Objective   To understand the clinical characteristics and risk factors of Norwalk-like virus(NLVs)infection in children with diarrhea.

  Methods   Fecal specimens were collected from children with acute gastroenteritis and their parents were inquired with a questionnaire at the same time.The specimens were detected for rotavirus(RV)and NLVs by ELISA and RT-PCR respectively.The questionnaire data was analysed by 1:1 paired case(NLVs)-case(RV)comparision study and 1:1 paired case-contol study for its clinical characteristic and risk factors.

  Results   648 fecal specimens were collected and detected.As a result, 339 RV positive specimens and 80 NLVs positive specimens were found.The clinical characteristic between NLVs cases and RV cases was different.Among the earliest symptoms, vomitting in NLVs cases(62.82%)was more often occuring than in RV cases(14.10%).The amount of cases with vomiting in NLVs cases were more than in RV cases, also.But the cases with the symptoms such as fever, the highest temperature, the number of days in fever and diarrhea, transfusion or not and the times to see a doctor were more commonly occurring in RV cases than that in NLVs cases.The probable risk factors of NLVs infection were analyzed by one-variable and mutivariable logistic regression and four risk factors were determined in the end, such as eating crude or cold foods, touching with diarrhea cases, having the habit of sucking hands and less washing hands.

  Conclusion   The clinical characteristic between NLVs cases and RV cases is different.The symptoms of RV cases are more severe than those of NLVs cases, but the burden brought by NLVs infection cannot be neglected.