Detection Of Enteroviruses In Specimens Research Articles

Association of outcomes in acute flaccid myelitis with identification of enterovirus at presentation: a Canadian, nationwide, longitudinal study

Acute flaccid myelitis (AFM) is characterised by rapid onset of limb weakness with spinal cord grey-matter abnormalities on MRI scan. We aimed to assess whether detection of enterovirus in respiratory or other specimens can help predict prognosis in children with AFM. In this nationwide, longitudinal study, we evaluated the significance of detection of enterovirus in any sample in predicting outcomes in a cohort of Canadian children younger than 18 years presenting with AFM to tertiary paediatric hospitals in Canada in 2014 and 2018. All patients fulfilled the 2015 US Centers for Disease Control and Prevention case definition for definite AFM or probable AFM. Clinical data, laboratory findings, treatment, and neuroimaging results were collected (follow up period up to 5 years). We assessed neurological function and motor outcomes using Kurtzke's Expanded Disability Status Scale (EDSS) and a Weakest Limb Score. 58 children with AFM (median age 5·1 years, IQR 3·8-8·3) were identified across five of Canada's ten provinces and three territories. 25 (43%) children had enterovirus detected in at least one specimen: 16 (64%) with EV-D68, two (8%) with EV-A71, two (8%) with coxsackievirus, 10 (40%) with untyped enterovirus. Children who were enterovirus positive were more likely than those that were negative to have had quadriparesis (12 [48%] of 25 vs four [13%] of 30; p=0·028), bulbar weakness (11 [44%] of 25 vs two [7%] of 30; p=0·028), bowel or bladder dysfunction (14 [56%] of 25 vs seven [23%] of 30; p=0·040), cardiovascular instability (nine [36%] of 25 vs one [3%] of 30; p=0·028), and were more likely to require intensive care unit admission (13 [52%] of 25 vs 5 [17%] of 30; p=0·028). On MRI, most children who were enterovirus positive showed brainstem pontine lesions (14 [61%] of 23), while other MRI parameters did not correlate with enterovirus status. Median EDSS of enterovirus positive (EV+) and enterovirus negative (EV-) groups was significantly different at all timepoints: baseline (EDSS 8·5, IQR 4·1-9·5 vs EDSS 4·0, IQR 3·0-6·0; p=0·0067), 3 months (EDSS 4·0, IQR 3·0-7·4 vs EDSS 3·0, IQR 1·5-4·3; p=0·0067), 6 months (EDSS 3·5, IQR 3·0-7·0 vs EDSS 3·0, IQR 1·0-4·0; p=0·029), and 12 months (EDSS 3·0, IQR 3·0-6·9 vs EDSS 2·5 IQR 0·3-3·0; p=0·0067). Kaplan-Meier survival analysis of a subgroup of patients showed significantly poorer motor recovery among children who tested positive for enterovirus than for those who tested negative (p=0·037). Detection of enterovirus in specimens from non-sterile sites at presentation correlated with more severe acute motor weakness, worse overall outcomes and poorer trajectory for motor recovery. These results have implications for rehabilitation planning as well as counselling of families of children with these disorders. The findings of this study support the need for early testing for enterovirus in non-CNS sites in all cases of AFM. None.

Identification of Enterovirus at Presentation Predicts Outcomes in Acute Flaccid Myelitis A Canadian Nationwide Study in Canada

