Health Canada says it is "closely monitoring" the resurgence of mpox cases, after the World Health Organization (WHO) declared a public health emergency of international concern on Wednesday.

While cases of the new strain spreading mainly in Africa have yet to be confirmed in Canada, epidemiologists are calling on the federal government to do more to help prevent the international outbreak from worsening.

Here's what you need to know about Canada's response to the current outbreak.

No 'clade I' cases confirmed in Canada

As of Aug. 15, Health Canada says there have been no cases of the more severe "clade I" variant of the mpox – previously known as monkeypox – detected in Canada.

"We've been doing wastewater monitoring… and so far, we have not detected clade I in Canada to date, but that could change," said Canada's Chief Public Health Officer Dr. Theresa Tam.

Federal officials say they have the ability to test for both types, and are working with provinces and territories on reporting.

"We really still need to be vigilant. We need to study any cases that might arise," Tam said.

This type of the virus is different than the strain that sparked a months-long global emergency in 2022. Cases of that version of mpox continue to spread in Canada, with some regions reporting a summer surge.

According to Tam, as of mid-July, 164 cases of "clade II" mpox have been reported across Canada this year.

She advises Canadians within the category of eligible adults considered at a high-risk of exposure – such as men who have sex with men – to get vaccinated.

Otherwise, individuals should minimize their risk of exposure through reducing contact with people who may be sick, maintaining good hygiene and sexual health practices, and be vigilant when attending events that entail prolonged close contact with others.

Travel advice in effect

In terms of the new strain, the federal government says the risk to Canadians in this country "remains low," though work is being done to update travel advisories.

For now, Canadians are being urged to take precautions if travelling to countries with outbreaks.

A travel health notice to "practise enhanced health precautions" has been in effect for the Democratic Republic of Congo (DRC) since April, where this version first appeared. 

While the current major outbreak started in the DRC, it has since spread to neighbouring African countries, resulting thousands of cases and hundreds of deaths.

On Thursday, the first case of the contagious variant outside of the continent was reported in Sweden.

What do we know about this strain?

Scientists say the mutation prompting the new WHO warning is more transmissible and appears to be more easily spreading through human-to-human contact, with a number of children contracting this current strain in Africa.

"We're talking about a new, what we call sub-lineage of one of the types, and it's called clade Ib and it's showing quite a different behaviour than some of the other types of this virus," said Doctors Without Borders infectious disease specialist Aula Abbara.

Mpox can spread through physical contact with infected lesions, scabs, blood or other body fluids, as well as through respiratory droplets from coughs and sneezes.

The virus can also be transmitted through direct contact with contaminated objects such as bedding or toothbrushes, as well as through animal contact.

Noting the spread can occur beyond sexual activity, the WHO has reported seeing children in Africa being infected through close contact.

Symptoms usually begin five to 21 days after exposure, and can include fever, chills, swollen lymph nodes, muscle and joint pain, headache, exhaustion and the onset of a rash or lesions.

"Just like in any infectious disease response, we need to know who is sick so these people do not infect other people. So testing and surveillance is the key," said WHO spokesperson Tarik Jasarevic.

"And by declaring a global health emergency, we really want to make sure that all governments are on alert for any mpox cases on their territory."

What's the vaccine situation?

Health Canada says it has secured a "sufficient supply" of vaccines to sustain current prevention and control efforts. Imvamune, as the vaccine is called, protects against both clade I and II.

National guidance still limits the two-dose vaccination series to those at high-risk of exposure, and at this time, vaccination of the general public is not recommended.

Epidemiologists say in order to prevent the virus from becoming a bigger threat to Canadians, the government should consider quickly donating doses to harder-hit countries.

With global disease control experts warning in a new medical publication that a failure to act or offer little more than "performative charity," could be disastrous. 

In an interview with CTV News, Jason Kindrachuk, Canada Research Chair in emerging and re-emerging viruses at the University of Manitoba, said there is "an unprecedented need" in hot spot countries for vaccines, diagnostics, and funding to maintain the ongoing response.

"If we don't try and get things contained on the ground… we inevitably are going to have to over-invest in response efforts when these types of outbreaks escalate. And certainly we run the risk of seeing potential introduction more broadly," he said.

"It's obviously the ethical thing to do and the moral thing to do… But there also is a larger economic and certainly national public health preparedness strategy that that needs to also fall in line."

The United States announced Wednesday that it would be donating 50,000 doses of a joint smallpox and mpox vaccine to the DRC.

"Vaccination will be a critical element of the response to this outbreak," said the U.S. Department of Health and Human Services in a statement. 

"The United States is working with other countries, WHO, and international partners to encourage donations that support vaccine efforts and address challenges to vaccine delivery."

So far, the federal government has yet to confirm next steps, pointing in its statement to the millions of dollars donated in recent years to the WHO's emergency contingency fund, and past partnership with a global vaccine alliance.

"Canada has been closely working with our international partners. At the moment, we're waiting to see specifically what is being asked," Tam said.

Health Canada has vowed to provide updates, as the situation evolves.