The tally of cases in the largest hepatitis A outbreak in Hawaii in decades jumped by more than 45 percent in a week, according to the state Department of Health.

Health officials said Wednesday that 42 new cases have surfaced since July 27, in addition to the 93 announced about a week ago, for a total of 135 cases.

“It’s frustrating. We hoped it would stay small in scope,” state epidemiologist Dr. Sarah Park said.

The Centers for Disease Control and Prevention has given $3.7 million to the Health Department to help in the surveillance and investigation of infectious diseases, including hepatitis A, U.S. Sen. Brian Schatz announced Wednesday.

“This investment in public health helps to ensure that our state is prepared to address diseases before they spread,” Schatz said in a news release. Also, he said, “These funds help support the critical work being done … to research, monitor and control diseases such as Zika and dengue.”

Park said the increase in the number of cases was not alarming, given the ability of hepatitis A to spread widely.

Noting that her investigators have several strong leads tracing the sources of the viral outbreak, Park added, “I can say we’re in a better spot than we were several weeks ago.”

She said state health officials are also trying to control the outbreak by encouraging people who may have been exposed to the contagious liver disease to get an immunization shot. Other prevention measures include frequent hand-washing and thoroughly cooking food.

All of the 42 new hepatitis A cases in Hawaii involved adults with the onset of illness ranging from June 12 to July 24.

While the outbreak appears to be focused on Oahu, its source remains unclear.

Seven people who have contracted the virus live on neighbor islands, and one was a visitor who has returned to the U.S. mainland.

Hepatitis A spreads through fecal matter that gets into food or drink and then is consumed.

Officials say finding the source is difficult because it’s possible to contract hepatitis A one month before symptoms appear. Among the symptoms are loss of appetite, fatigue, fever, abdominal discomfort, dark urine, diarrhea and yellow skin and eyes.

So far, about a half-dozen cases involve food service-related workers, most recently a Hawaiian Airlines flight attendant and an employee at Chili’s restaurant in Kapolei. Customers who could have been exposed to food service items handled by the workers are being asked to contact their health care provider.

Other businesses that had a food service worker with hepatitis A include Baskin-Robbins, Costco Bakery, Sushi Shiono and Taco Bell.