Infectious syphilis | The epidemic is becoming more and more established in Quebec, according to the INSPQ

After a significant decline during the pandemic years, 2022 was marked by a significant resurgence in syphilis cases, according to the Institut national de santé publique du Québec (INSPQ). And preliminary data indicate that the same was true for 2023.

This is one of the findings made by the institute in its most recent portrait of sexually transmitted and blood-borne infections (STBBIs) in Quebec. It states that “the syphilis epidemic is increasingly taking hold in the heterosexual population.” As proof, among women, 200 cases of syphilis in the infectious phase were reported in 2022, approximately 7 times more than 10 years ago.

While the incidence rate was 4.6 cases per 100,000 women in 2022, preliminary data indicate that this figure could have increased to 5.4 by 2023. From 2003 to 2015, there was less than one case per 100,000 women each year.

The fact remains that men are significantly more affected by syphilis: they account for 84% of all cases.

In the regions

The epidemic, initially concentrated in the Montreal region, is also “growing in most regions” of the province, according to the INSPQ. So much so that at least one case of infectious syphilis has been recorded in each of the regions, with the exception of Nord-du-Québec. However, in light of the INSPQ’s figures, the metropolis remains the epicentre of the epidemic, with 55% of reported cases.

Among the cases recorded among women, six regions accounted for 86% of cases: Nunavik, Lanaudière, Montreal, Laval, Montérégie and the Laurentians.

Congenital syphilis – the type that develops in newborns – is also gaining ground, with 14 cases detected in infants under the age of 2 in 2022. There were only one per year in 2017 and 2018.

The prevalence of syphilis in Quebec remains well below that of other Canadian provinces. In 2022, for every 100,000 Quebecers, 14.5 cases were recorded, compared to 23.6 cases for every 100,000 Ontarians and 73.2 for every 100,000 Albertans.

Other findings

In its report, the INSPQ also notes that chlamydia remains – “by far” – the most common reportable STI. In 2022, 25,339 cases were reported, for an overall rate of 291 cases per 100,000 people. “This infection is widespread throughout Quebec,” the institute states.

Another STI in the INSPQ’s sights, gonococcal infection, commonly known as gonorrhea, saw a marked increase in 2022 compared to 2021. The number of infections reported per 100,000 people increased from 76 to 93, an increase of 21%. According to projections, the overall incidence rate could also increase to 107 cases per 100,000 people in 2023.

As for HIV infections, they also increased in 2022. The number of new diagnoses increased by 72% compared to 2021. Of these new diagnoses, the majority (61%) concern people who arrived in Canada in 2022.