The Guardian reports that Heston Blumenthal has temporarily closed his London restaurant Dinner after a suspected outbreak of the same winter vomiting virus that was linked to contamination at another of his restaurants five years ago.

The chef said he was erring on “the side of extreme caution” by shutting the establishment in the Mandarin Oriental hotel overlooking Hyde Park after a number of guests fell ill.

Dinner specializes in historic British dishes and has two Michelin stars. It has also been rated in the world’s top 10 restaurants. Food safety officers have told staff to wash their hands more often.

Blumenthal’s Fat Duck restaurant, in Bray, Berkshire, was hit by an outbreak involving at least 240 people in 2009. It was later said to be the worst norovirus contamination at a restaurant.

Norovirus (previously called “Norwalk-like virus” or NLV) is a member of the family Caliciviridae.  The name derives from the Latin for chalice—calyx—meaning cup-like, and refers to the indentations of the virus surface. The family of Caliciviridae consists of several distinct groups of viruses that were first named after the places where outbreaks occurred. The first of these outbreaks occurred in 1968 among schoolchildren in Norwalk, Ohio. The prototype strain was identified four years later, in 1972, and was the first virus identified that specifically caused gastroenteritis in humans.  Other discoveries followed, with each strain name based on the location of its discovery—e.g., Montgomery County, Snow Mountain, Mexico, Hawaii, Parmatta, Taunton, and Toronto viruses. A study published in 1977 found that the Toronto virus was the second most common cause of gastroenteritis in children. Eventually this confusing nomenclature was resolved, first in favor of calling each of the strains a Norwalk-like virus, and then simply, a norovirus – the term used today.