#Enterovirus D68–Associated Acute Flaccid #Myelitis – Rising to the #Clinical and #Research #Challenges (JAMA, summary)

[Source: JAMA, full page: (LINK). Summary, edited.]

February 15, 2019

Enterovirus D68–Associated Acute Flaccid MyelitisRising to the Clinical and Research Challenges

Kevin Messacar, MD1,2; Kenneth L. Tyler, MD3,4

Author Affiliations: 1 Hospital Medicine and Pediatric Infectious Disease Sections, Department of Pediatrics, University of Colorado, Aurora; 2 Children’s Hospital Colorado, Aurora; 3 Neuroinfectious Disease Section, Department of Neurology, University of Colorado, Aurora; 4 Departments of Medicine and Immunology-Microbiology, University of Colorado, Aurora

JAMA. Published online February 15, 2019. doi:10.1001/jama.2019.1016



In the summer of 2014, the emergence of an upsurge in cases of a poliomyelitis-like paralytic syndrome in the United States, designated acute flaccid myelitis (AFM), generated substantial concern among the medical community and the public. There were 120 confirmed AFM cases in 34 states in the summer and fall of 2014. In 2016, this increased to 149 cases in 39 states, and in 2018 there were at least 210 confirmed cases from 40 states (as of February 10, 2019).1 These numbers compare to a likely baseline incidence of 22 to 35 cases per year scattered throughout the intervening years of 2015 and 2017.1



Corresponding Author: Kenneth L. Tyler, MD, University of Colorado Denver Health Sciences Center, 12700 E 19th Ave, Aurora, CO 80045 (ken.tyler@ucdenver.edu).

Published Online: February 15, 2019. doi:10.1001/jama.2019.1016

Conflict of Interest Disclosures: Dr Messacar reported receiving grants from NIAID during the conduct of the study and is a member of the CDC Acute Flaccid Myelitis Task Force. Dr Tyler reported receiving grants from NINDS and from Taiga Biotechnologies during the conduct of the study; personal fees from DNAtrix, grants from the Department of Veterans Affairs, and grants from NIH outside the submitted work. Dr Tyler is also a member of the CDC Acute Flaccid Myelitis Task Force.

Funding/Support: The authors acknowledge support from NIH grants 1K23AI128069 (Dr Messacar) and 1R01NS101208 (Dr Tyler).

Role of the Funder/Sponsor: Funding agencies had no role in the preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Disclaimer: This Viewpoint is not intended to represent the views of the CDC or CDC Task Force.

Additional Contributions: We thank Mark J. Abzug, MD, and Samuel R. Dominguez, MD (Infectious Diseases Section, Department of Pediatrics, University of Colorado School of Medicine and Children’s Hospital Colorado), for their suggestions and critical review of the manuscript.

Keywords: Enterovirus; AFM; AFP; EV-D68.



An increase in #reports of acute flaccid #paralysis (#AFP) in the #UK, 1 January 2018–21 January 2019: early findings (Euro Surveill., abstract)

[Source: Eurosurveillance, full page: (LINK). Abstract, edited.]

An increase in reports of acute flaccid paralysis (AFP) in the United Kingdom, 1 January 2018–21 January 2019: early findings

The United Kingdom Acute Flaccid Paralysis (AFP) Task Force1

Affiliations: 1 Members of the UK AFP task force are listed at the end of the article.

Correspondence:  Richard Pebody

Citation style for this article: The United Kingdom Acute Flaccid Paralysis (AFP) Task Force. An increase in reports of acute flaccid paralysis (AFP) in the United Kingdom, 1 January 2018–21 January 2019: early findings. Euro Surveill. 2019;24(6):pii=1900093. https://doi.org/10.2807/1560-7917.ES.2019.24.6.1900093

Received: 04 Feb 2019;   Accepted: 07 Feb 2019



In October 2018, Public Health England (PHE) observed an increase in routine EV-D68 laboratory detections. PHE and other United Kingdom (UK) national public health agencies reminded clinicians of the potential respiratory and neurological associations of EV-D68 infection and the requirements for appropriate microbiological investigations including exclusion of poliomyelitis. In November 2018, PHE began to receive reports of acute flaccid paralysis (AFP). A national task force was established to investigate the apparent increase. Here, we describe the preliminary epidemiological, clinical and microbiological features of cases as at 21 January 2019.

