Enteroviruses are very common viruses that cause many different types of illness, ranging from mild cold-like symptoms (e.g. runny nose, cough and sneezing) to fever and rash illness to more severe respiratory illness (e.g. difficulty breathing) and neurologic illness (e.g. encephalitis – an infection of the brain – and meningitis – an infection of the lining of the brain or spinal cord). However, most people who get infected by enteroviruses will not get sick at all. 

Overall, there are more than 100 different types of enteroviruses. Infants, children and teenagers are more likely to get infections partly because they have not been previously exposed to as many kinds of enteroviruses as adults and have not developed immunity (i.e. protection) to these viruses. In Canada and the United States, enterovirus infections are more common during the late summer and fall. 

Enterovirus D68 (EV-D68) is a specific type of non-polio enterovirus. It was first identified in California in 1962 but since then was only rarely reported in the United States compared to other non-polio enteroviruses. In the fall of 2014, EV-D68 was associated with a nationwide outbreak of severe respiratory illness in the United States and Canada. In some patients, EV-D68-associated illness was severe enough to require intensive care unit (ICU) admission.

EV-D68 causes mild to severe respiratory illness. Mild cold-like symptoms include: runny nose, cough, and sneezing. 

EV-D68 can also cause more severe respiratory illness (e.g. difficulty breathing), sometimes including wheezing. Children with a history of asthma or wheezing are at higher risk for severe illness due to EV-D68 infection. 

Fever may not be a common symptom. Severe respiratory symptoms, such as difficulty breathing, may occur even in the absence of fever.

EV-D68 is found in secretions of the nose, throat and airways (e.g. saliva, nasal mucus or sputum). It can spread from person-to-person when an infected person coughs or sneezes. It can also be spread by having close contact (e.g. touching or shaking hands) with an infected person or by touching contaminated objects or surfaces.

Most enterovirus infections will cause only mild cold-like illness. However, serious complications can occur with EV-D68 infection and include asthma-type symptoms such as wheezing and difficulty breathing, hypoxemia (i.e. not getting enough oxygen in the blood), atelectasis (i.e. blockage of the air passage), pneumonia and, in severe cases, possible death. 

During the 2014 outbreak, children with a history of asthma or wheezing were at higher risk for serious complications. Some children required ICU admission and mechanical ventilation (i.e. using a machine to assist with breathing), and deaths in children with EV-D68 infection were reported in the United States and Canada. However, although a small number of cases will develop severe infections and complications, the risk for most individuals is considered low.

While EV-D68 has been mostly known to cause respiratory illness, during the 2014 outbreak, some children with EV-D68 infection developed a sudden onset of weakness in one or both of their arms or legs. Symptoms like muscle weakness can have many different causes. Even though EV-D68 has been found in some people with muscle weakness, it is not known for sure if EV-D68 was the actual cause of those symptoms.

Doctors and nurses can test for EV-D68 by collecting a swab from a patient’s nose or throat and submitting it to the BC provincial laboratory for testing. 

Only certain laboratories are able to test patient specimens for enterovirus infection. However, most of these laboratories will be unable to tell if the infection is caused by EV-D68 or some other type of enterovirus. Only the BC provincial laboratory can conduct this type of testing and confirm EV-D68 infection. 

The BCCDC does not know how many enterovirus infections occur in BC each year. This is because most people with mild cold-like illness do not seek medical care, testing for enterovirus infection is not routinely done, and public health practitioners are not required to report enterovirus infections to their local health authority. Because patients in hospital are more likely to be tested for enterovirus infection, the cases that are identified are more likely to be severe presentations.

There is no specific treatment or vaccine for EV-D68. 

Most people will get better on their own without any treatment. For mild cold-like symptoms (e.g. runny nose, cough, sneezing) and fever, over-the-counter medications can help relieve symptoms. Aspirin should not be given to children. 

People with respiratory illness, especially children with a history of asthma or wheezing, should contact their doctor if their symptoms get worse or they have difficulty breathing. Severe cases may need to be hospitalized and occasionally may require intensive care (e.g. oxygen therapy, intravenous hydration, mechanical ventilation – using a machine to assist with breathing).

The following prevention measures can help reduce the spread of EV-D68 and other respiratory infections:

• Wash your hands often with soap and water for 20 seconds;
• Avoid touching eyes, nose and mouth with unwashed hands;
• Avoid kissing, hugging and sharing cups or utensils with people who are sick; ·
• Cover your mouth with your elbow when you cough or sneeze;
• Clean and disinfect frequently touched surfaces, such as toys and doorknobs, especially if someone is sick; and ·
• Stay at home from work or school when sick.

Parents of children with asthma should make sure their children regularly take their prescribed asthma medication (e.g. puffers or inhalers) and make sure their illness is well controlled. In the event that symptoms worsen, especially difficulty breathing, medical care should be sought immediately.