The largest Hawaii outbreak of hepatitis A in at least 25 years is largely over despite the report of another case on Wednesday, which raised the number of those afflicted by the food-borne illness to 289.

“What we are seeing now is the mop-up,” said Dr. Sarah Park, state epidemiologist.

The time has passed where any new illness will emerge directly from the scallops found to have carried the virus this summer, officials said Wednesday.

If any new cases are identified in the next few weeks, they will belong to victims who either confirmed their illness late or have a secondary case, meaning they caught the virus from someone originally infected by the contaminated scallops.

“But secondary cases have been rare,” said Jonathan Hilts of the state Disease Outbreak Control Division. He said such cases have been limited to household members or close contacts of those who were infected.

“We’re watching out,” Hilts said. “We’ve got to wait and see if there are any more cases.”

Typically, Hawaii sees an average of 10 hepatitis A cases a year.

But this year was different. Not only did Hawaii experience the worst outbreak in at least a quarter-century, but it was the worst in the U.S. since green onions from Mexico sickened more than 600 people in Pennsylvania in 2003.

Since mid-June, 289 people in Hawaii contracted the contagious liver disease that results from infection with the hepatitis A virus. In 71 of the cases, the illness was so severe it required hospitalization.

Health officials first alerted the public about the outbreak on July 1, announcing the investigation of a cluster of at least 12 cases with an illness onset date going back to June 16.

Following months of investigation, Health Department officials determined that the source of the outbreak was raw scallops imported from the Philippines by Sea Port Products Corp. The frozen scallops were sold to Koha Oriental Foods and True World Foods distributors and served at Genki Sushi restaurants on Oahu and Kauai.

On Aug. 15, health officials ordered the product embargoed statewide and temporarily closed Genki Sushi restaurants.

Operating with extra caution, the Health Department identified eateries where food service workers sickened by the disease were employed, fearing that the risk of infection would be greater in places where food is being handled.

Workers at 13 different restaurants, two Hawaiian Airlines flight attendants and two school cafeteria employees at different campuses contracted the virus. None was an employee at Genki Sushi.

The outbreak also resulted in a couple of class-action lawsuits against Genki Sushi and at least one other suit from a Hauula man who claimed he contracted the virus aboard a Hawaiian Airlines flight.

Hepatitis A symptoms take from two weeks to as long as 50 days after exposure to appear, and people are infectious even before they realize they are sick. The virus spreads through contaminated food or water, or close physical contact.

As part of their fight against the outbreak, the Health Department recommended that people get the vaccine to protect against hepatitis A — the only food-borne disease with a vaccine that offers protection.

Tens of thousands of people responded, according to the department’s surveys.

“It was pretty amazing,” Park said. “There was a great response to this outbreak, and it was heartwarming to see.”

Park said it’s important for anyone who got the vaccination to also get the second dose to receive maximum protection. The hepatitis A vaccine is given as two shots, six months apart.

“Please don’t forget to get the second shot,” she said. “If you don’t do it, you’re not fully immune.”

Park said that while such outbreaks are rare in the U.S., hepatitis A is a common problem in Asia, Southeast Asia, the South Pacific, Latin America and Africa, and it can easily end up here again because many food products are imported to Hawaii.

More than 125 people from eight states on the East Coast this summer came down with hepatitis A. It was traced to smoothies with strawberries imported from Egypt.

Because the U.S. Centers for Disease Control and Prevention recommended in 2006 that the hepatitis A vaccine be administered to young children, there’s hope there will be fewer outbreaks in the future, Park said.

On the other hand, she said, developed nations, such as the United States, are experiencing the loss of agricultural lands and are relying increasingly on food grown in underdeveloped nations.

The outbreak, she said, is a reminder to think about hand-washing, proper food-handling techniques and getting the vaccine, which is also recommended those traveling outside the country.

Avoiding uncooked foods is also helpful, she said, because it increases the chance of exposure to the virus.

“If the scallops were cooked, it would not have been an issue. We never would have known they were contaminated,” Park said.

Park said she’s proud of the detective work her department — and the agency’s U.S. Food and Drug Administration partners — accomplished this summer to find the source of the hepatitis A outbreak.