Mumps sweep Iowa; total hits 17-year high

DES MOINES, Iowa – A mumps epidemic is sweeping across Iowa in the nation’s biggest outbreak in at least 17 years, baffling health officials and worrying parents.

As of Thursday, 245 confirmed, probable or suspected cases of mumps had been reported to the Iowa Department of Public Health since mid-January.

The federal Centers for Disease Control and Prevention said it is the nation’s only outbreak, which the CDC defines as five or more cases in a concentrated area.

“We are calling this an epidemic,” said Iowa state epidemiologist Dr. Patricia Quinlisk, explaining that mumps has spread to more than one-third of the state and does not appear to be confined to certain age groups or other sectors of the population.

Quinlisk said Iowa has had about five cases of mumps a year in recent years, and this is its first large outbreak in nearly 20 years.

“We’re trying to figure out why is it happening, why is it happening in Iowa and why is it happening right now. We don’t know,” she said.

CDC spokeswoman Lola Russell said the federal agency has no answers yet. But Quinlisk said one theory is that the infection was brought over from England – perhaps by a college student – because the strain seen in Iowa has been identified by the CDC as the same one that has caused tens of thousands of cases of the mumps in a major outbreak in Britain over the past two years.

The Public Health Department said 23 percent of the 245 reported patients are in college.

The CDC said it is the nation’s biggest epidemic of mumps since 269 cases were reported in Douglas County, Kan., from October 1988 to April 1989.

Mumps is a viral infection of the salivary glands. Symptoms include fever, headache, muscle aches and swelling of the glands close to the jaw. It can cause serious complications, including meningitis, damage to the testicles and deafness.

A mumps vaccine was introduced in 1967. Iowa law requires schoolchildren to be vaccinated against measles and rubella, and the mumps vaccine is included in the same shot. The state’s last major outbreak was in 1987, when 476 people were infected.

Of the 245 patients this year, at least 66 percent had had the recommended two-shot vaccination, while 14 percent had received one dose, the Public Health Department said.

“The vaccine is working,” Quinlisk said. “The vaccine certainly was made to cover this particular strain, because it’s a fairly common strain of mumps.” Quinlisk said the vaccine overall is considered about 95 percent effective.

Quinlisk said the mumps outbreak started in eastern Iowa and is spreading statewide and possibly into the neighboring states of Illinois, Minnesota and Nebraska. Those states may have one or two cases, she said.