Q&A: What to know about parechovirus, subject of CDC alert

The CDC recently issued a health advisory alerting clinicians that parechovirus, a common childhood pathogen, is circulating in the United States.

The CDC said it has received reports from multiple states since May of parechovirus infections in neonates and young infants, although it is unclear if there has been an increase in cases this year because there is no systematic surveillance of parechoviruses.

“Be aware that [parechoviruses] circulate in the summer and fall,” the CDC said. “In the absence of an identified pathogen, consider [parechovirus] infection in a neonate or infant presenting with fever, sepsis-like syndrome, or signs of neurologic involvement.”

We spoke with Roberta L. DeBiasi, MD, MS, chief of the division of pediatric infectious diseases at Children’s National Hospital in Washington, D.C., about how to identify and treat parechovirus infections.

Healio: How do parechovirus infections typically present in children?

DeBiasi: For older children, parechovirus infection usually causes minor illness — such as a common cold or a diarrheal type of illness, so it's not very distinct from any of the other common childhood viral, respiratory or gastroenteritis illnesses. But for younger babies, particularly those aged younger than 3 months, they can become very ill. It doesn't mean all these children get severely ill, but they can develop symptoms of sepsis, where their heart may not pump normally or may not distribute blood normally to their body and internal organs, or they can develop meningitis or encephalitis.

Healio: How are these viruses typically treated?

DeBiasi: There's not a particular medication that treats parechovirus. There are some investigational agents that are under development but nothing that can be used right now. However, if a baby is very ill and requires hospitalization — and we have had 10 babies like this in recent months — then we support their body function with measures such as medications to improve blood pressure, IV fluids, antiseizure medications if they're having seizures, and medications to lower temperature if there is fever. We also can conduct specialized diagnostic tests to assess if the brain, spinal fluid or heart are affected by the virus.

Healio: Is it unusual to see a CDC health alert about parechovirus?

DeBiasi: We receive health alerts regularly from the CDC and our local health departments when there is a cluster of infections that is known to be occurring just so that there's awareness in the community and that doctors are looking for it. Parechovirus is a relatively newly described virus. It used to be considered part of another family of viruses called enteroviruses. About a decade or more ago, technology improved so that we could do more specific sequencing of the genetic sequence of viruses, and it became apparent that parechoviruses are different enough from enteroviruses by genetic sequence that they should be entitled to their own name. There have always been parechoviruses, but they were lumped into the family of enteroviruses in the past.

There is a not a routinely available test that will look for parechovirus — other than some specialized tests sent on hospitalized patients with meningitis — so a doctor will have to think about it and request to do parechovirus-specific testing, usually with the help of an infectious disease expert in conjunction with their local health department. Part of the reason we're seeing an increased number of parechovirus cases right now is we have specific tests and are more aware of it. But there is also truly a cluster of increased number of cases because of circulating virus right now as well.

Healio: What should clinicians do considering this alert?

DeBiasi: Pediatricians take care of children with fever, colds and diarrhea every day in and out. So, there's really nothing different about their general practice that they need to do in older children with these minor illnesses. It's not recommended that people do special testing for parechovirus in these cases just to try to find out. However, for children aged younger than 3 months who may be severely ill, doctors should consider that parechovirus could be a cause, and there is specific testing that can be sent with the assistance of their pediatric infectious disease consultants in conjunction with the health departments and CDC.

Healio: Do you have any advice for readers from your personal experience as a physician in treating parechovirus?

DeBiasi: We’ve had 10 cases just in the last few months, just as most major pediatric centers have across the country, so we’re no exception to that. Parechovirus infection is very similar to enterovirus infection, which can also be very severe in babies aged younger than 3 months. And the treatments are essentially identical, which is supportive measures, which usually can include intensive care for babies who have heart dysfunction, seizures or blood pressure problems. But as I said, there's not a specific medication to treat the virus itself and it must run its course. With babies who are very ill, it is very useful for pediatricians to have a relationship with a major academic center that has pediatric intensive care and infectious disease experience just because we do have experienced specialists treating these babies and supporting them through a critical illness. I would encourage pediatricians to make sure they have good connections with their referring institutions while we're in the middle of this cluster because they might see some young infants who are very ill and need transfer and help quickly.

References:

CDC. Recent reports of human parechovirus (PeV) in the United States – 2022. https://emergency.cdc.gov/han/2022/han00469.asp. Accessed July 21, 2022.