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.
An increase in cases of syphilis across Wales could be linked to the use of dating websites and mobile phone apps for casual sex, according to Public Health Wales.
Thirty-nine cases of the bacterial infection have been reported in North Wales since the middle of 2013, compared with a usual average of around seven per year.
In South Wales, 55 cases have been reported so far this year.
A Public Health Wales spokesperson said: "There is evidence that the infection is spreading particularly quickly in people who use dating websites and apps to meet other people for casual sex."
Three people who fell ill after taking the drug Mephedrone are likely to have been affected by the amount consumed and not because the drug was contaminated, according to a Public Health Wales investigation.
Two were admitted to intensive care following the incident earlier this month. One has now been discharged but the other remains critically ill.
Laboratory tests on the drug have ruled out any contamination and the investigation has now concluded.
Two people from the Swansea area are critically ill in hospital after taking mephedrone. Public Health Wales say they are treating three adults and are carrying out lab tests to see whether the drug was contaminated by bacteria or a chemical cutting agent.
Public Health Wales has urged anyone with symptoms of syphilis, or who may be at risk of infection, to attend their local sexual health clinic to be tested.
Health officials say that, to date, most cases have been in cases of men who have sex with men.
People with syphilis may develop painless ulcers in their genital or mouth area. They may also develop a rash over their body, palms of the hands and soles of their feet.
These symptoms may disappear without the person being aware of them, but they will remain infected and risk infecting other sexual partners.
The symptoms of tertiary syphilis, which will occur many years after acquiring infection, can be dangerous enough to cause death.
Syphilis can be cured with a course of antibiotics. The best way to prevent syphilis and other sexually transmitted diseases is to use a condom.
Public Health Wales and Betsi Cadwaladr University Health Board have introduced enhanced surveillance, communication with health workers and targeted promotion to the most at-risk people, to try to stop the increase in the number of cases.
Public health experts have warned that there has been a "significant increase" in infectious syphilis cases in North Wales.
There have been 39 cases reported to Public Health Wales in North Wales since the middle of 2013.
Normally, there are around seven cases a year in the area.
The rise in cases was first seen in residents on Anglesey - but there are now cases across North Wales.
Syphilis is a bacterial infection that can be passed on through sexual contact.
A campaign's been launched to make hospital patients aware of the risk of developing a blood clot while they're recovering.
Research has shown most people associate blood clots - or thrombosis - with travelling by aeroplane. But two-thirds of blood clots occur in hospital or in the three months after leaving. Carole Green reports.
Everyone can develop a blood clot, but there are certain groups that are more at risk.
They include people who are:
- over 60
- receiving treatment for cancer
- undergoing serious surgery
- suffering from ongoing medical conditions.
People are 10 times more at risk of developing a blood clot when being treated for a serious illness in hospital, but around 70 per cent of cases could be avoided with preventative treatment.
Click here to find our more about the 'Ask about Clots' campaign.
Wyndham Thomas suffered his first blood clot after he fell off his bike fracturing his pelvis in 1984. He told ITV News that when he started having back pains and difficulty breathing doctors said it was kidney stones.
It was only when he coughed up a clot that he was told clots were a possibility due to the nature of his injury. He said that it doesn't matter how fit you are, you can still develop clots.
Around 62 per cent of people in Wales believe they are more likely to develop a clot - also known as thrombosis - on an plane than in hospital. But the risk can be 1,000 times higher in hospital than during a flight.
It's an important message for both patients and NHS Wales staff. Most people associate developing a thrombosis with flying. However, two thirds of blood clots occur in hospital or in the 90 days following discharge.
That's why it's so important for patients in hospital to ask for an assessment for blood clots and for their families to also be aware to ask on their behalf if necessary.
'Ask about Clots' will also encourage our healthcare professionals to be more aware of the risks and ensure all patients are assessed. Thrombosis is a condition that can be prevented.
Hospitals are being encouraged to use a special check list to evaluate a patient's risk of developing a clot. Wearing leg stockings, taking small doses of blood thinning medication and keeping mobile can all help prevent clots.
We need to highlight the very real danger of thrombosis, which is why the 'Ask about Clots' campaign is very important.
It has the potential to save many lives by encouraging patients and their families to talk to doctors and health professionals. It means more people will received the necessary treatment to prevent thrombosis.