In addition to known Borrelia pathogens causing Lyme disease, the tick Ixodes ricinus also transmits Borrelia miyamotoi, which causes a relapsing fever-like disease. This disease is not detected by blood testing for Lyme disease. We now offer the screening for this dangerous pathogen as an important complementary test to Lyme disease.
Borrelia miyamotoi is the only Borrelia strain causing a relapsing fever-like disease, which is transmitted in Europe by the tick Ixodes ricinus. The disease is well known in the USA, where it is mainly transmitted by ticks of the family Argasidae, but it has recently been diagnosed in Europe as well. It is therefore a new disease to be wary of in Europe. Other commonly occurring Borrelia strains cause Lyme disease, which shows completely different clinical symptoms from those caused by B. miyamotoi. A shorter sucking period is sufficient to transmit B. miyamotoi from ticks to the host than for the other species of Borrelia.
The relatively frequent occurrence of B. miyamotoi in ticks in the Czech Republic is surprising. During the development of diagnostics of this species, we confirmed 18% of Borrelia miyamotoi in Borrelia-positive ticks. This means that every fifth Borrelia positive tick has a high probability of having B. miyamotoi species present. The analyzed ticks come from the whole Czech Republic, so it is not a result of a random local occurrence.
The most common manifestations of disease caused by Borrelia miyamotoi are fever, chills and headache. The onset of the disease is faster and more acute than in the case of Lyme disease. Symptoms may appear between days 2-9 after the tick attaches and fever may return repeatedly. Muscle and joint pain, fatigue and nausea may also be present. In elderly and immunocompromised patients, meningoencephalitis may also occur. Laboratory tests of patients show decreased white blood cell counts, platelets and increased liver enzyme levels, which may lead to confusion with human granulocytic ehrlichiosis.
The frequent occurrence of this pathogen in the Czech Republic may be related to a number of pathogenic conditions for which the causative agent has not been definitively identified. Borrelia miyamotoi may also be responsible for a set of symptoms that persist in humans for years after tick attachment and are defined as the so-called persistent polymorphic tick syndrome. It is a set of clinical symptoms that persist for several years. Manifestations include general physical weakness, dizziness, joint pain, sleep disturbances and other neurological disorders.
The disease is well treatable with antibiotics, most commonly doxycycline (oral) or ceftriaxone (intravenous in more clinically severe cases). In children and pregnant women, amoxicillin with clavulanate.
References:
Borrelia miyamotoi: A Comprehensive Review