NAVAL HEALTH RESEARCH CENTER SAN DIEGO CA SAN DIEGO United States
In 2016, among residents of the Federal Republic of Germany, norovirus incidence reported during the winter season was unusually high and reported earlier than usual. In November 2016, at least 14,872 laboratory-confirmed cases were reported in Germany, representing almost twice the median number of cases reported 7,810 cases in the same month over the past 5 years. During the 20162017 norovirus season October-March, Epidemiological Weeks 3913, a total of 79,378 cases were reported by the Robert Koch Institute. The total case count was greater than the counts during each of the previous four seasons 42,621 cases in 2015-2016 67,646 cases in 2014-2015 59,587 cases in 2013-2014 and 66,783 cases in 2012-2013. The largest number of norovirus cases in recent years in Germany was the 95,575 cases reported during the 2011-2012 season. The Robert Koch Institute reported an emerging norovirus recombinant strain GII.P16G.II.2 during the 2016-2017 outbreak. The strain was identified in nine federal states across Germany by sequencing two open reading frames ORF1 polymerase and ORF2 capsid. Herd immunity in the German civilian population was likely attained against previously circulating norovirus strains however, Niendorf et al. concluded that the acquired immunity against previous strains may not have been effective against the emerging variant strain, further propagating the outbreak. This study characterizes norovirus isolates from Military Health System MHS beneficiaries which corresponded temporally and geographically with the 2016-2017 outbreak in Germany.
Medical Surveillance Monthly Report, 24, 7, 01 Jan 0001, 01 Jan 0001,