High level excretion of Norwalk-like virus following resolution of clinical illness.

We report the case of an elderly woman excreting high levels (about 5 x 10(5) virions per gram of faeces) of Norwalk-like virus (NLV) in the absence of any clinical symptoms of gastroenteritis. Analysis by reverse transcription, polymerase chain reaction and DNA sequencing was carried out on a 342-nucleotide region of open reading frame 1. This indicated that the NLV belonged to genogroup 2 and was more closely related to the Camberwell subgroup, the most common circulating in southeast Australia at present, than to the Norwalk and Mexico viruses.