Prevalence of Norwalk-Like Virus Infections in Cases of Viral Gastroenteritis among Children in Osaka City, Japan

Surveillance of Norwalk-like virus (NLV) infections in cases of pediatric gastroenteritis between April 1996 and March 2000 showed that NLVs were an important causative agent in viral gastroenteritis cases among children between November and January in those years. The predominant type of NLV was closely related to Lordsdale virus in genogroup 2. During the 1999-2000 season, Arg320-like strains, which may be genetic recombinants, suddenly appeared and spread.