Situation

Northwestern Health Unit’s (NWHU) catchment area has recently seen an increase in invasive meningococcal disease (IMD). Since April 2025, four cases of IMD have been identified in our region. These have mostly been concentrated in remote First Nations. All four cases have been identified as serogroup W.  While some linkages exist, some cases have been sporadic.  Prior to the recent increase, the last case of IMD in the NWHU region was in July 2023. There has also been a recent increase in Meningococcal cases serogroup W in Manitoba in 2024.

Issue

IMD is a rare but serious bacterial infection caused by Neisseria Meningitidis, a gram-negative diplococci, that generally presents as either meningitis or sepsis. Both are extremely serious and require urgent hospital attention. Between 8-15% of individuals with this disease will die, and 10-20% of those who survive will have long term disabilities.

IMD can progress very rapidly. In the early stages, IMD can have similar symptoms to other respiratory viral infections, it can also occur at the same time or after these infections. Early diagnosis and treatment are the most important mechanism for preventing morbidity and mortality.  Risk of IMD can be significantly reduced with meningococcal vaccine.

Requested actions

• Remain vigilant for signs and symptoms of IMD when assessing patients in the region. 
• Follow current testing guidance for IMD. 
• Immediately report to NWHU any suspected or confirmed cases of IMD.  After hours reporting is available 24/7 at 866-475-6505. 
• Be aware that close contacts of IMD cases are eligible for chemoprophylaxis as per the Infectious Disease Protocol for IMD.  
• Promote or provide vaccination to those eligible for Meningococcal vaccine as per the Publicly Funded Immunization Schedules for Ontario: 
  • Men-C-ACWY is a one dose vaccine given in grade 7, those born 1997 or later are eligible as an adult.  
  • High risk eligibility is for those age 9 months and older who have one of the following (based on age refer to the appropriate schedule in the Ontario vaccine schedule)  
    • Acquired complement deficiencies 
    • Asplenia (functional or anatomic) 
    • Cochlear implant recipients (pre/post implant) 
    • Complement, properdin, factor D or primary antibody deficiencies 
    • HIV

Resources

• Government of Canada – Invasive Meningococcal Disease for Health Care Professionals 
• Public Health Ontario – Invasive Meningococcal Disease 

Contact
Dr. Kit Young Hoon, MPH, MSc., FRCPC 
Medical Officer of Health 
Northwestern Health Unit