The incidence of syphilis has quadrupled in Sunderland, Durham and Teesside, areas in UK where Facebook is most popular.
This was due to social network that gives people new ways to meet several unknown sexual partners.
Professor Peter Kelly, director of the Department of Public Health in Teeside, said that his team found a link between social networks and the alarming increase in syphilis infections, especially among young women.
“Syphilis is a devastating disease. Anyone who makes unprotected sex with people who do not know, are exposed to a very high risk. ”
According to telegraph.co.uk, in Teeside were announced 30 cases last year, but unofficial figures are much higher.
A spokesman for Facebook warned users to be careful when meeting with people they have met online.