An awareness campaign of the health risks around syphilis is being launched in Gloucestershire on Tuesday.
In 2004, according to the Health Protection Agency, there were 19 new cases diagnosed in the county - against one case in the previous three years.
The agency says syphilis is one of the most serious sexually transmitted diseases and can cause permanent damage to the brain, heart, bones and liver.
The campaign is primarily aimed at gay and bisexual men in the county.
A new no-appointment service at clinics in Gloucester and Cheltenham are being set up, and posters will be displayed about the risks.
Dr Toyin Ejidokun, of the Gloucestershire Health Protection Team, said: "We have been working closely with the gay community in the county to relay advice and work up the campaign."
"Safer sex - using condoms - is the best protection."
Across Gloucestershire, Avon and Wiltshire, cases of syphilis have risen from five in 2000 to more than 60 last year.