A Public Health Wales spokesperson says syphilis is "very serious" if left untreated.
Figures have revealed a rise in cases of the infection across Wales.
We are seeing an increase in cases of syphilis across Wales, the majority being in men who have sex with men.
However, we also have cases in people who are bisexual and heterosexual, and many of these have become infected after meeting people on dating websites and apps.
We would advise anyone who thinks they may have been put at risk to contact their local sexual health clinic for a test, as the infection can be treated with antibiotics but can be very serious if left untreated.
We are also reminding everyone that it’s a good idea to use a condom.
– Dr Gwen Lowe, Consultant in Communicable Disease Control for Public Health Wales