The resurgent syphilis epidemic in the UK shows no signs of abatement, a new report from the Health Protection Agency (HPA) shows. In 2007, over 3700 cases of the infection were diagnosed, the focus of the epidemic being gay men.
More encouragingly, however, there are some indications that the pace of the lymphogranuloma venereum (LGV) epidemic appears to be slowing.
By the late 1990s, syphilis had become a rare sexually transmitted infection in the UK. In 1997, however, an outbreak occurred amongst heterosexuals in Bristol, followed by a series of outbreaks from 2001 onwards amongst gay men in Brighton, London and Manchester.
Between 1997 and 2007 there was a ten-fold increase in the number of syphilis infections diagnosed in the UK, from 301 in 1997 to 3762 in 2007.
Over the last ten years, 73% (9560) of all syphilis cases have involved gay men. The HPA report notes that “the characteristics of these patients have changed little over the course of the epidemic.” Around a third of patients are aged between their mid-30s and mid-40s, 90% are white, and a third are also infected with HIV. The infection is thought to have been contracted through oral sex in a third of cases.
Contract tracing has traditionally been an important component of syphilis control, but the HPA notes that 56% of cases involving gay men were reported to have been acquired from casual partners, making this strategy impractical.
There have also been 3375 syphilis diagnoses in heterosexuals. In 2008, 68% of new infections were acquired in the UK and 63% involved white patients. As with gay men, a third of infections were diagnosed in individuals aged between 35 and 44.
Diagnoses of congenital syphilis have also increased markedly, from 136 in 1999 to 448 in 2007. Antenatal screening can detect the infection in pregnant women, but the HPA notes that in some areas only 77% of pregnant women are being screened for the infection.
After the introduction of antibiotics, LGV became a very rare sexually transmitted infection in the UK. However, the infection reappeared in 2003/04 and by the end of 2008 a total of 849 cases had been diagnosed in the UK.
As with syphilis, the infection’s main focus has been in white gay men aged between 35 and 44. Most cases of LGV in the UK have involved HIV-positive men (75%). Moreover, a third were also infected with another sexually transmitted infection.
New diagnoses reached a peak in the third quarter of 2005, when there were 80 cases. There has been a general downward trend since then and, in the last quarter of 2008, there were just 25 diagnoses.
The vast majority (72%) of LGV cases have been in London, with smaller outbreaks in Brighton (7%) and Manchester (4%). However, the HPA notes that isolated cases have been reported throughout the UK. Only 7% of LGV infections are thought to have been acquired abroad.
“The epidemics of infectious syphilis and LGV have both been influenced by developments in the HIV epidemic,” comment the report’s authors. Both infections have disproportionately affected HIV-positive gay men, a group who have more sexual partners and often select other HIV-positive men for unprotected sex. This has facilitated the spread of these, and other infections, through networks of HIV-positive gay men. “The delivery of effective interventions within the context of these dynamic, diverse epidemics remains a challenge,” add the authors.
Syphilis and lymphogranuloma venereum: resurgent sexually transmitted infections in the UK. Health Protection Agency, 2009.