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Norwalk Virus and Norwalk-like viruses (NLVs) are reportedly responsible for 2.5-4.0% of nonbacterial acute gastroenteritis (NBAG) worldwide. To help clarify the impact of NLVs on NBAG in Indonesia, stool specimens from 102 patients, 74 with NBAG and 28 with BAG, were screened for the presence of NLVs, using a reverse transcription-polymerase chain reaction (RT-PCR) assay. The specimens were subtyped using prototype-specific oligonucleotide probes and were sequenced and compared with published NLV sequences. Of the 102 specimens examined, 31 (30%) were found to be positive for NLVs. Type-specific probe analysis of the RT-PCR products indicated that 31 isolates hybridized to UK1 (Taunton agent) and UK3/4 (Hawaii agent/Snow Mountain agent) prototype strains. The results of this study indicate that prototype strains of NV or NLVs co-circulate in Indonesia and contribute to the overall level of acute gastroenteritis throughout the region., (Copyright 2002 Wiley-Liss, Inc.)

Norwalk virus (NV) and Norwalk-like viruses (NLVs) are common etiologic agents of viral gastroenteritis. Viral gastroenteritis is a common disease that is highly transmissible, spreading rapidly through families, institutions, and communities. Because methods for in vitro cultivation of Norwalk etiologic agents are not available, information regarding this syndrome has come largely from studies in human volunteers. Sequential passaging of an NLV through an immunoincompetent newborn pigtail macaque (Macaca nemestrina) may allow for the adaptation of a human NLV to a primate host, thus providing an animal model for investigating this disease. A fecal filtrate of human origin containing NLV, Toronto virus P2-A, was obtained from a patient during an epidemic of viral gastroenteritis. The filtrate was administered via nasogastric tube to three newborn pigtailed macaques. Clinical illness, which was characterized by diarrhea, dehydration, and vomiting, occurred in three monkeys. Reverse transcription-polymerase chain reaction (RT-PCR) and oligonucleotide probe analysis of RNA extracted from the stool samples following infection revealed viral RNA in all inoculated monkeys. Infection was also transmitted experimentally by feeding two additional newborn macaques a fecal filtrate prepared from the three previously infected animals. Detection of viral RNA in the stools of animals that received the fecal filtrate indicates that viral replication occurred in association with clinical illness. The susceptibility of Macaca nemestrina to infection with a Norwalk-like agent will facilitate the study of the mechanisms of the pathogenesis of NLV. This system may also have the potential to serve as a vaccine test model for human epidemic viral gastroenteritis., (Copyright 2002 Wiley-Liss, Inc.)