Vaccination remains best defense vs. measles virus

Unlike several states, Indiana has had no reported cases of measles this year. But that’s no reason to lower our guard.

More than 90 people from 11 states developed measles in the first three weeks of the year, most of them infected during an outbreak that started at Disneyland in December.

Indiana health officials remain wary. In a media interview, Dr. Joan Duwve, chief medical consultant with the Indiana State Department of Health, said, “Only one case of measles constitutes an outbreak for that disease here.”

And when there’s one case of measles, more are likely to follow, especially among people who have not been vaccinated.

A quick spread of the disease is due to the fact the measles virus is incredibly hardy, is airborne and can be passed on before an infected person becomes symptomatic. If an infected person is in a room with 100 unvaccinated people, 90 of them will become ill, health experts say.

Last year saw the highest number of measles cases since 2004 — 644 in 27 states, according to the federal Centers for Disease Control and Prevention. Indiana has seen two recent measles outbreaks, one in the northern part of the state in 2011 and one in central Indiana in 2012. In both instances, a person from overseas brought measles into this country, infecting a group of people who were largely unvaccinated. Each resulted in 14 cases.

The best defense remains vaccination. Shots are effective at keeping people from getting measles, but they also protect anyone the vaccinated person comes in contact with. So quick spread of the disease is stymied.

Indiana allows parents to opt out of mandatory vaccination of elementary and high school students for religious reasons. In addition, parents have to file for that exemption every year. As a result, state health officials estimate only about 1 percent of Hoosier students are not vaccinated against measles.

But adults who didn’t get vaccinated as children need to get shots in order to protect themselves and others, and parents of preschoolers need to make sure they stay up to date with their child’s shots.

The state so far has been lucky with regard to measles, but continued diligence about vaccinations is required.