Identification of a distinct common strain of "Norwalk-like viruses" having a global distribution.

"Norwalk-like viruses" (NLVs) are the most common cause of outbreaks of non bacterial gastroenteritis. During molecular surveillance of NLV strains fro m 152 outbreaks of gastroenteritis that occurred in the US between August 1 993 and July 1997, we identified an NLV strain that predominated during the 1995-1996 season. The "95/96-US" strain caused GO outbreaks in geographica lly distant locations within the US and was identified, by sequence compari sons, in an additional 7 countries on 5 continents during the same period. This is the first demonstration linking a single NLV strain globally and su ggests that the circulation of these strains might involve patterns of tran smission not previously considered. The diagnostic techniques are now avail able to establish a global network for surveillance of NLV strains that wou ld highlight the importance of NLVs worldwide and allow molecular identific ation of common strains having a global distribution so as to consider inte rventions for their control.