#16,876
During the summer months we often see reports of non-influenza respiratory viruses, such as RSV, adenovirus, and non-polio enteroviruses (NPVs) - like EV-71 and EV-D68 - which often impact infants and young children.
Most cause mild gastrointestinal and respiratory symptoms, but NPVs - and less well known human parechoviruses (HPeV) - can also cause serious neurological complications like meningitis, encephalitis, and AFM (Acute Flaccid Paralysis).
In 2014, 2016, and again in 2018 we saw the summer-time spread of EV-D68, sparking hundreds of thousands of mild infections, and hundreds of cases of AFM, primarily in young children across the nation (see CDC MMWR/Vital Signs: Acute Flaccid Myelitis (2020 Edition)).
This biannual pattern was disrupted by the pandemic, and did not return in 2020. So far, we've not seen any sign of an EV-D68 resurgence in 2022, but today the CDC is warning of recent reports of PeV-A3 in small children.
First some excerpts from the Advisory, after which I'll return with a postscript.Since PeV testing is limited and cases are often not reported, it is uncertina if these reports represent an unusual surge in cases, but it is concerning enough that the CDC has issued the following HAN Advisory.
Recent Reports of Human Parechovirus (PeV) in the United States—2022
Distributed via the CDC Health Alert Network
July 12, 2022, 1:15 PM ET
CDCHAN-00469
SummaryThe Centers for Disease Control and Prevention (CDC) is issuing this Health Alert Network (HAN) Health Advisory to inform clinicians and public health departments that parechovirus (PeV) is currently circulating in the United States. Since May 2022, CDC has received reports from healthcare providers in multiple states of PeV infections in neonates and young infants. Parechoviruses are a group of viruses known to cause a spectrum of disease in humans. Clinicians are encouraged to include PeV in the differential diagnoses of infants presenting with fever, sepsis-like syndrome, or neurologic illness (seizures, meningitis) without another known cause and to test for PeV in children with signs and symptoms compatible with PeV infection (see below). Commercial laboratory assays, multiplex platforms for meningitis and encephalitis, and testing through state public health laboratories (SPHLs) are available to test cerebrospinal fluid (CSF) for PeV to confirm a diagnosis. CDC laboratory support is also available for testing and typing patient specimens.
To date, all PeV positive specimens tested and typed at CDC were type PeV-A3. Because there is presently no systematic surveillance for PeVs in the United States, it is not clear how the number of PeV cases reported in 2022 compares to previous seasons. PeV laboratory testing has become more widely available in recent years, and it is possible that increased testing has led to a higher number of PeV diagnoses compared with previous years.
BackgroundHuman parechoviruses (PeVs), members of the Picornaviridae family, are common childhood pathogens associated with various clinical manifestations, ranging from asymptomatic or mild symptoms to severe illness. PeV share the same taxonomic family with enteroviruses. There are four species, of which only PeV-A is known to cause disease in humans. PeV-A has multiple types; PeV-A3 is most often associated with severe disease. Symptoms such as upper respiratory tract infection, fever, and rash are common in children between 6 months and 5 years, with most children having been infected by the time they start kindergarten. However, in infants less than 3 months, severe illness can occur, including sepsis-like illness, seizures, and meningitis or meningoencephalitis, particularly in infants younger than 1 month. Upon examination, the spinal fluid in infants with PeV often has few to no white blood cells. Long-term neurodevelopmental outcomes can occur, although this is rare. There is no specific treatment for PeV infection (1). However, diagnosing PeV in infants might change management strategies and provide important health information for families.
Both symptomatic and asymptomatic infected individuals can transmit PeV via the fecal-oral and respiratory routes. Shedding from the upper respiratory tract can occur for 1-3 weeks and from gastrointestinal tract for as long as 6 months after infection. The incubation period is unknown. PeVs are widespread and circulate worldwide. Some types show a clear seasonality of later summer and fall, similar to enteroviruses. PeV-A3 has been seen to demonstrate a cyclical pattern with peaks occurring biennially (2-4).
Recommendations for Clinicians
- Be aware that PeVs circulate in the summer and fall. In the absence of an identified pathogen, consider PeV infection in a neonate or infant presenting with fever, sepsis-like syndrome, or signs of neurologic involvement.
- Become familiar with specimen collection, storage, and shipping procedures. Testing for PeV is available at commercial clinical laboratories and SPHLs, and hospitals may use multiplex meningitis and encephalitis panels for CSF testing that include PeV. Testing and typing for PeV are also available at CDC when other options are unavailable; clinicians should still work with their state public health department to send specimens to CDC. Please contact PicornaLab@cdc.gov before submitting specimens. Accepted specimens include CSF, throat or nasopharyngeal swabs, blood, and stool.
- Consider cohorting an infant hospitalized with detected PeV infection with other affected infant(s) to avoid healthcare-associated transmission in nurseries or neonatal intensive care units.
- Use Contact, Droplet, and Standard Precautions. In most clinical situations, alcohol-based hand sanitizer (ABHS) is preferred for cleaning hands with an alcohol content of at least 60%. However, soap and water is the preferred method after patient care involving diapering or toileting, before eating or feeding, and if hands are visibly soiled (e.g., dirt, blood, body fluids). Although non-enveloped viruses may be less susceptible to alcohol than enveloped viruses, ABHS offers benefits in skin tolerance, compliance, and overall effectiveness, especially when combined with glove use. See Core Infection Prevention and Control Practices for Safe Healthcare Delivery in All Settings –Recommendations of the HICPAC for more information.
- Consult the state health department with questions about PeV.
Recommendations for Public Health Departments and Public Health Jurisdictions
- Be aware of circulating PeV and be prepared to receive inquiries about cases from healthcare providers in your jurisdiction.
- Upload reports of specimens that test positive for PeV to the National Enterovirus Surveillance System (NESS) to improve surveillance for this pathogen.
- Direct specimen testing questions to CDC at PicornaLab@cdc.gov.
The extent of PeV-A3's circulation in the United States this year is unknown. This HAN advisory should encourage testing and reporting to the CDC, so that a proper threat analysis can be made.
After two years of masking and social distancing, our immunity to a lot of viruses has probably waned. Now that people have ditched masks and have begun to socialize again, we're seeing sporadic, unusual, and out-of-season outbreaks of RSV, influenza, and other respiratory viruses around the world.Given the impacts of EV-D68 outbreaks over the past decade, and the recent spate of acute hepatitis tentatively linked to adenovirus infection in young children, the CDC is obviously eager to get ahead of any potential new threat.
China NIC Report: Summer Influenza Surge In Southern China
Australia's Early and Impressive Flu Season
CDC HAN: Increased RSV Reports Across The Southern United States
Denmark SSI: Update On Summer Surge Of RSV
While influenza and other respiratory viruses are highly unpredictable, based on what we have seen over the past few months, we could be in for a difficult fall and winter.
Stay tuned. And if you are running low on hand sanitizer or face masks, I'd stock up now.
