The first peak of tick activity begins in April and continues to the middle of June. Every year, several hundred patients turn to doctors of different profiles about bites. Usually, 10-14 days after the incident, experts recommend taking the tests to the laboratory.
Why take tests?
Ixodid mites spread at least two socially significant pathologies. This is all known tick-borne encephalitis and Lyme disease (borreliosis). Diseases are by no means harmless, as it may seem at first glance. In some cases, infection of the body with Borrelia causes very severe long-term consequences. Evidence of damage to the heart, joints, and the nervous system develops. Only with a thorough investigation can they be linked to Lime's disease, once suffered. That's why it is recommended to take a blood test after a tick bite.
With late-started treatment, the percentage of transition to chronic course can reach 50%. Timely laboratory testing and appropriate therapy ensure a favorable outcome of these and other serious bacterial diseases transmitted by ticks.
What tests should I take?
Basically, with a tick bite, a blood test for tick infections is carried out by serological methods:
- Immunoenzyme analysis (ELISA).
Determines the presence in the body of specific antibodies to the virus. There are two classes of antibodies: IgG and IgM. They are specific antiviral immunoglobulin proteins, which are produced by the immune system in response to infection with the virus. These proteins indicate a current or transferred infectious process, and also indicate the success of vaccination.
A week after the first symptoms, class G immunoglobulins are registered. In the blood, they reach their maximum after 1.5-2.5 months from the moment of the bite and last a lifetime. This ensures a stable immunity.
Detection of IgG class antibodies is possible 10 days after tick bite. Immunoglobulins of class M are diagnosed at the first symptoms of the disease. After 3.4-4.5 weeks after infection, their value will be very high, but within a few months it will decrease.
Immunoenzymatic analysis is very accurate and allows you to determine the pathology in the early term, but in order to rule out a false result, western blot is sometimes used.
- Western blot.
Confirming the final analysis for borreliosis and encephalitis in the list of immunological studies. The test is necessary after detection of positive antibodies of class lgG. The material, as in IFA, is venous blood.
- Immunofluorescence analysis.
The most accessible and cheap method for use by a wide range of medical institutions, which makes it possible to identify antibodies to known antigens. Investigate serum, liquor, intraarticular fluid. Specific antibodies are recorded as fluorescein-labeled complexes that contain an antigen, a specific antibody and serum against human globulins.
When pathogens are present in the material, they glow like fireflies when viewed in a fluorescent microscope. The test loses IFA for the sensitivity and objectivity of the results, but wins in specificity.
Sensitive method of polymerase chain reaction, which indicates the presence of molecules of foreign DNA or RNA in the biomaterial: tick, blood, skin biopath, urine. For additional diagnosis, also use spinal and articular fluid.
PCR makes it possible to determine the pathogen prior to genovid, to identify cases of secondary infection with borreliosis. The results will be more reliable when using several PCR systems.
Among all tests that need to be done after a tick bite, the PCR analysis for the detection of tick-borne encephalitis is inappropriate, since in the lgM-positive phase it will give a negative result in many cases. The combination of the first two tests is quite sufficient for a serological study of tick infections.
When to donate blood after a tick bite?
If the tick was bitten to give blood tests for the PCR test, it is necessary not earlier than 10 days later. On antibodies (lgM) to tick-borne encephalitis virus two weeks after the bite, on antibodies (lgM) to borrelia - after three weeks.
To determine the hidden infections after a tick bite, it is recommended to take tests twice. The first examination depends on how many days have passed since the bite, and the second - is carried out a month after the first delivery of the analysis. The first and second analyzes use the same method. The second analysis is done only if the previous one was negative.
Due to the variety of clinical signs of diseases transmitted to mites, a wide range of laboratory tests is used. The diagnostic value depends on the characteristics of the analysis itself, from the pathological stage and from the preliminary therapy with antibiotics. What tests to hand over if the tick is bitten by a doctor. He also decides on how long to re-examine if necessary.
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