The Wheeze That Wasn't – An Observation on Enterovirus D-68

Your next 3 patients…

#1: Neonate w/ fever/runny nose
#2: Teenager w/ wheezing; no asthma hx
#3: 10 yo F w/ severe dyspnea; h/o “lung condition”

Enteroviruses are a genus of single-stranded RNA viruses within which you will find many notable causes of human disease: Coxsackievirus, Echovirus, Enterovirus, Rhinovirus, and Poliovirus. The non-polio enteroviruses generally cause a mild, self-limited disease (common cold) but can rarely cause serious disease (myocarditis, pericarditis, meningitis, etc).

Enterovirus D-68 (EV-D68) was first identified in California in 1962 and since that time it has been a very rarely identified pathogen with only 79 cases between 2005 and 2008. However, in the last 3-4 months there have been almost 700 confirmed cases of EV-D68 in 46 states by the CDC (outbreak began in MO/IL in 8/2014).   This number is likely an underestimation of the true prevalence. At University of Maryland (a major academic city in a large, East-coast metropolis), the respiratory viral panel does not discern between Enterovirus and Rhinovirus; in addition, it does not determine serotype. Furthermore, Enteroviruses are not a nationally reportable infection, and the CDC only reports cases which are voluntarily submitted to them via the National Enterovirus Surveillance System. However, the CDC has found that about half of patients with severe respiratory illness have tested positive for EV-D68.

Many Pediatric Intensive Care Units are full of patients who tested positive for Enterovirus/Rhinovirus on respiratory viral panels. Below are useful tidbits from experiential learning backed up by best evidence available.

• Age 6 weeks to 16 years; <5 yo do worse
• Spread via respiratory secretions / body fluids; peak in summer/fall
• Consider in any patient acute, severe respiratory illness
• Underlying airway disease is a common theme. Asthma is the most prevalent comorbidity; younger patients have bronchopulmonary dysplasia or a very strong family history of reactive airway disease => more severe course.
• Present with cough, coryza, rhinorrhea, body aches, usually afebrile, and wheezing => rapid progression to hypoxia/respiratory distress
• Most patients require significant non-invasive respiratory support. Early institution of noninvasive positive pressure ventilation seems to greatly improve respiratory distress.
• Most patients clear their wheezing and improve aeration with usual asthma therapies. However, their tachypnea, retractions, and overall respiratory effort do not always improve.
• Most patients are suitable for transfer to the floor or discharge home within 36 hours.
• No definitive cure; focus on supportive care

Recommendations

These children are often a mixed picture of viral bronchitis/bronchiolitis PLUS an asthma exacerbation. Treatment with albuterol, ipratropium, magnesium sulfate, steroids, fluids, etc are all reasonable and prudent in this population. If they begin to clinically improve within 30 minutes then you can feel good about soothing their reactive airways. However, they still have underlying viral issues which may require non-invasive positive pressure ventilation (either high-flow nasal cannula or BIPAP). If they do not improve within 30 minutes then you should begin to plan for IMC/ICU admission as these patients will require significant monitoring and respiratory support.