An array of laboratory tests exist to assist with the diagnoses of tick-borne encephalitis. Polymerase chain reactions (PCR) are most effective during the first week of infection. An early detection as a result of a successful PCR enables quicker medical treatment and ultimately a potentially higher survival rate. Other test useful during the later stages of infection include immunofluorescence assays, antibody titers, ELISA, and other serologic tests.

• Real-time polymerase chain reactions and other viral isolation techniques in mammalian cell cultures may be used to identify a tick-borne encephalitis infection during the initial, viremic phase.
• These methods are considered slightly inferior since a patient is less likely to seek medical attention prior to neurological manifestations when these methods are most effective.
• Polymerase chain reaction is a key element of differential diagnose when testing for tick-borne encephalitis.
• An RT-PCR for a differential diagnoses should be taken within the transient viremia stage, which occurs during the first week of the infection.
• If examined and confirmed early in the infection, a patient may receive quicker treatment.
• An early detection and treatment, as a result of a successful RT-PCR, may result in a higher survival rate and lessened complications due to infection.
• RT-PCR is also a better method in individuals suffering from immediate onset of severe infection as well as those who have not yet produced any subsequent antibodies.^[1]

• Immunofluorescence assays, immunoassays, IgM and IgG titers, as well as other serologic testing techniques may all be helpful in diagnosing an infection.
• Diagnosis is primarily determined according to this method.
• An ELISA, or enzyme-linked immunosorbent assay, is commonly used as a method for diagnoses in later stages.
• An ELISA is also considered the gold standard method in TBE diagnostic testing.^[1]