the epidemic. It also reveals that despite HIV awareness and education, men still engage in unsafe sex. It would be very useful to know more about the index case.
Related posts brought to you by Yet Another Related Posts Plugin.
Maybe I'm just stupid… but the graph doesn't tell me very much. I lack the relevant kind of literacy needed to read it. I don't just want to know who's connected to whom, but *how* they are connected — not just epidemiologically but socially, and specifically what were the qualities of those connections. Were the two guys who had a number of shared contacts (index and B) both members of the same bunch of mates? Was that an explicitly sexual grouping, as opposed to a bunch of guys who drink (and privately also play) together? The very fact the authors were able to trace so many contacts in the network suggests that guys in the cliques knew each other pretty well – it wasn't a network connected by anonymous sexual encounters. If that is the case, then it's highly likely they share or participate in some kind of local sexual culture. They might be adventurous sex players, some of whom are positive, some of whom are negative, but all of whom accept the possibility of infection or onward transmission as a corollary of their preferred modes and intensities of sexual play. The researchers found "the highest risk of onward transmission in relatively few individuals" — a curious phraseology I find quite frequently in phylogenetic studies — and while this sounds like a value-neutral statement, in the culture of public health practice, it really isn't. The implication is that you can remove a lot of risk if you could just identify and remove a few individuals.
Right now, you can only do that if they put someone at risk without their knowledge/consent, using sexual assault or wrongful transmission laws. However, there are a number of jurisdictions, including my own in Victoria, Australia, where regulation (compulsory behaviour change programs) may apply even though every partner knew of and consented to the risk. And it's probably not hard to find someone who has become positive, regrets it and now wants someone to blame, despite consenting to the sex and the risk, to make a complaint to police.
Dear Daniel,
The point the authors wanted to make is that it is possible to do contact tracing and by doing so identifying new infections and potentially prevent further infections. Obviously the data set is much richer and it is a bit desapointing that they are not sharing more!
I agree with you that it would be so much more interesting, and useful, to know more bout who's who in this network. I am particularly interested in the "online connection". But let's not forget that this network is located in a small area, and the demographics show clearly that it's members are familiar with each other or move in the same spheres (they are mostly in the managerial sector or student, Whites, and locals).
We may hear more about this research in the future…
Forgive me for seeming a little oppositional in my responses. I work in a rather different tradition of community-based prevention, rather than public health / health promotion / health sciences. I get a little bit frustrated with research like this, since it seems to set the bar rather low — proving that such-and-such public health technique (contact tracing, phylogenetic analysis, online health promotion, SMS health promotion) is "possible". It's also curiously solipsistic, in that it focuses on public health and advancing (published, peer reviewed) knowledge of best practice in its techniques inch by incremental inch. I agree that it's disappointing the research didn't take a more ethnographic approach, because I think a deep and rich understanding of local sexual cultures will get us a lot closer to effective prevention than de-contextualised proof of concept publications ever will. But then, I'm clearly partisan. Thanks for bringing this to our attention, though!
Daniel,
You may be interested by this other article which addresses some of the issues you raise.
http://rapidshare.com/files/369870390/Gonococcal_transmission.pdf.html
Leave your response!
Recent Comments
StatPress
Visits today: 95Monthly turn over: 3721
RSS Feed by Feedburner
HIV/AIDS News
Blogroll
Tag cloud
Web Hosting
Archives
Most Commented
peripheries bookshelf
Planned books:
Current books:
Bad Samaritans: The Guilty Secrets of Rich Nations and the Threat to Global Prosperity by Ha-Joon Chang
Recent books:
View full Library