ICD-9-CM Code Expansions for Swine and Avian Flu

On Oct. 1, 2009, two new codes were created to identify influenza due to identified avian influenza virus (488.0) and influenza due to identified novel H1N1 influenza virus (488.1). These codes have been further expanded effective Oct. 1, 2010. The rationale and review of this expansion is discussed below.

Codes 488.0, Influenza due to identified avian influenza virus, and 488.1, Influenza due to identified novel H1N1 influenza virus, do not provide the additional specification as the codes under category 487, Influenza. To allow for consistent coding of all forms of influenza with pneumonia, codes 488.0 and 488.1 have been expanded to match the codes at category 487.

Avian Influenza
Avian influenza or flu is an infection caused by avian influenza viruses. Most cases of avian influenza infection in humans are a result of contact with infected poultry or surfaces contaminated with secretions or excretions from infected birds. The spread of the virus from one ill person to another has been very rarely reported.

Signs and symptoms include conjunctivitis, cough, fever, sore throat and muscle aches and often occur after recent travel to a part of the world where bird flu occurs. Less frequently some people may develop life-threatening complications such as viral pneumonia and acute respiratory distress syndrome leading to severe breathing difficulties.

Code 488.0, Influenza due to identified avian influenza virus, has been expanded to create three new codes:

  • 488.01, Influenza due to identified avian influenza virus with pneumonia
  • 488.02, Influenza due to identified avian influenza virus with other respiratory manifestations
  • 488.09, Influenza due to identified avian influenza virus with other manifestations

The expansion of code 488.0 differentiates the occurrence of confirmed cases of avian influenza with pneumonia, with other respiratory conditions, or with other specified manifestation.

When assigning code 488.01 code also the coexisting pneumonia. Avian influenza, NOS, is reported with code 488.02.

H1N1 Influenza
H1N1 (swine) influenza is a strain of influenza or flu that emerged in 2009, originating from a virus that afflicted pigs. H1N1 influenza is classified as novel because humans have never been infected with this strain of influenza before. Swine flu is spread only from person to person similar to the seasonal flu, not from pigs or related products such as pork. Those at highest risk of contracting H1N1 are healthy young adults, children and pregnant women.

Signs and symptoms are similar to seasonal flu and include fever, cough, sore throat, runny or stuffy nose, headache, chills, muscle aches and fatigue. Diarrhea and vomiting have also been reported in H1N1. Patients with chronic medical conditions such as asthma, diabetes, heart disease, suppressed immune systems and those who are pregnant are at high risk of developing complications. Also like the seasonal flu, deaths have also been reported as a result of illnesses associated with swine flu.

Code 488.1, Influenza due to identified novel H1N1 virus, has been expanded to create three new codes

  • 488.11, Influenza due to identified novel H1N1 influenza virus with pneumonia
  • 488.12, Influenza due to identified novel H1N1 influenza virus with other respiratory manifestations
  • 488.19, Influenza due to identified novel H1N1 influenza virus with other manifestations

Like the expansion of the avian influenza codes the new H1N1 codes differentiate the occurrence of cases of H1N1 influenza with pneumonia, with other respiratory conditions or with other specified manifestation.

When assigning code 488.11 code also the coexisting pneumonia. H1N1 influenza, NOS, is reported with code 488.12.

General Reporting Guidelines
According to the “ICD-9-CM Official Guidelines for Coding and Reporting” effective Oct. 1, 2010, these new codes should only be assigned for confirmed cases and should be based on the physician’s documentation that the patient has avian influenza or novel H1N1 influenza. Confirmed cases do not require documentation of a positive lab test. This guideline is similar to guidelines provided for coding HIV and is an exception to the hospital inpatient guideline for coding of uncertain diagnoses.

Case with documentation of “suspected” or “possible” or “probable” should be assigned to the appropriate category 487 influenza code. Codes from sub-categories 488.0 and 488.1 should not be assigned.

Sequencing these conditions depends on the circumstances of admission.

Review the ICD-9-CM Official Guidelines for Coding and Reporting at (http://www.cdc.gov/nchs/data/icd9/icdguide10.pdf) and Coding Clinic 1st quarter 2010 p. 3, and 4th Quarter 2007 p. 87 then test your knowledge with the following quiz:

Questions
1. A patient who has recently returned from a trip to Asia reports to the physician with a fever, sore throat and respiratory distress. The patient’s history indicates that she visited a poultry market while in Asia. Chest X-ray results are consistent with pneumonia. The physician documents possible avian flu with pneumonia. Which of the following would be the appropriate diagnosis code(s)?

a. 488.01, 486

b. 488.01

c. 487.0, 486

d. 487.0

2. An 8-year-old female presents to the hospital with flu like symptoms of cough, fever and chills that has worsened over the last few days to include severe chest congestion. She was admitted to the hospital to rule out H1N1 influenza with pneumonia and was treated with Tamiflu. The patient’s symptoms resolved and she was discharged home. The physician documented “H1N1 flu” in the discharge summary. Which of the following would be the appropriate diagnosis code(s)?

a. 488.11, 486

b. 488.12

c. 487.0, 486

d. 487.1

This month’s column has been prepared by Cheryl D’Amato, RHIT, CCS, director of HIM, facility solutions, and Melinda Stegman, MBA, CCS, clinical technical editor, Ingenix. The authors thank Beth Ford, RHIT, CCS, for her assistance with the clinical information found in this article.

Answers:

1. c. Assign code 487.0, Influenza with pneumonia, for possible avian influenza. Per the updated coding guidelines only confirmed cases of avian flu are reported. When the final diagnostic statement indicates “possible,” “probable” “suspected” or “questionable” a code from sub-category 488.0 is not assigned. Assign code 486, pneumonia, organism unspecified, as an additional diagnosis. You may want to query the physician to ask if the specific type of pneumonia has been identified.

2. b. Assign code 488.12, Influenza due to identified novel H1N1 influenza virus with other respiratory manifestations. Code 488.11, H1N1 with pneumonia, should not be coded in this instance because the physician did not indicate that the patient had a possible or confirmed case of pneumonia. The physician should be queried if additional info is needed.

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