SYPHILIS rates in Scotland are the highest in more than 60 years amid a spike in diagnoses among gay and bisexual men.

The incidence of the sexually transmitted infection has been rising steadily but reached a new peak in 2016 when a total of 356 diagnoses were confirmed, up 13 per cent year on year. It the highest annual total since at least 1952.

The majority of patients - 336 - were men, including 295 who were either gay or bisexual. Men who have sex with men accounted for 83 per cent of the diagnoses last year. There were also 20 cases diagnosed among women.

The latest increase in syphilis comes after the number diagnoses doubled between 2014 and 2015, from 159 to 316.

A report by Health Protection Scotland said the trend in Scotland "mirrors the epidemiological picture observed in London, and England as a whole", where a rise in case of syphilis has been driven by an increase in diagnoses among gay and bisexual men.

It said this "could be related to HIV seroadaptive behaviours", which refers to the practice of HIV positive men having unprotected sex with other men who are also HIV positive.

Of the 295 cases identified among gay and bisexual men, 19 said they had had between 10 and 20 sexual partners in the three months prior to diagnosis and six reported more than 20. However, the majority - 195 - said they had had fewer than five, and 27 had had between five and nine. The remainder did not provide an estimate.

This compared to four or fewer partners in each of the heterosexual cases.

The report added that gay and bisexual patients reported the internet and phone apps as their most popular method of meeting partners, with sex parties, saunas and bars and clubs also cited.

Lesley Wallace, healthcare scientist for Health Protection Scotland, said: "The figures indicate a continuing high level of casual unprotected sexual intercourse among an appreciable minority of men who have sex with men."

Ms Wallace added that more research was being done to dissect what was behind the upward trend.

Syphilis is potentially deadly if untreated, but can be cured easily with antibiotics. In 1945 there were more than 2,500 cases a year in Scotland, but the incidence fell dramatically when became widely available with the launch of the NHS.

Liz Porter, Director of Clinical Service at Terrence Higgins Trust, said: “This data in Scotland provides yet more evidence that we still have much to do to address the alarming inequalities in the sexual health of different populations.

"We know that men who have sex with men are disproportionately affected by STIs, and last year accounted for 83 per cent of all syphilis diagnoses in Scotland. This has risen sharply."