Norwalk virus is known as winter vomiting virus, which was originally named after Norwalk, Ohio, in the United States, where an outbreak of acute viral gastroenteritis occurred among children at Bronson Elementary School in November 1968.

Viruses are classified into family, genus, and species by the International Committee on Taxonomy of Viruses (ICTV), and Norwalk virus is the only species of the genus Norovirus, which belongs to the family Caliciviridae. 

Formerly, Norwalk virus was included in the genus “Norwalk-like virus” between 1999 and 2002, and the “Norwalk-like virus” was replaced with Norovirus on the 8th Report of the ICTV in response to the approval of the new name of Norovirus at the 12th International Congress of Virology in Paris (2002). 

Because the genus Norovirus has only one species (Norwalk virus) as well as the fact the genus “Norwalk-like virus” was officially replaced with the genus Norovirus, these often cause confusion on the correct usage of the term Norovirus and that of Norwalk virus. 

Currently, the term norovirus has been more frequently used in the media and by health authorities.