Introduction Syphilis cases continue to increase in London. We aimed to investigate the characteristics and risk factors of patients diagnosed with syphilis at our centre.

Methods Retrospective case note analysis of all syphilis cases diagnosed in our sexual health clinic in 2016.

Results 56 cases were identified; mean age was 42 (range 16–69 years), with 80% male. The two commonest ethnicities were Black Caribbean (20%) and White Other (20%). 18% were HIV positive, and 18% had concomitant STIs, with one new HIV diagnosis. 26% had been treated for syphilis previously.

Just under a third of patients were symptomatic, the rest being identified through routine screening in clinic or through online testing. Just over a fifth of the cases (12/56) were primary syphilis, with secondary syphilis diagnosed in 7% of patients. All primary and secondary syphilis cases occurred in MSM, and there was a correlation with reported chemsex, with 38% prevalence.

Two of the patients were vulnerable, one being a vulnerable child aged 16. One of the patients was on PREP.

There were 21 cases in heterosexual patients, all were late latent syphilis. Heterosexual men were older (mean 50 years); most heterosexual patients came from regions with high syphilis rates and endemic treponematoses.

Discussion There is high ongoing transmission of syphilis in MSM in our cohort, linked to risky sexual practices and drug use. Increased awareness of syphilis symptoms might facilitate earlier presentation to clinics. As many patients were asymptomatic, there is a pressing need for regular screening in high risk groups.