WASHINGTON A boy with measles who was on the Japanese team in last year's Little League World Series triggered a U.S. outbreak of the disease that sickened at least six other people, health officials said on Thursday.
Measles cases were diagnosed in Pennsylvania, Michigan and Texas after the boy, age 12, traveled from Japan while ill with the highly contagious viral illness, the U.S. Centers for Disease Control and Prevention said in a report that tracked the outbreak's course.
"This outbreak highlights the need to maintain the highest possible vaccination coverage in the United States," the CDC said in the report.
Measles is spread by contact with droplets from the nose, mouth, or throat of an infected person, or can be airborne.
Just dozens of measles cases are reported annually in the United States, which the CDC said appeared to stem from infected travelers. Before a vaccine was introduced in the United States in the 1960s, more than half a million measles cases were reported annually.
The disease causes fever, cough, redness and irritation of the eyes and a rash. Serious complications include encephalitis and pneumonia that can be fatal, and measles remains a leading cause of death among children in poor countries.
This outbreak occurred last August and September, the CDC said. The Little League World Series is held annually in Williamsport, Pennsylvania, bringing together youth teams from around the world to play U.S. teams in a tournament.
The CDC said the Japanese boy, who was not identified for privacy reasons, was exposed in Japan to a sibling who appeared to have measles in late July and developed symptoms, but flew anyway to the United States on August 13.
A woman, 53, who sat near the boy on a flight from Detroit to Baltimore became infected, as did a man, 25, who worked at Detroit's airport and was exposed to the boy in the customs area, the CDC said.
A man, 40, who worked as a corporate sales representative, got measles after being exposed to the boy in Pennsylvania. Two Houston-area college students, men ages 18 and 19, caught it after being near the sales representative in Texas.
Another Japanese boy, 12, who traveled to the United States and was exposed to the initial patient also got sick. A second Detroit airport employee developed measles a month later, but the CDC said it is unclear if this case is related to the others.
The CDC recommends children get a first dose of the MMR -- measles, mumps and rubella vaccine -- at ages 12 to 15 months and a second dose at ages 4 to 6 years.
U.S. organizers of big events attended by international travelers, especially youths, should consider requiring documentation of vaccination, the CDC said.
Everyone recovered in this outbreak, it said. Worldwide about 242,000 people, mostly children, died from measles in 2006, according to the World Health Organization.