Keywords: AFP; AFM; EV-D68; UK.


Acute flaccid #myelitis caused by #EVD68: Case #definitions for use in #clinical practice (Eur J Paediatr Neurol., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Eur J Paediatr Neurol. 2019 Jan 11. pii: S1090-3798(18)30281-2. doi: 10.1016/j.ejpn.2019.01.001. [Epub ahead of print]

Acute flaccid myelitis caused by enterovirus D68: Case definitions for use in clinical practice.

Kramer R1, Lina B2, Shetty J3.

Author information: 1 European Public Health Microbiology Training Programme (EUPHEM), European Centre for Disease Prevention and Control, Stockholm, Sweden; Centre National de Référence des Enterovirus et Parechovirus, Laboratoire de Virologie, Institut des Agent Infectieux, HCL, Hôpital de la Croix-Rousse, Lyon, France. Electronic address: kramer-rolf@gmx.de. 2 Centre National de Référence des Enterovirus et Parechovirus, Laboratoire de Virologie, Institut des Agent Infectieux, HCL, Hôpital de la Croix-Rousse, Lyon, France; Virpath, CIRI, Université de Lyon, INSERM U1111, CNRS 5308, ENS de Lyon, UCBL, Lyon, France. 3 Paediatric Neurosciences, Royal Hospital for Sick Children, Edinburgh, UK; Child Life and Health, University of Edinburgh, Edinburgh, UK.



Acute flaccid myelitis (AFM) was increasingly detected in recent years, coinciding with upsurges of enterovirus D68 (EV-D68) infections. We reviewed the evidence for a causal relationship between both. Based on reported cases, we provide case definitions for AFM caused by EV-D68 infections to enable a standard procedure for affected patients. Current case definitions are focussing on epidemiological aspects but clinical case definitions are still missing. We propose the following case definitions to be used in clinical practice in order to mirror clinical realities and facilitate a common systematic approach in case management: A possible case is defined as a person presenting with either acute myelitis/paralysis or Guillain-Barré Syndrome (GBS), particularly during periods of EV-D68 circulation. A probable case is defined as a person presenting with symptoms of either acute myelitis/paralysis or GBS and at least one of the following criteria: i) MRI abnormality representing with T2 hyperintensity in spinal cord grey matter with or without hyperintensity at dorsal brain stem, ii) investigations showing an axonal neuropathy including reduced compound motor action potentials with normal conduction velocities and absence of conduction blocks compatible with anterior horn cell disease or iii) detection of enteroviruses in a respiratory specimen obtained from the lower respiratory tract during periods of EV-D68 circulation. A confirmed case is defined as a person presenting with acute flaccid myelitis/paralysis, MRI abnormality and detection of enterovirus-D68-specific nucleic acids in a respiratory specimen using a validated PCR assay targeting the VP1 gene with subsequent sequencing and typing.

Copyright © 2019 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

KEYWORDS: Acute flaccid myelitis; Clinical case definitions; Enterovirus D68; Enteroviruses; Paralysis

PMID: 30670331 DOI: 10.1016/j.ejpn.2019.01.001

Keywords: AFM; EV-D68; GBS.


Acute Flaccid #Myelitis Associated with #Enterovirus D68 in #Children, #Argentina, 2016 (Emerg Infect Dis., edited)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Edited.]

