Nausea, vomiting, abdominal pain, diarrhea and fever were the main symptoms.Norwalk-like virus antigen was detected in some stool samples during the outbreak.

• 疫情全部发生在学校，发病时间均在冬春季，症状以恶心、呕吐、腹痛、腹泻、发热为主，每起疫情均从部分患者粪便标本中检出诺瓦克样病毒抗原。