Children’s Hospital Colorado is heightening its surveillance for enterovirus D68 to quickly detect any circulation of the virus that last summer and fall caused a devastating nationwide outbreak of severe respiratory illness among children and young adults.
The outbreak, which erupted in mid-August and continued through January 2015, also was associated with rare cases of polio-like partial paralysis of limbs, including 13 young patients treated in Colorado.
Children’s Hospital has adopted a new diagnostic test – very rapid, sensitive and specific to EV-D68 – developed by researchers at Washington University School of Medicine in St. Louis.
“We have adopted that assay for our surveillance at Children’s Hospital so we can tell when EV-D68 is circulating again in Denver, and be prepared if cases surge again this year,” said Dr. Kevin Messacar, an infectious disease specialist.
Last year, the only tests available for EV-D68 early in the onslaught required days for sequencing of the viral DNA, and very limited amounts of testing occurred at the time, Messacar said.
The Centers for Disease Control and Prevention eventually developed a faster assay. But Washington University, which had more time to refine its technique, recently provided a testing method that is perhaps a little more sensitive – able to detect even small amounts of the virus, Messacar said.
“An enormous amount of work has gone into making us as prepared as we can be if this virus returns to the Denver area,” Messacar said. “But there is so much that is unknown right now. We’re doing our best to learn as much as we can.”
In 2014, the CDC and public-health laboratories confirmed 1,153 cases in 49 states and the District of Columbia – almost all among children – but officials acknowledged there likely were millions of EV-D68 infections never treated or tested.
“We think that number is likely a vast underestimate of the burden of the disease,” Messacar said. “We had 100 samples confirmed of EV-D68 at Children’s. But so few samples got tested. We looked at how busy we had been during that season, August through October, over the last three years. It looks like we had 1,000 extra visits in 2014. And many sought care, but were not tested. And there were so many other cases that were mild and (the children) never came to the hospital.”
By contrast, respiratory cases with high fevers that later developed partial paralysis – called acute flaccid myelitis – were rare, Messacar said. From Aug. 2, 2014, to April 14, the CDC verified reports of 118 children in 34 states meeting their definition. The CDC continues to investigate, along with hospitals and labs nationwide, the connection of the condition with EV-D68.
Messacar said Children’s Hospital Colorado has set up a multidisciplinary clinic of physicians, neurologists, rehabilitation experts and occupational and physical therapists for the children, whose symptoms range from mild impairment of limbs to full paralysis.
