Human Parechovirus Type Research Articles

First whole genome sequencing and analysis of human parechovirus type 3 causing a healthcare-associated outbreak among neonates in Hungary.

In November 2023, the National Reference Laboratory for Enteroviruses (Budapest, Hungary) received stool, pharyngeal swab and cerebrospinal fluid samples from five newborns suspected of having human parechovirus (PEV-A) infection. The neonates were born in the same hospital and presented with fever and sepsis-like symptoms at 8-9 days of age, and three of them showed symptoms consistent with central nervous system involvement. PEV-A positivity was confirmed by quantitative reverse transcription polymerase chain reaction. To determine the PEV-A genotype responsible for the infections, fecal samples of four neonates were subjected to metagenomic sequencing. For further analyses, amplicon-based whole genome sequencing was performed directly from the clinical samples. On the basis of whole genome analysis, sequences were allocated to PEV-A genotype 3 (PEV-A3) and consensus sequences were identical. Two ambiguities were identified in the viral protein 1 (VP1) region of all sequences at a frequency of 17.7-53.7%, indicating the simultaneous presence of at least two quasispecies in the clinical samples. The phylogenetic analysis and similarity plotting showed that all sequences clustered without any topological inconsistencies between the P1 capsid and P2, P3 non-capsid regions, suggesting that recombination events during evolution were unlikely. Our findings suggest that the apparent cluster of cases were microbiologically related, and the results may also inform future investigations on the evolution and pathogenicity of PEV-A3 infections.

Clinical Spectrum and Epidemiology of Human Parechovirus Infections in Infants: A Retrospective Study in the Western Part of Sweden.

Human parechovirus (HPeV) infections can cause sepsis and meningoencephalitis in infants. To improve our knowledge of the consequences of HPeV infections in young children, the incidence, clinical spectrum, and short-term outcome among infants infected with HPeV were investigated retrospectively. The presence of HPeV RNA was investigated by polymerase chain reaction in cerebrospinal fluid from 327 children aged 0 to 12 months sampled between 2014 and 2017. Eighty-one were infected with HPeV and included in the study. These infants were divided into 3 groups based on clinical assessment: HPeV was the presumed cause of disease (n = 35); HPeV could have contributed to or been considered the cause of disease (n = 24); and HPeV was not considered the cause of disease (n = 22). Infection with HPeV type 3 was common in all groups (n = 54), and most children were younger than 3 months (n = 63). The children in the first group (HPeV as presumed cause) had meningoencephalitis (n = 20), viral sepsis (n = 9), or non-severe viral infection (n = 6). The youngest were more prone to develop meningoencephalitis, while the slightly older children had symptoms of viral sepsis or nonsevere viral infection (P < .05). Eleven had symptom onset within 2 days after birth. Two infants diagnosed with sudden infant death syndrome were HPeV infected when tested postmortem. HPeV infections were identified in 25% of children with suspected central nervous system infection. The clinical presentation of those infected with HPeV varied with age. HPeV infections may be associated with sudden infant death syndrome, although this is not well studied. The results suggest that HPeV infections may be underdiagnosed in young infants.

A Human Intestinal Cell Line Suitable for the Propagation of Human Parechovirus Type 1 to 6 with a Clear Cytopathic Effect.

Human parechoviruses (HPeVs) are being increasingly recognized as pathogens that cause mild-to-life-threatening diseases in children and adults. Recently, nucleic acid detection has become the mainstream method for pathogen detection. However, virus isolation is important for virus detection and further virologic characterization studies, and securing human pathogenic virus bioresources. We recently explored conventional cell lines suitable for human sapovirus isolation and accidentally identified a human duodenal cell line, HuTu80, that supported efficient growth of human parechovirus type 3 (HPeV-3) with clear cytopathic effects (CPE). Subsequently, we confirmed that all representative prototype HPeV type 1-6 strains were propagated efficiently in HuTu80 cells with clear CPE within 4 days. Another human ileocecal cell line, HCT-8 (HRT-18), also supports HPeV propagation except for HPeV-3. Titer values in HuTu80 and HCT-8 reached approximately 6.83-8.83 and 6.50-8.17 log10 50% tissue culture infectious dose/50 μL, respectively, when inoculated with multiplicity of infection of 0.0025. Previously reported cell lines likely support HPeV types 1-6 with different efficiency, especially for HPeV-3. In summary, HuTu80 can be used as an additional cell line for HPeV isolation, propagation with a clear CPE to produce a high titer value and for the virus neutralization assays.

