Invasive meningococcal disease cases have risen sharply in the U.S. and Canada since the pandemic, with both countries seeing their highest rates in more than a decade. Driven primarily by Neisseria meningitidis serogroup Y, Canada had 155 cases in 2025, and the U.S. had 503 in 2024 (the latest figures available).
Meningococcal disease is an umbrella term for any infection caused by the bacteria Neisseria meningitidisincluding meningitidis (which is inflammation of the brain and spinal cord lining). While meningococcal disease can cause severe bloodstream infections (sepsis) without meningitis, meningitis is the most common form of meningococcal disease.
Both, however, are critical, with symptoms (i.e., high fever, stiff neck, serve headache, and nausea/vomiting) typically coming on suddenly within 3 to 7 days of exposure, and rapidly progressing, requiring emergency healthcare and antibiotic treatment.
Additionally, both can be transmitted through direct contact with an infected person’s oral
secretions, but meningitis could also occur through contaminated food. Transmission typically does not occur through casual contact or breathing air where an infected person has been.
The advent of meningococcal vaccines in the early 2000s led to a significant reduction in cases, which were further reduced by the 2021 restrictions of the pandemic. However, the pandemic also led to a number of teens missing their recommended vaccines, and the vaccine hesitancy that has spouted since then are likely one cause of the rising case trend.
With vaccines being the best prevention against meningococcal diseases, the CDC recommends vaccination for all preteens and teens, as well as other children and adults at increased risk.
