The increase has been most marked in heterosexual men and women aged over 20, and in gay and bisexual men and other men who have sex with men.
The health board has launched a public awareness social media campaign to promote safer sex and prevent further infections occurring and to encourage anyone who may have put themselves at risk to see their GP or attend a sexual health clinic in order to be assessed and tested.
Even though an increase in the number of cases of syphilis in 16-20-year-olds has not been seen, the campaign will also target this important group.
Dr John Logan, NHS Lanarkshire consultant in public health medicine, said: “The festive party season is often associated with an increase in risk-taking sexual behaviour.
“Some people are not aware of the risk of syphilis or see it as an infection of the past.
“That’s not the case and with an increase in the number of people in Lanarkshire being diagnosed with syphilis, we feel it is important to highlight to people the risks of unprotected sex.
“Although the number of cases is relatively small, in Lanarkshire in 2017 the 19 cases of heterosexually acquired syphilis did account for one third of the heterosexual cases in Scotland, and 48 cases in men who have sex with men.
“We want people to be aware of what syphilis is, how it can be prevented and treated, and what the harmful long-term impact of untreated syphilis infection can be.
“When diagnosed syphilis can be treated with antibiotics, but if not treated it can cause serious damage to the heart, arteries, nervous system and may lead to blindness.”
For further information and where to access sexual health clinics visit www.LanarkshireSyphilis.org.