Genetic analysis of human parechovirus type 5 isolated from children in Sapporo, Japan in the summer of 2018

Human parechovirus (HPeV) types 1 and 3 are frequently detected in Japan, but HPeV5 is not detected. HPeV5 was isolated for the first time in Japan from seven clinical samples collected from children in Sapporo as part of the National Epidemiological Surveillance of Infectious Diseases from July to August in 2018. Seven HPeV5 strains that were detected in Sapporo (HPeV5 Sa) were analyzed in the VP1 region by direct sequencing using Sanger sequencing methods. Whole genome sequence of these strains was determined by next-generation sequencing. The VP1 region of HPeV5 Sa was closely related to HPeV5 strains detected in Belarus and Germany in 2018, and to those detected in Australia in 2019. The 3D polymerase region of HPeV5 Sa strains showed a high nucleotide identity to HPeV3 strain detected in Australia in 2013. These findings suggest that HPeV5 Sa is a recombinant virus of HPeV5 and HPeV3, and HPeV5 strains that are genetically closely related to each other may have circulated in Europe, Japan, and Australia between 2018 and 2019.

Isolation of human parechovirus type 3 from an infant with sudden death.

Pediatrics InternationalVolume 64, Issue 1 e15305 Clinical Notes Isolation of human parechovirus type 3 from an infant with sudden death Yuko Hayashi, Yuko Hayashi Department of Pediatrics, Iwate Prefectural Chubu Hospital, Kitakami, Iwate, Japan Department of Pediatrics, School of Medicine, Iwate Medical University, Yahaba, Iwate, JapanSearch for more papers by this authorTakashi Odagiri, Takashi Odagiri Division of Infectious Diseases and Immunology, Department of Microbiology, School of Medicine, Iwate Medical University, Yahaba, Iwate, JapanSearch for more papers by this authorTaketora Echizenya, Taketora Echizenya Department of Pediatrics, Iwate Prefectural Chubu Hospital, Kitakami, Iwate, JapanSearch for more papers by this authorKoji Dewa, Koji Dewa Department of Forensic Medicine, School of Medicine, Iwate Medical University, Yahaba, Iwate, JapanSearch for more papers by this authorYasushi Muraki, Corresponding Author Yasushi Muraki ymuraki@iwate-med.ac.jp orcid.org/0000-0001-8772-8018 Division of Infectious Diseases and Immunology, Department of Microbiology, School of Medicine, Iwate Medical University, Yahaba, Iwate, JapanCorrespondence: Yasushi Muraki, MD PhD, Division of Infectious Diseases and Immunology, Department of Microbiology, School of Medicine, Iwate Medical University, 1-1-1 Idaidori, Yahaba, Iwate 028-3694, Japan. Email: ymuraki@iwate-med.ac.jpSearch for more papers by this author Yuko Hayashi, Yuko Hayashi Department of Pediatrics, Iwate Prefectural Chubu Hospital, Kitakami, Iwate, Japan Department of Pediatrics, School of Medicine, Iwate Medical University, Yahaba, Iwate, JapanSearch for more papers by this authorTakashi Odagiri, Takashi Odagiri Division of Infectious Diseases and Immunology, Department of Microbiology, School of Medicine, Iwate Medical University, Yahaba, Iwate, JapanSearch for more papers by this authorTaketora Echizenya, Taketora Echizenya Department of Pediatrics, Iwate Prefectural Chubu Hospital, Kitakami, Iwate, JapanSearch for more papers by this authorKoji Dewa, Koji Dewa Department of Forensic Medicine, School of Medicine, Iwate Medical University, Yahaba, Iwate, JapanSearch for more papers by this authorYasushi Muraki, Corresponding Author Yasushi Muraki ymuraki@iwate-med.ac.jp orcid.org/0000-0001-8772-8018 Division of Infectious Diseases and Immunology, Department of Microbiology, School of Medicine, Iwate Medical University, Yahaba, Iwate, JapanCorrespondence: Yasushi Muraki, MD PhD, Division of Infectious Diseases and Immunology, Department of Microbiology, School of Medicine, Iwate Medical University, 1-1-1 Idaidori, Yahaba, Iwate 028-3694, Japan. Email: ymuraki@iwate-med.ac.jpSearch for more papers by this author First published: 18 October 2022 https://doi.org/10.1111/ped.15305 Yuko Hayashi and Takashi Odagiri contributed equally to this work. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume64, Issue1January/December 2022e15305 RelatedInformation