Volume 25, Number 3—March 2019 / Dispatch

Acute Flaccid Myelitis Associated with Enterovirus D68 in Children, Argentina, 2016

Carolina M. Carballo  , Marcela García Erro, Nora Sordelli, Gabriel Vazquez, Alicia S. Mistchenko, Claudia Cejas, Manlio Rodriguez, Daniel M. Cisterna, Maria Ceclilia Freire, Maria M. Contrini, and Eduardo L. Lopez

Author affiliations: de Niños “Ricardo Gutiérrez,” Buenos Aires, Argentina (C.M. Carballo, M. García Erro, N. Sordelli, A.S. Mistchenko, M. Rodriguez, M.M. Contrini, E.L. Lopez); Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia (FLENI) Hospital, Buenos Aires (G. Vazquez, C. Cejas); Administración Nacional de Laboratorios e Institutos de Salud (ANLIS) “Dr. Carlos G. Malbrán,” Buenos Aires (D.M. Cisterna, M.C. Freire)



After a 2014 outbreak of severe respiratory illness caused by enterovirus D68 in the United States, sporadic cases of acute flaccid myelitis have been reported worldwide. We describe a cluster of acute flaccid myelitis cases in Argentina in 2016, adding data to the evidence of association between enterovirus D68 and this polio-like illness.


We report a cluster of acute flaccid myelitis (AFM) cases in Buenos Aires, Argentina, in 2016. AFM was defined as acute flaccid paralysis (AFP) with magnetic resonance imaging (MRI) showing lesions predominantly affecting the gray matter of the spinal cord (1). We prospectively studied all patients with AFP who were admitted to Hospital de Niños “Ricardo Gutiérrez” in Buenos Aires during April 24–August 24, 2016 under the Argentine National Surveillance Acute Flaccid Paralysis Program for poliovirus as part of the World Health Organization AFP Program in the Americas. We obtained fecal samples or rectal swab specimens, serum samples, nasopharyngeal swab specimens, and cerebrospinal fluid (CSF) samples.

Fecal samples were tested at the National Reference Center for the Argentine National Surveillance Acute Flaccid Paralysis Program for enterovirus, including wild-type and vaccine-derived poliovirus. We screened clinical samples for enterovirus D68 (EV-D68) using a panrhinovirus and enterovirus nested PCR of enterovirus targeting the 5′ untranslated region (2). We purified the amplified products and prepared them for Sanger sequencing. We performed BLAST searches (https://blast.ncbi.nlm.nih.gov/Blast.cgi) of GenBank sequences to identify which picornavirus was present. We obtained viral protein 1 partial sequences as previously described (3). In addition, we studied a wide panel of viruses (parainfluenza virus 1, 2, and 3; influenza A/B; respiratory syncytial virus; adenovirus; metapneumovirus; rhinovirus; varicella zoster virus; herpes simplex virus; cytomegalovirus) by reverse transcription PCR (RT-PCR) and studied bacteria by culture. We performed MRI and electromyography for all patients.

Fourteen children were admitted with AFP during April–August 2016. Six were confirmed to have AFM by case definition; the other 8 had alternative diagnoses, including Guillain-Barré syndrome (3), influenza virus myositis (2), encephalitis by echovirus (in 1 child with Down syndrome), acute transient hip synovitis (1), and transverse myelitis (1). Patients’ clinical, demographic, and outcome findings are shown in Table 1, diagnostic findings in Table 2.

In 4 (66.7%) of 6 patients, we confirmed EV-D68 infection by nested RT-PCR. In 1 patient, enterovirus was detected but not typed; in 1 patient, no agent was detected. All patients had distinctive neuroimaging changes. We followed confirmed AFM cases for 6 months to assess clinical improvement.

The median age of patients with AFM was 3.9 (range 1–5) years; 4 (66.7%) of the 6 were female, and 3 (50%) had a history of asthma. All patients had prodromal signs or symptoms before onset of neurologic symptoms: 100% had upper respiratory tract infection (URTI); 4 (66.7%) had fever: and 1 (16.7%) had vomiting and abdominal pain. Neurologic symptoms appeared 1–11 (median 2) days after URTI symptoms.

Results of hematology and chemistry analysis were normal for 5 (83%) patients. Patient 1 had leukocytosis (leukocytes 18,000 cells/mm3, with 82% neutrophils) and elevated levels of alanine aminotransferase (103 IU/L [reference 10–43 IU/L]), aspartate aminotransferase (97 IU/L [reference 10–35 IU/L]), and creatine kinase (6,591 IU/L [reference 24–170 IU/L]). During follow-up, patient 1 showed an increased creatine kinase level that could not be related to enterovirus infection.

