The state still doesn’t have a handle on controlling Hawaii’s worst outbreak in decades of the mumps, a disease that continues to plague mostly young adults and children.

The number of cases had risen to 770 as of Thursday, according to the state Department of Health.

The mumps update comes after a scathing state auditor’s report earlier this week blasted the Health Department for poor public communication during certain disease outbreaks.

Mumps is a contagious disease that causes flu-like symptoms and is spread by coughing, sneezing, talking and touching infected items.

There have been 21 cases of complications from mumps — including hearing loss and testicular inflammation that can lead to sterility. There are likely significantly more mumps cases that have not been reported.

“In the past six months we’ve seen more cases of the mumps than we’ve ever seen before,” said Dr. Robert Ruggieri, owner of Island Urgent Care. “We’re not putting mumps to rest. It’s time to step it up by making sure more people get the vaccine, especially those in close quarters. If you’re in an environment in close proximity to a lot of other people, that would raise the risk for the spread of mumps.”

Health officials are urging people to get an extra mumps vaccine to stop the spread of the disease, which is typically reported as fewer than 10 cases a year. The DOH recommends getting an extra “outbreak dose” of the MMR (measles, mumps and rubella) vaccine, especially those who reside, work or socialize in crowded settings. The major health plans have been covering the extra dose, Ruggieri said.

“A lot of people are reluctant to get it because they’re not sure they need it, and they don’t want to get it if it’s not free,” Ruggieri said. “By getting the vaccination, you’re preventing the spread of mumps, and you could be protecting someone you love.”

The outbreak began in March with two clusters of cases involving nine people. By late October the number of cases surged to 500. A majority of the recent mumps cases, the Health Department said, involve adults ranging in age from 20 to their early 40s, and adolescents age 10 and older. Symptoms include swollen glands of the ears or jaw, fever, muscle aches, headaches, loss of appetite and fatigue.

“We’re one of 48 states now that have been having outbreaks and one of quite a few that has had over 300 cases. We’re still in the middle of it. We don’t know when the end point will be,” said state epidemiologist Dr. Sarah Park. “Mumps is incredibly difficult to control because there’s so many factors that are contributing to transmission. The vaccine itself is effective but not as effective as we would like.”

The mumps vaccine protects about 88 percent of people, so “you’re going to always have susceptibles,” she said.

“If you drop mumps into the middle of 1,000 people, that means 120 people are going to have the infection,” Park added. “There may be waning immunity. As time goes by from your last vaccination, it’s possible when you’re in a crowded setting … that could increase the potential for the force of infection to occur.”

Last week the DOH was criticized by state Auditor Les Kondo for “communication breakdowns” during the dengue fever outbreak on Hawaii island, when hepatitis A was found in frozen scallops on Oahu and Kauai, and when salmonella was found in ogo on Oahu in 2015 and 2016.

“Outbreaks happen at various times to various states. It’s not the Department of Health’s fault that we have the mumps outbreak,” said state Rep. John Mizuno (D, Kalihi Valley), chairman of the House Health and Human Services Committee. “Nonetheless, we can certainly always look to improve on how we manage and provide communication to the public to protect our people from certain outbreaks such as mumps or hepatitis A or some tainted food that we need to be aware of. We need to ensure that doesn’t happen again at the cost of public safety. We need to have our A-game on all of these. We’ve got a big mumps outbreak — we’re almost going to hit 1,000 people infected — and that’s not good at all.”

For more information, go to health.hawaii.gov/docd/advisories/mumps.