Rapid molecular diagnosis of Parechovirus infection using the reverse transcription loop-mediated isothermal amplification technique.

Human parechovirus (HPeV), especially HPeV A3 (HPeV3), causes sepsis-like diseases and sudden infant death syndrome in neonates and young infants. Development of rapid and easier diagnostic laboratory tests for HPeVs is desired. Original inner primers, outer primers, and loop-primers were designed on the 5' untranslated region of HPeV3. HPeV3 ribonucleic acids (RNAs), other viral RNAs, and clinical stool samples were used to confirm whether the designed primers would allow the detection of HPeV3 with the reverse transcription loop-mediated isothermal amplification (RT-LAMP) technique. Three combinations of primers were created and it was confirmed that all primer sets allowed the detection of HPeV3 RNAs. The primer sets had cross-reactivity with HPeV type 1 (HPeV1), but all sets showed negative results when applied to coxsackievirus, echovirus, enterovirus, norovirus, and adenovirus genomes. Four of six stool samples, obtained from newborn and infant patients with sepsis-like symptoms, showed positive results with our RT-LAMP technique. This manuscript is the first description of an RT-LAMP for the diagnosis of HPeVs, allowing a faster, easier, and cheaper diagnosis. This technique is clinically useful for newborns and infants who have sepsis-like symptoms.

Characterization of Pathogenesis and Inflammatory Responses to Experimental Parechovirus Encephalitis.

Human parechovirus type 3 (PeV-A3) infection has been recognized as an emerging etiologic factor causing severe nerve disease or sepsis in infants and young children. But the neuropathogenic mechanisms of PeV-A3 remain unknown. To understand the pathogenesis of PeV-A3 infection in the neuronal system, PeV-A3-mediated cytopathic effects were analyzed in human glioblastoma cells and neuroblastoma cells. PeV-A3 induced interferons and inflammatory cytokine expression in these neuronal cells. The pronounced cytopathic effects accompanied with activation of death signaling pathways of apoptosis, autophagy, and pyroptosis were detected. A new experimental disease model of parechovirus encephalitis was established. In the disease model, intracranial inoculation with PeV-A3 in C57BL/6 neonatal mice showed body weight loss, hindlimb paralysis, and approximately 20% mortality. PeV-A3 infection in the hippocampus and cortex regions of the neonatal mouse brain was revealed. Mechanistic assay supported the in vitro results, indicating detection of PeV-A3 replication, inflammatory cytokine expression, and death signaling transduction in mouse brain tissues. These in vitro and in vivo studies revealed that the activation of death signaling and inflammation responses is involved in PeV-A3-mediated neurological disorders. The present results might account for some of the PeV-A3-associated clinical manifestations.

Parechovirus Genotype 3 Outbreak Among Young Infants in Portugal.

