Rapid increase in gonorrhoea and syphilis diagnoses in England in 2011

There has been a rapid rise in the number of gonorrhoea and syphilis diagnoses in England during 2011, an increase of 25% and 10% respectively. Large increases of both gonorrhoea (61%) and syphilis (28%) were observed among men who have sex with men. Although these rises can partly be attributed to increased testing, ongoing high-levels of unsafe sexual behaviour probably contributed to the rise. The rise in gonorrhoea rates is worrying in an era of decreased susceptibility to treatments. The number of new sexually transmitted infections (STIs) diagnosed in England during 2011 increased by 2% (419,773 to 426,867) from 2010. This rise in STIs followed a small decline in diagnoses seen in 2010 and is a return to the steady increase in STI diagnoses observed over the past decade. However, unlike previous years, in 2011 there was a particularly pronounced rise in the number of diagnoses of gonorrhoea (25%; 16,835 to 20,965) and infectious (primary, secondary and early latent) syphilis (10%; 2,650 to 2,915).

There has been a rapid rise in the number of gonorrhoea and syphilis diagnoses in England during 2011, an increase of 25% and 10% respectively.Large increases of both gonorrhoea (61%) and syphilis (28%) were observed among men who have sex with men.Although these rises can partly be attributed to increased testing, ongoing high-levels of unsafe sexual behaviour probably contributed to the rise.The rise in gonorrhoea rates is worrying in an era of decreased susceptibility to treatments.
The number of new sexually transmitted infections (STIs) diagnosed in England during 2011 increased by 2% (419,773 to 426,867) from 2010.This rise in STIs followed a small decline in diagnoses seen in 2010 and is a return to the steady increase in STI diagnoses observed over the past decade.However, unlike previous years, in 2011 there was a particularly pronounced rise in the number of diagnoses of gonorrhoea (25%; 16,835 to 20,965) and infectious (primary, secondary and early latent) syphilis (10%; 2,650 to 2,915).Rate of diagnoses per 100,000 population (gonorrhoea and syphilis) Only laboratory-confirmed diagnoses are reported.

Surveillance of sexually transmitted infections in England
In England, all specialist sexual health clinics submit the mandatory Genitourinary Medicine Clinic Activity Dataset (GUMCAD) to the Health Protection Agency (HPA) every quarter.This dataset is an electronic pseudo-anonymised patient-level data return that contains information on all STI diagnoses made and services provided in the clinic (e.g.sexual health screening, HIV testing, hepatitis B vaccination and partner notification)along with patient demographic information (i.e.sexual orientation, age, sex, country of birth and patient-defined ethnicity, (based on national standard categories).GUMCAD is a new data return that started in 2009 and enables more detailed epidemiological analysis of STIs in England.Prior to GUMCAD, aggregated STI surveillance data were reported through a paper-based system.Data are also collected from community settings that carry out chlamydia screening as part of the National Chlamydia Screening Programme, which offers opportunistic chlamydia tests to people aged 15-24 years.The case definitions for gonorrhoea and syphilis are described in [1].

Trends in gonorrhoea
In 2011, gonorrhoea diagnoses increased by 25% with 20,965 cases reported (40.1 per 100,000 population).There were 14,992 male cases (58.2 per 100,000) and 5,972 female cases (22.6 per 100,000).Half of the male cases (7,487) were in men who have sex with men   (MSM), among whom there was a substantial rise in diagnoses of 61% from 2010 (4,651 to 7,487).Among heterosexuals, 57% (6,678/11,778) of diagnoses were in those aged 15-24 years; however, in MSM, more diagnoses were reported in the older age groups, with 42% (3,128/7,487) of diagnoses in those aged 25-34 years (Figure 2).A total of 19% (1,389/7,487) of MSM diagnosed with gonorrhoea had previously been diagnosed with HIV infection.
A number of different factors will have contributed to the sharp increase in diagnoses particularly in MSM.
Clinics are likely to have carried out more screening of extra-genital (rectal and pharyngeal) sites in MSM using nucleic acid amplification tests (NAATs) in response to new testing guidance [2] and the ongoing lymphogranuloma venerum (LGV) epidemic in England [3].However, diagnoses among heterosexuals also increased by 14% in 2011 which cannot be attributed to changes in testing extra-genital samples, suggesting that there are continuing high levels of unsafe sexual behaviour among MSM and young adults in particular.The high rates of gonorrhoea infection are especially concerning given the backdrop of decreasing susceptibility to front-line antimicrobials seen in England [4] and across Europe [5] and the emergence of treatment failures [6][7][8][9].

Trends in syphilis
Infectious syphilis diagnoses increased by 10% in 2011 with 2,915 cases reported (5.6 per 100,000 population).Rates of syphilis were nine times higher among men (10.2 per 100,000) than women (1.1 per 100,000 population).Syphilis continues to be predominantly seen in MSM, with 75% (1,955/2,622) of the male cases being in this group.Diagnoses among MSM rose by 28% (1,523 to 1,955) in 2011 but fell by 1% (749 to 739) among heterosexuals (Figure 4).Two thirds (1,283/1,955) of cases in MSM were in those aged 25-44 years.Almost a third (620/1,955) of MSM diagnosed with syphilis had previously been diagnosed with HIV infection.

Discussion
There was a large increase in the number of gonorrhoea and syphilis diagnoses reported in England during 2011.Of particular concern is the large rise in STIs observed in MSM.These rises can partly be attributed to increased STI screening and the testing of MSM for gonorrhoea and chlamydia at extra-genital sites and overall use of molecular testing for sexual health screens.However, the continuing LGV epidemic in England and outbreaks of other STIs such as shigellosis [10] suggests that ongoing high levels of unsafe sexual behaviour will have been an important factor behind the rise in diagnoses seen among MSM.People coinfected with HIV and other STIs are more likely to be infectious, facilitating HIV transmission [11] and in England, a considerable proportion of syphilis (32%), gonorrhoea (19%) and LGV (78%) cases in MSM were HIV positive.HIV-positive MSM diagnosed with gonorrhea are also more likely to report higher-risk sexual behaviours than HIV-negative MSM [4].This suggests HIV sero-adaptive strategies may play an important role in STI transmission among MSM [12].
There is huge inequality in the distribution of gonorrhoea and syphilis across ethnic groups in England, with black ethnic minorities experiencing the highest rates of infection.This may be partly explained by higher levels of socio-economic deprivation although other cultural influences on sexual behaviour may contribute [13,14].
Prevention efforts, such as greater STI screening coverage and easy access to sexual health services, need to be sustained and continue to focus on the groups at highest risk.Health promotion and education to increase public awareness and encourage safer sexual behaviour such as consistent condom use with all new and casual sexual partners remain vital in preventing STIs.This is of particular importance given the backdrop of emerging decreased susceptiblity to gonorrhoea treatments and the publication of both a European response plan [15] and global action plan [16].The HPA recommends that MSM having unprotected sex with casual or new partners should have an HIV/STI screen at least annually, and every three months if changing partners regularly [17].

Figure 2
Figure 2Proportion of gonorrhoea diagnoses in each age group by sexual orientation, England, 2011

Figure 3
Figure 3Proportion of gonorrhoea and syphilis diagnoses by region of birth, England, 2011

Figure 4
Figure 4Proportion of syphilis diagnoses in each age group by sexual orientation, England, 2011