The number of people who have contracted hepatitis A in Hawaii has climbed to 228, a nearly 11 percent increase over the last week, health officials announced today.

All the victims are adults, and 58 were so ill they required hospitalization. Three were visitors who returned to the mainland.

The state Health Department has traced the outbreak to contaminated scallops that were imported frozen from the Philippines and served raw at Genki Sushi restaurants on Oahu and Kauai. All Genki Sushi outlets on the two islands were shut down last week and the scallops were recalled by their importer, Sea Port Products Corp., of Kirkland, Wash.

Because the virus has a long incubation period, cases will continue to crop up long after the product was removed from circulation.

The state Department of Education said a cafeteria worker at Kipapa Elementary School told her principal on Monday of a positive test for the virus.

The school closed the cafeteria and is testing all of its workers. Lunches are being prepared at another school.

On Tuesday, the Health Department confirmed that a second Hawaiian Airlines flight attendant had contracted the disease, but said the source was not the airline and the risk to passengers was “extremely low.”

“This case is a reminder that hepatitis A symptoms can appear up to 50 days after exposure,” State Epidemiologist Dr. Sarah Park said Tuesday. “This is why we expect to continue to see cases in coming weeks, and why we need to remain vigilant to prevent further transmission, even though the product has been pulled off the market.”

The Health Department announces the number of cases every Wednesday. The pace of the outbreak is slowing. The total of 206 cases announced on Aug. 17 was a 22.6 percent increase over the previous week’s tally.

Symptoms of hepatitis A include fatigue, nausea, abdominal pain, fever, dark urine, pale stool and jaundice. Anyone with symptoms should contact their doctor.

Vaccination is the best prevention against the liver disease. Vigorous hand washing after using the toilet and before eating can stem the spread of the infection. Thoroughly cooking food kills the virus.