Case Manifestations and Public Health Response for Outbreak of Meningococcal W Disease, Central Australia, 2017

Abstract

Neisseria meningitidis serogroup W has emerged as an increasingly common cause of invasive meningococcal disease worldwide; the average case-fatality rate is 10%. In 2017, an unprecedented outbreak of serogroup W infection occurred among the Indigenous pediatric population of Central Australia; there were 24 cases over a 5-month period. Among these cases were atypical manifestations, including meningococcal pneumonia, septic arthritis, and conjunctivitis. The outbreak juxtaposed a well-resourced healthcare system against unique challenges related to covering vast distances, a socially disadvantaged population, and a disease process that was rapid and unpredictable. A coordinated clinical and public health response included investigation of and empiric treatment for 649 febrile children, provision of prophylactic antimicrobial drugs for 465 close contacts, and implementation of a quadrivalent meningococcal ACWY conjugate vaccine immunization program. The response contained the outbreak within 6 months; no deaths and only 1 case of major illness were recorded.

Keywords: Central Australia; MenACWY vaccine; Neisseria meningitidis; Torres Strait Islander; aboriginal; bacteria; case manifestations; indigenous population; invasive meningococcal disease; meningitis/encephalitis; meningococcal W disease; outbreak; public health response; serogroup W.

Figure 1

Alice Springs Hospital catchment area, Central Australia. Red dot indicates Alice Springs township; orange dots indicate Northern Territory communities; purple dots indicate Western Australia communities; gray dots indicate South Australia communities.

Figure 2

Timeline for outbreak of meningococcal W disease, showing case manifestations, by month, Central Australia, 2017. MenACWY, quadrivalent meningococcal A, C, W, Y conjugate vaccine.