Australian Rotavirus Surveillance Program: annual report, 2009/2010

Area of Science:

• Virology
• Epidemiology
• Public Health

Background:

• The Australian Rotavirus Surveillance Program monitors rotavirus strains nationwide.
• This surveillance occurs in the third year post-introduction of rotavirus vaccines into the National Immunisation Program.
• Focus is on hospitalizations of children with acute gastroenteritis.

Purpose of the Study:

• To determine the G and P genotypes of rotavirus strains causing hospitalizations in children.
• To analyze rotavirus genotype distribution following the introduction of national rotavirus vaccination.

Main Methods:

• Collection and analysis of 778 fecal samples from children with acute gastroenteritis.
• G and P genotype determination using hemi-nested multiplex reverse transcription-polymerase chain reaction (RT-PCR).
• Surveillance conducted from July 1, 2009, to June 30, 2010.

Main Results:

• Rotavirus was confirmed in 422 samples.
• Genotype G1P[8] was the most prevalent (49.3%), followed by G2P[4] (21.1%).
• An increase in uncommon rotavirus genotype combinations (e.g., G1P[4], G2P[8]) was observed post-vaccine introduction.
• A significant G1P[8] outbreak occurred in the Northern Territory.

Conclusions:

• Rotavirus genotype G1P[8] remains dominant, with significant fluctuations observed.
• Limited evidence of vaccine-driven genotype selection, but potential vaccine pressure on wild-type strains suggested by the Northern Territory outbreak.
• Continued surveillance is crucial for understanding rotavirus epidemiology in the context of vaccination.