Early Summer Meningoencephalitis: Test and Diagnosis

1st order laboratory parameters – obligatory laboratory tests.

• Antibody to TBE virus: TBE-specific immunoglobulin M (IgM) and IgG antibody in serum (can also be determined from cerebrospinal fluid (CSF)).
  • Approximately 2-4 weeks after tick bite are found serologically to the first TBE-specific IgM antibodies, about 1-2 weeks later also specific IgG antibodies.
  • [if specific IgM antibodies are detected in serum, IgM and IgG antibody testing should be repeated after 1 to 3 weeks to document the increase in specific antibodies;Note: serology in the prodromal phase usually negative.
  • The diagnosis is confirmed in the case of:
    • Simultaneous detection of significantly elevated TBE-specific IgM and IgG antibodies;
    • New occurrence or significant increase in concentration of IgG antibodies in the second antibody test]
• TBE RNA detection in CSF by PCR – usually only useful in the early phase of the disease (most likely in the prodromal phase), when antibodies (see above) are not yet detectable and pleocytosis in the CSF (see below) is still missing.
• Small blood count [leukocytosis (increase in the number of white blood cells (leukocytes))/median: 12,000; thrombocytopenia (decrease in the number of platelets (thrombocytes)]
• Inflammatory parameters – CRP (C-reactive protein) or ESR (erythrocyte sedimentation rate) [CRP ↑ (range: 1-60 mg/dl; ESR (range: 12-120 mm in the 1st hour]

Laboratory parameters 2nd order – depending on the results of the history, physical examination, etc. – for differential diagnostic clarification.

• Borrelia serology
• CSF puncture (collection of cerebrospinal fluid by puncture of the spinal canal) for CSF diagnosis [almost all patients pleocytosis/appearance of increased cell count in CSF (extremely rare: normal cell count); acute phase of disease about 50% of patients: marked IgM synthesis and occasionally IgA and IgG synthesis; 15 days after onset of disease: TBE-specific CSF/serum antibody index increased in all].

Serological detection of TBE is reportable by name according to the Infection Protection Act (IfSG).

Vaccination status – control of the vaccination titer