About 100 people were left sickened in California after eating Canadian oysters following a norovirus outbreak and now health officials are warning residents to avoid consuming the raw shellfish, CNN noted.
The California Department of Public Health released a report noting that the 100 cases were recorded in California as of April 27 and applied to residents who had eaten raw British Columbian oysters that were sold by restaurants and retailers across the state.
A further 172 cases linked to the consumption of raw oysters were reported in Canada.
"Laboratory testing has confirmed norovirus infection in several patients from both California and Canada," the report said, per CNN. "Although the number of reported new illnesses has decreased during the last week, the investigation is ongoing."
The outbreak is tied to a unique strain of norovirus, which The Centers for Disease Control and Prevention described as a highly contagious virus that comes from contaminated food or water, contaminated surfaces, or people.
In a statement, the Center for Infectious Disease Research and Policy noted that "multiple states are currently affected by outbreaks related to raw oysters from British Columbia," Food Safety News reported.
"Lab analysis has identified that an uncommon type of norovirus is involved," CIDRAP added.
The U.S. Food and Drug administration confirmed the outbreak, noting that additional states may have received the contaminated oysters either directly from Canada or through further distribution within the U.S.
The administration said it was conducting investigations to determine where the raw oysters were distributed and to ensure that they are removed from the food supply.
Dr. Karen Smith, a public health officer in California, has advised residents to "avoid eating raw and undercooked shellfish, including oysters, to reduce your risk of illness," according to CNN.
"If you do eat shellfish, cook it until it reaches an internal temperature of at least 145°F. Quick steaming isn't sufficient to kill norovirus," she added.
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