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v1.0.0
ICD-10 Guide
ICD-10 CodesA84.1

A84.1

Tick-borne viral encephalitis

BILLABLE STATUSYes
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/05/2025

Code Description

ICD-10 A84.1 is a billable code used to indicate a diagnosis of tick-borne viral encephalitis.

Key Diagnostic Point:

Tick-borne viral encephalitis (TBE) is a viral infection that affects the central nervous system, primarily transmitted through the bite of infected ticks. The disease is endemic in certain regions of Europe and Asia, where the ticks are prevalent. Clinically, TBE can present with a range of neurological symptoms, including fever, headache, and in severe cases, encephalitis, which can lead to long-term neurological complications such as cognitive deficits, motor dysfunction, and seizures. The incubation period typically ranges from 7 to 14 days, after which patients may experience a biphasic illness characterized by an initial febrile phase followed by a symptom-free interval before the onset of neurological symptoms. Diagnosis is primarily based on clinical presentation and serological testing for specific antibodies against the TBE virus. Vaccination is available and recommended for individuals at high risk, such as those living in or traveling to endemic areas. Understanding the vaccination status of patients is crucial for accurate diagnosis and management.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Varied clinical presentations and severity of the disease.
  • Need for serological confirmation and understanding of vaccination history.
  • Differentiation from other viral encephalitides.
  • Potential for co-infections with other tick-borne diseases.

Audit Risk Factors

  • Inadequate documentation of clinical symptoms.
  • Failure to document vaccination status.
  • Misdiagnosis due to overlapping symptoms with other conditions.
  • Lack of serological test results in the medical record.

Specialty Focus

Medical Specialties

Infectious Disease

Documentation Requirements

Detailed clinical history, laboratory results, and vaccination status.

Common Clinical Scenarios

Patients presenting with fever and neurological symptoms after tick exposure.

Billing Considerations

Consideration of co-infections and regional epidemiology.

Neurology

Documentation Requirements

Neurological examination findings, imaging studies, and follow-up assessments.

Common Clinical Scenarios

Patients with confirmed TBE presenting with seizures or cognitive impairment.

Billing Considerations

Long-term follow-up for neurological sequelae.

Coding Guidelines

Inclusion Criteria

Use A84.1 When
  • Follow ICD
  • CM guidelines for coding infectious diseases, ensuring accurate documentation of clinical findings, laboratory results, and vaccination history
  • Include any relevant co
  • morbidities

Exclusion Criteria

Do NOT use A84.1 When
No specific exclusions found.

Related CPT Codes

86788CPT Code

Viral serology for TBE

Clinical Scenario

Used when serological testing for TBE is performed.

Documentation Requirements

Document the reason for testing and results.

Specialty Considerations

Infectious disease specialists should ensure comprehensive testing.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of tick-borne diseases, improving the accuracy of epidemiological data and facilitating better patient management.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of tick-borne diseases, improving the accuracy of epidemiological data and facilitating better patient management.

Reimbursement & Billing Impact

The transition to ICD-10 has allowed for more specific coding of tick-borne diseases, improving the accuracy of epidemiological data and facilitating better patient management.

Resources

Clinical References

  • •
    CDC Tick-Borne Diseases

Coding & Billing References

  • •
    CDC Tick-Borne Diseases

Frequently Asked Questions

What are the common symptoms of tick-borne viral encephalitis?

Common symptoms include fever, headache, and neurological manifestations such as confusion, seizures, and motor dysfunction.