After declaring in 2000 that measles had been eliminated from the U.S. through a successful vaccination program, government officials now say the number of confirmed cases has reached a 20-year high as people who get the disease abroad bring it back to America.
Unvaccinated Americans and foreign visitors who traveled to the Philippines, Europe, Africa and Asia are the main culprits in a growing spike of U.S. measles cases that began several years ago and exploded this year.
As of last Friday, 288 cases have been reported in 18 states, the highest year-to-date total since 1994, when 963 cases were reported by year's end. Ninety-seven percent – 280 – of the 2014 U.S. cases were imported from other countries.
"Measles is coming in on airplanes from places where the disease still circulates or in where large outbreaks are occurring," said Dr. Anne Schuchat, the director of the National Center for Immunization and Respiratory Diseases at the U.S. Centers for Disease Control and Prevention.
A highly contagious viral respiratory disease that grows in cells at the back of the throat and lungs, measles is spread through the air by coughing, sneezing and even breathing. It can cause fever and coldlike symptoms, along with a stubborn rash.
Fifteen measles outbreaks, involving three or more related cases, have occurred in places such as New York City and in California, where six outbreaks were reported in six counties. Forty-three people have been hospitalized nationally, but no deaths have been reported.
The imported virus is "landing in places in the U.S. where groups of unimmunized people live," Schuchat added. "That setting gives the measles virus a welcome wagon by providing a chance for outbreaks to occur. And the larger the outbreak, the more difficult to stop."
Ohio's 138 cases have been linked to Amish communities in which several members had traveled to the Philippines, which is experiencing its own measles outbreak, with more than 32,000 cases and 41 deaths this year, Schuchat said.
Low vaccination rates in Amish communities have been a long-standing health issue.
Ninety percent of reported U.S. measles cases are among people who haven't been vaccinated for the disease or who didn't know their vaccination status.
Of 195 unvaccinated U.S. residents with measles, 165, or 85 percent, chose to go without vaccinations for personal, religious or philosophical reasons, "not because they were too young or had medical reasons that they couldn't be vaccinated," Schuchat said.
"Unfortunately, when we have larger communities of unimmunized people, it's more likely that bigger outbreaks will occur, making it much more difficult to control the spread of disease and making us vulnerable to have the virus re-establish itself in our country again," Schuchat said.
Health officials are urging people to get vaccinated for measles, especially before international travel.
About 10 percent of children who get measles also get ear infections and about 5 percent develop pneumonia. About 1 in 1,000 measles patients contract encephalitis, and 1 or 2 out of 1,000 die.
Before the U.S. measles-vaccination program, which began in 1963, 3 million to 4 million people in the U.S. developed measles each year, leading to 48,000 hospitalizations and 400 to 500 deaths.
As measles vaccinations took off in the 1960s, the rate of transmission steadily declined, prompting health officials to declare in 2000 that the indigenous spread of the disease had been eradicated in the United States.
Its re-emergence through imported cases is a troubling development for health officials. U.S. measles patients this year range from 2 weeks old to age 65, with more than half over age 20. Forty-eight, or 17 percent, are ages 1 to 4.
In addition to the 229 measles cases in Ohio, California and New York state, 15 have been confirmed in Washington state, eight in Massachusetts, five each in Tennessee and Oregon, four in Texas and three each in Missouri, New Jersey and Pennsylvania.
About 164,000 people around the world die from measles each year. Measles can also cause women to miscarry or give birth prematurely.
By Tony Pugh
McClatchy Washington Bureau