Investigation of Enterovirus-Induced Polyradiculoneuropathy
Primary Diagnostic Approach
- The investigation of choice for enterovirus-induced polyradiculoneuropathy is RT-PCR testing of respiratory specimens, combined with stool samples and CSF, with respiratory specimens being particularly critical since certain enterovirus types are rarely detected in CSF or stool 1, 2
- Multiple specimens from different anatomical sites should be collected simultaneously as soon as possible after symptom onset, including respiratory specimens, stool samples, and CSF 3, 2
- Respiratory specimens, such as nasopharyngeal aspirate or throat swab, are mandatory for all cases with CNS/paralysis/myelitis involvement 1, 2
- Stool samples should be obtained in all suspected cases 1, 2
- CSF should be tested but may be negative even in confirmed cases 1, 2
- Blood samples should be collected before any blood products, especially intravenous immunoglobulin, are administered 3, 2
Diagnostic Testing Method
- Reverse transcriptase PCR (RT-PCR) assays targeting the 5′non-coding region (5′NCR) should be used for diagnosis due to superior sensitivity, specificity, and short turnaround time compared to viral culture 3, 1, 4
- RT-PCR has been shown to be far more sensitive than cell culture for detection of enteroviruses in clinical samples 3, 1
Methods to Avoid
- Virus isolation should NOT be used for routine diagnosis but can be reserved for further characterization at the national level 3, 1
- Serological methods, such as ELISA or neutralization tests, should NOT be used for diagnosis of acute enterovirus infection 3, 1
Clinical Interpretation Caveats
- Enteroviruses colonize the throat and gut for weeks to months, so detection in these sites must be interpreted cautiously and does not automatically demonstrate causation 3, 1, 2
- In immunocompromised patients, the threshold for investigation should be low, and viral shedding in stool can persist for years 3, 1