Human parechovirus type 3 has been recognized as a cause of pediatric infection, occasionally associated with seriousillness, including sepsis and meningitis, particularly among young infants. The aim of this study is to report the first known humanparechovirus type 3 outbreak in Portugal. Descriptive study of an outbreak that occurred between the 8th June to the 12th August 2016. Laboratory diagnosiswas made by reverse transcription - polymerase chain reaction in the cerebrospinal fluid and/or in stools. Genotyping was madeby reverse transcription - polymerase chain reaction and sequencing in stool samples from infants and family members. Human parechovirus type 3 infection was detected in seven infants, of which six were male. Median age was 23 days (5 - 52).One had seizures, with a magnetic resonance imaging scan showing white matter diffusion restriction. The mean duration of admissionwas 5.6 days (3 - 11), with favourable outcome in all. In three cases there were symptomatic close family members. Human parechovirustype 3 was identified in the stools of three mothers. Even though human parechovirus type 3 infection has been well described in the presented age group, most Portuguesehospitals do not have this laboratory diagnosis. Our results are comparable to those obtained in other countries. Besides detection ofthe virus in the cerebrospinal fluid, there were no raised local or systemic inflammatory markers. This study reports the first known outbreak, in infants, of human parechovirus type 3 in Portugal. Although there is nospecific treatment, this diagnosis can avoid unnecessary empirical antibiotic treatment and prolonged admissions.

HPeV3-associated acute encephalitis/encephalopathy among Japanese infants

ObjectiveThe current study aimed to identify and compare the clinical characteristics of human parechovirus type 3 (HPeV3)-associated acute encephalitis/encephalopathy (HPeV3E/E) between infants with abnormal brain magnetic resonance imaging (MRI) findings (typical, or MRI-positive HPeV3E/E) and those with MRI-negative findings (MRI-negative HPeV3E/E). MethodsThis is a retrospective study on patients with HPeV3 infection, and a two-step questionnaire survey performed on 837 hospitals in Japan between 2014 and 2016. ResultsWe identified 240 infants with HPeV3 infection, of which 34 had been clinically-diagnosed HPeV3E/E (cHPeV3E/E). However, detailed clinical data were provided by 32 of the 34 patients. Among these 32, 23 had undergone MRI and were categorized into two groups, MRI-positive (n = 17) and -negative (n = 6). There were no significant intergroup differences in clinical lab results or symptoms, except for gastrointestinal symptoms that were only present in the MRI-negative patients. The MRI-positive group showed white matter involvement on brain MRI during the acute phase, and 8 patients presented with lesions on follow-up MRI. Furthermore, 4 (50%) of the 8 patients had neurological sequelae. ConclusionClinical characteristics of cHPeV3E/E patients with and without lesions on brain MRI showed no significant differences. Therefore, considering the difficulty in distinguishing febrile infants with cHPeV3E/E from those with a sepsis-like illness, during an HPeV3 infection epidemic, it is imperative to frequently perform brain MRI in febrile infants presenting with severe disease for the early diagnosis of HPeV3E/E presenting with brain lesions.

Development of Monoclonal Antibodies and Antigen-Capture ELISA for Human Parechovirus Type 3.

Human parechovirus type 3 (HPeV3) is an etiologic agent of respiratory diseases, meningitis, and sepsis-like illness in both infants and adults. Monoclonal antibodies (mAbs) can be a promising diagnostic tool for antigenic diseases such as virus infection, as they offer a high specificity toward a specific viral antigen. However, to date, there is no specific mAb available for the diagnosis of HPeV3 infection. In this study, we developed and characterized mAbs specific for HPeV3 capsid protein VP0. We used cell-free, wheat germ-synthesized viral VP0 protein for immunizing BALB/c mice to generate hybridomas. From the resultant hybridoma clones, we selected nine clones producing mAbs reactive to the HPeV3-VP0 antigen, based on enzyme-linked immunosorbent assay (ELISA). Epitope mapping showed that these mAbs recognized three distinct domains in HPeV3 VP0. Six mAbs recognized HPeV3 specifically and the other three mAbs showed cross-reactivity with other HPeVs. Using the HPeV3-specific mAbs, we then developed an ELISA for viral antigen detection that could be reliably used for laboratory diagnosis of HPeV3. This ELISA system exhibited no cross-reactivity with other related viruses. Our newly developed mAbs would, thus, provide a useful set of tools for future research and ensure HPeV3-specific diagnosis.

