Manitoba detects 1st confirmed case of recently identified mpox strain in Canada

Manitoba has recently confirmed the first case of clade Ib mpox in Canada, marking a significant development in the ongoing global outbreak of the virus. This particular strain of mpox, formerly known as monkeypox, is part of a newly identified lineage that has been causing concern among health officials.

The mpox virus is categorized into two main forms: clade I and clade II. The term “clade” is used in virology to track the evolutionary family tree of viruses, similar to how variants are used to describe different strains of SARS-CoV-2, the virus behind COVID-19. The global outbreak of mpox in 2022 was primarily dominated by clade II, which typically results in milder illness and is spread through sexual contact.

According to Health Canada, as of October 31, there had been no confirmed cases of clade I mpox in Canada. Clade I is further divided into subclades Ia and Ib. The case detected in Manitoba is the first instance of clade I mpox in the country and is believed to be travel-related, originating from an outbreak in central and eastern Africa.

Clade I mpox has historically been circulating in Congo and is associated with more severe disease and higher death rates. It has primarily spread from infected animals to people in rural regions, particularly affecting vulnerable children. A new lineage within clade I, known as clade Ib, was identified earlier this year by a Canadian-Congolese research team. This particular lineage showed signs of efficient human-to-human transmission and was impacting a high number of sex workers, raising concerns about its potential spread beyond Congo.

Several cases of the travel-associated mpox clade I subclass Ib have been reported in other countries, including the United States. The individual infected in Manitoba was diagnosed shortly after returning to the province and is currently isolating. A public health investigation, including contact tracing, is underway to prevent further spread of the virus.

While mpox often causes mild disease characterized by pox lesions, it can also lead to more serious symptoms such as a painful rash, enlarged lymph nodes, and fever. The overall risk to the general public in Manitoba is considered low, as mpox does not spread easily between people unless there is close contact with an infected individual.

Both clades of mpox can be transmitted through close contact, including sexual contact, with an infected person, as well as contact with contaminated materials or infected animals. It is essential for individuals to practice good hygiene and follow public health guidelines to prevent the spread of the virus.