Australian Meningococcal Surveillance Programme Annual Report, 2022

Area of Science:

• Epidemiology
• Microbiology
• Infectious Diseases

Background:

• Invasive meningococcal disease (IMD) is a significant public health concern globally.
• Australia reports IMD cases to the National Notifiable Diseases Surveillance System (NNDSS).
• The easing of COVID-19 containment measures may influence disease incidence.

Purpose of the Study:

• To analyze the epidemiology and characteristics of IMD cases in Australia in 2022.
• To identify the predominant serogroups and their distribution across age groups.
• To assess the antimicrobial susceptibility of circulating Neisseria meningitidis strains.

Main Methods:

• Retrospective analysis of IMD case data reported to the NNDSS in 2022.
• Laboratory confirmation using bacterial culture and nucleic acid amplification testing.
• Serogroup determination, fine typing (porA, MLST), and antimicrobial susceptibility testing (MIC).

Main Results:

• IMD notifications increased by 81% in 2022 compared to 2021, totaling 127 cases.
• Serogroup B (MenB) was the predominant cause (83%), followed by MenY (10%) and MenW (4%).
• Children under 5 and adolescents (15-19 years) were most affected; MenB predominated in these groups. Most isolates were susceptible to ceftriaxone, ciprofloxacin, and rifampicin, though 5% showed penicillin resistance.

Conclusions:

• The rise in IMD cases in 2022 highlights the need for continued surveillance.
• Serogroup B remains the primary driver of IMD in Australia, with specific porA types identified.
• While most isolates remain susceptible to key antibiotics, vigilance regarding penicillin resistance is warranted.