[Molecular epidemiology of diarrhea among children with Norwalk-like virus in a hospital of Guangzhou in autumn and winter].

Objective: To explore the epidemiological characteristics of Norwalk-like virus (NLVs) infection in children with diarrhea and to study the genotype and predominant cluster at a hospital in Guangzhou city.
Methods: Fecal specimens from 358 children with acute gastroenteritis from October 2003 to January 2004 and information about the cases were collected. NLVs was detected from the specimens by reverse transcription-polymerase chain reaction (RT-PCR) and the PCR products were purified and sequenced.
Results: Forty-two positive specimens were detected from the 358 fecal specimen with a positive rate of 11.73% (42/358). Of these, 40 specimens were obtained from infants younger than 3 years of age. The youngest infant infected with NLVs in this study was only 25 days. The positive rate in November (17.27%) was the highest. Eleven positive PCR products were selected and sequenced. Nucleotide sequence analysis revealed that 11 strains all belong to genogroup II (G II), and of these, 5 strains belonged to G II-3 cluster, with another 5 strains belonged to G II-4 cluster. However, one strain with its cluster could not be determined.
Conclusion: NLVs served as one of the important pathogens causing sporadic acute gastroenteritis among children at a hospital in Guangzhou. The predominant strains were identified as G II-3 and G II-4 cluster.