How does a bite from an encephalitic tick manifest in a person? - briefly
A tick bite infected with encephalitis virus typically produces fever, headache, muscle aches and fatigue within 1‑2 weeks. Neurological involvement may follow, presenting as confusion, seizures, meningitis or other central‑nervous‑system symptoms.
How does a bite from an encephalitic tick manifest in a person? - in detail
A bite from a tick carrying encephalitis virus initiates a sequence of clinical events that can be divided into three phases: incubation, systemic illness, and neurological involvement.
During the incubation period, which typically lasts 7‑14 days after the attachment, the patient may notice a small erythematous papule at the bite site. The lesion often remains painless and may be mistaken for a simple insect bite. In some cases, a central vesicle or a faint halo develops, indicating local viral replication.
The systemic phase emerges with flu‑like manifestations. Common findings include:
- Sudden onset of high fever (38.5‑40 °C)
- Severe headache, often described as retro‑orbital
- Myalgia and generalized weakness
- Nausea, vomiting, and loss of appetite
- Mild photophobia and neck stiffness
These symptoms usually persist for 2‑4 days and may be accompanied by a transient rash, most frequently a maculopapular eruption on the trunk and extremities.
Neurological involvement marks the third phase and signals encephalitic progression. Hallmarks are:
- Altered mental status: confusion, disorientation, or lethargy
- Focal deficits: hemiparesis, cranial nerve palsies, or ataxia
- Seizure activity: focal or generalized convulsions
- Meningeal signs: pronounced neck rigidity and positive Kernig/Brudzinski tests
- Elevated intracranial pressure: headache intensifies, papilledema may appear
Laboratory evaluation typically reveals lymphocytic pleocytosis in cerebrospinal fluid, elevated protein, and normal glucose. Serologic testing shows rising IgM titers against the specific tick‑borne encephalitis virus, while polymerase chain reaction can detect viral RNA in blood or CSF during early neuroinvasion.
Prompt recognition of these stages enables early supportive care and, where available, administration of antiviral agents or immunoglobulin therapy, which can reduce morbidity and mortality. Delay in diagnosis often results in prolonged hospitalization, persistent neurological deficits, or fatal outcome.