Ontario reports rise in mpox cases. Here is what you need to know

Ontario is reporting a rise in mpox cases, serving as a reminder that the infectious disease is still present, despite a descent from its peak two years ago.

In Ontario, 67 cases were reported between Jan. 1 and June 15, according to the latest Public Health Ontario (PHO) data. In 2023, 33 confirmed cases were reported for the entire year, PHO data shows.

Mpox, formerly known as monkeypox until the World Health Organization changed its name after an outbreak that spread to Europe, Canada and the United States, is a viral infectious disease. A total of 1,541 cases were reported in Canada at its height in June 2022.

It most often manifests as a rash or lesion, and can cause a fever, exhaustion, and swollen lymph nodes.

Of the recent cases reported in Ontario, over 95 per cent were among men, with cases disproportionately impacting gay, bisexual, and other men who have sex with men, the Public Health Agency of Canada reports.

“I always start by saying no stigma, no value judgment and no moralization. However, the vast majority of these cases are in the men who have sex with men community, and I think that frames that as you know, if you were not in that community, you're extremely unlikely to get this infection,” Infectious Diseases Specialist Dr. Isaac Bogoch said on Monday.

Mpox primarily spreads through sexual or close, intimate contact, PHO says. Public health investigations suggest that most cases in Canada were acquired locally, rather than during travel. Just over 79 per cent of cases were reported in Toronto with the remaining infections recorded in eight other Ontario public health units, including 7.5 per cent in Ottawa.

Further contextualizing the data, Bogoch notes that the reporting period only reaches to the middle of Pride month, and that several more exposures could have taken place during the remaining duration of June. “So, we might see some more cases in July and August, given the incubation period,” he added.

According to PHO data, second dose vaccinations of Imvamune have lagged with only 35 per cent of those who received a first dose also getting a second one.

“For people in the risk groups, it's just important that they're aware that this virus is still present. It has not gone away,” Bogoch said.

Eligibility for the vaccine in Ontario is limited to two-spirit, non-binary, transgender, cisgender, intersex, or gender-queer individuals who self-identify or have sexual partners who self-identify as belonging to the gay, bisexual, pansexual and other men who have sex with men community.

Individuals within these communities also need to have had a confirmed sexually transmitted infection within the last year, have or are planning to have two or more sexual partners, have attended venues for sexual contact, or who have had anonymous sex.

Receiving two doses of the vaccine is believed to reduce the risk of contracting mpox by 66 to 83 percent, according to Toronto Public Health.