A 2024 electron microscope image released by the National Institute of Allergy and Infectious Diseases shows green mpox virus particles inside blue-coloured infected cells. On Friday, the province of Manitoba announced it had confirmed the first case of the Ib strain of mpox in Canada. (NIAID/Associated Press)
Manitoba has confirmed Canada’s first case of a recently identified mpox strain known as clade Ib. Formerly referred to as monkeypox, this variant belongs to clade I, a strain linked to more severe illness compared to the globally dominant clade II, which typically causes milder symptoms.
The newly reported case is tied to travel and originates from an ongoing outbreak in central and eastern Africa. Clade I has historically been associated with the Congo region, where it mainly spreads through contact with infected animals. However, recent studies by a Canadian-Congolese research team revealed that clade Ib is adapting to human-to-human transmission, raising concerns about its potential spread beyond Africa.
Clade Ib has already been detected in other countries, including the United States. Manitoba’s case marks its first appearance in Canada. The infected individual was diagnosed after returning to the province and is now in isolation. Public health authorities are conducting contact tracing to monitor potential exposures.
Mpox, known for its pox-like skin lesions, typically causes mild symptoms like fever, swollen lymph nodes, and rashes. Most individuals recover fully, but severe cases can occur. The virus spreads through close contact, including sexual contact or exposure to contaminated items like bed sheets or towels.
The Manitoba government reassures residents that the risk to the public remains low. Both clades of mpox require close interaction with symptomatic individuals to spread, making widespread transmission unlikely without direct contact.
Experts continue to track the virus’s evolution closely. The emergence of clade Ib, with its higher transmissibility among humans, underscores the importance of public health vigilance. The province has emphasized protecting the privacy of the infected individual, releasing limited details while maintaining ongoing monitoring and response efforts.
This case highlights the interconnected nature of global health, with emerging diseases travelling across borders more easily than ever before. Officials urge travellers to remain vigilant, especially when visiting regions experiencing outbreaks, and to seek medical attention if they notice unusual symptoms after returning home.
