What Works for Controlling Meningitis Outbreaks: A Case Study from China

The meningococcal meningitis (MM) vaccine reduces the incidence of MM significantly; however, outbreaks still occur in communities with high vaccine coverage. We aimed to analyze the driving factors of infection from a community outbreak. A total of 266 children aged 9 to 15 years old from the three junior high schools of Tongzi county were identified. We documented infection cases using laboratory tests and analyzed attack rates, infection rates and risk factors for transmission. The index case in School A was identified, and the attack rate in School A was 0.03%. Children showed a significantly low infection rate of MenC in School A (13.2% vs. 19.5% in total children, p = 0.002), while exhibiting significantly high infection rates of MenA in School B (44.1% vs. 24.8% in total children, p < 0.001) and MenB in School C (11.1% vs. 4.1% in total children, p = 0.015). The infection rate of MenA for females (30.0%) was higher (p = 0.055) than for males (19.9%). In School A, 63.19% of children were vaccinated against MenC, while in School B the rate was 42.65% and in School C, it was 59.26%. Three male MenC infection cases were detected as breakthrough infection cases in addition to the index case. The findings suggest that the current full-course immunization has limited long-term effectiveness and is inefficient in preventing the transmission of MM among older children.