What happens after a bite from an encephalitis tick? - briefly
The bite can introduce the tick‑borne encephalitis virus into the bloodstream. Symptoms usually appear after an incubation of 3–14 days, ranging from mild fever to severe neurological impairment.
What happens after a bite from an encephalitis tick? - in detail
A tick that carries the virus responsible for tick‑borne encephalitis (TBE) injects saliva containing the pathogen while feeding. The bite itself may be painless and unnoticed; the skin often shows only a small erythema without inflammation.
Within 24–48 hours the virus begins to replicate at the site of inoculation. Local replication is usually asymptomatic, but the pathogen soon enters the bloodstream and lymphatic system, initiating a systemic phase. The incubation period varies from 7 to 14 days, occasionally extending to several weeks, during which the individual feels well.
The illness typically progresses through two distinct stages. The first stage presents as a nonspecific viral syndrome: fever, fatigue, headache, myalgia and occasional nausea. Laboratory findings often reveal mild leukopenia and elevated inflammatory markers. This phase lasts 3–7 days and may resolve spontaneously, giving the impression of recovery.
In a proportion of cases (approximately 30 %) the infection advances to the second stage, characterized by central nervous system involvement. Clinical manifestations include meningitis (neck stiffness, photophobia), encephalitis (confusion, seizures, focal neurological deficits) and, less frequently, meningo‑encephalomyelitis. Cerebrospinal fluid analysis shows pleocytosis with a predominance of lymphocytes, elevated protein and normal glucose. Magnetic resonance imaging may reveal hyperintense lesions in the thalamus, basal ganglia or brainstem.
Diagnosis relies on detection of specific IgM antibodies in serum or cerebrospinal fluid, confirmed by a rise in IgG titers in paired samples. Polymerase chain reaction testing of blood or CSF can identify viral RNA during the early phase, though sensitivity is limited.
Therapeutic options are primarily supportive. Antiviral agents with proven efficacy against TBE are unavailable; therefore, management focuses on fever control, hydration, seizure prophylaxis and monitoring of intracranial pressure. Severe cases may require intensive care, including mechanical ventilation and osmotherapy.
Prognosis depends on age and severity of neurological involvement. Younger patients often recover with minimal sequelae, whereas older individuals may experience persistent cognitive deficits, gait disturbances or hearing loss. Rehabilitation and regular neurological follow‑up improve long‑term outcomes.
Prevention centers on avoiding tick exposure: wearing protective clothing, using repellents containing DEET or permethrin, and performing thorough body checks after outdoor activities. Vaccination against TBE, administered in a three‑dose schedule, provides high protective efficacy and is recommended for residents and travelers in endemic regions.