CDC is working with the U.S. Food and Drug Administration (FDA), the Texas Department of State Health Services, along with other state and local officials to investigate a multistate norovirus outbreak linked to raw oysters from harvest area TX 1, Galveston Bay, Texas.

Restaurants and food retailers should not serve raw oysters from harvest area TX 1, Galveston Bay, Texas, harvested between 11/17/2022 and 12/7/2022, which will be printed on product tags.

The FDA has confirmed that raw oysters harvested in area TX 1, Galveston Bay, Texas were potentially contaminated with norovirus and distributed to restaurants and retailers in Alabama (AL), Florida (FL), Georgia (GA), Louisiana (LA), Mississippi (MS) North Carolina (NC), Tennessee (TN) and Texas (TX). It is possible that additional states received these oysters through further distribution within the U.S.

The Texas Department of State Health Services and the Florida Department of Health notified the FDA of illnesses associated with eating raw oysters harvested from TX 1, Galveston Bay, Texas. On December 8, 2022, the Texas Department of State Health Services issued a recall on all oysters harvested between 11/17/2022 and 12/7/2022 from harvest area TX 1, Galveston Bay, Texas. FDA Advises Restaurants, Retailers and Consumers to Avoid Potentially Contaminated Oysters from Harvest Area TX 1, Texas | FDA They also informed the Interstate Shellfish Sanitation Conference who notified other member states. This resulted in other states initiating recall measures consistent with the Interstate Shellfish Sanitation Conference agreement.

As of December 15, 2022, 211 norovirus illnesses have been reported from 8 states. CDC is working with state and local partners to determine a more accurate number of illnesses in this outbreak and will update this number as more information is gathered.

Norovirus is the leading cause of foodborne illness in the United States. However, state, local, and territorial health departments are not required to report individual cases of norovirus illness to a national surveillance system. That’s why we may not know about many cases, especially if people do not go to a doctor’s office or hospital. Each year, there are about 2,500 reported norovirus outbreaks in the United States. Norovirus outbreaks occur throughout the year but are most common from November to April.

State and local public health officials are interviewing people about the foods they ate a day to four days before they got sick. In interviews, many of the sick people reported eating raw oysters.

State and local officials have collected information about the source of oysters from restaurants where sick people ate. FDA has confirmed that potentially contaminated raw oysters were harvested in area TX 1, Galveston Bay, Texas. The FDA and the states are conducting a trace forward investigation to determine where the raw oysters were distributed and to ensure they’re removed from the food supply.

This investigation is ongoing. CDC will update the public as more information is gathered.

Norovirus is transmitted primarily through the fecal-oral route, with fewer than 100 norovirus particles needed to cause infection. Transmission occurs either person-to-person or through contamination of food or water. CDC statistics show that food is the most common vehicle of transmission for noroviruses; of 232 outbreaks of norovirus between July 1997 and June 2000, 57% were foodborne, 16% were spread from person-to-person, and 3% were waterborne. When food is the vehicle of transmission, contamination occurs most often through a food handler improperly handling a food directly before it is eaten.

Humans are the only host of norovirus, and norovirus has several mechanisms that allow it to spread quickly and easily. Norovirus infects humans in a pathway like the influenza virus’ mode of infection. In addition to their similar infective pathways, norovirus and influenza also evolve to avoid the immune system in a similar way. Both viruses are driven by heavy immune selection pressure and antigenic drift, allowing evasion of the immune system, which results in outbreaks. Norovirus can survive a wide range of temperatures and in many different environments. Moreover, the viruses can spread quickly, especially in places where people are in proximity, such as cruise ships and airline flights, even those of short duration.

Infected individuals shed the virus in large numbers in their vomit and stool, shedding the highest number of viral particles while they are ill. Aerosolized vomit has also been implicated as a mode of norovirus transmission. Previously, it was thought that viral shedding ceased approximately 100 hours after infection; however, some individuals continue to shed norovirus long after they have recovered from it, in some cases up to 28 days after experiencing symptoms. Viral shedding can also precede symptoms, which occurs in approximately 30% of cases. Often, an infected food handler may not even show symptoms. In these cases, people can carry the same viral load as those who do experience symptoms.

Norovirus illness usually develops 24 to 48 hours after ingestion of contaminated food or water. Symptoms typically last a relatively short amount of time, approximately 24 to 48 hours. These symptoms include nausea, vomiting, diarrhea, and abdominal pain.  Headache and low-grade fever may also accompany this illness. People infected with norovirus usually recover in two to three days without serious or long-term health effects.

Although symptoms usually only last one to two days in healthy individuals, norovirus infection can become quite serious in children, the elderly, and immune-compromised individuals. In some cases, severe dehydration, malnutrition, and even death can result from norovirus infection, especially among children and among older and immune-compromised adults in hospitals and nursing homes. Recently, there have been reports of some long-term effects associated with norovirus, including necrotizing entercolitis, chronic diarrhea, and post-infectious irritable bowel syndrome, but more data is needed to support these claims.

Diagnosis of norovirus illness is based on the combination of symptoms, particularly the prominence of vomiting, little fever, and the short duration of illness. If a known norovirus outbreak is in progress, public health officials may obtain specimens from ill individuals for testing in a lab. These lab tests consist of identifying norovirus under an electron microscope. 

There is no specific treatment available for norovirus. In most healthy people, the illness is self-limiting and resolves in a few days; however, outbreaks among infants, children, elderly, and immune-compromised populations may result in severe complications among those affected. Death may result without prompt measures. The replacement of fluids and minerals such as sodium, potassium and calcium – otherwise known as electrolytes – lost due to persistent diarrhea is vital. This can be done either by drinking large amounts of liquids, or intravenously.

Norovirus: Marler Clark, The Food Safety Law Firm, is the nation’s leading law firm representing victims of Norovirusoutbreaks. The Norovirus lawyers of Marler Clark have represented thousands of victims of Norovirus and other foodborne illness outbreaks and have recovered over $850 million for clients. Marler Clark is the only law firm in the nation with a practice focused exclusively on foodborne illness litigation. Our Norovirus lawyers have litigated Norovirus cases stemming from outbreaks traced to several food products and restaurants. 

If you or a family member became ill with Norovirus after consuming food and you’re interested in pursuing a legal claim, contact the Marler Clark Norovirus attorneys for a free case evaluation.