Prevalence and diversity of norovirus genogroups I and II in Hong Kong marine waters and detection by real-time PCR

► First report describing the prevalence and diversity of NoV genogroups I and II in Hong Kong waters. ► NoV GI.1 and GII.4 are the major genotypes circulating in Hong Kong marine waters. ► Lack of correlation between NoV GI and GII levels and E. coli counts in Hong Kong marine waters. ► Evidence that E. coli is inadequate to reflect NoV levels in Hong Kong marine waters.