Eastern Health says there were 26 confirmed cases of syphilis last year, and as of March 11 there have been 15 new confirmed cases.
It says the majority of the most recent cases are among males between the ages of 20 and 49 years old who have had sexual intercourse with men.
The cases are being seen in the eastern part of the health authority, which includes St. John's and all communities on the Avalon, Burin and Bonavista Peninsulas.
Ten of the 41 people who have been confirmed to have had syphilis have been co-infected with HIV.
Eastern Health says syphilis increases the potential spread of HIV infection and the sexually transmitted infection can cause serious and permanent damage to the body if it is untreated.
It says the use of latex condoms among people who are having sex outside of an exclusively monogamous relationship is the most effective way to prevent the transmission of the bacterial infection.
Dr. David Allison, the authority's medical officer of health, says over the last 10 years the number of recorded cases of syphilis has increased from a few cases a year to the numbers being seen today.
"By informing the public of the increased risk of contracting syphilis and enhancing our efforts to identify and treat those who may have come into contact with it, Eastern Health hopes to prevent the further spread of this infection, as well as HIV," he said in a statement Tuesday.
Symptoms of syphilis may first appear 10 to 90 days after an individual becomes infected, but not everyone experiences them. Symptoms can include an open sore at the point of infection, flu-like illness, muscle aches, fatigue or a rash that develops on the chest, back, palms and bottoms of the feet.
Eastern Health is encouraging people who think they might have contracted syphilis from unprotected sex to get tested. In response to the outbreak, it is increasing the number of sexual health clinics for testing and treatment of the infection.
ALSO ON HUFFPOST