In the US, outbreak-associated cases account for approximately 5% of all meningococcal disease cases, a recent study found. The retrospective review of all meningococcal disease cases reported from January 1, 2009 to December 31, 2013 was performed by state health departments and CDC to identify meningococcal disease outbreaks. An outbreak was defined as ≥2 primary cases of the same serogroup in <3 months in an organization, or an at-least 2-fold increase in disease rates in a community. Researchers found:
- From 2009 to 2013, 3,686 cases of meningococcal disease were reported in the US.
- Among these, 180 (4.9%) primary cases occurred as part of 36 outbreaks.
- Serogroup B was the primary cause of organization-based outbreaks.
- The majority of community-based outbreaks were due to serogroup C.
- Organization- and community-based outbreaks differed in predominant serogroup, age distribution of cases, and clinical syndrome.
Mbaeyi SA, Blain A, Whaley MJ, Wang X, Cohn AC, MacNeil JR. Epidemiology of meningococcal disease outbreaks in the United States, 2009–2013. [Published online ahead of print June 30, 2018]. Clin Infect Dis. doi:10.1093/cid/ciy548.