All confirmed AFM case-patients showed T2 gray matter hyperintensity within the spinal cord on MRI. Electromyography showed early signs of denervation and low motor neuron function in all 5 patients in whom the test could be done. Specimen collection was performed 9.5 (range 3–30) days after URTI symptoms started and 7.5 (range 1–18) days after onset of neurologic symptoms.

Results of nested RT-PCR for enterovirus were negative for all CSF samples; results of the respiratory virus panel were negative for all patients. Neither bacteria nor fungus were isolated in blood or CSF samples. Serum PCR to identify herpes simplex virus, varicella zoster virus, and cytomegalovirus also yielded negative results.

Intravenous immunoglobulin was empirically infused in 5 (83%) patients; 2 (33%) received systemic corticosteroids. Three patients required intensive care unit admission. All patients had neurologic sequelae: persisting palsy in >1 limbs and atrophy of muscles with a shortening of limbs. Two patients required chronic noninvasive ventilatory support during 6 months of follow-up. No patients died.



AFM has been associated with different etiologic agents (1). EV-D68 is a nonpolio enterovirus characterized by affinity for α2–6-linked sialic acids typically found in the upper respiratory tract, making the respiratory tract the preferred target for EV-D68 replication, unlike most enteroviruses, which replicate in the gut (1,7). Although there is no definitive evidence of causality between EV-D68 and AFM, since the 2014 EV-D68 respiratory outbreak in North America, AFM cases possibly associated with EV-D68 have been reported in the United States, Canada, Australia, Norway, Great Britain, and France (1,4). We report a cluster of AFM associated with EV-D68 in Argentina; another institution in Argentina (Hospital Garrahan) has also reported a case series of AFM (5,6).

The cluster in this report occurred over a 3-month period, during the 2016 autumn–winter season, which is the typical enterovirus season in Buenos Aires. Clinical and neurologic findings were similar to those of cases reported in other countries, including URTI preceding the neurologic features (4,8,9). Patients were admitted with asymmetric, acute, and progressive weakness of limbs; areflexia; and muscle pain. These symptoms have been reported as polio-like syndrome; however, testing and MRI should be performed for multiple viruses, including enteroviruses and EV-D68, to detect distinctive spinal cord lesions. No sensory sensitivity involvement was observed. Two patients had cranial nerve dysfunction. Laboratory findings were similar to those previously described, including CSF abnormalities (1,4,8).

Different hypotheses to explain difficulties in isolation of EV-D68 have been reported (4). It is possible that most of the nasopharyngeal specimens in previous studies and in our cluster were taken after 7 days of URTI, when the viral load is usually low, as reported by Imamura et al. (10). In our case series, enterovirus was identified in respiratory secretions in 5 (83.3%) of 6 patients, even though specimen collection was performed >7 days (mean 9 days) after AFM onset (in 1 patient, viral load was too low for genotyping). The negative nasopharyngeal specimen was collected at 18 days after onset.

Isolation of EV-D68 in fecal samples is uncommon because the virus is both heat and acid labile (1). However, in 2 (33.3%) of our 6 patients, EV-D68 was identified in fecal samples.

Reported rates of CSF detection of known neurotropic enteroviruses, such as polioviruses and enterovirus A71, are as low as 0%–5%, although viruses could be detected in brain or spinal cord tissue (4,11). A recent mouse model of AFM caused by EV-D68 showed that EV-D68 infects anterior horn motor neurons, resulting in motor neuron death (9). In our series, CSF samples tested negative for EV-D68 and other pathogens.

No specific treatment for EV-D68 AFM is available; the US Centers for Disease Control and Prevention recommends only support measures (7,12). Zhang et al. demonstrated that commercial immunoglobulin contained high levels of neutralizing antibodies against EV-D68 strains during the 2014 outbreak in the United States (13). No vaccines are available.

EV-D68 belonging to subclade B3 was identified in our cluster by molecular sequencing. This subclade was associated with EV-D68 circulation in the United States and Europe in 2016 (14).

We show a cluster of AFM associated with EV-D68 in Argentina. Our findings contribute to global evidence of EV-D68 as a possible cause of localized polio-like illness.


