Tick ​​born encephalitis virus IgG antibodies

General Information

Tick-borne encephalitis virus is a virus of the Flaviviridae family, the source of which is spread by Ixodian ticks. The virus causes an inflammatory disease of the human brain - encephalitis.

The reservoir of the virus is small rodents and ticks. Man is the definitive host.

The virus is transmitted through a tick bite, ingestion of tick secretions, or in the laboratory.

The risk of infection is higher in rural settlements, at the peak of tick activity - in the period from April to November. Cases of human-to-human transmission are practically nonexistent, except for transplacental transmission from mother to fetus.

The course of the disease

The disease proceeds in two phases: the initial stage with atypical general symptoms lasts 2-4 days, the next 4-7 days are remission, followed by the second phase with signs of inflammation of the central nervous system (meningitis, meningoencephalitis), which lasts 1-3 weeks.

The recovery process is long, with residual events.

Diagnosis

Serodiagnostics is based on the detection of IgM antibodies in blood and cerebrospinal fluid. The presence of IgG antibodies indicates an acquired infection or post-vaccination condition.

For laboratory confirmation of the infectious process, it is necessary to meet at least one of the listed criteria, namely:

• The presence of specific IgM or IgG in the blood
• Specific IgM in cerebrospinal fluid
• Presence of tick-borne encephalitis virus nucleic acid in the sample
• Detection of virus in the sample

In the first phase of the disease, blood analysis reveals leukopenia and thrombocytopenia. It is also worth noting the tendency of moderate increase of liver enzymes.

In the second phase, with the development of neurological diseases, there is an increase in the number of leukocytes in the blood and cerebrospinal fluid.

It is possible to isolate the virus from the blood in the first phase of the disease. Laboratory diagnostics is based on the detection of specific IgM antibodies in blood and/or cerebrospinal fluid, which is possible at the end of the first phase or in the second phase.

When is the survey conducted?

• During the differential diagnostics of tick-borne diseases (to exclude Lyme disease)
• A symptomatic patient who is at risk of having a tick bite
• Seroepidemiological studies of specific population

Research material  - Venous blood

Referral norms ​​:

• Tick-borne encephalitis virus antibodies IgG: < 16 RE/ml
• Antibodies to tick-borne encephalitis virus < 0.8 Ratio
• Tick-borne encephalitis virus antibody ratio IgG / IgM: IgG: < 16 RE/ml IgM: < 0.8