With half of HIV-positive gay and bisexual men surveyed at a collection of English sexual health clinics reporting recent drug use, a strong correlation emerged between drug use and sex that posed a risk for transmission of the virus, aidsmap reports. Publishing their findings in The Lancet, researchers in the ASTRA study surveyed 2,248 men who have sex with men (MSM) attending health clinics in central, north and east London and in Sussex and Manchester in 2011 and 2012.

There was a strong association between drug use and being younger, smoking, having disclosed being HIV positive to others, and lack of adherence to antiretrovirals (ARVs). Those reporting drug use were somewhat more likely to serosort, meaning to have sex with other HIV-positive men. Drug use was also linked to having sex in the past three months, having condomless intercourse, receiving a sexually transmitted infection (STI) diagnosis, and having group sex or having 10 or more sexual partners in the previous 12 months.

The men who reported using four or more drugs were more likely than other men who reported taking drugs or those who said they did not take drugs to either have a detectable viral load or not to be taking ARVs. They also were more likely to be younger and to have a higher proportion of HIV-positive partners.

Seven percent of the men surveyed, or 10 percent of those who used drugs, had had higher-risk sex, defined as having sex with an HIV-negative partner while not taking ARVs, or while having a detectable viral load, or while being infected with a diagnosed STI. The greater the number of drugs the men reported taking, the more sex, sex without a condom, higher-risk sex, STIs, group sex and number of partners they reported having.

Those who used drugs were 40 to 70 percent more likely to have higher-risk sex than non-drug users. Men reporting use of GHB, mephedrone, poppers, erectile dysfunction drugs, and cocaine were 90 percent more likely to engage in higher-risk sex. Those who reported crystal meth use were 170 percent more likely to have higher-risk sex than those who did not report drug use.

To read the aidsmap story, click here.

To read the Lancet study, click here.

To read an accompanying Lancet editorial, click here.