BROOKLYN - Health officials confirmed Friday that 75 percent of the Brooklyn residents who have contracted the mumps virus had been vaccinated against it.

According to data collected by the Department of Health, the current mumps outbreak is the largest in nearly 20 years, affecting at least 57 people living primarily in Borough Park.

Officials believe the outbreak may have originated at a summer camp in upstate New York. Most of the patients are children between the ages of 10 and 15.

The airborne disease can cause swelling of the salivary glands, fever and sore throat. Health officials are urging residents to report any suspected cases to the Bureau of Immunization.