Dr. Carballo is a pediatric infectious diseases specialist at the Hospital de Niños “Ricardo Gutierrez” in Buenos Aires. Her research interests are pediatric infectious diseases.



  1. Messacar  K, Abzug  MJ, Dominguez  SR. 2014 outbreak of enterovirus D68 in North America. J Med Virol. 2016;88:739–45.
  2. Casas  I, Klapper  PE, Cleator  GM, Echevarría  JE, Tenorio  A, Echevarría  JM. Two different PCR assays to detect enteroviral RNA in CSF samples from patients with acute aseptic meningitis. J Med Virol. 1995;47:378–85.
  3. Centers for Disease Control and Prevention. Enterovirus D68 (EV-D68) 2014 outbreak strain-specific real-time reverse 327 transcription/polymerase chain reaction (rRT-PCR) assay instructions. 2014 [cited 2017 Jul 14]. http://www.cdc.gov/non-polio-enterovirus/hcp/ev-329 d68-hcp.html
  4. Holm-Hansen  CC, Midgley  SE, Fischer  TK. Global emergence of enterovirus D68: a systematic review. Lancet Infect Dis. 2016;16:e64–75.
  5. Pérez  G, Rosanova  MT, Freire  MC, Paz  MI, Ruvinsky  S, Rugilo  C, et al. Unusual increase of cases of myelitis in a pediatric hospital in Argentina [in Spanish] Arch Argent Pediatr. 2017;115:364–9.https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=28737865&dopt=AbstractPubMed
  6. Ruggieri  V, Paz  MI, Peretti  MG, Rugilo  C, Bologna  R, Freire  C, et al. Enterovirus D68 infection in a cluster of children with acute flaccid myelitis, Buenos Aires, Argentina, 2016. Eur J Paediatr Neurol. 2017;21:884–90.
    Centers for Disease Control and Prevention. Enterovirus D68. 2016 [cited 2017 May 26]. https://www.cdc.gov/non-polio-enterovirus/about/ev-d68.html
  7. Greninger  AL, Naccache  SN, Messacar  K, Clayton  A, Yu  G, Somasekar  S, et al. A novel outbreak enterovirus D68 strain associated with acute flaccid myelitis cases in the USA (2012-14): a retrospective cohort study. Lancet Infect Dis. 2015;15:671–82.
  8. Hixon  AM, Yu  G, Leser  JS, Yagi  S, Clarke  P, Chiu  CY, et al. A mouse model of paralytic myelitis caused by enterovirus D68. PLoS Pathog. 2017;13:e1006199.
  9. Imamura  T, Okamoto  M, Nakakita  S, Suzuki  A, Saito  M, Tamaki  R, et al. Antigenic and receptor binding properties of enterovirus 68. J Virol. 2014;88:2374–84.
  10. Kreuter  JD, Barnes  A, McCarthy  JE, Schwartzman  JD, Oberste  MS, Rhodes  CH, et al. A fatal central nervous system enterovirus 68 infection. Arch Pathol Lab Med. 2011;135:793–6.
  11. Rhoden  E, Zhang  M, Nix  WA, Oberste  MS. In vitro efficacy of antiviral compounds against enterovirus D68. Antimicrob Agents Chemother. 2015;59:7779–81.
  12. Zhang  Y, Moore  DD, Nix  WA, Oberste  MS, Weldon  WC. Neutralization of Enterovirus D68 isolated from the 2014 US outbreak by commercial intravenous immune globulin products. J Clin Virol. 2015;69:172–5.
  13. Wang  G, Zhuge  J, Huang  W, Nolan  SM, Gilrane  VL, Yin  C, et al. Enterovirus D68 subclade B3 strain circulating and causing an outbreak in the United States in 2016. Sci Rep. 2017;7:1242.


Suggested citation for this article: Carballo CM, García Erro M, Sordelli N, Vazquez G, Mistchenko AS, Cejas C, et al. Acute flaccid myelitis associated with enterovirus D68 in children, Argentina, 2016. Emerg Infect Dis. 2019 Mar [date cited]. https://doi.org/10.3201/eid2503.170897

DOI: 10.3201/eid2503.170897

Original Publication Date: 1/2/2019

Keywords: AFP; AFM; EV-D68; Argentina.


