It was announced on Tuesday by the Centers for Disease Control and Prevention (CDC) that parechovirus, a virus that can be fatal to infants under the age of one in extremely rare cases, is spreading across multiple states.
The CDC has issued an advisory warning healthcare providers to be on the lookout for the disease when caring for severely ill infants and children younger than 12 months of age.
According to Claire Bocchini, MD, an infectious disease specialist at Texas Children's Hospital, parechovirus is a seasonal virus that typically spreads in the summer and fall. In fact, she stated that it is believed that the vast majority of people have been exposed to the parechovirus by the time they enter kindergarten.
However, the CDC cited reports of an increase in parechovirus type 3 infections as the reason for their warning.
Dr. Bocchini expressed concern to Health that the prevalence of disease caused by the Parechovirus Species A Type Three (PeV-A3), which has been linked to more severe disease in infants, was increasing. "It belongs to a large family of viruses that circulate frequently throughout the year. And this year there seems to be an abundance of the strain responsible for the most severe cases."
When Do Enteroviruses Show Up?
Parechovirus Symptoms in Infants
Most people who contract parechovirus experience only very mild symptoms.
Dr. Bocchini explained that "in older children," defined as those aged 2, 3, 4, and 5, "you usually have no symptoms or you can have upper respiratory symptoms" (such as a runny nose and cough). "Gastroenteritis and diarrhea can occur together at times."
According to the head of the pediatric infectious diseases and immunology division at Connecticut Children's Hospital, Ian Michelow, MD, FCPaed, parechovirus is a member of the enterovirus family. Hand, foot, and mouth disease is caused by a member of this virus family, but typically only mild symptoms manifest.
According to Dr. Michelow, who spoke with Health, "other types of viruses that are in the same family will cause skin infections or rashes, or they can cause respiratory illnesses, or they can cause maybe some gastrointestinal illnesses like stomach bugs, diarrhea, vomiting." In very rare cases, and usually in very young children, pediatricians diagnose their patients with much more severe diseases.
However, for infants of that age (typically 3 months or younger), a brush with parechovirus, especially PeV-A3, can be much more dangerous, mainly because their immune systems are not fully developed.
Health quotes Kristin Moffitt, MD, associate professor in the pediatric division of infectious diseases at Boston Children's Hospital, as saying, "What it can cause in infants is fever and sepsis, which is kind of like an overwhelming inflammatory reaction to an infection that in itself can be damaging to the body." "In particular, it can infect the central nervous system of very young infants, and may be linked to seizures."
Parechovirus can cause encephalitis, or swelling of the brain, in infants. Dr. Bocchini emphasized that other organs, such as the liver and heart, may be impacted.
This means that parents need to be on the lookout for any indication that their child is experiencing a more severe case of parechovirus than the more typical mild case, since infants this young can't point to specific symptoms they're feeling.
Infants who "are not feeding, stop feeding well, are floppy, or perhaps have abnormal movements, which could indicate seizures, or have a high fever," as described by Dr. Michelow. "In some cases, nursing can help a sick baby feel better, even if it's just a minor illness. The possibility of a brain infection makes these infants difficult to comfort. For this reason, they become extremely agitated."
Due to the lack of an effective antiviral treatment, Dr. Michelow explained, the hospital staff can only focus on identifying the source of the baby's severe symptoms, making them more comfortable, and ensuring they stay hydrated. He also noted that most hospitalized infants do well despite the severity of their symptoms and the absence of antiviral treatment. Extremely rare cases do result in death.
"I've diagnosed and treated three infants [for parechovirus] in the past month. Unfortunately, encephalitis was brought on by infections on several occasions, "- Dr. Michelow remarked. "We confirmed the diagnosis, and the outcomes for these infants were very positive. They weren't bothered by anything, and they seemed to be back to normal within a few days."
It is unclear whether or not a very young infant will experience life-threatening symptoms from the parechovirus. Whether or not they become ill depends on whether they contract the milder type 1 strain or the more severe PeV-A3 strain. Dr. Michelow theorizes that infants who experience milder parechovirus illness may have been immunized by their mothers during pregnancy. Preventative measures are the best option because there is no way to tell which infants will have some natural resistance to the virus.
Increased Cases of Childhood Melatonin Poisoning: Recognizing the Warning Signs to Protect Your Family from Parechovirus
Dr. Michelow advised that, in the absence of antiviral treatments or vaccines, the best way to protect infants from parechovirus is to use the preventative strategies that we are now familiar with, thanks to the COVID-19 pandemic: frequent hand washing, avoiding infants when sick, and possibly wearing a mask.
Dr. Bocchini warned that the parechovirus is highly contagious and can be spread through feces and respiratory droplets such as coughs and sneezes. These measures aid in guaranteeing the highest level of safety for infants.
Similar measures for prevention are being recommended, but the CDC has not warned of an impending parechovirus pandemic. Doctors Moffitt, Bocchini, and Michelow all agreed that this should not be cause for alarm, but rather a warning to be cautious about the parechovirus. In fact, the CDC has suggested that an increase in reported cases may not be all that unusual.
"There are fluctuations with these particular viruses and other viruses from year to year," Dr. Michelow said. It could just be that this year there are more of these viruses around, and that's why we're experiencing a natural uptick in the number of cases.
Dr. Bocchini adds that due to the absence of typical transmission and immunity development during the early months of the COVID-19 pandemic, there are currently many more viruses circulating than usual. Possible flare-up of parechovirus activity as COVID precautions are loosened. However, she cautioned that it is too soon to draw any firm conclusions.
Dr. Moffitt said that while it's possible that this is just a season with a higher swell of parechovirus, diagnostic testing has also greatly improved over the past decade. In previous years, the parechovirus might not have been identified as the cause of a child's high fever or septic shock. The CDC warned that improved diagnostics could be to blame for the surge in parechovirus cases.
Recently, "especially PCR-based testing," also known as molecular testing, has become widely available, which, as Dr. Moffitt explained, has greatly increased their capacity to identify the causative agent of these infections. "We haven't had the same similarly widespread diagnostics as we have in the last few years, so we're not sure how different this season is from typical seasons."
However, Dr. Bocchhini hopes that reports like the CDC's will get the word out to parents and medical providers and encourage them to become more aware of the Parechovirus.
She clarified that "at the present time, it is not mandatory reporting for this infectious disease." With increased reporting, we can learn more about the seasonality of this virus's spread.
