Abstract
Norovirus (NoV) is one of the most important causative agent of food-borne gastroenteritis outbreaks. Studies of NoV outbreaks associated with food-handlers who were infected with NoV have been frequently reported. However, precise reports on the duration of NoV shedding from food-handlers are not found. In this report, we examined 94 stool specimens from 28 food-handlers in 10 food-borne outbreaks for the duration of NoV RNA excretion during the period from April 2009 to March 2010. The median duration of viral shedding was 21.9 days after causative foods were prepared. 17 food-handlers out of 28 (61%) excreted NoV RNA in the stool until 18 days after causative foods were prepared. However, five food-handlers out of 28 (18%) excreted NoV RNA more than one month. When more than ten days have passed after causative foods were prepared, the quantity of NoV excreted in feces from all 5 food-handlers decreased in the range of 1.7×104 to 9.6×106/g, and became negative after the excretion continued in the same range for three to five weeks. We should monitor carefully food-handlars who excreted NoV RNA to prevent the spread of food poisoning associated with NoV.
