The number of sexually transmitted infections being spread in gay men is soaring, according to Public Health England.
Figures for 2014 showed a 46% increase in syphilis infections, 32% in gonorrhoea and 26% in chlamydia.
The report said there were "high levels of condomless sex" in general and "rapid" transmission of infections in HIV-positive men.
Public Health England recommends regular STI testing.
Across all groups in England, the number of sexually transmitted infections fell by 0.3% from the previous year, to 439,243 new cases.
Chlamydia was the most common STI, accounting for nearly half of all diagnoses.
But there is a very different picture in men who have sex with men:
- Syphilis infections increased from 2,375 to 3,477
- Gonorrhoea increased from 13,629 to 18,029
- Chlamydia diagnoses increased from 9,118 to 11,468
- Genital warts increased by 10% from 3,156 to 3,456
Gonorrhoea is one of the biggest worries because of the rise of antibiotic-resistant strains of the infection, which are very hard to treat.
Dr Gwenda Hughes, the head of STI surveillance at Public Health England, said: "The stats published today show that too many people are getting STIs, reducing this spread must be a public health priority.
"We are particularly concerned about the large rises in diagnoses among gay men."
The report said high levels of sex without a condom "probably account for most of this rise", but it also drew attention to the rapid spread of infections "in dense sexual networks of HIV-positive men who have sex with men".
Dr Hughes added: "Health promotion and education to increase risk awareness and encourage safer sexual behaviour remain the cornerstones of STI prevention.
"Ensuring easy access to sexual health services and STI screening is a vital component in the control of STIs."
Gay men are advised to have HIV and STI testing every year, or every three months if they have sex without a condom or with casual partners.
Public Health England adds that all sexually active under-25-year-olds should have a chlamydia test each year and whenever they have a new sexual partner.
Dr Michael Brady, the medical director of the Terrence Higgins Trust, said: "The continued rise in both syphilis and gonorrhoea is a worry and evidence that we still have much to do to address the nation's poor sexual health and rates of STIs in those most at risk.
"We should make better use of new technologies and approaches - local awareness raising through targeted social media based on the geographical breakdown of the data we are seeing today and an offer online testing - to reach those who are not accessing 'traditional' services"