#Surveillance of #enteroviruses from #paediatric patients attended at a tertiary #hospital in #Catalonia from 2014 to 2017 (J Clin Virol., abstract)

[Source: Science Direct, full page: (LINK). Abstract, edited.]

Journal of Clinical Virology / Available online 30 November 2018 / In Press, Accepted Manuscript

Surveillance of enteroviruses from paediatric patients attended at a tertiary hospital in Catalonia from 2014 to 2017

Cristina Andrés a, Jorgina Vila b, Laura Gimferrer a , Maria Piñana a, Juliana Esperalba a, Maria Gema Codina a, Meritxell Barnés b, Mariadel Carmen Martín a, Francisco Fuentes a, Susana Rubio a, Pilar Alcubilla a, Carlos Rodrigo b, Tomàs Pumarola a, Andrés Antón a

{a} Respiratory Viruses Unit, Virology Section, Microbiology Department, Hospital Universitari Vall d’Hebron, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain; {b} Paediatric Hospitalisation Unit, Department of Paediatrics, Hospital Universitari Maternoinfantil Vall d’Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain

Received 4 September 2018, Revised 26 October 2018, Accepted 16 November 2018, Available online 30 November 2018.

DOI: https://doi.org/10.1016/j.jcv.2018.11.004



  • The study reports virological and clinical enterovirus surveillance in Catalonia.
  • The four enterovirus species cocirculated, distinguishing up to 27 different types.
  • Most of neurological studied cases were from the 2016 spring outbreak.
  • EV-A71 was one of the most detected EV, mostly during the outbreak.
  • Rhombencephalitis cases were related to EV-A71 infection.
  • EV-D68 was associated with lower respiratory tract infections.
  • Necessity to perform EV surveillance in primary care settings.




Enterovirus (EV) infections are usually asymptomatic or mild, but symptomatic infections can evolve to severe complications. Outbreaks of EV-A71 and EV-D68 have been recently reported worldwide, sometimes related to severe clinical outcomes.


To describe EV genetic diversity and the clinical outcomes from paediatric patients attended at a tertiary university hospital in Barcelona (Catalonia, Spain) from 2014 to 2017.

Study design

Specimens were collected from paediatric (<17 years old) cases with suspicion of respiratory tract infection or EV infection. EV laboratory-confirmation was performed by specific real-time multiplex RT-PCR assay. Partial viral VP1 protein was sequenced for genetic characterisation by phylogenetic analyses.


A total of 376 (7%) from 5,703 cases were EV laboratory-confirmed. Phylogenetic analyses of VP1 (210; 81%) sequences distinguished up to 27 different EV types distributed within EV-A (82; 40%), EV-B (90; 42%), EV-C (5; 2%), and EV-D (33; 15%), in addition to 50 (19%) rhinoviruses. The most predominant were EV-A71 (37; 45%) and EV-D68 (32; 99%). EV-A71 was highly related to neurological complications (25/39, 63%), of which 20/39 were rhombencephalitis, and most EV-D68 (28/32, 88%) were associated with lower respiratory tract infections (LRTI), and exceptionally one (3%) with flaccid paralysis.


EV-A71 and EV-D68 were the most detected EV in respiratory specimens. EV-A71 was highly related to neurological disease and EV-D68 was often associated with LRTI. However, both potential relatedness to neurological diseases makes the monitoring of EV circulation obligatory.

Keywords: enteroviruses – respiratory infections – surveillance – genetic diversity – molecular epidemiology – paediatric population

© 2018 Elsevier B.V. All rights reserved.

Keywords: Enterovirus; EV-A71; EV-D68; Rhomboencephalitis; AFP; Spain.


Contemporary Circulating #Enterovirus D68 Strains Have Acquired the Capacity for Viral Entry and #Replication in #Human #Neuronal Cells (mBio, abstract)

[Source: mBio, full page: (LINK). Abstract, edited.]

