Australian Meningococcal Surveillance Programme annual report, 2019

Area of Science:

• * Infectious Diseases
• * Microbiology
• * Public Health Surveillance

Background:

• * Invasive meningococcal disease (IMD) is a significant public health concern and a notifiable disease in Australia.
• * Surveillance data is crucial for understanding disease epidemiology and informing public health interventions.

Observation:

• * In 2019, Australia reported 206 IMD notifications, with 202 laboratory-confirmed cases analyzed.
• * Neisseria meningitidis serogroup B (MenB) was the most common cause (50.0%), followed by MenW (26.2%), MenY (20.8%), and MenC (3.0%).
• * The hypervirulent MenW strain (PorA type P1.5,2, ST-11) was identified in a significant proportion of MenW cases.

Findings:

• * IMD incidence peaked in infants under one year and adults aged 65 and over.
• * Age-specific serogroup distribution showed MenB predominant in younger age groups, while MenW and MenY were more common in older adults.
• * Antimicrobial susceptibility testing revealed low-level penicillin resistance in 92% of isolates and rare resistance to rifampicin, though all remained susceptible to ceftriaxone and ciprofloxacin.

Implications:

• * Understanding serogroup prevalence and age distribution is vital for targeted vaccination strategies.
• * Monitoring antimicrobial resistance is essential to ensure effective treatment of IMD.
• * The continued circulation of hypervirulent strains necessitates ongoing surveillance and potential public health responses.