Genki Sushi USA agreed Thursday to use social media to alert customers who ate scallops at its restaurants this summer that they may have been exposed to hepatitis A — just in case they haven’t already heard.

The voluntary, stipulated agreement came in connection with a Circuit Court lawsuit filed by the firm of Perkin &Faria on behalf of a Genki Sushi customer, Jamilyne Maglangit, and others who were exposed to the virus and had to be vaccinated.

Meanwhile, the state Health Department announced Thursday that an employee of Ohana Seafood, a vendor in the Sam’s Club warehouse store in Pearl City, had tested positive for the liver disease. It said anyone who consumed Ohana Seafood products bought from Aug. 29 to Sept. 11 may want to get a protective vaccine or immune globulin, although the risk of transmission is very low.

“While this case involves a food handler working with raw seafood, the food handler is another victim, and none of the products sold by Ohana Seafood at Sam’s Club have been identified as a source of the ongoing outbreak,” said Dr. Sarah Park, state epidemiologist.

Health officials have identified no other source of the outbreak than the tainted scallops imported from the Philippines and served at Genki Sushi, which were pulled off the market last month.

So far, 271 people have come down with hepatitis A since June, with the vast majority of cases connected to eating scallops. While there have been several secondary cases of hepatitis A, all have been household members of people who contracted the disease.

The disease is spread when people ingest microscopic amounts of fecal matter through contaminated food or close personal contact. The U.S. Food and Drug Administration confirmed hepatitis A in two samples of scallops that it tested, imported from the Philippines.

Although several food service workers at Hawaii establishments have fallen ill, no cases have been reported of them passing it on in their workplaces.

None of Genki Sushi’s employees has tested positive for hepatitis A.

In the past week, 19 new cases were identified and the department is investigating each one.

“So far most, if not all, of the new cases can report some Genki Sushi exposure,” said Jonathan Hilts, public health educator at the Health Department.

The Health Department on Sept. 9 cleared Genki Sushi to reopen its restaurants on Oahu and Kauai, after they were shut down for three weeks and thoroughly sanitized, and all workers were medically screened and cleared.

On Thursday, the Hawaii Restaurant Association’s board of directors and Executive Director Gregg Fraser ate at Genki Sushi’s Ward Centre restaurant in a “Support Genki Sushi Lunch” event.

“The board made a collective decision that as soon as they open, we want to go there and support, because if anything like this happened to any of our restaurants, we would appreciate the same type of efforts,” Fraser said.

Later Thursday afternoon, in court, Stefan Reinke, attorney for Genki Sushi USA, told Circuit Judge Karl Sakamoto that the company will establish a Facebook page and pay for online ads to alert customers who dined at Genki Sushi earlier in the summer.

“We are going to establish what’s called Facebook advertising with the goal of reaching out as far as we can for the people that may not have heard,” he said. “We’re going to actively manage these Facebook ads. This is going to happen very promptly.”

The agreement was voluntary and does not infer liability or fault on anyone’s part, he said.

The media campaign will run through Oct. 5, which is 50 days since the restaurants last served the scallops. That is the longest incubation period for the disease.

“We expect to continue seeing new cases of hepatitis A infection through at least early October because of the long incubation period for this illness, even though the source of the outbreak has been identified as contaminated scallops,” said Park, the state epidemiologist.

Despite widespread publicity about Hawaii’s hepatitis A outbreak, the plaintiffs in the court case argued that some customers may be unaware, including those who may have left the islands.

“The ads are going to be generated and targeted towards people that would have been exposed,” said plaintiffs’ attorney Brandee Faria. “I think Genki has 126,000 ‘likes,’ so hopefully it will go viral that way and we can get the word out for people who are not newsy here locally, or people on the mainland or Australia or wherever else this has extended to.”

Perkin &Faria had sought to force the restaurant chain to identify all credit and debit card purchasers of the tainted scallops and get their addresses from the issuing banks, so customers could be notified and seek medical treatment or take measures to prevent the spread of the virus. Vaccination can protect against the disease if given within two weeks of exposure, and hand washing can help prevent its spread.

But the motion for a mandatory injunction was dropped in favor of the social media effort. In opposing the injunction, Genki Sushi argued in court filings that it would be unworkable and ineffective, and that it appeared to be an effort by the plaintiffs to identify potential clients. In any case, the restaurants’ credit card records identify only the name of the customer and the amount spent, not who ate the scallops, or contact information.

Perkin &Faria filed suit on Aug. 26 against Genki Sushi and distributor Koha Foods on behalf of Maglangit, who ate several pieces of “scallop mayo” in early July, and others with similar experiences. They are seeking to represent, in a class-action lawsuit, people who were exposed to hepatitis A and got vaccinated, but did not get sick.

Another firm, Starn O’Toole Marcus &Fisher, filed a similar class-action lawsuit on Aug. 23 against Genki Sushi, distributor Koha Foods and importer Sea Port Products.