ASHLAND, Neb. (AP) — A staff member at a Nebraska summer camp has the mumps.

Officials at the Carol Joy Holling Camp in Ashland say Friday that the virus was identified quickly when the staff member noticed symptoms. He has seen a doctor and was quarantined at home. Officials say he was vaccinated but incubated the illness at a nearby university. They didn’t say which university.

The camp is not yet in session, but typically serves 1,600 campers and 20,000 other guests yearly. It is run by the Nebraska Lutheran Outdoor Ministries.

Nebraska health officials announced earlier this week that the number of mumps cases related to an outbreak at Midland University in Fremont increased from 10 to 21.

The viral infection’s symptoms include swollen salivary glands, fever, jaw pain and muscle aches.