Eastern Health is reporting an outbreak of syphilis in eastern Newfoundland, with 15 cases confirmed so far this year.

In all of last year, there were 26 confirmed cases.

Dr. David Allison, medical officer of health for Eastern Health, said the number of cases has steadily increased over the last decade.

"That's way above the number of cases of syphilis we would expect to see in this period of time and it really seems to be growing and growing," Dr. Allison told CBC News Tuesday.

Most of the new cases involve males between the ages of 20 and 49 who have had sexual intercourse with men.

The health authority is going public in order to raise awareness and hopefully prevent further infections.

Dr. Allison said it's important that those engaging in sex outside of a monogamous relationship protect themselves by wearing a condom.

Syphilis is a bacterial sexually transmitted infection (STI) contracted through unprotected anal, vaginal or oral sex.

Latex condoms, when used consistently and correctly, are the most effective way to prevent the sexual transmission of syphilis.

Of the 41 cases of syphilis reported since January 2014, Allison said 10 have been co-infected with HIV.

Syphilis increases the potential for the spread of HIV infection, Allison explained.

"One of the challenges with syphilis is that because it's an ulcer causing infection, at least in the initial stages, it can contribute to the transmission of HIV by making the virus easier to pass along from one person to another," he said.

Eastern Health to increase clinics

According to the health authority, syphilis can cause serious and permanent damage to the body if untreated.

Symptoms may appear anywhere from 10 to 90 days after an person becomes infected. The average is 21 days.

In some cases, people may not experience any symptoms, but here's what to look for:

an open sore at the point of infection (genital area, anus, mouth or lips);

flu-like illness;

muscle aches and pains;

fatigue; and/or

a rash on the chest, back, palms of hands and bottoms of feet.

Allison said it is important for anyone who believes they may have contracted syphilis to see a doctor as soon as possible.

A blood test is the simplest method of checking for the infection.

Meanwhile, in response to the outbreak, Eastern Health will begin increasing sexual health clinics for testing, treatment and follow-up.

Anyone requiring more information can call 1-877-752-4358 or visit www.easternhealth.ca/TCDT.