Over this summer and fall, enterovirus-D68 spread across the United States. This virus belongs to a virus family that is subclassified into familiar categories, including polio viruses, coxsackie A and B viruses, echoviruses and other enteroviruses.
These viruses cause a variety of illnesses, including gastrointestinal illness, rash and neurologic illnesses, such as aseptic meningitis. The respiratory tract is mildly affected.
EV-D68, however, was recognized as causing moderate to severe respiratory illness in children in the Midwest in August 2014. These affected children usually had a preexisting respiratory condition such as asthma.
Indeed, children with asthma seem to be particularly vulnerable with these children presenting symptoms such as cough, shortness of breath and difficulty breathing. Fever, which occurs in only about 30 percent of affected children, is not a major component of this illness. Thomas Bernard Kinane is an HMS associate professor of pediatrics at Massachusetts General Hospital and an international expert in pediatric respiratory conditions. Here he talks with Harvard Medicine News about EV-D68.
HMS: How concerned do people need to be about enterovirus?
KINANE: Most EV-D68 infections cause very mild symptoms, like a cough, runny nose or muscle aches. In patients with respiratory disease it can cause more serious symptoms, such as difficulty breathing or wheezing. These patients can be severely affected but almost all recover.
HMS: Who in particular might be more vulnerable or at most risk?
KINANE: Children with asthma seem to be particularly vulnerable, but asthma is not the only respiratory condition that is exacerbated by this virus. Patients with neuromuscular disease and interstitial lung disease seem to be similarly affected.
HMS: How does it differ from other more common viruses such as cold and flu?
KINANE: Enteroviruses are a different viral family from the cold (rhino) virus and the flu (influenza) virus. Enteroviruses do not usually affect the respiratory system as cold and flu viruses do. Indeed, this enterovirus is different from other enteroviruses as it seems to predominantly affect the respiratory systems.
HMS: In what sorts of ways is the biomedical research community making progress against these sorts of pathogens?
KINANE: This virus is relatively new and has only caused minor outbreaks of viral illness over the last 40 years. The medical community has focused on supportive care, which has allowed almost everyone to recover.
However, there is intense focus on another illness. Over the last two years, there was another unusual illness affecting a very small number of children. This illness causes acute muscle weakness, similar to polio. Two of these cases tested positive for EV-D68. It is difficult to know if this new condition is related to EV-D68 but is subject to intense research.
HMS: Are there more of these kinds of dangerous viruses out there in the community then there have been in the past, or are we just more aware?
KINANE: From time to time a new virus emerges; most of the viruses are variations of well-known viruses. The CDC has an excellent surveillance system. There is no reason to be concerned.
