THURSDAY, April 19 (HealthDay News) -- There were 222 cases and 17 outbreaks of the measles in the United States last year, more than four times the usual annual rate, U.S. health authorities reported Thursday.

"In 2011, we had the most number of reported measles in the U.S. in 15 years," said Dr. Anne Schuchat, director of the National Center for Immunization and Respiratory Disease at the U.S. Centers for Disease Control and Prevention.

In the prior decade, an average of 60 cases and four outbreaks were reported annually.

As of last Friday, CDC had received reports of 27 cases of measles for 2012, though "it is too soon in the year to know whether this year will be as bad or worse than last year," said Schuchat, who spoke at a news conference on Thursday.

The highly infectious illness seems to be making an unexpected comeback. Measles was declared eliminated in 2000 after public health measures successfully interrupted the transmission of disease from person-to-person in the United States. The disease is still endemic in many other parts of the world, however.

In fact, 200 of the 222 U.S. cases in 2011 were related to foreign travel, with 72 of the cases emerging in people who had recently traveled abroad, more than half of them to Europe, which has experienced its own explosion in the disease in recent years.

Authorities weren't able to determine the source in the other 22 cases.

Although the United States has a high vaccination rate of 90 percent, "measles is extremely infectious and very good at finding those few people who aren't vaccinated," Schuchat warned.

Of the 196 U.S. residents who had measles in 2011, 166 were unvaccinated or didn't know if they'd been vaccinated, although 141 were eligible to be vaccinated, the CDC report found.

Sixty-six percent of the 141 who were eligible for vaccination were between the ages of 16 months through 19 years, the time span a person is most likely to be vaccinated. Three-quarters had not received the vaccine because of a philosophical, religious or personal exemption.

There have been no deaths from measles in the United States since 2008, noted Dr. Jane Seward, deputy director of the CDC's Division of Viral Diseases. But one of every three people who contracted the disease last year had to be hospitalized.

Measles is extremely contagious, with symptoms including a total-body rash along with flu-like symptoms such as cough and fever. The CDC and other public health authorities strongly recommend that all individuals keep up to date with their vaccinations, especially if they are planning to travel abroad.

The CDC recommends that all children receive two doses of the measles-mumps-rubella (MMR) vaccine, the first at 12-15 months of age and the second at 4-6 years. Very young infants can get vaccinated earlier if they are going to be traveling abroad or if they are going to be in contact with an international visitor.

"Measles is preventable and unvaccinated people put themselves and others at risk for measles and its complications, particularly those who are too young to be vaccinated who can sometimes have the worst complications," Schuchat said.

Authorities are particularly worried with the summer travel season looming and many Americans planning to attend the Olympics in London.

More information

Find out more about measles at the Nemours Foundation.