(CNN) — Sixty cases of mumps have been diagnosed in Champaign County, Illinois, since April, according to a local health official, who told CNN on Friday all the cases are linked to the University of Illinois at Urbana-Champaign campus.
There are 13 additional cases, that may or may not be linked, elsewhere in the state.
Mumps is a vaccine-preventable virus that’s contagious and spreads via droplets of saliva through coughing, sharing eating utensils or touching surfaces without washing hands after a sick person has done so.
The Champaign-Urbana Public Health District usually has 10 to 12 cases of mumps a year, according to Dr. Awais Vaid, an epidemiologist there. He said he worries the number of people infected could increase when students return to campus for the fall semester in two weeks.
“We were at 25 cases when the semester ended in the middle of May. We thought the outbreak would be over as we have seen in other outbreaks, that when students leave the outbreak is over,” Vaid said, noting that many students, including athletes, stayed on campus.
The key, he said, is for vaccination to be verified and for sick patients to isolate themselves.
The Champaign-Urbana Public Health District is working closely with the university and Illinois Department of Health to prevent the outbreak from spreading.
All the patients in this outbreak had minor flu-like symptoms, plus swollen salivary glands, which led to their diagnosis, Vaid said. Most are university students, although a few are family members or from the nearby community.
Most of them are between the ages of 16 and 30 and are up to date on their measles, mumps and rubella, or MMR, vaccine. However, the vaccine is not 100% protective and, according to the Centers for Disease Control and Prevention, it is less protective — about 88% — against mumps than it is against measles and rubella. Still, the vaccine is the best protection against the virus.
Vaid said one reason they aren’t seeing severe cases associated with this outbreak is likely because the vaccine is offering some level of protection. The CDC concurs that the vaccine has reduced the number of complications from the illness. The MMR vaccine is recommended for 12- to 15-months-olds, with a follow-up booster to be administered between ages 4 and 6.
“It’s not something we haven’t seen before,” said Dr. Greg Wallace, who leads the CDC team dedicated to measles mumps, rubella and polio.
Outbreaks tend to occur in settings where people are in close proximity to one another such as a college campus.
The telltale symptoms of mumps are puffy cheeks and a swollen jaw but can also include fever, headache, muscle aches, fatigue and loss of appetite. Symptoms begin 12 to 25 days after a person is infected.
In looking at the past 15 years, Wallace said that about 400 to 500 cases of mumps happen in the United States every year, with five outbreaks of more than 1,000 cases within that time.
Still, he said, “These numbers pale in comparison to what we saw before there was a vaccine.”
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