Bimodal Seasonality and Alternating Predominance of Norovirus GII.4 and Non-GII.4, Hong Kong, China, 2014-2017 1

Emerg Infect Dis. 2018 Apr 17;24(4):767-769. doi: 10.3201/eid2404.171791. Online ahead of print.


We report emerging subtropical bimodal seasonality and alternating predominance of norovirus GII.4 and non-GII.4 genotypes in Hong Kong. GII.4 predominated in summer and autumn months and affected young children, whereas emergent non-GII.4 genotypes predominated in winter months and affected all age groups. This highly dynamic epidemiology should inform vaccination strategies.

Keywords: China; GII.4; Hong Kong; age distribution; bimodal seasonality; geographic hotspot; non-GII.4; norovirus; surveillance; vaccine strain; viruses.