What symptoms appear with an encephalitic tick and after what period?

What symptoms appear with an encephalitic tick and after what period? - briefly

The incubation period after a bite from a tick infected with the tick‑borne encephalitis virus is usually 7–14 days (range 4–28 days). Initial flu‑like signs—fever, headache, malaise, myalgia—are followed by a second phase featuring meningitis, encephalitis, ataxia, tremor, or seizures.

What symptoms appear with an encephalitic tick and after what period? - in detail

Tick‑borne encephalitis (TBE) follows a biphasic clinical course. After a bite from an infected Ixodes tick, the incubation period typically ranges from 7 to 14 days, although intervals of 4 to 28 days have been reported. The first phase is characterized by nonspecific, flu‑like manifestations:

  • Sudden fever (often >38.5 °C)
  • Headache, sometimes frontal or occipital
  • Malaise and fatigue
  • Myalgias and arthralgias
  • Nausea, vomiting, or abdominal discomfort
  • Occasionally a mild rash at the bite site

These symptoms last 2–7 days and may resolve spontaneously, leading to a brief asymptomatic interval of 1–8 days. The second phase, when the virus invades the central nervous system, presents with neurological signs that develop abruptly after the remission period. Typical findings include:

  • High fever persisting beyond the first phase
  • Severe headache, often accompanied by neck stiffness
  • Photophobia and altered mental status (confusion, lethargy)
  • Focal neurological deficits: cranial nerve palsies, ataxia, tremor, or paresis
  • Meningeal signs: positive Kernig’s or Brudzinski’s reflexes
  • Seizures in severe cases
  • In children, irritability and vomiting may predominate

The neurological phase may last from several days to weeks, with the most intense symptoms occurring within the first 3–5 days after onset. Recovery varies: many patients improve within weeks, while a minority retain long‑term sequelae such as persistent cerebellar ataxia, cognitive impairment, or chronic fatigue. Prompt recognition of the biphasic pattern and early supportive care reduce morbidity and mortality.