More than two dozen people are thought to have contracted the mumps in an outbreak centered on a Long Island town, officials said.

Health officials in Long Beach said that there have been four confirmed cases of the virus along with another 14 suspected cases in recent weeks.

Authorities said that all of the people thought to have contracted the disease are in their 20s and that the outbreak is most likely attributable to a new strain of the virus that is resistant to vaccines. Most of the people who contracted the virus had already been vaccinated.

None of those infected contracted serious illness, but officials are urging anyone who may have come in contact with an infected person to consider getting a mumps booster shot.

"Some people will say 'well you have 18 cases that is a lot of cases,'" said Dr. Lawrence Eisenstein, the Nassau County health commissioner. "We don't know how many cases have not happened because people are protected and vaccinated."

Mumps is transmitted by coughing, sneezing and transfer of saliva. If a person contracts the virus, the symptoms are typically mild and go away within a few days.