Close watch on invasive meningococcal disease

Victorian health authorities are monitoring the rise in invasive meningococcal disease caused by a previously seldom-seen strain which can present atypically in the elderly.

Surveillance shows that the proportion of cases caused by Neisseria meningitides serogroup W sequence type 11 (Men W STII) has risen from 4% in 2013 to 30% in 2015 and it’s suspected that it might now be endemic.

The state’s Chief Health Officer has told clinicians that Men W ST11 should be considered as a differential diagnosis of atypical infections in older patients, including septic arthritis and epiglottitis.

However, more widespread use of the quadrivalent meningococcal vaccine has not been recommended as case numbers of the disease remain low.

Writing in the US Centers for Disease Control journal Emerging Infectious Diseases, Victorian public health officers say the ST11 strain took off in the