Children With Fever Without a Source: Use of Blood PCR Testing

Research Article| May 01 2020 Children With Fever Without a Source: Use of Blood PCR Testing AAP Grand Rounds (2020) 43 (5): 53. https://doi.org/10.1542/gr.43-5-53 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Children With Fever Without a Source: Use of Blood PCR Testing. AAP Grand Rounds May 2020; 43 (5): 53. https://doi.org/10.1542/gr.43-5-53 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search toolbar search search input Search input auto suggest filter your search All PublicationsAll JournalsAAP Grand RoundsPediatricsHospital PediatricsPediatrics In ReviewNeoReviewsAAP NewsAll AAP Sites Search Advanced Search Topics: fever, polymerase chain reaction, bacterial infection, serious Source: L’Huillier AG, Mardegan C, Cordey S, et al. Enterovirus, parechovirus, adenovirus and herpes virus type 6 viraemia in fever without source. Arch Dis Child. 2020; 105(2): 180– 186; doi: https://doi.org/10.1136/archdischild-2019-317382Google Scholar Investigators from Geneva, Switzerland, conducted a prospective cross-sectional study to assess whether rates of serious bacterial infection (SBI) differed among children with fever without a source (FWS) who were, or were not, positive for human enterovirus (HEV), human parechovirus (HPeV), adenovirus (AdV), and human herpesvirus type 6 (HHV-6). Children <3 years old were eligible if they presented to the study institution’s ED with fever for <7 days and had no identified focus of infection on exam. Participants received usual care and had blood polymerase chain reaction (PCR) testing for HEV, HPeV, AdV, and HHV-6. Treating physicians remained blinded to PCR test results. A control group of similarly aged children without FWS presenting to dental or fracture clinics were enrolled and received PCR testing. Among participants with FWS, demographics, clinical symptoms and course, and laboratory findings were abstracted from the medical chart. The primary exposure variable was PCR test results, with participants considered positive if either HEV, HPeV, AdV, or HHV-6 were detected. The primary outcome was rate of SBI, defined as a positive blood, urine, or cerebrospinal fluid (CSF) culture judged not to be a contaminant. Secondary outcomes included rates of hospital admission and receipt of antibiotics. Investigators compared the prevalence of virus detection among participants with FWS to controls as well as outcomes among virus-positive and virus-negative participants with FWS. There were 135 participants with FWS and 50 controls included in analysis. There were significantly more participants with FWS (vs controls) who had a least one virus detected (34.8% vs 6%; P < .001). The most common virus detected in participants with FWS was HEV. Blood, urine, or CSF cultures were obtained in 96%, 94%, and 26% of participants with FWS, respectively, with no difference between virus-negative and virus-positive groups in whether cultures were obtained. Among those with culture results, there were significantly higher rates of SBI in virus-negative (vs virus-positive) participants (20.5% vs 4.3%; P = .011). All SBIs in the virus-positive group were UTIs. There was no difference between the 2 groups in receipt of antibiotics, but significantly fewer virus-positive participants were hospitalized. The investigators conclude that HEV, HPeV, AdV, and HHV-6 are common in children with FWS and are associated with a lower risk of SBI. Dr Chung has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device. Identifying the source of fever in young children in the absence of other symptoms continues to be the subject of much debate, in large part related to the extent to which clinicians test for SBI, treat with antibiotics, and hospitalize patients for further evaluation and monitoring.1,2 Over the past 3 decades, investigators have proposed a number... You do not currently have access to this content.

