Enterovirus D-68

Mary Naeger, Pharm.D. candidate, 2015 St. Louis College of Pharmacy

Mary Naeger, Pharm.D. Candidate, 2015
St. Louis College of Pharmacy

The beginning of this year’s “cold and flu season” has brought new attention to and concern for enteroviruses among the U.S. pediatric population. Enterovirus is a genus of RNA viruses that includes twelve distinct Enterovirus and Rhinovirus species. The genus consists of approximately one hundred non-polio enterovirus strains that can cause the common cold, including at least fifty known strains of Enterovirus. The Centers for Disease Control and Prevention (CDC) states that, each year, a mix of Enterovirus strains is noted to cause infection in humans, with a different strain predominating annually. This year, an uncommon strain of Enterovirus known as EV-D68 has been identified as a re-emerging public health concern (Midgley et al., 2014).

EV-D68 was first identified in 1962 among children in California and has rarely been reported in recent years, with only 79 cases reported in the U.S. from 2005 to 2008 (Midgley et al., 2014). EV-D68 is not typically a predominant strain, and experts do not know why it is predominant this year. It has been speculated that children are getting sicker from the EV-D68 strain this year for the very reason that it is uncommon. Children are very unlikely to have encountered the strain before and, therefore, have not built up immunity to it. Pediatric patients with asthma or other respiratory conditions are at a higher risk for developing respiratory symptoms due to EV-D68, because the underlying disease process increases susceptibility to respiratory infections (Owens, 2014).

In 2014, EV-D68 cases were first reported in August in Kansas City, Mo., and Chicago, Ill., with severe respiratory illness noted and several children requiring hospitalization and/or intensive care (Midgley et al., 2014). Among the initial specimens tested by the CDC in August, 19 of 22 specimens collected from the Kansas City hospital and 11 of 14 collected from the Chicago hospital were identified as EV-D68. Of these patients, more than half had a previous history of asthma or wheezing (Midgley et al., 2014). Enteroviruses are not nationally reported, but the CDC does have a voluntary National Enterovirus Surveillance System (Owens, 2014). The implication of the lack of standard national reporting is that the data about cases are not comprehensive and conclusions cannot be accurately drawn.

From mid-August to the end of September, 277 patients in 40 states tested positive for EV-D68, with the majority of these patients being children (Owens, 2014). Although much is unknown about the EV-D68 strain and we do not know if the strain will continue to infect children into the winter months, Enterovirus infections historically tend to peak during late summer/fall and taper out by November (Owens, 2014). The most commonly used test for the virus does not differentiate between Rhinovirus and Enterovirus because of the similarities of chemical makeup (nucleic acid sequence) between many strains of Rhinovirus and Enterovirus (Shaw, Welch, & Milstone, 2014). The CDC has the equipment to perform confirmatory testing to determine the viral strain. Many specimens from throughout the U.S. have been sent to the CDC for testing, and the backlog of specimens that need to be identified has delayed accurate reporting on the virus (Owens, 2014).

After awareness grew about the cases of EV-D68 in late summer, several U.S. hospitals enacted emergency preparedness plans in anticipation of increased transmission of the virus in conjunction with the start of the school year. The emergency preparedness plans have allowed hospitals to mobilize healthcare resources and to communicate with healthcare workers and the community. Communication has enabled education about the virus in an effort to combat the media’s “sensationalization” of the severity of EV-D68 (Shaw, Welch, & Milstone, 2014). Early detection and understanding of the EV-D68 strain has allowed healthcare systems across the country to promote proactive community awareness and to appropriately train and prepare medical staff (Shaw, Welch, & Milstone, 2014). Development of an immunization against EV-D68 has not been possible to date, due largely to the high number of variable strains of Enterovirus species, and antiviral medications have not been shown to be effective against enteroviruses. Treatment for EV-D68 infection consists of symptomatic relief and supportive care—treating fever and pain, providing hydration, stabilizing respiratory status, and providing respiratory support, as appropriate (Owens, 2014).

During the fall and winter months, when children and adults alike tend to get sick with the common cold or influenza, it can be challenging to determine when parents should seek medical treatment for a sick child. Parents should seek medical treatment for their children at a pediatrician’s office or emergency department, as appropriate, if mild cold-like symptoms are noted (sneezing, coughing, runny nose, fever, body aches) along with severe symptoms such as wheezing or difficulty breathing (CDC, 2014). Special attention should be paid to children who have asthma, as they can be predisposed to respiratory illnesses (Siegel, 2014). Children with asthma should receive an annual influenza immunization and should take medications prescribed for asthma as directed (CDC, 2014).

The best way to prevent transmission of EV-D68 is to practice proper infection control and prevention methods (Siegel, 2014). Effective hand washing techniques can help stop the spread of viruses and should be taught to all children. Children and adults should stay home from school or work if illness is suspected, and avoidance of sick contacts should be practiced whenever possible. All people should cover their mouths with a tissue or shirt sleeve when coughing or sneezing and should minimize touching their eyes, nose, and mouth. In addition, surfaces at home, school, and work should be kept clean to minimize transmission (CDC, 2014). Although the influenza immunization will not protect against EV-D68, it will help provide immunity against influenza and should be received by all people over six months old, unless contraindicated.

Mary Naeger, Pharm.D. Candidate, 2015
St. Louis College of Pharmacy

 

References

Centers for Disease Control and Prevention (2014, October 14). What parents need to know about enterovirus D68. Retrieved from http://www.cdc.gov/features/evd68/

Midgley, C.M., Jackson, M.A., Selvarangan, R., Turabelidze, G., Obringer, E., Johnson, D., Giles, B.L., Patel, A., Echols, F., Oberste, M.S., Nix, W.A., Watson, J.T., & Gerber, S.I. (2014). Severe respiratory illness associated with enterovirus d68-Missouri and Illinois, 2014. MMWR Morb Mortal Wkly Rep, 63(36):798-799.

Owens, B. (2014). Rare enterovirus continues to circulate in North America. The Lancet, 384(9950):1250. doi: 10.1016/S0140-6736(14)61753-0

Shaw, J., Welch, T.R., & Milstone, A.M. (2014). The role of syndromic surveillance in directing the publich health response to the enterovirus D68 epidemic. JAMA Pediatr. Published online September 26, 2014. doi: 10.1001/jamapediatrics.2014.2628

Siegal, M. (2014, October 6). 6 things all parents should know about enterovirus D68. Retrieved from http://www.foxnews.com/health/2014/10/03/6-things-all-parents-should-know-about-enterovirus-d68/

Tan, S.H., Ong, K.C., & Wong, K.T. (2014). Enterovirus 71 can directly infect the brainstem via cranial nerves and infection can be ameliorated by passive immunization. J Neuropathol Exp Neurol, 73(11):999-1008. doi: 10.1097/NEN.0000000000000122

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