Meningococcal Serogroup C Outbreak in Chicago Highlights Importance of Outreach

Officials with the ACIP heard details today about a meningococcal serogroup C outbreak in Chicago.

An outbreak of meningococcal serogroup C virus in Chicago put men who have sex with men at high risk of exposure, according to a presentation today at the Advisory Committee on Immunization Practices (ACIP) 2015 meeting.

Sarah Kemble, MD, MPH, of the Chicago Department of Public Health (CDPH), presented details of the outbreak, noting there were 6 cases in the Chicago area, with 1 additional case in a neighboring county, predominantly among African American men. The first case was identified in May in an HIV-positive male in a monogamous relationship.  Within 2 weeks, 2 more cases were reported among men who have sex with men (MSM).

“We estimated that the meningococcal serogroup incidence had reached 19 out of 100,000 as of June 3rd among MSM with HIV,” said Dr Kemble. “So this was reaching the threshold that would define an outbreak.”

Among the 7 patients, 5 were HIV-positive, 5 reported anonymous sex, and 5 reported using “hook up” apps to meet sexual partners, Dr Kemble explained. On June 3, 2015, the CDPH issued an initial meningococcal vaccination recommendation for MSM who are HIV-positive, have close contact with anonymous partners, or who used “hook up” apps to find sexual partners.

As part of the investigation, health officials traced all contacts who were intimate with infected individuals 90 days prior to the illness onset.  On average, 4 contacts per case met the indications for prophylaxis. “Some people were willing to post vaccination campaigns on their [social media] pages,” Dr Kemble added.

The CDPH initiated federally funded programs to increase access to the meningococcal vaccine. Health officials also used pop-up clinics, and also partnered with existing clinic sites in Chicago. They also partnered with community-based organizations like HIV providers, sexually transmitted infection clinics, and the LGBT Aldermen’s Caucus to raise awareness.

The CDPH also initiated a media campaign that included press releases, paper canvassing, billboard ads, push notifications on “hook-up sites” like Grindr, and digital ads on Facebook, Twitter, and Google.

“We looked at upcoming events, and Pride Week was just around the corner,” said Dr Kemble. “This represented a greater risk of disease transmission in the MSM population. It also represented an opportunity to get the vaccine out.”

The CDPH used popular Chicago festivals and events to raise awareness and set up the pop-up clinics to provide vaccines. They handed out information about clinics and reminded everyone who came to the clinic that men who are HIV-positive require 2 doses of the vaccine, given 8 weeks apart.

The meningococcal vaccination campaign imposed a substantial financial burden on the CDPH, according to Dr Kemble. The total cost for setting up the pop-up clinics was around $50,000, with an additional $19,000 for the media campaign. It also required approximately 3,700 staff hours to promote vaccination awareness and administration.

Most of the vaccines administered early on in the outbreak were given during Pride Week and other festivals, but Dr Kemble noted that permanent clinical sites are required for sustained vaccination efforts.


1. Kemble S. Meningococcal Vaccines Introduction Serogroup C Outbreak Among Men Who Have Sex With Men (MSM), Chicago, 2015. Presented at the Advisory Committee on Immunization Practices, Oct. 21, 2015, Atlanta.