Changes in norovirus incidence in Victoria, Australia, during the COVID-19 pandemic, 2020–2021

Abstract

There were 142 norovirus positive outbreaks in Victoria for the 2020–2021 calendar years; however, almost half of these (48.6%) occurred in Q1 (January–March) of 2021. For the two-year period, 69.0% of all norovirus positive outbreaks were in childcare settings, and the predominant genotype was GII.P16/GII.2 (64.9%) followed by GII.P31/GII.4_2012 (20.9%). Norovirus incidence was particularly low in 2020 (n = 26) and close to average in 2021 (n = 116), but genotype diversity was low in both years. With the thought that 2022 will approach a more normal aspect to socialising and travel, norovirus incidence in 2022 may be predicted to increase above typical levels.