Genotype GI.6 Norovirus, United States, 2010–2012 - Vol. 19 No. 8 - August 2013 - Emerging Infectious Disease journal - CDC
Table of Contents
Volume 19, Number 8–August 2013
Volume 19, Number 8—August 2013
Genotype GI.6 Norovirus, United States, 2010–2012
Noroviruses are the leading cause of epidemic gastroenteritis, including foodborne outbreaks, and a major cause of sporadic gastroenteritis in the United States (1–3). Hospitalizations and deaths associated with norovirus infection occur most frequently among elderly persons, young children, and immunocompromised persons (2,4). Noroviruses can be divided into at least 5 genogroups (GI–GV) and at least 35 genotypes. Human disease is primarily caused by GI and GII noroviruses, and most norovirus outbreaks are caused by genotype GII.4 viruses (5). During the past decade, new GII.4 strains have emerged every 2–3 years, replacing previously predominant GII.4 strains (6–8). GI noroviruses are relatively uncommon, and systematic descriptions of GI outbreak epidemiology and characteristics are scarce (9). Before 2010, genotype GI.6 noroviruses were rarely reported in the United States; < 5 GI.6 outbreaks were reported each year to the Centers for Disease Control and Prevention (J. Vinjé, pers. comm.). We report the emergence of GI.6 norovirus as a cause of outbreaks in the United States and discuss its effect on public health.