Noroviruses love to be where we are, and this invisible guest can make a get-together memorable for all the wrong reasons.
Last week, a couple of news outlets in Portland, Oregon, highlighted an unfortunate event that befell one of their fellow agencies a little while ago.
The Oregonian, a long-running Portland newspaper, held a party on May 31st to recognize staff achievements. Cake and coffee were served, and within 24 hours of the event, at least 14 employees developed diarrhea, vomiting, and abdominal pain. This prompted an investigation by the Multnomah County Health Department, and according to a spokesperson for the Department, samples from two people did test positive for norovirus, and samples of the cake were also sent off for testing. Investigators believe the outbreak was an isolated event and a staff member with the newspaper wrote that while unfortunate, such events would not stop them from holding celebrations in the future.
Cakes are not a common culprit for foodborne norovirus outbreaks and it is unclear if it was the cause in this instance, but cake-borne norovirus outbreaks do happen from time to time. (For some fun, check out the CDC’s FOOD Tool for foodborne outbreaks and search for “norovirus” and “cake,” then compare the results to other foods like sandwiches and salads.)
One notable example involved 46 weddings in Massachusetts that happened over the same weekend in 2002. The journal article is here if you want the accounts of some enjoyably thorough epidemiologists. Long story short, they figured out that one bakery had supplied all of the cakes, where the brides and grooms had selected the cake and filling types they wanted. The investigators performed a case-control study (where you compare a group of cases to a group of people who did not get sick and play Spot-the-Difference) and 90% of the case patients had eaten strawberry-filled cakes, out of seven possible filling options. The strawberry filling was always made fresh, and was the only one that needed hand contact to prepare. The bakery had at least two employees out the week of the weddings with norovirus-like symptoms, and the investigators observed poor hand hygiene practices at the bakery, letting Occam’s Razor (and some genetic evidence) connect the dots.
If we learn that The Oregonian’s cake is implicated by lab results, we will post about it here.