Identification and molecular characterization of the first complete genome sequence of Human Parechovirus type 15

Using a metagenomics approach, we have determined the first full-length genome sequence of a human parechovirus type 15 (HPeV15) strain, isolated from a child with acute flaccid paralysis and co-infected with EV-A71. HPeV15 is a rarely reported type. To date, no full-length genome sequence of HPeV15 is available in the GenBank database, where only limited VP1 sequences of this virus are available. Pairwise comparisons of the complete VP1 nucleotide and deduced amino acid sequences revealed that the study strain belongs to type 15 as it displayed 79.6% nucleotide and 93.4% amino acid identity with the HPeV15 prototype strain. Comparative analysis of available genomic regions and phylogenetic analysis using the P2 and P3 coding regions revealed low nucleotide identity to HPeV reference genomes. Phylogenetic and similarity plot analyses showed that genomic recombination events might have occurred in the UTRs and nonstructural region during HPeV15 evolution. The study strain has high similarity features with different variants of HPeV3 suggesting intertypic recombination. Our data contributes to the scarce data available on HPeVs in Africa and provides valuable information for future studies that aim to understand the evolutionary history, molecular epidemiology or biological and pathogenic properties of HPeV15.

Cytokine Profiles in Human Parechovirus Type 3-induced Sepsis-like Syndrome.

We aimed to assess the kinetics of the release of proinflammatory cytokines and to clarify clinical usefulness as an indicator of the disease activity in human parechovirus type 3 virus (HPeV3)-induced sepsis-like syndrome. We measured serum levels of neopterin, interleukin (IL)-6 and the soluble forms of tumor necrosis factor (TNF) receptor types I (sTNF-RI) and II (sTNF-RII). Serum samples were obtained from 12 patients with HPeV3-induced sepsis-like syndrome and 28 healthy children. Disease course after onset was divided into 3 phases: early (day 1-2), peak (day 3-6) and recovery (day 9-16) phases. Serum IL-6 levels rapidly and markedly elevated in early phase and gradually decreased to those in healthy children in recovery phase. Furthermore, serum neopterin, sTNFR-I and sTNFR-II levels increased rapidly and markedly in onset phase and remained elevated in peak phase. These levels gradually decreased in recovery phase. Serum IL-18 levels increased from onset phase to peak phase and decreased in recovery phase. These results indicate that proinflammatory cytokines, in particular, interferon gamma, TNF-α and IL-18 are closely related to the development of HPeV3-induced sepsis-like syndrome. Serum levels of these cytokines might be a useful indicator of the disease activity.

Enterovirus, parechovirus, adenovirus and herpes virus type 6 viraemia in fever without source

ObjectivesTo evaluate the potential associations between fever without a source (FWS) in children and detection of human enterovirus (HEV), human parechovirus (HPeV), adenovirus (AdV) and human herpesvirus type 6 (HHV-6)...

Detection and Characterization of Human Enteroviruses, Human Cosaviruses, and a New Human Parechovirus Type in Healthy Individuals in Osun State, Nigeria, 2016/2017.

Human enteroviruses and human parechoviruses are associated with a broad range of diseases and even severe and fatal conditions. For human cosaviruses, the etiological role is yet unknown. Little is known about the circulation of non-polio enteroviruses, human parechoviruses, and human cosaviruses in Nigeria. A total of 113 stool samples were collected from healthy individuals in Osun State between February 2016 and May 2017. RT-PCR assays targeting the 5′ non-coding region (5′ -NCR) were used to screen for human enteroviruses, human parechoviruses, and human cosaviruses. For human enteroviruses, species-specific RT-PCR assays targeting the VP1 regions were used for molecular typing. Inoculation was carried out on RD-A, CaCo-2, HEp-2C, and L20B cell lines to compare molecular and virological assays. Ten samples tested positive for enterovirus RNA with 11 strains detected, including CV-A13 (n = 3), E-18 (n = 2), CV-A20 (n = 1), CV-A24 (n = 1), EV-C99 (n = 1), and EV-C116 (n = 2). Three samples tested positive for human parechovirus RNA, and full genome sequencing on two samples allowed assignment to a new Parechovirus A type (HPeV-19). Thirty-three samples tested positive for cosavirus with assignment to species Cosavirus D and Cosavirus A based on the 5′-NCR region. Screening of stool samples collected from healthy individuals in Nigeria in 2016 and 2017 revealed a high diversity of circulating human enteroviruses, human parechoviruses, and human cosaviruses. Molecular assays for genotyping showed substantial benefits compared with those of cell-culture assays.

