A second case of measles has been confirmed in the Milwaukee area.

The news came as 12 children have already been quarantined after coming in contact with a toddler who has measles.

Health officials told the parents of the dozen children to keep them at home until April 18th to prevent measles from spreading.

The children attend Kingdom Care Child Center, as does the 23-month-old child from Franklin who has measles.

Milwaukee Health Commissioner Bevan Baker says the new case involves a Milwaukee man who developed measles-like symptoms, went to the doctor and had the diagnosis confirmed.

His symptoms started before those of the 23-month-old girl who recently became ill.

Authorities are investigating whether the two cases are related.

In an unrelated case, the Rockland County, N.Y. Health Department is reporting that a man with measles attended an April 1 event at the Atrium Plaza Grand Ballroom in Spring Valley, Long Island; it is being reported by Newsday.

Hundreds of guests at the Rockland County wedding are being warned to watch for signs of the highly infectious disease.

In late March, a woman infected with measles flew into Portland, Ore., and exposed other passengers, according to KGW-TV.

She had flown from Amsterdam to Seattle on Northwest Flight 33 on March 26, and boarded a smaller plane to Portland on Horizon Airlines’ Flight 2243.

Health officials said travelers who are going out of the country should make sure they are vaccinated against the illness, which causes a fever, rash, cough, and red, watery eyes, according to the Mayo Clinic.

The Associated Press contributed to this report.