By Betsy Todd, MPH, RN, CIC, AJN clinical editor
As news coverage focuses on the latest clusters of suspected—and, in some instances, confirmed—cases of human enterovirus D68 (EV-D68) as they occur in successive regions of the U.S., here’s a quick primer on what is known about EV-D68.
Is this a new, dangerous virus?
EV-D68, a non-polio enterovirus, is not a “novel” virus—the term used to describe emerging infections such as SARS and MERS. It’s more accurate to describe it as the CDC does: it is an “increasingly recognized” cause of respiratory infections, especially in children.
EV-D68 was first isolated in 1962. While reports of EV-D68 since then have been sporadic, the CDC in 2011 reported on clusters of this viral infection in Georgia, Pennsylvania, and Arizona as well as in Asia and Europe. It’s likely that there are hundreds or even thousands of EV-D68 infections every year in the U.S. But as with many other viral infections, they will range in severity, and an infection that looks like “a cold” isn’t usually brought to the attention of a health care provider.
According to the CDC, most enterovirus infections are actually asymptomatic; this may be the case with EV-D68 as well.
Diagnostic testing for EV-D68 involves RT-PCR and gene sequencing. Most hospital labs therefore are unable to test for it. Some readily available diagnostic tests do identify “enterovirus” but don’t type the virus further; some tests misidentify EV-D68 as a rhinovirus. (Specimens from suspect cases in the U.S. therefore almost always are handled by CDC labs.)
Because treatment is symptomatic, the lack of a widely available test for EV-D68 is not an issue for the patient. But as more sensitive and specific tests become more widely available, more cases will be correctly identified, and we can learn more about the course of the disease.
Genetically similar to cause of common cold.
EV-D68 belongs to a genus of viruses that includes polioviruses, rhinoviruses, coxsackieviruses, and echoviruses. It is not “polio-like.” Biologically and epidemiologically, it is most similar to human rhinoviruses, which cause the common cold.
Severe respiratory infections in children? Visitor restrictions?
While we are seeing reports of severe respiratory illness in patients with suspected or confirmed EV-D68, it should be noted, as the CDC points out, that many/most of those hospitalized with this and other respiratory infections are people with chronic conditions such as asthma or other health issues. Visitor restriction is a routine response in any hospital when there is a cluster of respiratory infections in the community.
But this is an outbreak!
Like other enteroviruses, EV-D68 seems to be seasonal, with most cases identified during the late summer or early fall. It may be that EV-D68 infections occur “cyclically,” as do some other viruses, with a particularly high number of cases once every several years. And inevitably, many people in the outbreak locations who develop respiratory infections ultimately will be found to have had other seasonal respiratory illnesses.
A good response to these clusters of infections at this time:
- Keep alarmist news stories in perspective.
- Closely monitor people with chronic lung problems who develop respiratory symptoms or fever, and report possible cases to your local (city or county) health department for further investigation.
- When assessing people with respiratory problems: take a careful history and do a thorough exam (is there wheezing? retraction? hypoxemia? rash?). Make note of comorbidities in order to evaluate risk, and ask about travel history (has this person been to one of the areas where cases have been identified?).
- Wash your hands, cover your cough, and disinfect frequently touched surfaces.
Caveat: There are no epidemiologic guarantees, and it’s always terrifying when your own child needs to be hospitalized (for any reason). But with what we know about EV-D68 and the viruses to which it’s most closely related, there is no reason to expect widespread disaster as these infections continue to appear.
Here’s the CDC’s recently updated page on the virus.