An Emerging Human Parechovirus Type 5 Causing Sepsis-Like Illness in Infants in Australia.

Human parechovirus (HPeV), particularly type 3 (HPeV3), is an important cause of sepsis-/meningitis-like illness in young infants. Laboratory records identified a total of ten HPeV-positive cases in Southeastern Australia between January and July 2019. The HPeV present in these cases were typed by Sanger sequencing of the partial viral capsid protein 1 (VP1) region and selected cases were further characterised by additional Sanger or Ion Torrent near-full length virus sequencing. In seven of the ten cases, an HPeV type 5 (HPeV5) was identified, and in the remaining three cases, an HPeV type 1 was identified. The HPeV5-positive cases were infants under the age of 3 months admitted to hospital with fever, rash, lethargy and/or sepsis-like clinical signs. Near full-length virus sequencing revealed that the HPeV5 was most likely a recombinant virus, with structural genes most similar to an HPeV5 from Belarus in 2018, and a polymerase gene most similar to an HPeV3 from Australia in 2013/14. While HPeV5 is not typically associated with severe clinical signs, the HPeV5 identified here may have been able to cause more severe disease in young infants through the acquisition of genes from a more virulent HPeV.

Epidemiology of Human Parechovirus Type 3 Upsurge in 2 Hospitals, Freiburg, Germany, 2018.

In 2018, a cluster of pediatric human parechovirus (HPeV) infections in 2 neighboring German hospitals was detected. Viral protein 1 sequence analysis demonstrated co-circulation of different HPeV-3 sublineages and of HPeV-1 and -5 strains, thereby excluding a nosocomial outbreak. Our findings underline the need for HPeV diagnostics and sequence analysis for outbreak investigations.

Evolutionary analysis of human parechovirus type 3 and clinical outcomes of infection during the 2017\u201318 Australian epidemic

Human parechovirus type 3 (HPeV3) can cause severe sepsis-like illness in young infants and may be associated with long term neurodevelopmental delay later in childhood. We investigated the molecular epidemiology of HPeV infection in thirty three infants requiring hospitalization before, during and after the peak of the 2017/18 HPeV epidemic wave in Australia. During the peak of the epidemic, all cases were infected with an HPeV3, while before and after the peak, HPeV1 was the predominant type detected. The predominant HPeV3 was the recombinant HPeV3 also detected in the 2013/14 and 2015/16 Australian epidemics. Sepsis-like or meningitis-like symptoms were only reported in cases infected with the recombinant HPeV3. Phylogenetic analysis of the recombinant HPeV3 revealed that the virus continued to evolve, also between the Australian outbreaks, thus indicating continued circulation, despite not being detected and reported in Australia or elsewhere in between epidemic waves. The recombinant HPeV3 continued to show a remarkable stability in its capsid amino acid sequence, further strengthening our previous argument for development of a vaccine or immunotherapeutics to reduce the severity of HPeV3 outbreaks due to this virus.

