Detection of La Crosse virus RNA in clinical specimens obtained from children with La Crosse infection

Area of Science:

• Virology
• Infectious Diseases
• Pediatric Neurology

Background:

• La Crosse virus (LACV) is a leading cause of pediatric neuroinvasive arboviral infection in the US.
• Current diagnosis relies on serological antibody detection (IgG/IgM) or seroconversion.
• Nucleic acid amplification tests (NAATs) for LACV are primarily used in non-clinical settings.

Purpose of the Study:

• To evaluate the performance of LACV-specific NAATs in clinical specimens from children diagnosed with LACV encephalitis.
• To assess the utility of NAATs for early diagnosis in living pediatric patients.

Main Methods:

• Retrospective analysis of remnant clinical specimens (serum, plasma, CSF, throat swabs, nasopharyngeal samples) from children with confirmed LACV encephalitis.
• LACV-specific PCR testing was performed on 179 specimens from 61 patients.
• Medical records were reviewed for clinical data and diagnostic results.

Main Results:

• LACV RNA was detected in 10 out of 179 (5.3%) specimens from 8 out of 61 (13.1%) unique patients.
• Positive detection rates varied by specimen type: 3.2% for serum, 0% for plasma, 6.5% for CSF, 3.5% for nasopharyngeal, and 21.7% for throat swabs.
• NAATs showed overall limited diagnostic yield in this cohort.

Conclusions:

• NAATs have limited utility for routine diagnosis of LACV infection in pediatric patients.
• NAATs may be beneficial in specific scenarios, such as immunocompromised individuals or cases with delayed serological confirmation.
• Further research into optimal NAAT applications for arboviral encephalitis is warranted.