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Salem Health: Infectious Diseases & Conditions, 2nd Edition

Parechovirus

by Christine M. Carroll, , RN, BSN, MBA

Category: Pathogen

Transmission route: Ingestion, inhalation

Definition

Parechovirus is the new genus for echoviruses 22 and 23. They are small RNA viruses. Parechovirus (HPeV) is in the same Family, Picornaviridae, as the Enteroviruses (EV). In 1999, the genus EV viruses included the: polioviruses 1-3, Coxsackie A and B viruses, echoviruses, and enteroviruses. The members of the genus EV were discovered to have a different DNA sequence than echoviruses 22 and 23. As a result, echoviruses 22 and 23 were put in a new genus called parechovirus. Echoviruses 22 and 23 became the species: human parechovirus 1 (HPeV1) and 2 (HPeV2).

Since then, 4 new HPeV species have been discovered. They are: HPeV3, HPeV4, HPeV5 and HPeV6. HPeV3 and HPeV4 were found to be more virulent than HPeV1 and HPeV2. HPeV5 and HPeV6 are rare and their symptoms are not well known.

Causes

The HPeV1-4 viruses may be passed from person to person via respiratory droplets, stool, and saliva. There are persons who carry these viruses and have no symptoms, but can spread the viruses. The HPeV viruses can be passed from mother to child in utero.

Bank voles (Myodes glareolus) and humans are natural hosts for parechovirus. It is not known whether the virus is zoonotic at this time. Photo by AnemoneProjectors via Wikimedia Commons.

Infect2e_p0782_1.jpg

Risks

The risk of contracting one of the HPeV viruses is most common in full term infants less than 3 months of age. These viruses can be contracted by young children from ages 1-5 years. To decrease the spread of the HPeV viruses, good hygiene is important when caring for infants and young children.

Symptoms

HPeV1 and HPeV 2 infections usually cause mild symptoms, such as cough, sore throat, flu-like symptoms, wheezing, a rash, diarrhea, and croup, which causes a whooping-like cough. HPeV3 causes many symptoms such as, fever, low blood pressure, irritability, abnormal body movements, widespread rash, rapid breathing, drowsiness, seizures, extended abdomen, diarrhea, and muscle weakness in one or more extremities. It usually causes more serious illnesses. HPeV3, similar to EV, can cause a sepsis-like illness, meningoencephalitis, acute flaccid myelitis, paralysis, myocarditis, hepatitis, and permanent damage to the central nervous system. HPeV2 and HPeV4 are found less often HPeV1 and HPeV3. HPeV virus illnesses have a yearly seasonal distribution. Infections usually occur in the spring, summer, or fall.

Diagnosis

The first tests performed to identify the HPeV viruses are stool culture, blood cultures, a blood count and chemistry profile, and assessment of upper respiratory tract symptoms. Elevated levels of lymphocytes indicate an infection. If no organism is found, a spinal tap is done to remove a sample of spinal fluid (CSF) for analysis. More advanced tests performed are a cranial ultrasound, magnetic resonance imaging (MRI) of the head and spinal cord, and an assessment of neurodevelopmental symptoms. The sign that indicates that there is HPeV3 in their CSF is the presence of HPeV3 RNA and increased protein in the CSF.

To determine the presence of HPeV3, the CSF will be tested by Real-Time, Polymerase Chain Reaction (RT-PCR). There is a version of this procedure specific to HPeV. This procedure replicates the RNA of this virus. First, the virus is cultured. Then the RT-PCR makes hundreds of copies of the virus.

Treatment/Therapy

The treatment for infants or children with HPeV viruses is supportive care. They are usually hospitalized, where they can receive intravenous (IV) fluids and antibiotics. However, infants and children with HPeV3 will be in the ICU for close monitoring. These patients may receive virus-specific treatment depending on their symptoms.

Prognosis

Most infants and children survive illnesses with HPeV viruses, although some are left with consequences, like paralysis, from these illnesses. The HPeV viruses are found all over the world.

Further Reading

1 

Einav, Keet. (16 May 2018) New Report Highlights the Need for Improved Enterovirus and Parechovirus Surveillance. Retrieved on 12/8/2018 from https://www.contagionlive.com/news/new-report-highlights-the-need-for-improved-enterovirus-and-parechovirus-surveillance

2 

Verboon-Maciolek, Malgorzata A., MD, PhD; Krediet, Tannette G., MD, PhD; Gerards, Leo J., MD, PhD; et al. Severe Neonatal Parechovirus Infection and Similarity With Enterovirus Infection. Pediatric Infect Dis. 2008; 27(3):241-245, Retrieved on 12/8/2018 from https://www.medscape.com/viewarticle/573961_print

3 

Wolthers, Katja C.; Benschop, Kimberly S. M.; Schinkel, Janke; et al. Human Parechoviruses as an Important Viral Cause of Sepsislike Illness and Meningitis inYoungChildren. Clinical Infectious Diseases, 1 August 2008, Volume 47(3), 358-363, Retrieved in 12/8/2018 from https://doi.org.1086/589752

Web Sites of Interest

About Kids Health

http://www.aboutkidshealth.ca

American Academy of Family Physicians

http://familydoctor.org

American Academy of Pediatrics

http://www.healthychildren.org

See also: Childbirth and infectious disease; Children and infectious disease; Coxsackie virus infections; Encephalitis; Enterovirus infections; Fecal-oral route of transmission; Myocarditis; Pregnancy and infectious disease; Viral infections.

Citation Types

Type
Format
MLA 9th
Carroll, Christine M. "Parechovirus." Salem Health: Infectious Diseases & Conditions, 2nd Edition, edited by H. Bradford Hawley, Salem Press, 2020. Salem Online, online.salempress.com/articleDetails.do?articleName=Infect2e_0413.
APA 7th
Carroll, C. M. (2020). Parechovirus. In H. B. Hawley (Ed.), Salem Health: Infectious Diseases & Conditions, 2nd Edition. Salem Press. online.salempress.com.
CMOS 17th
Carroll, Christine M. "Parechovirus." Edited by H. Bradford Hawley. Salem Health: Infectious Diseases & Conditions, 2nd Edition. Hackensack: Salem Press, 2020. Accessed December 14, 2025. online.salempress.com.