Southwark has the second highest rate of syphilis in London according to new figures, putting it among the highest in the country.
According to the stats published on Friday by Public Health England, the borough saw 348 cases in 2017.
However this was dwarfed by Lambeth, which witnessed 498 cases.
Men who have sex with men (‘MSM’) were most at risk of getting syphilis, accounting for 90% of all London syphilis cases in 2017.
The research’s authors said the continued increase in cases was “particularly concerning” because it comes “despite active campaigns targeted towards MSM to promote condom provision and use, and where a fully functioning sexual health care system provides open access to testing and treatment.”
An increase in heterosexual syphilis cases across the capital was also labelled “concerning”, because of the risk of transmitting syphilis from mothers to unborn children.
High-risk behaviour including not using a condom, use of hook-up apps like Grindr, and chemsex – using drugs before or during sex – were the main drivers of syphilis cases.
Nearly half of all the syphilis cases diagnosed in the country throughout the year were also diagnosed in London.
The sexually transmitted infection can be cured with antibiotics but if left untreated can lead to serious and life-threatening problems such as strokes, meningitis and heart problems.
The organisation called for interventions to deal with the “continuing epidemic.”
They include raising awareness of syphilis symptoms and encouraging the use of condoms for every new partner.