02/06/2015 10:00 am ET Updated Apr 08, 2015

Relearning the Horrors of Measles

This piece was originally published here in the Dallas Morning News.

I expected to battle rare and exotic diseases when I joined the Epidemic Intelligence Service as a disease detective in 2011. Instead, I fought outbreak after outbreak of vaccine-preventable diseases as they spread through kindergartens, day care centers and even hospitals in the U.S.

In my first outbreak investigation, five newborns contracted whooping cough in a neonatal intensive care unit in Arizona. Coughing health care workers who had not been vaccinated against the disease exposed 40 sick babies to the bacteria.

In another outbreak, a sick health care worker continued to work while coughing and exposed patients and colleagues to whooping cough.

It was puzzling that those who chose to care for the most vulnerable patients in the hospital chose not to receive vaccines. Arguing that it was a personal choice, they missed the fact that their actions had consequences for those too young to protect themselves.

The rapid rise of measles of this year has highlighted the importance of vaccines. They are heralded as one of the top 10 successes of public health in the 20th century. So why do some people -- even some health care workers -- choose not to use them?

A fraudulent study published in 1998 in a widely-respected medical journal is one reason. It purported that the MMR vaccine was linked to autism in children. The study was later retracted and one of the authors lost his medical license but the damage was done. Some parents still cite that study when they sign vaccination exemption forms for their children.

But the reasons are more complex than just one study. Most millennials growing up in the U.S. have grown up without witnessing the potential horrors of these childhood diseases. Measles kills one in every 500 people infected. Children younger than five years are particularly vulnerable. One in 10 will suffer an ear infection that can cause permanent deafness; one in 20 will develop pneumonia.

Most doctors of my generation have not seen these diseases outside of textbooks. Until now.

Before there was a vaccine for measles, the virus infected 4 million Americans and killed 500 every year. That number dropped to about 40 infections and a handful of deaths after a vaccine was available.

We thought our work was done but our success backfired. A new report by YouGov found millennials were most skeptical of vaccines while people over the age of 65 years -- those who have confronted these diseases -- showed the most confidence in vaccines.

There were more cases of measles in the U.S. last month than in the whole of 2012 and health officials say they expect to see more cases of vaccine-preventable diseases. We may have to relearn the horrors of these diseases before we are rid of them again.