Molecular epidemiology of norovirus gastroenteritis outbreaks in New Zealand from 2002–2009

Authors

  • Gail E. Greening,

    Corresponding author
    1. Norovirus Reference Laboratory, Institute of Environmental Science and Research Ltd., Kenepuru Science Centre, Porirua, New Zealand
    • Norovirus Reference Laboratory, Institute of Environmental Science and Research Ltd., Kenepuru Science Centre, PO Box 50-348, Porirua 5240, New Zealand.
    Search for more papers by this author
  • Joanne Hewitt,

    1. Norovirus Reference Laboratory, Institute of Environmental Science and Research Ltd., Kenepuru Science Centre, Porirua, New Zealand
    Search for more papers by this author
  • Malet Rivera-Aban,

    1. Norovirus Reference Laboratory, Institute of Environmental Science and Research Ltd., Kenepuru Science Centre, Porirua, New Zealand
    Search for more papers by this author
  • Dawn Croucher

    1. Norovirus Reference Laboratory, Institute of Environmental Science and Research Ltd., Kenepuru Science Centre, Porirua, New Zealand
    Search for more papers by this author

Abstract

Noroviruses are the most common cause of acute non-bacterial gastroenteritis outbreaks worldwide, including New Zealand. New Zealand has a population of 4.4 million, which allows for centralized outbreak surveillance and a Norovirus Reference Laboratory, which facilitates efficient diagnosis, surveillance, and tracking of norovirus outbreaks. Norovirus outbreak strains are identified, sequenced, and compared with international reference strains. Between January 2002 and December 2009, 1,206 laboratory-confirmed norovirus outbreaks were recorded. The predominant outbreak settings were healthcare institutions for the elderly and acute care patients. Other outbreak settings included catering establishments, cruise ships, homes, community events, school camps, child-related settings, and consumption of contaminated shellfish. Of the 1,206 outbreaks, 105 (8.7%) were caused by norovirus genogroup I (GI) strains, 1,085 (89.9%) were caused by genogroup II (GII) strains, and both GI and GII strains were detected in 9 (0.8%) outbreaks. The genogroup was not identified in 7 (0.6%) outbreaks. A range of norovirus genotypes, including GI genotypes 1–6, GII genotypes 2–8, and GII.12, were associated with these outbreaks. The predominant genotype was GII.4, which was identified in 825 (68.4%) outbreaks. Norovirus GII.4 variant strains, including 2002 (Farmington Hills), 2004 (Hunter), 2006a (Laurens, Yerseke), 2006b (Minerva), and 2010 (New Orleans) implicated in overseas outbreaks also occurred in New Zealand, providing evidence of global spread. J. Med. Virol. 84:1449–1458, 2012. © 2012 Wiley Periodicals, Inc.

Ancillary