Three new cases of mumps have been confirmed on Oahu, bringing the total number sickened this year to 27.
The new cases are in east Honolulu and Waipahu.
Dr. Sarah Park, state epidemiologist, has said health care providers are aware of the cases because mumps is easily spread.
"We expect additional cases to be reported in the coming weeks,” Park said. "There is no specific treatment for mumps infection and while most people will recover completely, mumps can occasionally cause complications, especially in adults."
In December, the U.S. Centers for Disease Control and Prevention said the country was in the midst of its worst mumps outbreak in a decade, with six states reporting more than 100 cases of the virus.
The disease is not considered life-threatening, but there are some lasting side effects, including the swelling of salivary glands and swollen jaws.
With two doses, health department officials say, a vaccine is nearly 90 percent effective against the disease.