Eight new cases this week have increased the state Department of Health’s tally of hepatitis A cases to 284 as the worst outbreak of the viral disease in two decades in Hawaii continues to run its course.

The department first issued a medical advisory to all health care providers on June 30 urging them to report all suspected hepatitis A infections in the search for the cause of the outbreak. The infectious liver disease is usually spread through food or drink contaminated with traces of the feces of an infected person. It can also spread through close personal contact.

Authorities in August determined the source of the hepatitis A outbreak was tainted scallops imported from the Philippines and served raw at Genki Sushi, triggering closure of restaurants on Oahu and Kauai. Genki was cleared to reopen after three weeks in which its restaurants had been thoroughly sanitized and all workers had been medically screened and cleared.

The onset of illnesses from this week’s new cases ranges between June 12 and Sept. 16.

The state said all cases have been in adults, and 71 people have required hospitalization.

State Epidemiologist Dr. Sarah Park has said more cases are expected to surface in October because of the viral disease’s long incubation period of up to 50 days after exposure.