An unprecedented outbreak of infectious syphilis has health officials in Winnipeg scrambling to educate the people most at risk.

The Winnipeg Regional Health Authority said Wednesday it has already encountered 120 cases of the sexually transmitted infection through the first six months of 2018 — a total that exceeds the number of annual cases in the past three years, it said.

"This year is the highest we've ever seen," said Dr. Pierre Plourde, medical officer of health with the WRHA. "And if you go back to 2008, we had less than a dozen."

The infectious disease, which Plourde says has gradually been on the rise in Winnipeg since 2012, can cause anything from painful sores to brain damage if left untreated.

Most cases this year have involved heterosexual men and women.

"That is a bit unusual," he said. "It's increasing at a phenomenal rate."

Plourde said the outbreak among heterosexual people is mostly located in the downtown and Point Douglas area.

It was unheard of, and now we've had a handful. - Dr. Pierre Plourde

For the first time, the WRHA says, newborns have been diagnosed with syphilis. The severe, disabling and life-threatening disease was transmitted by their mothers during pregnancy.

"We can't remember a case in Winnipeg, through all the history of monitoring and counting syphilis cases going back 50 years," Plourde said. "It was unheard of, and now we've had a handful."

The medical officer said the steep increase in syphilis rates has been seen in several different demographic groups.

In addition to the unexpected rise among heterosexual persons, the WRHA says 50-60 per cent of persons infected with syphilis self-report as being Indigenous. As well, Plourde said about 20-30 per cent of infected people are crystal meth users and about 20 per cent are homeless.

To help stem the outbreak, Plourde said the WRHA is looking at what he called "a more upstream approach." He said this involves looking at the causes of homelessness, addiction and the effects of racism and colonization.

"Unless those things change, these communicable diseases — syphilis and others included — are likely going to continue to spread no what kind of medical or public health approach we use."

Dr. Pierre Plourde explains why syphilis is on the rise in Manitoba (Warning: This video contains graphic images):

Dr. Pierre Plourde says there's a "combination of things" responsible for the sudden outbreak in the sexually transmitted illness. 3:25

In addition to sexual transmission, Plourde says drug users can also transmit syphilis through injection or by exchanging needles.

Historically, a key contributor to the number of syphilis infections in urban centres are men who have sex with men, but Plourde says those numbers are actually decreasing due to education efforts in the community.

"That's not what's fuelling the increase," he said.

Last month the WRHA cautioned health-care providers about the syphilis outbreak in an internal letter.

Plourde says it wasn't shared publicly because the health authority was already communicating the problem with vulnerable populations and the organizations that support them.

"The general public, at large, is really not at risk," Plourde said.

At-risk populations

Still, the WRHA needs help to share its messaging, particularly among Indigenous communities.

"Many of these people, we can't find them," he said. "We need our community partners and primarily Indigenous community partners to be working with us."

Cases have been reported throughout Winnipeg, as well as other regional health authorities in the province.

Anyone who experiences syphilis symptoms such as painless genital or oral ulcers, maculopapular rash (a flat, red area on the skin that is covered with small confluent bumps) and lymphadenopathy (disease of the lymph nodes in which they are abnormal in size, number, or consistency) should be tested for the sexually transmitted illness, according to the WRHA.

The authority also encourages people who engage in unprotected sex with casual or anonymous partners, pregnant persons or people who use intravenous drugs to be checked for signs of syphilis.

In 2016, the Public Health Agency of Canada said reported rates of syphilis, as well as chlamydia and gonorrhea, have been steadily rising nationwide since the late 1990s.