California officials have closed some commercial shellfish farming areas while they investigate an outbreak of norovirus that has sickened at least 44 people who reported eating raw oysters from Hog Island Oysters.

The company agreed to recall its “Sweetwater” and “Atlantic” oysters from a total of more than 40 restaurants and retailers in California, according to a notice posted by the California Department of Public Health (CDPH). The company did not appear to have any information about the recall or illnesses on its website as of last night.

A spokesperson for the CDPH told Food Safety News that the source of the highly contagious norovirus had not been determined as of yesterday afternoon. It has, however, been confirmed that norovirus is responsible for the illnesses, as opposed to other foodborne pathogens.

Marin County Environmental Health Services notified the state health department on Jan. 3 about reports of illnesses associated with the oysters. State investigators began looking for the cause and by 2:30 that afternoon they had closed all commercial shellfish growing areas in Tomales Bay.

“On Jan. 4, implicated product and future product distribution were determined and samples collected. The firm initiated a recall of the oysters and notified CDPH of that on Saturday, Jan. 5. CDPH started web posting on Monday, Jan. 7,” according to a department statement provided to Food Safety News.

State officials are aware of 44 people who ate Hog Island Oysters before becoming ill. None of those people have been admitted to hospitals. The sick people reported symptoms consistent with norovirus infection, which are primarily intense diarrhea, nausea and vomiting. Raw oysters are well-documented as a source of norovirus infections.

Infected foodservice workers can easily contaminate foods, utensils and dishes, kitchen surfaces and equipment. However, norovirus is known to survive in fresh and saltwater fish and shellfish. It has been found in species from farms and in the wild.

State officials will not allow commercial harvesting in the growing areas of Tomales Bay until further notice. Investigators continue to collect and review data. The state is working with local jurisdictions on the investigation.

A number of consumers have posted online reports about becoming sick after eating raw oysters from Hog Island Oysters on New Year’s Eve and in the first couple of days of January.

Quade, iwaspoisoned.com founder, said Monday there are reports of people becoming ill after eating raw oysters that were listed as being from Hog Island Oysters on menus at a restaurant in Grand Central Station in New York City. Those illnesses coincide with the timing of the California illnesses.

The list of restaurants and retailers in California wher the suspect oysters were recalled is good information for consumers, but Quade said he doesn’t understand why there aren’t laws to compel food companies to post recall and outbreak information on their own websites.

“We do not know why some food companies do not post their recall notices on their website and social media channels. It is clearly the responsible thing to do, especially when lives are at stake. It reflects very badly on those companies who act in this way,” Quade said.

California officials said the U.S. Food and Drug Administration was notified of the outbreak on Jan. 4. The agency was notified of the recall on Jan. 8. As of Jan. 15, the FDA had not posted the company’s recall notice.