What you need to know about the latest parechovirus outbreak

The Centers for Disease Control and Prevention (CDC) sounded the alarm this month, alerting physicians and public health departments that a large number of cases of parechovirus are circulating nationally.

Parechovirus, a common childhood virus that is close to the enterovirus family, can range from asymptomatic to mild symptoms to severe illness. Parechovirus type PeV-A3, which is currently circulating, is associated with more severe illness. It is usually more common in the summer and fall.

We asked Dean Blumberg, chief of pediatric infectious diseases at UC Davis Children’s Hospital, what we need to know about this current outbreak.

What are the symptoms of parechovirus?

Normally when older children get it, it is a very mild illness. It causes a rash and a fever. Children are sick for a few days, but they aren’t severely sick, and then they recover.

But when newborns and babies less than six months of age – especially those less than three months old -- get it, it can be very severe and affect many organ systems. It can cause:

• a sepsis-like syndrome that looks like an overwhelming bacterial infection
• meningitis (inflammation of the protective membranes covering the brain and spinal cord)
• seizures
• encephalitis (inflammation of the brain)
• myocarditis (inflammation of the heart)
• pneumonitis (inflammation of the lungs)
• gastroenteritis (inflammation of the stomach and intestines)
• hepatitis (inflammation of the liver)

These kids are often very sick and will be hospitalized in the pediatric intensive care unit.

Parechovirus is a virus that is commonly transmitted in the community. But what we’re seeing now is an outbreak of it.

What does the rash look like?

The rash can have a variety of manifestations. It can be flat red macules that look like red lesions. It can be raised into small papules. It can also have an interesting distribution, presenting only on the palms of the hands and the soles of the feet. Or sometimes it is just generalized redness all over the body.

How is parechovirus diagnosed?

We have a PCR test that can confirm parechovirus.

What is the treatment for parechovirus?

It can be treated with supportive care. Make sure babies get enough fluids, that their blood pressure is maintained and that they get enough oxygen in their blood. We also can give antibody therapy, IVIG, to try to decrease the concentration of the virus when they are hospitalized. There is no antiviral therapy available.

Is there a vaccine for parechovirus?

No, there is no vaccine for parechovirus or the related viruses that are similar to this.

When should parents be concerned?

If your newborn or baby less than six months old has a fever and a rash, or is lethargic and not responding as usual, you should contact your child’s health care provider because there are a variety of illnesses that it could be, including parechovirus.

How contagious is parechovirus?  

It is very infectious. Virtually every child gets parechovirus eventually. It is transmitted through the respiratory route. Those who are acutely ill will be the most contagious so we recommend that children isolate from others until they recover from the acute illness.

But children who have recovered from their illness can still shed virus up to six months after the infection.    

Why are we seeing so many cases of parechovirus now?

I think one of the reasons that we are seeing so many cases now is because of the pandemic. During lockdown, many people had very few interactions with others outside of their household. This caused a change in the circulation of many common childhood viruses in the community, including parechovirus. A large number of children are not immune and now as more people are out and about and interacting with others, all of these common childhood viruses are being transmitted. It is why we are seeing this outbreak now. Older kids and younger kids are getting it.

Can adults get parechovirus?

Yes, but most adults don’t get it because they are already immune from having had it in childhood.