Outbreak of Serogroup C Invasive Meningococcal Disease Among MSM in Southern California

Outbreaks of invasive meningococcal disease caused by serogroup C (NmC) among men who have sex with men (MSM) have occurred in various U.S. cities including New York, Chicago, and Los Angeles, as well as in Europe, since 2010. As a result, the meningococcal vaccine containing serogroup C (MenACWY) has been recommended for MSM who are infected with HIV, have multiple sex partners, or who find partners using the Internet or social media. Between March and August 2016, 25 cases of invasive disease caused by NmC (1 of unknown serogroup), including 2 deaths, were reported in Southern California. Most were MSM, 2 were HIV-infected, and 8 were Hispanic; median age was 32 years. The estimated attack rate was 6.4 cases per 100,000 population — rough…