Annual Summary of Norovirus Infections, 2017

In 2017, HPS received 866 laboratory reports of norovirus (NV), a rate of 16.3 per 100,000. This was a decrease of 683 (44.1%) on the 1549 reports received in 2016 and was the lowest number of reports over the past 10 years (Figure 1). The average number of reports per year in the previous nine years had been 2013 reports, with a range of 1306 to 3109 reports.