Molecular analysis of noroviruses involved in acute gastroenteritis outbreaks in military units in Israel, 1999-2004.

The study presented here was conducted to determine the genetic properties of noroviruses (NoVs) identified between 1999 and 2004 in army recruits with acute gastroenteritis. Partial sequence analysis of the RNA-dependent RNA polymerase gene revealed the presence of two major sub-genogroups, all of which were related to genogroup II of NoV. Serological analysis using recombinant antigens confirmed this observation. Local strains associated with a 1999 outbreak were closely related to GII-6 strains, while those identified later were very closely related to GII-4 strains. GII-4 strains were also associated with an outbreak in civilian nursing homes in Israel in 2002 and samples from this outbreak were included in this study for comparison. This is the first report describing the molecular properties of NoV strains associated with diarrhea-related morbidity in Israel.