A Mumps Lesson

These days, doctors often misdiagnose people with mumps. They look for the other rare, out-of-the-way explanations instead, Ernst says. One girl he saw when he worked in San Francisco had been diagnosed with a simple “enlarged gland in the neck” rather than the mumps.

Mumps is usually prevented through two vaccinations. The first shot is administered to children around their first birthday. The second shot is given as they enter school, between the ages 4 and 6. Many states require the combined measles, mumps, and rubella vaccination before children enroll in public school.

“It works quite well in most individuals,” says Morse, who is also the director of the Center for Public Health Preparedness at the Mailman School of Public Health.

When vaccines fail

Many of the Iowan college students and their web of family, friends, and classmates who caught the mumps were failed by their immunizations. Most of the affected Iowans received one shot of the MMR vaccine and over half got the booster shot later.

They, like the victims of the British outbreak, had a subtype of the mumps virus known as genotype G. However, the subtype is not the reason for them falling ill. The vaccine covers this genotype, stresses Lon Kightlinger, the South Dakota State epidemiologist.

But vaccines, however effective they are, can wane over time.

“These are mainly individuals who have been immunized, but lost immunity,” says Pomerance. Their protection diminished, he explains, because people are no longer constantly exposed to the virus. Each new exposure would give another jolt to the immune system, keeping it prepared. To combat waning immunity, Pomerance suggests a third MMR booster, to be given at about age 12.

Containment

In the beginning of June, the Iowa Department of Public Health declared that the mumps outbreak was contained because the number of new cases reported was dropping. Midwestern states, including Iowa and South Dakota, developed vaccination programs that targeted people at risk of contracting the virus to keep it from spreading through the population.

In South Dakota, once someone showed symptoms of the mumps–swollen neck glands–he was quarantined for at least nine days. Susceptible people, who had not been fully vaccinated, were quarantined from the twelfth to twenty-sixth day after exposure, says Kightlinger.

As of mid-June, South Dakota vaccinated 8,899 people, according to the Department of Health. Anyone in contact with children or young adults could receive free vaccinations, says Kightlinger. The state even brought the vaccine to the outbreak site, whether it was a college or a daycare center.

And New York City’s Department of Health and Mental Hygiene says it too would be able to handle such an epidemic. According to Morse, New York may be better equipped than other cities, despite its size, to deal with outbreaks of disease.

How New York decides to combat a disease outbreak will depend on the number of cases reported and how much vaccine is available, explains Morse. Because of the threat of smallpox bioterrorism, New York already has a plan if it becomes necessary to spring into action and vaccinate susceptible people. All of the city’s residents can be vaccinated in a matter of days, according to the New York City Office of Emergency Management. The vaccinations would be carried out at 200 currently undisclosed centers.

“I think we could do it,” remarks Morse. But when dealing with a disease like the mumps, such mass immunizations, he says, “might not be the first choice.”

Instead, New York will most likely do what South Dakota did—start with targeted vaccinations, says Morse.

Doctors and epidemiologists can learn from each outbreak or incident like the one in the Midwest. They can then plan future responses based on those lessons, making the next outbreak less severe.

“We do what works and learn from our mistakes,” says Morse.