VICENZA, Italy -- Army medical staff vaccinated some 200 soldiers against mumps after several paratroopers in Italy showed symptoms of the virus and one tested positive for it in Germany.
The response was done out of "an abundance of caution," said Maj. Chris Bradley, a 173rd Airborne Brigade spokesman. "We wanted to make sure that nobody was spreading it."
Bradley said that over the past month or so, about 10 brigade soldiers sought care at the garrison health clinic after feeling sick and developing symptoms that could indicate mumps.
Their lab tests were negative or inconclusive, including a soldier deemed a "probable" case. But false negative results are common and do not "rule out mumps as a diagnosis," according to the Centers for Disease Control and Prevention website.
All the soldiers who showed symptoms at the Vicenza clinic were prevented from traveling to Germany for training with the brigade and were isolated for five days, as recommended by medical protocols to contain the virus.
There is no treatment for mumps other than supportive care.
But one soldier felt fine and did not seek medical attention until after arriving in Grafenwoehr. He was diagnosed with mumps on Aug. 5; test results two days later confirmed he had the virus.
By Friday, all those who had been in close contact with soldiers with suspected or confirmed cases had been vaccinated or revaccinated, Bradley said.
The CDC says children should get two doses of the MMR vaccine, which immunizes against measles, mumps and rubella. Servicemembers who cannot provide proof of vaccination are given a single booster of MMR, according to the Defense Health Agency.
After the U.S. began giving the two-dose MMR vaccine in 1989, the number of cases of mumps declined from more than 186,000 to just a few hundred a year.
But several military studies have suggested that because the mumps component of the MMR vaccine is the least effective and tends to wane the fastest, immunity could fall below levels that protect communities, leading to outbreaks.
In recent years, mumps cases have been on the rise in the U.S., according to the CDC.
The agency reported 150 outbreaks involving more than 9,000 cases from 2016 through 2017. From January to July this year, nearly 1,800 cases of have been reported in the U.S., the CDC said.
Some of the recent outbreaks occurred in military units. The crew of USS Fort McHenry was essentially quarantined at sea with no port calls for four months earlier this year after 28 of the 703 people on board came down with mumps.
Before the vaccine was licensed in 1967, mumps was known to frequently affect armies during mobilization, according to the CDC. In World War I, hospitalization rates for mumps were exceeded only by the rates for influenza and gonorrhea.
Why outbreaks have been on the rise in recent years in highly vaccinated populations such as the military isn't entirely clear. Researchers have suggested that the immune response provoked by the mumps vaccine may weaken significantly over time.
A person vaccinated twice against mumps is about nine times less likely to get the illness than an unvaccinated person exposed to the virus, the CDC said. If infected, vaccinated people are also likely to have less severe illness than an unvaccinated person.
Mumps is usually a mild disease of about two weeks duration, causing fatigue, fever and painful, swollen salivary glands resulting in puffy cheeks and jaws. But it can also cause swelling of the testes, ovaries and pancreas, and, in rare cases, complications such as hearing loss.