Background: Acute flaccid myelitis (AFM) is characterized by rapid onset of limb weakness with spinal cord grey matter abnormalities on magnetic resonance imaging (MRI). It is unclear whether detection of enterovirus (EV) in respiratory or other specimens can help predict prognosis in children with AFM. Methods: In this nationwide longitudinal study, we evaluated the significance of peripheral detection of EV in predicting outcomes in a cohort of Canadian children presenting with AFM in 2014 and 2018. Clinical data, laboratory findings, treatment, and neuroimaging were collected (follow up period up to five years). We assessed neurologic function and motor outcomes using Kurtzke’s Expanded Disability Status Scale (EDSS) and a “weakest limb score” (WLS). Findings: 58 children with AFM (median 5⋅1 years [IQR 3⋅8-8⋅3]) were identified across five provinces. Twenty-two (39%) children had detectable EV in at least one specimen: EV-D68 in 14 (64%), EV-A71 in two (9%), coxsackievirus, and untyped EV in eight (36%). Children with EV detected were more likely to have had quadriparesis (55% vs. 12%, p=0⋅005), bulbar weakness (50% vs 6%, p=0⋅004), bowel/bladder dysfunction (59% vs 24%, p=0⋅033), cardiovascular instability (36% vs 6%, p=0⋅032), and were more likely to require intensive care unit admission (59% vs. 15%, p 0⋅005). On MRI, most children with EV positivity showed brainstem pontine lesions (59%), while other MRI parameters did not correlate with EV status. EDSS of EV+ and EV- groups was significantly different at baseline (median 8⋅5 [interquartile range, IQR 4-9⋅5] vs. 4⋅8 [IQR 3⋅4-7⋅1], p=0⋅012) and 12 months (median 3 [IQR 3-7] vs. 3 [IQR 2-3], p=0⋅036). Kaplan-Meier survival analysis of a subgroup of patients showed significantly poorer motor recovery among children with detected EV than those tested negative (p=0⋅032). Interpretation: Detection of EV in specimens from non-sterile sites at presentation correlated with more severe acute motor weakness, worse overall outcomes and poorer trajectory for motor recovery. Funding Statement: None. Declaration of Interests: EAY reports grants from Canadian Network of MS Clinics during the conduct of the study; grants from Biogen, grants from NMSS, grants from CMSC, grants from 18 MSSC/MS Foundation, grants from OIRM, grants from SCN, grants from SickKids Foundation, personal fees from ACI, personal fees from US FDA, grants from CBMH, grants from TEVA, grants from Guthy Jackson Foundation, personal fees from Juno, outside the submitted work. All other authors have no conflict of interest to disclose. Ethics Approval Statement: This study was approved by the research ethics board/committee of all above-listed participating institutions. Informed consents were obtained according to individual institutional requirements.

Diagnosis of Enteroviral Meningitis by Use of Polymerase Chain Reaction of Cerebrospinal Fluid, Stool, and Serum Specimens

Because enteroviruses can be detected in various clinical samples during enteroviral meningitis, we analyzed the combined diagnostic utility of polymerase chain reaction (PCR) of cerebrospinal fluid (CSF), feces, and serum for detection of enterovirus in specimens obtained from adults with aseptic meningitis or encephalitis. PCR results were analyzed for 34 adults for whom enteroviral meningitis was diagnosed on the basis of virus isolation and antibody detection in our hospital during 1999-2003. PCR results were also analyzed for 77 adults with meningitis or encephalitis of another defined cause for whom this assay was used for diagnostic evaluation during that period. Twenty-six (76%) of 34 CSF samples and 24 (96%) of 25 fecal samples collected from patients with enteroviral meningitis had positive PCR results. The diagnostic yield of the test was lower for CSF specimens obtained >2 days after clinical onset, compared with CSF collected < or =2 days after onset. Instead, PCR of feces was highly useful also later, because 12 of the 13 fecal specimens obtained 5-16 days after clinical onset had positive test results. None of 75 CSF samples and 2 of 48 fecal samples obtained from patients with nonenteroviral infection had positive PCR results. All serum samples were PCR negative. PCR of fecal specimens obtained throughout the course of enteroviral meningitis had the highest clinical sensitivity for detecting enterovirus. It is recommended that, in addition to performance of CSF PCR, fecal samples collected from patients with suspected enteroviral meningitis should be tested by PCR, especially when the duration of symptoms is >2 days.

Rapid diagnosis of enterovirus infection by magnetic bead extraction and polymerase chain reaction detection of enterovirus RNA in clinical specimens

We describe a rapid method for extraction and detection of enterovirus RNA in clinical samples. By using magnetic bead technology, enterovirus RNA was efficiently and rapidly extracted from cerebrospinal fluid, stool, saliva, blood, pericardial fluid, urine, and cryopreserved or formalin-fixed solid tissue. Enterovirus RNA was then detected by reverse transcription followed by polymerase chain reaction amplification with primers designed to allow detection of most enterovirus serotypes. For detection of enteroviruses in specimens from patients with acute enteroviral disease, the overall sensitivity of enzymatic RNA amplification was greater than that of cell culture isolation, especially in blood specimens and in stool specimens from patients with acute cardiac disease. Enterovirus RNA was also detected in cryopreserved and archival formalin-fixed myocardial tissue from patients with acute myocarditis and chronic dilated cardiomyopathy. The ability to study archival specimens is of particular value in conducting retrospective investigation. The RNA extraction procedure used was considerably faster than extraction methods using organic reagents, used less hazardous reagents, and was of similar sensitivity. This detection protocol may therefore be useful both for the diagnosis of enterovirus infection and in studying the pathogenesis of acute and chronic enterovirus-induced disease.