Australian Rotavirus Surveillance Program: Annual Report, 2024

Area of Science:

• Virology
• Epidemiology
• Public Health

Background:

• Rotavirus remains a significant cause of gastroenteritis globally, particularly in young children.
• The Australian Rotavirus Surveillance Program monitors circulating rotavirus strains and genotypes.
• Vaccination programs aim to reduce rotavirus disease burden, necessitating ongoing surveillance of vaccine effectiveness and circulating strains.

Purpose of the Study:

• To describe the circulating rotavirus genotypes in Australia from January 1 to December 31, 2024.
• To assess the burden of rotavirus disease and identify dominant strains.
• To provide data for evaluating the national rotavirus vaccination program and informing public health strategies.

Main Methods:

• Collection and analysis of 2,118 faecal specimens referred to the National Rotavirus Reference Centre (NRRC).
• G- and P-genotyping of rotavirus strains using molecular methods.
• Comparison of identified genotypes with national surveillance data and vaccine strains.

Main Results:

• A total of 1,880 rotavirus-positive specimens were identified, indicating a high disease burden.
• The equine-like G3P[8] variant was the dominant wildtype genotype (80.6%).
• Rotarix vaccine-like strains were detected in 14.3% of positive samples, and 10,108 national rotavirus notifications were recorded, the highest since program inception.

Conclusions:

• The equine-like G3P[8] genotype continues to be the predominant strain circulating in Australia.
• High numbers of rotavirus cases and the detection of vaccine-like strains highlight the ongoing impact of rotavirus disease and the importance of surveillance.
• Continuous monitoring of rotavirus genotypes is essential for assessing vaccination program effectiveness and guiding public health responses to outbreaks.