Public health and gay and bi men’s adherence helped bring Canada’s mpox epidemic under control

An aggressive public health response and immediate buy-in from men who have sex with men — the group hardest hit by the outbreak — helped contain mpox in Canada, public health doctors say.

High vaccination rates and behavioral change – mostly among gay and bisexual men – have all but eliminated the viral illness formerly known as « monkeypox » since cases peaked over the summer.

« It’s a remarkable story of success in an outbreak that was completely unanticipated and has spread globally, » said Zain Chagla, an infectious disease physician and professor at McMaster University.

« The community has really been leveraged to protect theirs and have done an amazing job of reaching the networks they needed to reach what typical public health officials couldn’t. »

Mpox is a viral disease closely related to smallpox that is transmitted by close physical contact and can pass from animals to humans.

Most common in Central and West Africa, mpox is only occasionally found elsewhere in the world. But in early May, multiple outbreaks appeared simultaneously in non-endemic countries, such as Canada and the United States, for the first time.

Although gay men are not particularly predisposed to contracting the virus, about 99% of recorded cases in Canada have been among men, most of them gay or bisexual, according to the Public Health Agency of Canada. said at the top of hatching.

After a sharp increase in the total number of cases from May to the end of August, the number of mpox cases in Canada has since plateaued.

Because so few Canadians are now infected with mpox, some provinces have stopped providing regular disease updates. The Public Health Agency of Canada now considers current levels of mpox to be “low”.

This reversal is due to a series of factors, Chagla said. First, mpox spreads through prolonged close contact and is therefore easier to control through contact tracing and isolation than more communicable diseases, such as COVID-19.

Second, most governments already have stocks of smallpox vaccine to guard against a chance outbreak or the threat of bioterrorism. The vaccine, called Imvamune, had already been approved by Health Canada when cases of mpox began to appear here and could be used immediately.

Dr. Zain Chagla, an infectious disease physician and associate professor of medicine at McMaster University, said several factors worked in Canada’s favor when it came to dealing with the mpox outbreak. (Craig Chivers/CBC)

Finally, a broad public health response—which relied heavily on men’s sexual health groups—convinced gay and bisexual men to get vaccinated, limit sexual contact, and self-isolate at the onset. symptoms.

“There was a very early and aggressive focus on at-risk communities and an early and significant focus on partnerships in that community to ensure that education, messaging, counseling support – it was all two-way “, said Chagla.

Grassroots involvement

Dane Griffiths is director of the Gay Men’s Sexual Health Alliance, a Toronto-based sexual health organization. He said he first heard of mpox following reports in May that cases had been found in Western Europe.

Less than a week later, officials have reported that the first cases of mpox in Canada was found in Montreal.

The alliance responded by developing a dedicated mpox web page, running an information campaign on multiple social media platforms, designing resources for clinical care settings, and collaborating with summer festivals, such as Toronto Pride, to make those present aware of the risks.

Pride Toronto volunteers carry a large rainbow flag during the 2019 Toronto Pride Parade on Sunday, June 23, 2019. (Andrew Lahodynskyj/The Canadian Press)

Griffiths said the alliance could leverage its existing network to deliver public health messages « directly to the community » facing the highest risk.

“I think we really took the advice from health officials and community representatives very seriously,” Griffiths said. « And vaccination rates were exceptionally high. »

Although the percentage of gay and bisexual men in Canada who received the mpox vaccine is difficult to estimate, the Public Health Agency of Canada said in an email to CBC that vaccination clinics administered 111,520 doses of the Imvamune vaccine as of November 13, 2022. .

A full series of Imvamune includes two doses, but due to limited availability at the start of the epidemic, most people at high risk were encouraged to receive only one.

Griffiths said now that the outbreak is more contained, the alliance’s priority is to encourage people who have received their first dose to complete their vaccination.

The epidemic is “retreating” on a global scale

Rosamund Lewis, technical lead for mpox at the World Health Organization, said the state of the outbreak in Canada is similar to outbreaks in the United States and some European countries. As new cases continue to emerge, the global total is rapidly declining.

« That means the epidemic is receding, » Lewis said. « It’s self-contained. »

Lewis said the outbreak in Canada has followed a « classic bell curve », with cases rising rapidly through the summer, followed by a brief spike and a steep decline since.

“Low-level circulation” likely persists in Canada, Lewis said, with small, unreported cluster outbreaks.

Although some World Health Organization officials have say it’s possible to eliminate mpox in Europe, it is unlikely that the disease will be completely eliminated worldwide.

Christopher Labos, a Montreal cardiologist with a degree in epidemiology, said the presence of an « animal reservoir » means the virus could still come back to humans, even if cases drop to zero.

Currently, outbreaks are largely confined to African countries where cases are caused by a different strain than that found in Canada.

Chagla said the continued presence of cases abroad underscores the need for global vaccination efforts to help prevent future global outbreaks.

« It may not be the last [mpox] event that we see,” he said.


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