Cases of syphilis – the sexually transmitted disease which left untreated can lead to meningitis and heart problems – have risen by a fifth in just one year.
Public Health England (PHE) said there were over 7,000 cases of the STI in 2017, with the vast majority among men who have sex with men.
The figures were released as an Australian study uncovered that the uptake of the HIV prevention drug PrEP was accompanied by an increase in unprotected sex.
Public Health England said overall STI rates were stable, with 16 to 24-year-olds having the highest rates of diagnoses.
But gonorrhoea rates were dramatically up, with a 22 per cent increase in 2017 compared to 2016.
For syphilis, PHE said there has been a 148 per cent increase in diagnoses since 2008.
Dr Gwenda Hughes, a Consultant Scientist at PHE, noted the “serious consequences” to health posed by STIs, and claimed they could be mitigated by using condoms.
However, in Australia a study published in the Lancet HIV journal showed condom usage was down among men who had been given drugs aimed at preventing HIV.
Ahead of the NHS beginning to issue the drugs in 2017, concerns were raised about such a scheme encouraging promiscuous behaviour.
The Australian Government-funded study, between 2013 and 2017, used data from around 27,000 men.
Of those, nearly 17,000 “reported sex with casual male partners in the 6 months before survey”.
Researchers noted that pre-exposure prophylaxis (PrEP) had been “rapidly rolled out in large, publicly funded implementation projects” in Victoria and New South Wales.
And the study concluded: “A rapid increase in PrEP use by gay and bisexual men in Melbourne and Sydney was accompanied by an equally rapid decrease in consistent condom use.”