Dozens of confirmed cases of mumps at Harvard and Fairfield universities in Connecticut have threatened commencement and raised concerns -- although health officials say such outbreaks will happen at schools, colleges and camps.
"In some years, there are more cases of mumps than usual because of outbreaks," the Centers for Disease Control says. "A major factor contributing to outbreaks is being in a crowded environment, such as attending the same class, playing on the same sports team, or living in a dormitory with a person who has mumps."
A decade ago, the U.S. had a multi-state outbreak affecting an estimated 6,500 students on several different Midwestern college campuses, the CDC reports.
Several mumps outbreaks were also reported on college campuses in California, Virgina and Maryland in 2011-2013, the center says.
"However, these all had limited spread," it reports, "and national case counts for these years were at usual levels (several hundred cases per year)."
Two large outbreaks occured in 2009 and 2010.
One affected about 3,000 mostly high school-aged students "who were part of a close-knit religious community in New York City and attended schools in which they had very close contact," the center reports.
"The outbreak started when an infected student in this religious community returned from the United Kingdom where a large mumps outbreak was occurring," it says.
The second outbreak occurred in Guam and affected nearly 500 people.
An outbreak at Harvard that began in early March has reached 41 cases as of Thursday, and could threaten the school's May 26 graduation ceremonies.
A statement on the Sacred Heart University website says the eight cases were detected March 22, and the students have recovered. Nine probable cases have also been identified.
Mumps outbreaks can occur at any time but are more common in winter and spring, the center says.
The MMR vaccine prevents most cases but not all, it says: Two doses are 88% effective; one is 78% effective.
Anyone born in 1957 or later who doesn't have evidence of immunity against mumps should have two doses of MMR vaccine, separated by at least 28 days, the center says. Those born before 1957 don't need vaccinations unless they work in a healthcare facility.
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