Influence of Serogroup on the Presentation, Course, and Outcome of Invasive Meningococcal Disease in Children in the Republic of Ireland, 1995–2000

To test the hypothesis that the infecting meningococcal serogroup modulates the presentation, course, and outcome of invasive meningococcal disease (IMD), we performed a retrospective review of cases of IMD in 407 children from 2 tertiary referral centers and 2 regional centers in Ireland. Patients infected with serogroup C meningococci (n = 104) were older than those infected with serogroup B (n = 303; median, 2.5 vs. 1.5 years; P = .04); all other demographic and clinical parameters were similar for the 2 groups. Among serogroup B patients, mortality was 3.6% and morbidity was 10%; for serogroup C patients, mortality was 4.8% and morbidity was 12.5% (P = .81 and P = .76, respectively). Serogroup C—associated sequelae more often were multiple (P = .003). Despite the introduction of serogroup C conjugate vaccine into the routine immunization schedule of some countries, ongoing morbidity from IMD is anticipated, because group B disease was very similar to group C disease in this pediatric population.