Enterovirus 68: The New Respiratory Virus on Our Radar
A previously uncommon respiratory virus has shown up on our radar: Enterovirus 68 (EV-D68), a non-polio enterovirus. According to the Centers for Disease Control and Prevention (CDC) website, from mid-August to October 1 of this year, 500 people in 42 states and the District of Columbia were confirmed to have EV-D68 infections, but these probably only represent “the tip of the iceberg,” as healthcare professionals are not required to report known or suspected cases of EV-68. CDC reports that infants and children under 5 years old, children with asthma, and teenagers are at risk to contract enteroviruses, which are known to peak in the United States in late summer and early fall. Many of the children affected in the recent outbreak required care in hospital intensive care units.
Blurring the Lines between Enteroviruses and Rhinoviruses
The five known species of enterovirus include Poliovirus and Human enteroviruses A, B, C and D. Of all the known enteroviruses, the only one for which there is a vaccine is poliovirus. The three main species of rhinovirus, rhinoviruses A, B, and C, are responsible for more than half of all cold-like illnesses. Enteroviruses generally can withstand the acidic environment of the human stomach and tolerate higher temperatures better than rhinoviruses, which thrive at the temperature of the human nose. Enteroviruses infect the digestive system and are transmitted through the mucous and stool of infected individuals. Rhinoviruses infect the respiratory system and are transmitted only through the mucous of infected individuals. In their 2004 study, however, Oberste et al. concluded EV-D68 shares biological characteristics with rhinovirus (HRV) 87, potentially blurring the lines between certain enteroviruses and rhinoviruses. More recent studies (e.g., Jacobs et al., 2013), categorize some rhinoviruses as enteroviruses based on a new understanding of genomic structures.
Asthma-like Symptoms
EV-D68 was first identified in four children in California in 1962, but until recently, was considered relatively rare. The virus is making headlines because it does not seem to follow the classic pattern of viral infections, according to an article in Web MD. Instead of starting out with fever, cough and runny nose, EV-D68 causes fever in only about 25 to 30 percent of cases. It does cause coughing and breathing difficulties and sometimes wheezing. The virus may produce asthma-like symptoms in some children who have no history of asthma. Children with a medical history of asthma and breathing problems are particularly at risk, and may need to be given supplemental oxygen. There is no vaccine to prevent EV-D68 nor antiviral medications to treat it.
Recent Developments
CDC is currently investigating whether limb paralysis in children is caused by EV-D68. Ten children in Colorado have developed acute focal limb weakness and spinal cord lesions. CDC is asking physicians to report possible cases to their health departments. Criteria for reporting include: patients 21 years and younger, acute onset of focal limb weakness that began before August 1 of this year, and MRI results of a spinal cord lesion largely limited to gray matter. Additionally, CDC reports that EV-D68 has been detected in four patients who died, but what role the virus played in these deaths is unknown as of yet.
Tips for Preventing the Spread of EV-D68
- Wash hands often with soap and water for 20 seconds, especially after changing diapers.
- Avoid touching eyes, nose and mouth with unwashed hands.
- Avoid kissing, hugging, and sharing cups or eating utensils with people who are sick.
- Teach children to cover their mouth with a tissue when they cough or cough into the crook of their elbow or upper sleeve instead of their hand.
- Disinfect surfaces as EV-D68 can remain viable on surfaces for at least several hours. Disinfect frequently touched surfaces, such as toys and doorknobs, especially if someone is sick. Viruses are destroyed by weak bleach solutions. Mix up a simple germ-busting solution of chlorine bleach by adding ¼ cup of regular household bleach to one gallon of water.[1] Apply to frequently touched doorknobs, handrails and faucets. Leave surface wet for 10 minutes, then rinse with plain water.
If You Have Asthma…
- Take all asthma medications.
- Have an “Action Plan”; make sure it is up to date. If you develop worsening asthma symptoms, contact your doctor.
- Get a flu shot to avoid additional respiratory illness.
Ralph Morris, MD, MPH, is a Physician and Preventive Medicine and Public Health official living in Bemidji, MN.
[1] If using concentrated bleach, reduce the amount of bleach to 2 ½ tablespoons.