Outbreak detection: Increase in Neisseria meningitidis serogroup W invasive disease in Canada: 2009–2016

Background: Since 2010, there has been an increase in serogroup W Neisseria meningitidis (MenW) disease in many countries due to an emerging sequence type-11 clonal complex (ST-11 CC). In 2016, a small increase in MenW disease due to the ST-11 CC was documented in Ontario, Canada