Tick Infection Testing: An Algorithm for Diagnosing a Parasite to Identify the Risk of Infection
Contrary to popular belief, ticks are not only active in the summer. The first attacks of bloodsuckers are noted in early spring, and they go into hibernation only in late autumn. Their bites are fraught with serious consequences, and in order to start preventive measures in time after a tick attack, you need to find out if it was infected with an infection. Therefore, it is recommended to figure out in advance where to take the extracted tick for analysis.
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Where do ticks live
Ixodes ticks, the most dangerous for humans, live in the forest and forest-steppe zone. Their favorite places are moderately humid deciduous and mixed forests. Many pests are found along the bottom of forest ravines, on lawns, in dense herbage. Recently, ticks are increasingly attacking people and animals in the urban environment: parks, squares and even courtyards.
Why are ticks dangerous to humans?
The main danger of parasites lies in their ability to carry infections that are the causative agent of serious diseases.
The most common tick infections include:
- encephalitis;
- borreliosis (Lyme disease);
- piroplasmosis;
- erlichiosis;
- anaplasmosis.
These diseases become the cause of a person's disability, causing severe neurological and mental disorders, and destroy internal organs. The most dangerous tick-borne encephalitis: in some cases, the outcome can be fatal.
How to prevent a tick bite
Compliance with simple rules when hiking in the forest will help to avoid the attack of a bloodsucker and, as a result, infection with dangerous viruses:
- use of personal protective equipment: repellent and acaricidal preparations in the form of sprays and aerosols for humans, collars and drops for animals;
- the use of clothes of light colors - it is easier to notice the parasite on it in time;
- outerwear should be tucked into trousers, the ends of trousers - into socks and boots;
- the neck and head must be covered with a scarf or hood;
- during a walk, periodic inspections should be carried out for the presence of ticks on the body and clothes.
What to do if you are bitten by a tick
The tick must be removed and delivered to the laboratory within 24 hours of being bitten. To remove the parasite, it is best to contact the trauma center or the clinic at the place of residence.
When removing a tick yourself, you must adhere to the following recommendations:
The parasite should not be touched with bare hands, the skin must be protected with gloves or pieces of cloth.
For extraction, it is better to use special tools - a twister or pharmacy tweezers, but in the absence of such devices, you can use ordinary tweezers or thread.
The tick should be grabbed as close to the skin as possible.
You can not pull, try to pull out the parasite, the tick is easily pulled out by twisting.
After a bite, you need to treat the wound with any disinfectant.
Where to take a tick for analysis
The tick is taken to the microbiological laboratory for analysis. As a rule, such laboratories are available at the center of hygiene and epidemiology, as well as at many private medical centers.
Laboratory research of a tick
Removed bloodsuckers are examined by two methods:
- PCR - DNA / RNA of pathogens of tick-borne encephalitis, borreliosis, anaplasmosis and ehrlichiosis, rickettsiosis.
- ELISA is an antigen of the tick-borne encephalitis virus.
Indication for the purpose of the study
It is recommended to take a tick for analysis in all cases without exception. This will allow in the shortest possible time to assess the risk of infection with tick-borne infections and take the necessary measures in a timely manner.
Preparing for the procedure
The extracted parasite with a piece of damp cotton should be placed in a special container or any other container with a tight-fitting lid.
Several ticks taken from different people should not be placed in one container.
The live parasite may be stored in a refrigerator at a temperature of +2-8 degrees before examination. Taking into account the risk of developing encephalitis and the duration of the study, it is recommended that the tick be analyzed on the day of removal.
Tick testing for infection
Transmission of infectious agents occurs at the time of sucking the tick to the victim. Further, the causative agents of the infection and the clinical manifestations of the disease are described in more detail.
What can affect the result
The timing of the PCR studies may be extended when confirmatory tests are carried out.
Normal performance
If the result of the analysis is negative, the form will indicate “not found”. This means that no specific RNA or DNA fragments of tick-borne pathogens were found in the body of the tick.
Decoding indicators
As mentioned above, these studies are based on the detection of DNA and RNA fragments of pathogens of tick-borne infections in the body of the parasite. Indicators do not have a quantitative characteristic, they can be detected (then the response of the laboratory will indicate “detected”) or not (the response will indicate “not found”).
Deciphering the names of pathogens carried by ticks:
- Tick-borne encephalitis Virus, TBEV — the causative agent of tick-borne encephalitis;
- Borrelia burgdorferi sl - the causative agent of borreliosis, Lyme disease;
- Anaplasma phagocytophilum is the causative agent of human granulocytic anaplasmosis;
- Ehrlichia chaffeensis/E.muris-FL is the causative agent of ehrlichiosis.
An example of the interpretation of the survey result:
- Tick-borne encephalitis Virus, TBEV - detected;
- Borrelia burgdorferi sl - not found.
In the given example, the studied tick turned out to be infected with encephalitis, but not with borreliosis.
Additional examination in case of deviation from the norm
If it is not possible to examine the tick for the purpose of early detection of infection of the bitten, it is advisable to conduct a quantitative analysis of IgM class antibodies to the tick-borne encephalitis virus. In case of infection with encephalitis, antibodies are detected 10-14 days after the bite, so it makes no sense to take tests for encephalitis immediately after the bite - they will not show anything.
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