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v1.0.0
ICD-10 Guide
ICD-10 CodesA77.49

A77.49

Other ehrlichiosis

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

Code Description

ICD-10 A77.49 is a billable code used to indicate a diagnosis of other ehrlichiosis.

Key Diagnostic Point:

Other ehrlichiosis refers to infections caused by various species of the genus Ehrlichia, which are obligate intracellular bacteria transmitted primarily by ticks. These infections can lead to a range of clinical manifestations, from mild flu-like symptoms to severe illness. The most common species associated with human disease include Ehrlichia chaffeensis, which causes human monocytic ehrlichiosis (HME), and Ehrlichia ewingii, which is associated with human granulocytic ehrlichiosis (HGE). Symptoms typically include fever, chills, headache, muscle aches, and fatigue, often appearing within 1-2 weeks after a tick bite. Diagnosis is primarily based on clinical presentation and serological testing, as well as PCR assays for detecting Ehrlichia DNA. Treatment usually involves the use of doxycycline, which is effective against these infections. Given the vector-borne nature of ehrlichiosis, awareness of travel-related risks, especially in endemic areas, is crucial for prevention and early diagnosis.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Variety of species causing similar symptoms
  • Need for serological and PCR testing for accurate diagnosis
  • Differentiation from other tick-borne diseases
  • Potential for co-infection with other pathogens

Audit Risk Factors

  • Inadequate documentation of travel history
  • Failure to specify the species of Ehrlichia
  • Misdiagnosis due to overlapping symptoms with other diseases
  • Lack of laboratory confirmation in the medical record

Specialty Focus

Medical Specialties

Infectious Disease

Documentation Requirements

Detailed clinical notes including symptoms, travel history, and laboratory results.

Common Clinical Scenarios

Patients presenting with fever and recent tick exposure.

Billing Considerations

Ensure all relevant lab tests are documented to support the diagnosis.

Primary Care

Documentation Requirements

Thorough history and physical examination notes, including tick exposure and symptom onset.

Common Clinical Scenarios

Patients with flu-like symptoms after outdoor activities in endemic areas.

Billing Considerations

Documenting patient education on tick prevention and awareness.

Coding Guidelines

Inclusion Criteria

Use A77.49 When
  • Follow the official ICD
  • CM coding guidelines, ensuring that the diagnosis is supported by clinical documentation and laboratory results
  • Include any relevant travel history and exposure to ticks

Exclusion Criteria

Do NOT use A77.49 When
No specific exclusions found.

Related CPT Codes

87491CPT Code

Infectious agent detection by nucleic acid (DNA or RNA); Ehrlichia species

Clinical Scenario

Used when PCR testing is performed to confirm ehrlichiosis.

Documentation Requirements

Document the reason for the test and the clinical findings leading to the suspicion of ehrlichiosis.

Specialty Considerations

Infectious disease specialists should ensure comprehensive documentation of test results.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of ehrlichiosis, improving the ability to track and manage these infections more effectively.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of ehrlichiosis, improving the ability to track and manage these infections more effectively.

Reimbursement & Billing Impact

The transition to ICD-10 has allowed for more specific coding of ehrlichiosis, improving the ability to track and manage these infections more effectively.

Resources

Clinical References

  • •
    CDC - Ehrlichiosis

Coding & Billing References

  • •
    CDC - Ehrlichiosis

Frequently Asked Questions

What are the common symptoms of ehrlichiosis?

Common symptoms include fever, chills, headache, muscle aches, and fatigue, which typically appear 1-2 weeks after a tick bite.

How is ehrlichiosis diagnosed?

Diagnosis is based on clinical presentation, travel history, and laboratory tests such as serology and PCR.