Authors:
Donato CM, Cowley D, Snelling TL, Akopov A, Kirkness EF, Kirkwood CD
Authors notes:
Emerging Microbes and Infections. 2014;3:e47
Keywords:
Australia, diarrheal outbreak, G1P[8], full-genome analysis, rotavirus, Rotarix
Abstract:
In 2010, a large outbreak of rotavirus gastroenteritis occurred in the Alice Springs region of the Northern Territory, Australia.
The outbreak occurred 43 months after the introduction of the G1P[8] rotavirus vaccine Rotarix®.
Forty-three infants were hospitalized during the outbreak and analysis of fecal samples from each infant revealed a G1P[8] rotavirus strain.
The outbreak strain was adapted to cell culture and neutralization assays were performed using VP7 and VP4 neutralizing monoclonal antibodies.
The outbreak strain exhibited a distinct neutralization resistance pattern compared to the Rotarix® vaccine strain.
Whole genome sequencing of the 2010 outbreak virus strain demonstrated numerous amino acid differences compared to the Rotarix® vaccine strain in the characterized neutralization epitopes of the VP7 and VP4 proteins.
Phylogenetic analysis of the outbreak strain revealed a close genetic relationship to global strains, in particular RVA/Human-wt/BEL/BE0098/2009/ G1P[8] and RVA/Human-wt/BEL/BE00038/2008/G1P[8] for numerous genes.
The 2010 outbreak strain was likely introduced from a globally circulating population of strains rather than evolving from an endemic Australian strain.
The outbreak strain possessed antigenic differences in the VP7 and VP4 proteins compared to the Rotarix® vaccine strain.
The outbreak was associated with moderate vaccine coverage and possibly low vaccine take in the population.