Raw Oysters In Massachusetts May Be Linked To Norovirus: FDA

MASSACHUSETTS — Public health officials are issuing a warning about raw oysters sent to Massachusetts and other states after seeing a steady increase in cases of the highly contagious norovirus.

The Food and Drug Administration said oysters harvested in parts of Baynes Sound in British Columbia may be linked to the recent outbreak. This affects oysters shipped to restaurants and stores in 13 states, including Massachusetts.

As of Monday, 91 people had been sickened after eating the contaminated oysters, but the FDA warns that more states could be affected by further distribution.

The known states that received the suspect oysters aside from Massachusetts are California, Colorado, Florida, Hawaii, Illinois, Minnesota, New Jersey, Nevada, New York, Oregon, Texas, and Washington.

Norovirus is spread in a number of ways, including through vomit and feces particles that may remain on a person's hands or on surfaces during food preparation. It also can come from contaminated water that is used for irrigation of fruit and vegetable crops — or if food, such as oysters, is harvested in contaminated water.

Quick bouts of gastrointestinal norovirus illnesses are often referred to as the "stomach flu," though that's technically incorrect. Influenza is an infection of the respiratory system.

The majority of those sickened after eating the oysters were in Canada, where at least 279 illnesses have been reported, but also in mainly three U.S. states:

• California, 34 (read more on Patch)
• Minnesota, 29 (read more on Patch)
• Washington, 18 (read more on Patch)

According to federal health data, norovirus outbreaks were nearly nonexistent at the height of the COVID-19 pandemic - partially because people were staying away from places norovirus spreads and isolating more.

With the easing of coronavirus restrictions came an uptick in cases of norovirus, the stomach bug that is the leading cause of food-borne illnesses.

But even before the oyster-related outbreaks, norovirus was making a comeback. Data collected by the CDC's National Outbreak Reporting System shows that 448 norovirus outbreaks were reported from August 2021 to March 2022, compared with 78 outbreaks during the same period the previous year.

The number of outbreaks has increased from 10 or fewer per week from August until mid-November when they rose to near 30 before falling again and then spiked to around 60 outbreaks in February.

Agencies aren't required to participate in the norovirus surveillance system, which the CDC says makes it impossible to estimate the true number of norovirus cases. Many cases don't require a visit to the doctor's office, and most hospitals and other health care providers don't test for it, the agency says.

Symptoms of norovirus include stomach pain, nausea, fever, and headaches. People typically recover in one to three days. Washing your hands thoroughly is one of the best ways to help stop the spread.

Click here for the full FDA advisory.