MANITOBA – Canada’s public health agency on Friday confirmed the first case of clade Ib mpox in a person from Manitoba.
The Public Health Agency of Canada (PHAC) said this travel-related case was associated with an ongoing outbreak of clade I mpox in central and eastern Africa.
“The individual sought medical care for mpox symptoms in Canada shortly after their return and is currently isolating,” the agency said in a statement.
“PHAC is working closely with public health authorities in Manitoba. The National Microbiology Laboratory (NML) notified the province on November 22 that the sample tested positive for mpox clade Ib,” the agency added.
While clade II mpox has been circulating in Canada since 2022, this is the first case of clade I mpox confirmed in Canada, the PHAC further said.
The PHAC added that while the risk to Canada’s general population at this time remains low, it continues to actively monitor the situation. It also emphasised that a public health investigation, including contact tracing, is ongoing.
The mpox virus has two main forms: clade I and clade II. Clade I is divided into two subclades: Ia and Ib.
The term “clade” in virology refers to a group of related viruses that share a common ancestor, helping scientists trace the evolutionary relationships and lineage of viruses. It is commonly used to categorise different variants of a virus, such as the offshoots of SARS-CoV-2, the virus responsible for COVID-19. By identifying clades, researchers can track how the virus evolves and spreads over time, providing insights into its transmission patterns and the potential impact of mutations.
Clade I of mpox has been endemic in Congo for years, primarily transmitted from infected animals to humans in rural areas, often affecting vulnerable children and causing more severe symptoms with higher mortality rates.
However, by April of this year, a Canadian-Congolese research team identified a new lineage, clade Ib, which showed signs of human-to-human transmission. The team warned that this new clade could potentially spread beyond Congo, marking a significant shift in the virus’s transmission dynamics.
Accordingly, several cases of the travel-associated mpox clade I subclass Ib have been reported in other countries, including recently in the United States, the province of Manitoba said in its news release.
The World Health Organization earlier in the day had said that the mpox outbreak continues to represent a public health emergency.
The WHO declared mpox a global public health emergency for the second time in two years in August after a new variant of the virus, called clade Ib, spread from the Democratic Republic of Congo to neighbouring countries.
