Lynne Terry of The Oregonian reports that a private meeting of medical professionals at the Oregon Zoo last week ended with dozens of people falling ill. 

About 90 of the 220 people at a Wednesday morning meeting of Women’s Healthcare Associates developed severe gastro-intestinal symptoms, said Dr. Katrina Hedberg, state epidemiologist at Oregon Public Health. 

No one was hospitalized, but those who were sickened became severely ill. 
Investigators suspect they were infected with norovirus, which is highly contagious and spreads among people every winter. 

Oregon Public Health scientists are investigating the zoo outbreak, trying to determine the source of the contamination. Hedberg said that most likely a food handler infected with norovirus contaminated the food, which in turn sickened those who ate it. 
The virus is spread through human contact or through food, water or the environment. 

Zoo staff catered the event, held in one of the private spaces below the Cascade Grill that the zoo rents out to private parties.