Outbreak of invasive meningococcal disease caused by a meningococcus serogroup B in a nursery school, Wallonia, Belgium, 2018

• Published in: Euro surveillance : bulletin européen sur les maladies transmissibles 2022-03, Vol.27 (9), p.1
• Main Authors: Jacquinet, Stéphanie, Mattheus, Wesley, Quoilin, Sophie, Wyndham-Thomas, Chloé, Martin, Charlotte, Van der Linden, Dimitri, Mulder, André, Frère, Julie, Schirvel, Carole
• Format: Article
• Language: English
• Subjects: Belgium; Belgium - epidemiology; Child; Child, Preschool; Disease Outbreaks; Disease transmission; Epidemics; Epidemiology; Human health sciences; Humans; Immunization; Immunologie & maladie infectieuse; Immunology & infectious disease; Meningitis; Meningococcal Infections; Meningococcal Infections - diagnosis; Meningococcal Infections - drug therapy; Meningococcal Infections - epidemiology; Meningococcal Vaccines; Meningococcus B; Neisseria meningitidis, Serogroup B; outbreak management; Outbreaks; Pediatrics; Preschool children; prolonged outbreak; Public Health, Environmental and Occupational Health; Pédiatrie; Schools; Schools, Nursery; Sciences de la santé humaine; Serogroup; Vaccines; Virology
• ISSN: 1560-7917; 1025-496X; 1560-7917
• DOI: 10.2807/1560-7917.ES.2022.27.9.2100224

Although most invasive meningococcal disease (IMD) cases are sporadic without identified transmission links, outbreaks can occur. We report three cases caused by meningococcus B (MenB) at a Belgian nursery school over 9 months. The first two cases of IMD occurred in spring and summer 2018 in healthy children (aged 3-5 years) attending the same classroom. Chemoprophylaxis was given to close contacts of both cases following regional guidelines. The third case, a healthy child of similar age in the same class as a sibling of one case, developed disease in late 2018. Microbiological analyses revealed MenB with identical finetype clonal complex 269 for Case 1 and 3 (unavailable for Case 2). Antimicrobial susceptibility testing revealed no antibiotic resistance. Following Case 3, after multidisciplinary discussion, chemoprophylaxis and 4CMenB (Bexsero) vaccination were offered to close contacts. In the 12-month follow-up of Case 3, no additional cases were reported by the school. IMD outbreaks are difficult to manage and generate public anxiety, particularly in the case of an ongoing cluster, despite contact tracing and management. This outbreak resulted in the addition of MenB vaccination to close contacts in Wallonian regional guidelines, highlighting the potential need and added value of vaccination in outbreak management.