When the Maine Center for Disease Control and Prevention decided last week how to respond to a potential hepatitis A exposure at a Cumberland County restaurant, it did so without its top hepatitis coordinator and two leading epidemiologists, positions that have been vacant for months.

The state’s handling of that case has drawn criticism from public health leaders who say the state should have named the restaurant to alert diners who may have been exposed to the virus during the weeks when the worker served food there.

The Maine CDC is operating without a full staff trained to deal with such infectious diseases. And while the department grapples with concerns over Ebola and the approaching flu season, 14 of its roughly 50 public health nurse positions remain vacant – more than 25 percent of the workforce. Public health nurses are front-line workers who run vaccination clinics and respond to outbreaks.

“Our public health infrastructure is woefully inadequate,” said MaryAnne Turowski, legislative and politics director for the Maine State Employees Association, the union that represents public health nurses. The state is “not prepared for an infectious disease outbreak,” she said.

The public nurse program has not been hit by budget cuts, and it’s not clear why so many vacancies persist. Dr. Sheila Pinette, the CDC director, declined to comment Monday about the vacancies.

Dr. Dora Anne Mills, who directed the Maine CDC from 1996 to 2011, said the state is hampered in its response to infectious diseases by not having important positions filled. Last week, Mills criticized the CDC for not releasing the name of the restaurant, saying that any patrons who develop symptoms and need treatment would be better served by knowing they were exposed to hepatitis A.

Mills said the state’s hepatitis coordinator, top epidemiologist and deputy epidemiologist typically would consult with the Maine CDC director on how to respond.

“If there’s a hepatitis outbreak, she would be called in,” Mills said, referring to the state hepatitis coordinator who resigned in August, Mary-Kate Appicelli. “The decisions don’t sound that complicated, but they are really complicated.”

Through a family member, Appicelli declined to comment Monday.

Pinette is serving as acting state epidemiologist, although her background is in internal medicine.

John Martins, a spokesman for the Maine CDC, said that although the top infectious disease positions are unfilled, the state has many experts in place to make decisions.

“The Maine CDC has 13 capable state epidemiologists in its Infectious Disease Division, including one with advanced expertise regarding hepatitis A,” Martins said in an email. Martins also said the state has a contract to consult with former state epidemiologist Dr. Stephen Sears, who resigned in May. The state did not consult with Sears on the restaurant case, Martins said.

The Maine CDC is reviewing candidates to replace Sears, and Pinette said previously that she expects to have someone hired by the end of the year.

Martins defended the decision not to release the name of the restaurant in a public health alert sent out Thursday. The state did not learn of the potential exposure until two weeks had passed and it was too late to vaccinate restaurant patrons. Also, he said, releasing the name of the restaurant could have identified the employee, violating state law regarding patient privacy.

However, Mills said the department would typically release the name of the restaurant in similar situations when she was director.

Cindy Look, a public health nurse at the Maine CDC since 1989, said she has never seen so many vacant positions.

Martins declined to comment about the public health nurses.

“Our priority is communicable diseases,” said Look, who works in Lincoln, Waldo and Kennebec counties. “We have never been as short-staffed as we are right now. There are only so many of us to go around.”

Look said there has been a slow decline in staffing over the past few years and not a sudden exodus of nurses. As people retire or move to other jobs, the administration hasn’t replaced them, she said.

“It’s becoming more and more difficult to do our job,” she said.

In addition to responding to public health emergencies, the nurses educate the public on preventable diseases, work with pregnant moms on prenatal care, visit families with a newborn to give advice and check on the baby’s health, and give vaccines and provide health information to refugees and immigrants.