Researchers report that increased use of crystal methamphetamine is driving up incidence of HIV among men who have sex with men (MSM) in London. Ecstasy, cocaine, ketamine, y-butyrolactone, and speed are also widely available among MSM in London, according to Tony Kirby and Michelle Thornber-Dunwell, authors of the Lancet article.

There were 3,010 new cases of HIV in the United Kingdom in 2011, and 1,296 of these infections were diagnosed in London. Thornber-Dunwell and Kirby stated that use of crystal meth increases the risk of HIV, hepatitis C, and other STDs.

Increased incidence was noted at two London locations, the 56 Dean Street Clinic and the CODE clinic. Of the 511 new cases of HIV diagnosed at the Dean Street Clinic, 482 infections occurred among MSM. The CODE clinic is home to Antidote, which provides drug and alcohol services for LGBT people. UK drug clinics are struggling to meet the demand for services, reported David Stuart of Antidote. Stuart said 75 percent of the MSM using CODE's services are HIV-infected. Most of these men -- 60 percent -- say they do not take antiretroviral (ARV) medicines when they are using drugs. Not taking ARVs makes transmission of the virus more likely. Stuart said the availability of drugs and ease of finding sex parties and drug dens via the Internet compound the problem.

Kirby and Thornber-Dunwell reported that the practice of slamming -- dissolving crystal meth or mephedrone in water or blood and injecting them -- creates a "perfect storm" for the transmission of HIV and hepatitis C. Slammers sometimes stay high for days, having unprotected sex with multiple partners.

The full report, "High-Risk Drug Practices Tighten Grip on London Gay Scene," was published in the journal The Lancet (2013; 381(9861):101-102).