Mumps Outbreak Swells Across Midwest

April 7, 2006 — -- An outbreak of mumps continues to spread through the Midwest, so far infecting about 400 people, primarily college students in Iowa, Kansas, Illinois and possibly Nebraska.

While the word "outbreak" typically means bad news, there is a silver lining: Mumps is a fairly mild viral infection, causing swelling of the salivary glands and soreness in and around the mouth and jaw areas. It usually goes away after a few days and rarely causes complications.

But the bad news: The outbreak is probably not ending anytime soon, and it was likely brought over here from an infected traveler from the United Kingdom, where a much larger outbreak was in full swing last year.

It's not known precisely why this mumps outbreak is occurring, especially when so many U.S. residents receive a vaccination for it during childhood. Infectious disease expert Dr. William Schaffner said he hopes that the Centers for Disease Control and Prevention will fully investigate why Americans are coming down with the illness.

He said the outbreak also highlights an important area that needs to be researched: whether a booster shot, similar to the tetanus booster that adults are supposed to get every decade or so, would work for the mumps vaccine.

A mumps vaccine is currently given to almost all U.S. children in their second year of life, along with the measles and rubella vaccines, known as the MMR vaccine. A second MMR is recommended when children become teenagers.

That's because even under the best circumstances the mumps vaccine protects only about 96 percent of people who have been vaccinated. And it appears the vaccine's effectiveness may wear off with time, Schaffner said.

This isn't a problem for most people, but college students' lifestyles make them more vulnerable to infectious diseases. They live, study, eat and exercise in close quarters, Schaffner said, making transmission easier.

This is an especially important point to consider, he said, given how we now live in "a very small world."