A sexually transmitted infection (STI) that was close to being wiped out in the 1990s has made a comeback in recent years — and researchers say it may raise the risk of suffering a heart attack.
Syphilis, sometimes referred to as a ‘medieval STI’, can be hard to detect. Signs can fade and return, and in some cases symptoms don’t show up until long after the initial exposure.
Dr Kayla Stover, a professor and vice chair of pharmacy practice at the University of Mississippi, said of the symptoms to look out for: “The first stage of syphilis starts with a lesion in a person’s mouth or genital area that starts a couple of weeks after exposure.
“It is often painless, can disappear and, therefore, can go unnoticed.
“If untreated, a rash may appear on a person’s extremities – particularly the palms of the hands and soles of the feet – eight to 12 weeks after exposure. If still untreated, it may simply go away or lay dormant with possibility of reappearing, causing long-term damage.”
The infection can be passed on through oral, vaginal, or anal sex when someone comes into contact with infectious sores. Rising case numbers have been linked to factors such as lower condom use, fewer routine screenings, and limited access to healthcare.
In a newly published study, researchers reviewed health records for more than 1,400 adults diagnosed with syphilis between 2011 and 2025. They also compared outcomes against people without the STI who had similar underlying health characteristics.
The findings suggest syphilis bacteria can gradually harm blood vessels. People diagnosed with the infection were found to develop cardiovascular problems at notably higher rates than those in the comparison group.
Alarmingly, heart attacks were recorded in almost seven percent of syphilis patients, while strokes were reported in more than 10 percent.
The study also reported that the likelihood of a bleeding stroke was 92 higher among people who had the STI. Those infected were also said to have double the risk of developing aortic swelling — a weakened, stretched, or bulging section of the body’s main artery that may rupture.
If that happens, it can become life-threatening and requires urgent medical treatment.
One of the most striking figures from the research indicated that syphilis patients were six more times likely to die than people without the infection who otherwise shared a similar health profile.
In severe cases, tertiary syphilis — the final stage — can result in blindness, heart damage, nervous system complications, mental health disorders, and potentially brain damage.
Health experts advise regular testing, typically once a year, and more frequently for people who have multiple sexual partners.