What are the consequences of an encephalitic tick bite? - briefly
A tick bite transmitting encephalitic virus can trigger fever, severe headache, neck stiffness, seizures, and may progress to coma or death; survivors often experience lasting neurological deficits such as memory loss, motor weakness, or chronic fatigue. Early antiviral treatment lowers mortality but does not always prevent permanent impairment.
What are the consequences of an encephalitic tick bite? - in detail
Tick bites that transmit the virus responsible for tick‑borne encephalitis initiate a cascade of clinical events. The virus enters the skin with the feeding tick and may cause a brief local reaction, often a painless erythema that resolves within a few days.
Within one to two weeks, a systemic phase appears. Symptoms resemble a viral infection: fever, headache, malaise, myalgia, and nausea. Laboratory tests frequently reveal leukopenia and mildly elevated liver enzymes, but the condition remains self‑limited in most cases.
A second, neurological phase follows in 30‑40 % of infected individuals. Manifestations include:
- Meningitis: stiff neck, photophobia, and elevated cerebrospinal fluid pressure.
- Meningoencephalitis: altered consciousness, seizures, and focal neurological deficits.
- Myelitis: spinal cord inflammation leading to paresis or paralysis.
- Cranial nerve involvement: facial palsy, hearing loss, or diplopia.
Long‑term sequelae arise in a minority of patients. Persistent deficits may involve:
- Cognitive impairment (memory loss, reduced attention)
- Motor dysfunction (gait instability, limb weakness)
- Sensory disturbances (paresthesia, chronic pain)
- Psychiatric disorders (depression, anxiety)
Mortality rates range from 1 % to 5 % in Europe, increasing with age, immunosuppression, or delayed treatment. Early antiviral therapy is not routinely effective; supportive care, antipyretics, and management of intracranial pressure constitute the mainstay of treatment. Rehabilitation programs improve functional recovery for those with residual neurological impairment.
Preventive measures—vaccination in endemic regions, prompt removal of attached ticks, and use of repellents—reduce the incidence of severe outcomes.