EV-D68: Will Last Year's Outbreak Be Repeated?

Enterovirus D68 (EVD68) filled emergency rooms all over the US in the late summer and early fall of 2014.

Last year, EV-D68 sickened hundreds of people and was later blamed for five deaths. In a symposium at ID Week 2015, clinicians and researchers assessed the outbreak, offering lessons learned and mysteries remaining.

Among those unanswered questions: why did the virus appear to be associated with some cases of polio-like paralysis? Why did so many people escape getting the virus? Will EV-D68 be back this year? For Steve Oberste, PhD, of the polio lab branch at the Centers for Disease Control and Prevention (CDC) a major task was testing all the respiratory samples sent to the CDC. EV-D68 was confirmed in 1,153 cases and in 92% it was the same strain. That included 288 diagnoses made in a few states that have the necessary equipment to test for the virus. "All states but Alaska had outbreaks, but Alaska saw EV-D68 in 2013," Oberste said.

One puzzling finding, he said, was that the CDC analyzed representative US specimens it had on hand from other research done in 2012 to 2013 to try to learn whether people generally had antibodies to the virus. They found that EV-D68 was nothing new. Further, testing those samples revealed that 100 % of the people from whom they were taken from showed immunity to EV-D68.

Virtually everyone in the US should be able to be exposed to the virus without consequences.

"Almost everyone was immune, so the question is why people were getting infected," he said. None of the panelists could answer that question definitively.

"It could be that they got a heavy dose," said Jason Newland, MD, an infectious disease specialist at Children's Mercy Hospital in Kansas City, Mo.

Perhaps the patients "Were near someone who was really coughing and hacking." Or, he said in an interview after his presentation, perhaps there are genetic differences in individuals that put them at higher risk of getting sick with EV-D68.