What will happen if bitten by an encephalitic tick, what symptoms? - briefly
A bite from an encephalitis‑carrying tick may cause an initial fever, severe headache, and neck stiffness, then progress to neurological manifestations such as confusion, seizures, or muscle weakness. Prompt medical evaluation is essential to diagnose and treat the infection.
What will happen if bitten by an encephalitic tick, what symptoms? - in detail
A bite from a tick infected with a virus that causes encephalitis initiates a cascade of physiological events. The pathogen, most commonly the tick‑borne encephalitis virus (TBEV), is introduced into the dermal tissue and then travels via peripheral nerves to the central nervous system. During the incubation period—typically 7 to 14 days, but ranging from 4 to 28 days—no external signs appear, allowing the infection to progress unnoticed.
When the virus reaches the brain and spinal cord, the clinical picture divides into two phases. The first, a nonspecific flu‑like syndrome, includes:
- Fever of 38‑40 °C
- Headache, often frontal or occipital
- Malaise and muscle aches
- Nausea or vomiting
- Generalized weakness
These symptoms may resolve spontaneously within a few days, leading some patients to believe the illness has ended. In approximately one third of cases, a second, neurologic phase follows, characterized by more severe manifestations:
- High fever persisting beyond 48 hours
- Neck stiffness and photophobia, indicating meningeal irritation
- Altered mental status: confusion, disorientation, or somnolence
- Focal neurological deficits: weakness or paralysis of limbs, facial palsy
- Ataxia and loss of coordination
- Seizures, which may be focal or generalized
- Cranial nerve involvement, producing double vision or hearing loss
- Persistent headache, often severe and unresponsive to analgesics
Laboratory evaluation typically reveals lymphocytic pleocytosis in cerebrospinal fluid, elevated protein, and normal glucose. Serologic testing shows a rise in specific IgM and later IgG antibodies against TBEV. Magnetic resonance imaging may demonstrate hyperintense signals in the basal ganglia, thalamus, or brainstem.
Complications can include long‑term neurological sequelae such as chronic fatigue, cognitive impairment, and permanent motor deficits. Mortality rates vary by viral subtype, ranging from 1 % in the European strain to 20 % in the Siberian strain. Early recognition and supportive care—hydration, antipyretics, and seizure management—improve outcomes, although no specific antiviral therapy is currently approved.
Preventive measures, including vaccination in endemic regions and prompt removal of attached ticks, remain the most effective strategy to avoid these clinical consequences.