Human parechovirus (PeV) is a common virus that can lead to a range of symptoms. While many infections are mild or go unnoticed, the virus can cause significant illness in specific populations. The PeV-A species is known to cause disease in humans, and its PeV-A3 type is most frequently linked to more severe outcomes.
Recognizing the Symptoms
The presentation of a parechovirus infection varies with age. In most older children and adults, the illness is mild, with symptoms resembling a common cold, an upper respiratory infection, or a gastrointestinal issue with diarrhea and vomiting. A low-grade fever and a rash may also be present. Because these signs are common to many viral illnesses, most cases in these age groups are not formally diagnosed.
In infants under three months old, symptoms can be more severe. They may develop a high fever, exhibit high irritability or significant lethargy, and have a distinctive rash on the hands and feet or mottled skin. Other indicators in infants include poor feeding, a rapid heart rate, and fast breathing.
Vulnerable Populations and Complications
The risk of severe disease from parechovirus is highest in infants younger than three months old and individuals with compromised immune systems. The immature immune systems of young infants are not fully equipped to mount an effective defense against the virus, making them more vulnerable.
For these populations, an infection can lead to serious complications. One is a sepsis-like illness, a life-threatening condition where the body has an overwhelming response to infection. The virus can also invade the central nervous system, causing meningitis (inflammation of membranes around the brain and spinal cord) or encephalitis (inflammation of the brain). These neurological complications can have lasting consequences, though such outcomes are rare.
Diagnosis and Medical Care
Clinicians may suspect a parechovirus infection when an infant presents with fever, a sepsis-like syndrome, or neurological issues without a clear cause. A definitive diagnosis requires laboratory analysis, as symptoms can overlap with other conditions. The most common method is a polymerase chain reaction (PCR) test, which detects the virus’s genetic material in samples from cerebrospinal fluid, stool, or respiratory swabs.
There is no specific antiviral medication for parechovirus. Medical care focuses on supportive care to manage symptoms while the immune system fights the infection. This includes controlling fever and pain, ensuring hydration, and monitoring breathing and heart function. Hospitalization may be necessary for severe cases to provide this level of support.
Transmission and Prevention
Parechovirus spreads through respiratory droplets from an infected person’s coughs or sneezes. It also spreads via the fecal-oral route, which involves contact with stool particles from inadequate handwashing or touching contaminated surfaces. An infected person can shed the virus for one to three weeks from the respiratory tract and for as long as six months from the gastrointestinal tract.
Prevention strategies focus on hygiene and avoiding exposure. Frequent handwashing with soap and water is a primary defense, especially after using the toilet, changing diapers, and before preparing or eating food. Regularly disinfecting high-touch surfaces like doorknobs and toys, and avoiding close contact with sick individuals can also help reduce the spread.