The University of Richmond and Virginia Commonwealth University issued similar advisories last month after several cases of mumps were confirmed on their campuses.

Mumps is spread through droplets of fluid, usually when someone coughs or sneezes. Symptoms include headache, fever, and swollen or tender salivary glands.

The virus thrives on college and university campuses, where a large number of people live in close quarters and share drinks, lip balm or other items, said Dr. Doug Larsen, director of the Central Shenandoah Health District.

Statewide, there have been 66 mumps cases either confirmed or suspected since the beginning of March, the Virginia Department of Health reported.

“We always have a few throughout each season, and that’s pretty common,” Larsen said. “To say (why) we’re having more this time, it’s just a lot of conjecture. Still, the numbers are low compared to previous years.”

He said the recent cases could indicate that vaccines people received when they were younger are becoming less effective.

“What this tells us is that there may be a waning of immunity,” he said.

He said the vaccine can still reduce the severity of the virus and, in most cases, prevent illness.

“We still say vaccines are the best way of preventing infections,” he said. “If you think of the millions and millions of people (who were vaccinated), to see only this small number means it has worked pretty well.”