Australian Rotavirus Surveillance Program: Annual Report, 2018.

Area of Science:

• Virology
• Epidemiology
• Public Health

Background:

• Rotavirus is a leading cause of severe acute gastroenteritis in infants and young children globally.
• Australia's National Immunisation Program (NIP) switched to a single rotavirus vaccine (Rotarix) in July 2017.
• Ongoing surveillance is essential to monitor the impact of vaccination changes on rotavirus epidemiology.

Purpose of the Study:

• To determine the rotavirus genotypes circulating in Australia between January 1 and December 31, 2018.
• To analyze the distribution of wild-type and vaccine-like rotavirus strains.
• To provide data for assessing potential impacts of the NIP vaccination schedule change.

Main Methods:

• Collection and analysis of 690 fecal specimens from patients with acute gastroenteritis.
• G and P genotyping of 607 confirmed rotavirus-positive samples.
• Distinguishing between wild-type and vaccine-like rotavirus strains.

Main Results:

• G3P[8] was the dominant wild-type rotavirus genotype, identified in 52% of 457 analyzed samples.
• G2P[4] was the second most common genotype, found in 17% of samples.
• 150 out of 607 (24.7%) rotavirus-positive samples were identified as vaccine-like strains.

Conclusions:

• The G3P[8] genotype was the most prevalent wild-type rotavirus strain in Australia in 2018.
• The shift to Rotarix-only vaccination in the NIP warrants continued monitoring for effects on rotavirus genotype distribution.
• Surveillance data is vital for understanding rotavirus epidemiology and vaccine effectiveness in Australia.