Fordham University says several students have contracted the contagious mumps infection on its Rose Hill campus in the Bronx.
In an email to students Wednesday, the university's health services department said eight students have been diagnosed with mumps, four of them on Tuesday and three on Wednesday. There was one previous case in January.
All the students have either returned home or been isolated during the infectious phase of the illness, the school said. Typically, mumps patients are contagious for two days prior to the outbreak of symptoms and five days afterward.
All the affected students had prior vaccinations against mumps, Fordham officials say. Doctors say even vaccinations don't offer 100 percent protection.
"The immunity that's induced by the virus starts to wane. They believe that it holds until at least late teenage years, but then it starts to wane," said Dr. Dana Saltzman, a disease specialist not affiliated with Fordham. "There's no way to predict who's going to lose their immunity or not."
Student Paul Monaghan, who learned of the outbreak through email, said: "It's strange, because everybody gets vaccines a little after they're born. It's strange to think six kids have been sent home and possibly more will be infected."
Nearly 7,000 undergrad students attend classes at the Rose Hill campus, and more than 3,300 live in campus housing, according to the university's website.
The school also has a campus at Lincoln Center.
Symptoms include fever, headache, muscle aches, tiredness, loss of appetite and swollen or tender salivary glands under the ears or jaw. Mumps is spread from person to person through saliva contact or sneeze droplets.
Students and university community members have been encouraged to wash their hands regularly with soap and water, and to clean tables, counters and doorknobs.
-- Ida Siegal contributed to this report.