As more children with respiratory illness are hospitalized in parts of the United States and Canada, doctors are trying to determine the full scope of a relatively rare virus with potentially serious consequences. Enterovirus D68 is not a new virus, but fewer than 100 cases were documented in the U.S. until recently. On Wednesday, a Rhode Island boy with EV-D68 died of complications related to the infection. It was the first North American death from the virus this year.

What is EV-D68?

The virus is one of many so-called enteroviruses, which are associated with different types of diseases and affect millions of people around the world. According to the Centers for Disease Control and Prevention, EV-D68 was first identified in California in the 1962. It has not been commonly reported in the U.S. since then.

What are the symptoms?

In mild cases, EV-D68 typically mimics the effects of a common cold or the flu: fever, runny nose, sneezing, cough and muscle aches. The virus has a more serious effect on some patients, who end up wheezing and having difficulty breathing. Patients with more serious EV-D68 infections may have to be hospitalized.

Does the virus cause paralysis?

Doctors are investigating the possibility that EV-D68 may cause paralysis, after two patients in British Columbia exhibited “paralytic symptoms” in their limbs. Some patients with EV-D68 in the United States have also shown signs of paralysis.

Experts say this limb paralysis resembles the kind caused by polio, but they have not confirmed that EV-D68 causes paralysis.

The CDC classifies EV-D68 as a non-polio enterovirus.

How does it spread?

The CDC says EV-D68 likely spreads much like a typical cold – “when an infected person coughs, sneezes, or touches contaminated surfaces.” Lab tests are required to confirm an EV-D68 infection.

Who is at risk?

Although anyone can be infected with EV-D68, babies, children and teenagers are most likely to get sick because their immune systems are not as strong and they haven’t been previously exposed to the virus, the CDC says. Over the past few weeks, the majority of hospitalizations due to EV-D68 infections in the U.S. and Canada have involved children.

How are infections treated?

There is no specific treatment available for EV-D68 and there is no vaccine to prevent infections. Some patients with breathing problems and wheezing have received oxygen therapy in hospitals. The CDC says patients with mild symptoms can take over-the-counter medications for pain and fever.

How can I protect myself?

• Wash your hands frequently with soap and water

• Avoiding touching and kissing people who are sick. Don’t share utensils with them.

• Clean and disinfect frequently-touched surfaces.