Early engagement with affected communities helped to control mpox outbreak in Montreal

An analysis of the first large mpox outbreak in North America found that early, sustained engagement and rapid offering of preexposure vaccination to affected communities successfully controlled the spread of the outbreak. The analysis is published in Annals of Internal Medicine.

Mpox is historically endemic to west and central Africa but spread significantly in other countries in 2022, primarily among the men who have sex with men (MSM) community. During this time, Montreal, Quebec, Canada, emerged as the site of the first large outbreak in North America.

Researchers from McGill University Health Centre, Montreal, Canada characterized and analyzed the epidemiologic, clinical, and demographic data from 402 persons with probable or confirmed cases of mpox in Montreal and the public health response by Montreal Public Health.

The authors report that Montreal experienced its initial mpox outbreak in May 2022, followed by two peaks in early June and early July. This was followed by a decline in cases. Nearly all reported cases were among MSM who likely acquired the infection through sexual contact. Montreal public health authorities acted quickly to lead interventions to control the transmission.

These interventions included early and sustained engagement with the affected communities; alerting clinicians to promote rapid case detection and reporting; performing case investigation and contact tracing; and contributing to the development of interim guidance on diagnostic testing, case and contact management, and recommended infection and control prevention measures.

According to the authors, the prompt recognition of the importance of preexposure vaccination in at-risk populations and the extended offer of MVA-BN to tourists coming to Montreal led to many being vaccinated. They add that increasing and supporting equitable access to vaccines for at-risk populations worldwide should be a global priority for the prevention and control of mpox.