Contemporary Circulating Enterovirus D68 Strains Have Acquired the Capacity for Viral Entry and Replication in Human Neuronal Cells

David M. Brown, Alison M. Hixon, Lauren M. Oldfield, Yun Zhang, Mark Novotny, Wei Wang, Suman R. Das, Reed S. Shabman, Kenneth L. Tyler, Richard H. Scheuermann

Diane E. Griffin, Editor

DOI: 10.1128/mBio.01954-18



Enterovirus D68 (EV-D68) has historically been associated with respiratory illnesses. However, in the summers of 2014 and 2016, EV-D68 outbreaks coincided with a spike in polio-like acute flaccid myelitis/paralysis (AFM/AFP) cases. This raised concerns that EV-D68 could be the causative agent of AFM during these recent outbreaks. To assess the potential neurotropism of EV-D68, we utilized the neuroblastoma-derived neuronal cell line SH-SY5Y as a cell culture model to determine if differential infection is observed for different EV-D68 strains. In contrast to HeLa and A549 cells, which support viral infection of all EV-D68 strains tested, SH-SY5Y cells only supported infection by a subset of contemporary EV-D68 strains, including isolates from the 2014 outbreak. Viral replication and infectivity in SH-SY5Y were assessed using multiple assays: virus production, cytopathic effects, cellular ATP release, and VP1 capsid protein production. Similar differential neurotropism was also observed in differentiated SH-SY5Y cells, primary human neuron cultures, and a mouse paralysis model. Using the SH-SY5Y cell culture model, we determined that barriers to viral binding and entry were at least partly responsible for the differential infectivity phenotype. Transfection of genomic RNA into SH-SY5Y generated virions for all EV-D68 isolates, but only a single round of replication was observed from strains that could not directly infect SH-SY5Y. In addition to supporting virus replication and other functional studies, this cell culture model may help identify the signatures of virulence to confirm epidemiological associations between EV-D68 strains and AFM and allow for the rapid identification and characterization of emerging neurotropic strains.



Since the EV-D68 outbreak during the summer of 2014, evidence of a causal link to a type of limb paralysis (AFM) has been mounting. In this article, we describe a neuronal cell culture model (SH-SY5Y cells) in which a subset of contemporary 2014 outbreak strains of EV-D68 show infectivity in neuronal cells, or neurotropism. We confirmed the difference in neurotropism in vitro using primary human neuron cell cultures and in vivo with a mouse paralysis model. Using the SH-SY5Y cell model, we determined that a barrier to viral entry is at least partly responsible for neurotropism. SH-SY5Y cells may be useful in determining if specific EV-D68 genetic determinants are associated with neuropathogenesis, and replication in this cell line could be used as rapid screening tool for identification of neurotropic EV-D68 strains. This may assist with better understanding of pathogenesis and epidemiology and with the development of potential therapies.

Keywords: EV-D78; AFM; AFP.


#Investigation of #AFP Reported with #LaCrosse Virus #Infection, #Ohio, #USA, 2008–2014 (Emerg Infect Dis., abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 23, Number 12—December 2017 / Dispatch

Investigation of Acute Flaccid Paralysis Reported with La Crosse Virus Infection, Ohio, USA, 2008–2014

Morgan J. Hennessey, Daniel M. Pastula, Kimberly Machesky, Marc Fischer, Nicole P. Lindsey, Mary DiOrio, J. Erin Staples  , and Sietske de Fijter

Author affiliations: Centers for Disease Control and Prevention, Atlanta, Georgia, USA (M.J. Hennessey, D.M. Pastula); Centers for Disease Control and Prevention, Fort Collins, Colorado, USA (M.J. Hennessey, D.M. Pastula, M. Fischer, N.P. Lindsey, J.E. Staples); Ohio Department of Health, Columbus, Ohio, USA (K. Machesky, M. DiOrio, S. de Fijter)



Infection with La Crosse virus can cause meningoencephalitis, but it is not known to cause acute flaccid paralysis (AFP). During 2008–2014, nine confirmed or probable La Crosse virus disease cases with possible AFP were reported in Ohio, USA. After an epidemiologic and clinical investigation, we determined no patients truly had AFP.

Keywords: La Crosse Virus; AFP; USA.