13 Numbers That Explain The Resurgence Of Measles In The U.S.

Along with vaccines for polio and mumps, the measles vaccine was a triumph of investigative research and public health when it debuted in 1968. It quickly became part of the lineup of childhood injections that would inoculate the child and protect society from the scourge of the sometimes fatal and always painful disease. Widespread vaccinations eventually led to the elimination of measles in the U.S. in 2000 and the Americas (North, Central and South) in 2002.

But a series of stumbling blocks -- notably, a fraudulent and discredited 1998 study linking vaccinations to the onset of autism -- set vaccination rates back in certain communities in the U.S. The backsliding has resulted in several measles outbreaks in the past year in a country that had already declared measles defeated. Read on to see why the U.S. should be concerned about this unprecedented measles resurgence.

Miami Children's Hospital pediatrician Dr. Amanda Porro administers a measles vaccination to Sophie Barquin, 4, as her mother, Gabrielle Barquin, and Miami Children's Hospital RN Diane Lichtman (right) hold her during a visit to the hospital on January 28, 2015 in Miami, Florida. (Photo by Joe Raedle/Getty Images)

The CDC notes that before 1963, an estimated three to four million people in the U.S. got measles every year, and of those people, 400 to 500 would die, 48,000 would be hospitalized and 4,000 would develop encephalitis, a dangerous swelling of the brain.

The consequence has been a slow but steady increase in U.S. measles cases. In 2014, there were 644 cases, the most in 20 years.

While national vaccination rates remain steady, some areas of the country -- say, the Amish community in Ohio, or some suburbs in California -- are seeing more and more parents opt their children out of vaccinations. When travelers exposed to measles encounter large numbers of unvaccinated people in these communities, the virus can take hold.

"The national estimates hide what's going on state to state. The state estimates hide what's going on community to community. And within communities there may be pockets," explained Schuchat. "I think we do have some communities with many who have not received vaccines, and the size of those cohorts is increasing."

Parents who choose not to vaccinate their kids are likely using a personal belief exemption to opt out of the shots, as opposed to a medical exemption. In 2014, 79 percent of the unvaccinated cases of measles in the U.S. were unvaccinated due to personal belief exemptions, noted Schuchat.

When communities fall below that threshold, they could potentially be setting the stage for a future measles outbreak. According to a recent Kaiser Permanente study published in the journal Pediatrics, certain California counties like Marin and Napa had under immunization rates that ranged from 18 to 23 percent between 2010 and 2012. Outright vaccine refusal in these areas ranged from 5.5 percent to 13.5 percent.

So what can experts do to reach these communities? Patsy Stinchfield, MS, RN, director of the Children's Immunization Project at Children's Hospitals and Clinics of Minnesota, has been treating measles patients and convincing parents to vaccinate their children for 37 years.

She compared these under-vaccinated communities in the U.S. to impoverished villages in developing countries in a phone interview with HuffPost and said public health workers needed to approach parts of the U.S. with the same sense of urgency they would in under-resourced parts of the world.

"I think our job is to bring vaccines to U.S. neighborhoods with the same kind of vigor and commitment as we see people doing in war-torn Pakistan," said Stinchfield. "There are health care workers that are risking their life to bring vaccines to the under- and unvaccinated, and I think we have to have a renewed commitment to bring vaccines so that every daycare, every school, every city, state in our country sets a goal of 100 percent vaccination."

Stinchfield is also an infectious diseases nurse practitioner and says that when she encounters parents who hesitate to vaccinate their children, she discusses her experience treating kids with measles complications. She often shows parents a photo of a child being supported by a ventilator after the virus spread to the lungs (called measles pneumonia) in order to convince them to vaccinate.

In addition to measles pneumonia, patients can also experience these other complications:

Graphics by Alissa Scheller for The Huffington Post.