What You Should Know About Enterovirus D68

The Centers for Disease Control and Prevention (CDC) recently reported an outbreak of enterovirus D68 (EV-D68), confirming a total of 1,121 cases in 47 states and the District of Columbia between mid-August and November 20, 2014. Although the most common symptoms of this viral infection are mild and mimic those of the common cold, in children with asthma, the EV-D68 can be life-threatening.

A few deaths have been reported, but experts aren’t clear what role—if any—the virus played. So far, EV-D68 has been detected in specimens of 12 patients who died and had samples submitted for testing. Here’s what you need to know.

A Worrisome Strain, Especially for Younger Patients

EV-D68 is one of the at least 100 known varieties of non-polio enteroviruses in the world. Enteroviruses cause 10 to 15 million infections annually; the common cold is caused by one of them (the rhinovirus). Enteroviruses can also cause meningitis and gastrointestinal illness.

While EV-D68 is not new (it was first identified in 1962 in California), its newfound notoriety may be due to the fact that the current strain seems to be particularly virulent.

Clement Ren, MD, chief of the division of pediatric pulmonology at the University of Rochester, suspects EV-D68 contributed to the unusually high number of very sick children he treated in the hospital this fall: "We saw a ton of severe asthma attacks in children here from late summer through November, but the overwhelming majority of these young patients had asthma or a history of breathing difficulties," Ren says.

Ren and his colleagues can’t be 100 percent certain the breathing difficulties were triggered by EV-D68, but he suspects a link: "Kids without asthma weren’t getting as sick and the reaction we were seeing in the lungs of asthmatics was much more severe than what’s usually triggered by the common cold virus," he notes. Children with asthma who show any symptoms such as sneezing, coughing, fever, body aches, runny nose, wheezing, or difficulty breathing should be seen by their pediatrician as soon as possible, since "Early treatment is critical."

An Ongoing Investigation

In response to the outbreak, in mid-October the CDC developed and began using a faster lab test for detecting EV-D68 on samples submitted by state health officials. EV-D68 infections have since declined, but respiratory illnesses caused by other viruses, like influenza (flu) and respiratory syncytial virus (RSV), are increasing. The CDC is continuing to collect and test samples.

Ren and other experts also point out that the recent 1,121 confirmed cases of EV-D68 may not indicate an actual increase in infection numbers: "Enteroviruses change frequently over time, and since we weren’t specifically looking for it, we may have missed it. It’s also possible that it was being misdiagnosed until recently," he observes.

EV-D68 And Paralysis: A Possible Link

The other major concern with EV-D68 is muscle weakness: Following reports of children in California with unexplained polio-like illness in their arms or legs and common cold-like symptoms, 10 children in Colorado were hospitalized in August and September. Of those children, a small number had EV-D68 in their nose secretions. However, the CDC has not yet determined if the infection is linked to the muscle weakness. The illness was not polio—also an enterovirus—but many parents are worried.

However, experts point out that acute flaccid paralysis (AFP)—a catch all term that describes the sudden onset of paralysis in at least one limb—occurs in children under 15 at a rate of approximately one per 100,000 children annually. In the absence of polio, AFP can be triggered by a number of causes, including environmental toxins, bacterial infections, and previously undiagnosed genetic diseases.

Currently, a definitive link between EV-D68 and paralysis has not been proven, but the CDC continues its investigation. "Polio is also an enterovirus," explains Ren. "EV-D68 and polio are in the same family—cousins, if you will—but act very differently, so parents may have no reason to be anxious."

Keeping Your Child Healthy

Unfortunately there is no vaccine to prevent illness from the enterovirus infection, so standard preventive care to ward off infection is important, as is keeping sick children at home.

To prevent illness, "Wash hands often and sanitize frequently-used surfaces like faucets and toilet seats," Ren recommends. "Use tissues, avoid people who are sick, and contact your doctor at the earliest sign of a cold."

Parents of asthmatics should be especially vigilant: "Have your child’s asthma re-evaluated and consider having a lung function test performed," urges Ren. "Take medication as prescribed, have an asthma action plan in place, and be sure all medications are current."

In the meantime, the CDC recommends every person age six months and older be immunized against the flu.

Clement Ren, MD, approved this article.


Clement Ren, MD. Phone interview November 20, 2014.

"Non-Polio Enterovirus. Enterovirus D68 in the United States, 2014." The Centers for Disease and Prevention. Updated November 20, 2014. Accessed November 21, 2014.

"CDC Develops a New, Faster Lab Test for Entervirus D68." The Centers for Disease and Prevention. Updated October 14, 2014. Accessed November 21, 2014.

"Unexplained Paralysis Hospitalizes Children." The Centers for Disease and Prevention. Accessed November 30, 2014.

"Rare Polio-Like Disease in California." The University of California, San Francisco. Updated April 29, 2014. Accessed November 21, 2014.

"Poliomyelitis." World Health Organization. Page last updated December 15, 2014.