Diagnosis of tick infectivity as a source of information for patient treatment.

The diagnosis of tick infectivity developed by our specialists is based on the detection of known and unique nucleic acid sequences of pathogens. The tick for the examination does not have to be alive and only a larger part of it ("body" - in which the salivary glands and intestine are mainly found) is sufficient. About 20% of ticks in the Czech Republic transmit one of the serious infections.

In general, the risk of transmission of the agents of various serious infections – so called zoonoses (Lyme borreliosis, tick-borne encephalitis) depends on the infectious dose of the pathogenic organism, the state of the host's immune system and the time for which the tick has been attached. Understanding the mode of transmission of the two most important pathogenic agents in Europe (tick-borne encephalitis virus and Lyme borreliosis spirochete) from ticks to humans is important for an overall assessment of the risk of developing the disease.

Method of tick-borne encephalitis virus transmission

The tick-borne encephalitis (TBE) virus infects the whole organism of the tick and after the attachment of the tick, the virus is transmitted very quickly to the host (within the first hour after the tick is attached). At the same time, during the feeding of a tick, the TBE virus multiplies rapidly in the body of the tick, which means that a longer time of attachment of an infected tick increases the risk of infection many times.

Method of transmission of Lyme borreliosis spirochetes

The situation is slightly different in the cause of Lyme disease. Spirochetes (bacteria that causes Lyme disease - LD) reside in the gut of a tick. When a tick starts eating (blood), Borrelia activates, multiplies and migrates to the tick's salivary glands. LD spirochetes must also change their surface antigens (from OspA to Osp C) before they can be successfully transmitted to the host and cause disease in humans or animals. Thanks to this knowledge, we know that if we remove infected tick within about 12-24 hours of attachment, the risk of infection is absolutely minimal. On the other hand after 24 hours of attachment, the longer the feeding time, the higher the chances of developing the disease.

Information about a tick's infectivity does not mean that the person on whom the tick was attached really gets sick. However, this information is extremely valuable for further procedures and possible examinations by a doctor.

Tick-borne encephalitis and Lyme disease are diseases in which specific clinical manifestations are sometimes lacking in the early stages. Usually, "flu" symptoms occur, such as headache, fever, malaise, drowsiness, swollen lymph nodes and more. For example, in young children, these symptoms may not be recognized at all; the child can only be dormant or crying. Therefore, information on tick infectivity is important for successful and timely diagnosis (and treatment). This will allow the attending physician to take precautions to prevent the disease from developing into later and less treatable stages.

Lyme disease

If the test results are positive for Lyme borreliosis spirochetes, you can use short-term PREVENTIVE antibiotic treatment - usually doxycycline (200 mg) for 4-10 days. Alternatively, you can wait until the first symptoms of the disease (erythema migrans at the site of tick sucking, fatigue, fever) appear and start treatment early, without waiting for tests for specific antibody levels. Antibodies can be detected in 4-6 weeks after the attachment of an infected tick. At that time the disease is already fully developed and more difficult to treat and requires the administration of antibiotics, preferably for 21-28 days.

Tick-borne encephalitis

There is no specific treatment for tick-borne encephalitis. Usually only supportive treatment and treatment of symptoms are applied. Therefore, in the case of finding infectious agents in a tick, it is necessary to reduce physical effort, avoid stress and, take a rest. The immune system can be supported by a suitable diet with increased intake of vitamins and minerals (trace elements). Tick-borne encephalitis is a disease with varying intensity of manifestations, in most cases the immune system copes with the infection. The course is better and milder in children, while worse and more severe manifestations are in the elderly, where long-term neurological problems often persist.

Detection of the tick-borne encephalitis virus in the tick facilitates early diagnosis and, in the event of an outbreak, helps the doctor to choose the right and effective supportive treatment.

Seriously ill patients

In seriously ill patients, such as cancer patients, transplant patients or patients with congenital or acquired immunodeficiencies, information on tick infectivity is extremely important and, if positive, leads to immediate initiation of preventive treatment (antibiotics for LD; resting and supportive measures for TBE). For antibiotic treatment, doxycycline (200mg) or amoxicillin (3g / day) is recommended for 10-21 days depending on the severity of the disease.

Pregnant women

The importance of information on tick infectivity in pregnant women is indisputable. Especially in Lyme disease, which can be transmitted to the fetus via the placenta. Early diagnosis will help to select the appropriate treatment and thus prevent fetal damage.

The transmission of tick-borne encephalitis from mother to fetus has not been described to date and it is very likely that this transmission does not occur. However, an outbreak of tick-borne encephalitis in a pregnant woman is a serious condition that threatens not only the mother. Therefore early information about the possibility of infection from an infected tick is important in preventing the intensity of the disease.

Breastfeeding women

Information on tick infectivity should not be a reason to discontinue breastfeeding. The well-known positive contribution of breast milk to baby development is undeniable. If the mother suffers with Lyme borreliosis, the illness cannot endanger the breastfeeding baby, because Borrelia is not transmitted through milk. When using antibiotics in the treatment of Lyme disease in the mother, we recommend consulting everything with the infant's pediatrician, who will assess the risks of the mother's antibiotic treatment for the child.

Regarding the transmission of tick-borne encephalitis viruses from mother to child during breastfeeding, direct evidence is lacking. It is documented in the scientific literature that tick-borne encephalitis is transmissible through unpasteurized goat's milk to humans. Studies showing the transmission of TBE virus through breast milk are lacking, however, other members of the Flaviviridae family (e.g. ZIKA virus) can be transmitted through breastfeeding. On the other hand, it has been shown that although the virus is transmitted, the disease does not develop in the vast majority of cases. Breast milk contains antibodies against the infection, which neutralize the virus and help infants defend themselves against the disease.

Our recommendation for pregnant and breastfeeding women would be to focus on suitable preventive measures during their stay in nature (repellents, suitable footwear, clothing) and thorough inspection after returning home. The recommendation of the American CDC is a thorough examination of the entire body surface, shower and change of clothes no later than two hours after arriving home.

You can order a tick infection test here.