Quarsten et al.
No detection of tick-borne encephalitis virus RNA in blood, urine or saliva of hospitalised immunocompetent tick-borne encephalitis patients. PLoS One. 2024;19(6):e0305603. doi:10.1371/journal.pone.0305603
The standard procedure to detect an infection caused by TBE virus is the use of IgM and IgG ELISAs, while the neutralization assay is only used in special cases to verify an infection. Due to cross-reactivity with glycoprotein E of other flaviviruses, ELISAs can result in misleading interpretations. Therefore, detection of antibodies directed to TBE virus specific non-structural protein 1 (NS1) is increasingly used in TBE diagnostics.
An alternative diagnostic approach to antibody testing could be the detection of TBE virus RNA in blood and/or urine. A study has been carried out in Norway, in which a total of 31 patients suspected to have a viral infection of the central nervous system were included, and 11 of them were primarily classified as TBE patients based on antibody testing. The 11 TBE patients had symptoms typical for an infection by TBE virus.
RNA isolated from whole blood, urine and saliva of all study patients was tested by PCR (two methods), and no sample was positive.
According to these data, detection of TBE virus specific RNA in blood, urine, and saliva will mostly not be useful for diagnosing TBE patients, especially in the second phase of symptoms. These findings underline the conclusions of another research team which analyzed ELISA vs. PCR diagnosis in immunocompetent patients. This was discussed in Snapshot week 6/2024.