By Dan Whitcomb

LOS ANGELES (Reuters) - The leading U.S. pediatrician group on Friday urged parents, schools and communities to vaccinate children against measles in the face of an outbreak that began at Disneyland in California in December and has spread to more than 50 people.

The American Academy of Pediatrics said all children should get the measles, mumps and rubella vaccine between the ages of 12 and 15 months old and again between 4 and 6 years old.

"A family vacation to an amusement park – or a trip to the grocery store, a football game or school – should not result in children becoming sickened by an almost 100 percent preventable disease," Dr. Errol Alden, the group's executive director, said in a written statement.

"We are fortunate to have an incredibly effective tool that can prevent our children from suffering. That is so rare in medicine," Alden said.

The California Department of Public Health has reported 59 confirmed measles cases among state residents since the end of December, most linked to an initial exposure at Disneyland or the adjacent Disney California Adventure Park.

Nine more cases linked to the two Walt Disney Co-owned parks, were reported out of state - one in Mexico, three in Utah, two in Washington state and one each in Oregon, Colorado and Arizona.

Officials say the outbreak appeared to begin when an infected person, likely from out of the country, visited the Anaheim resort from Dec. 15 to Dec. 20.

Among those infected are at least five Disney employees and a student at Huntington Beach High School, some 15 miles (24 km) from the park. Earlier this week, the school ordered its unvaccinated students to stay home until Jan. 29.

Measles typically begins with fever, cough, runny nose and red eyes, followed by red rash that often starts on the face and spreads downward. The sometimes deadly viral disease can spread very swiftly among unvaccinated children.

There is no specific treatment for measles and most people recover within a few weeks. But in poor and malnourished children and people with reduced immunity, measles can cause serious complications including blindness, encephalitis, severe diarrhea, ear infection and pneumonia.

(Reporting by Dan Whitcomb; Editing by Susan Heavey)