Health chiefs say dating apps are to blame for a significant rise in people suffering from sexually transmitted infections.
The UK’s recent heatwave is being also believed to be behind an increase in the spread of the infection syphilis, with more people being sexually active in the warm weather.
Abertawe Bro Morgannwg University Health Board has seen five times as many people diagnosed with syphilis in the last four months compared to same period last year.
Since April there have been 56 confirmed cases of the infection in Swansea, Neath Port Talbot and Bridgend – with 16 of those coming in the last two weeks alone.
Most of the patients have been men, but several women have also tested positive.
Doctors believe the reason behind the steep rise could be an increase in people using online dating apps like Tinder and Bumble to meet up for unprotected sex, then deleting their partners profiles afterwards, preventing them from warning them if they are diagnosed with an infection later on.
Symptoms for syphilis can include small painless sores or ulcers, blotchy red rashes, small skin growths or white patches in the mouth.
It may also cause tiredness, headaches, joint pains and swollen glands, but some people may experience no symptoms at all.
If left untreated the infection can spread to the brain or other parts of the body, causing serious and long-term problems.
The health board, in South Wales, are urging people to contact sexual health clinic if they have had unprotected sex in recent months.
ABMU sexual health lead nurse Joanne Hearne said: “There has been an increase in syphilis generally across Wales.
“But we have seen a significant rise across the health board area, particularly over the last six weeks.
“It is possible that the heatwave earlier in the summer led to people becoming more sexually active.
“We also believe social media and the growth of dating websites and apps is another contributory factor.”
Sexual health sister Carly Porter added: “We have found that some diagnosed patients find it a lot more difficult to contact previous sexual partners as they have met them through a dating app. In some cases, they may have then deleted their profile.
“As a result, many people may be unaware they have the infection.”