Parechoviruses – Underestimated Risk

Abstract Parechoviruses are small, non-enveloped, icosahedral-shaped capsid viruses belonging to the Picornaviridae family. They are characterized by a single-positive-strand genomic RNA and as others RNA viruses have a great potential for genetic variation, the rapid evolution and adaptation. Genus Parechovirus has been established in the 90s and currently, 19 types of human parechoviruses (HPeV) are discovered. They usually cause mild respiratory or gastrointestinal illness, mainly in young children, but also can cause severe diseases such as encephalitis, meningitis, myocarditis, acute flaccid paralysis and sepsis. Severe HPeV infections in infants are also associated with a risk of long-term complications. Although it is known that HPeV plays a significant role in severe pediatric diseases, routine diagnostics are not performed in clinical practice. No antiviral drugs have been approved for the treatment of HPeV infections, and only symptomatic treatment is available. Increased detection of human parechovirus infection in infants and connection of serious clinical complication with parechovirus infection was the reason why surveillance was established in some countries, while the worldwide extensive surveillance needs to be performed in order to monitor prevalence, genetic diversity, and clinical significance of HPeV. Although the first HPeV strains were discovered 6 decades ago, recognition of HPeV biology, epidemiology, evolution and pathogenicity still requires more research to appreciate the risk for public health that these small viruses can be. 1. Introduction. 2. Classification, structure and replication. 3. Cellular receptors and HPeV variability. 4. Course of infection 5. HPeV types in the world 6. Diagnosis 7. Pathogenesis 8. Summary

2569. High Incidence of Enterovirus, HHV6, Parechovirus and Adenovirus Blood Viremia in Children 0 to 3 Years Old Presenting With Fever Without Source

BackgroundFever without source (FWS) is defined as a fever in which an extensive history and clinical examination fail to identify a cause. Although the vast majority of children with FWS have a self-limited viral infection, up to 10–25% have a serious bacterial infection (SBI). Therefore, many children require invasive diagnostic tests, hospital admission, and empirical administration of broad-spectrum antibiotics. The aim of this study was to assess the respective role of Human enterovirus (HEV), human parechovirus (HPeV), adenovirus (ADV) and herpesvirus type 6 (HHV6) viremia in children <3 years old presenting with FWS.MethodsProspective monocentric diagnostic study. Between November 2015 to December 2017, children <3 year olds with FWS had, in addition to the standardized institutional work-up for FWS, plasma tested by real-time (reverse-transcription) polymerase chain reaction (PCR) for ADV, HHV6, HEV, and HPeV. Specimens with cycle threshold values <40 were considered positive. Quantification was performed on positive specimens for HEV, ADV, and HHV6 specimens when volume permitted.ResultsOne hundred thirty-five patients had plasma PCR for ADV, HHV6, HEV, and HPeV. Male:female ratio was 1.45:1 and median age was 2.4 months (interquartile range 1.3–9.7). Among those, 47/135 (34.8%) had at least 1 virus detected in the plasma. More specifically, HEV was detected in 19 patients (14.1%), HHV6 in 15 (11.1%), HPeV in 8 (5.9%), and ADV in 7 (5.2%). Co-infection with 2 viruses was detected in 2 patients (ADV/HEV and ADV/HPeV). No patient with positive plasma PCR had a positive blood or CSF culture. Two patients with positive plasma PCR fulfilled American Academy of Pediatrics criteria for urinary tract infection. The first was HEV+ in plasma and CSF, midstream urine was positive for leukocytes and grew E. coli 106 CFU/mL, whereas the second was HHV6+ in plasma and catheter urine was positive leukocytes/nitrites and grew P. mirabilis 105 CFU/mL.ConclusionThis epidemiological study highlights the frequent detection of active enteroviral, adenoviral, and HHV6 infections in plasma of children with FWS. Virus–virus and virus–bacteria co-infections are rare. Further studies are needed to establish causality between FWS and viremia.Disclosures A. G. L’Huillier, Gertrude Von Meissner foundation: Investigator, Research grant. Ernst and Lucie Schmidheiny foundation: Investigator, Research grant. Research and Development Grant, Geneva University Hospitals: Investigator, Research grant. L. Kaiser, Swiss National Funds: Investigator, Research grant. A. Galetto-Lacour, Gertrude Von Meissner foundation: Investigator, Research grant. Ernst and Lucie Schmidheiny foundation: Investigator, Research grant. Research and Development Grant, Geneva University Hospitals: Investigator, Research grant.