Flu Season Has Arrived

The 2023-2024 flu season is upon us. This year the egg-based flu vaccines have been created for the following:

• Virus A/Victoria/4897/2022 HIN;
• Virus A/Darwin/9/2021 H3N2;
• Virus B/Austria/1359417/2021; and
• Virus B/Phuket/3073/2013 (Yamagata lineage).

The cell or recombinant-based vaccines are for the following:

• A/Wisconsin (H1N1);
• A/Darwin (H3N2);
• B/Austria or B/Victoria lineage; and
• B/Phuket or B/Yamagata lineage.

People with egg allergy may get any vaccine (egg-based or non-egg based) that is appropriate for their age and health status. All vaccines are quadrivalent. Vaccine manufacturers will supply the United States with 156.2 to 170 million doses.

For the week ending Nov. 11, 2023:
• Clinical labs are reporting 4-percent positive for flu, marking an increase.
• The most frequently reported influenza virus is influenza A-H1N1.
• The cumulative hospitalization rate is 1.7 per 100,000.
• There were 2,721 patients admitted to the hospital with influenza this week.
• No influenza-associated pediatric deaths were reported.

The activity map for the week of Nov. 18, 2023 shows nine jurisdictions with high or very high activity:

The Centers for Disease Control and Prevention (CDC) recommends the following:

• Get your flu shot (anyone six months or older is eligible);
• Take actions to help stop the spread of germs (e.g., wash your hands, avoid sick people, cover coughs/sneezes, etc.); and
• If flu anti-viral medications are prescribed to treat flu-like illness, take them.

The 2024 ICD-10-CM codes for influenza include the following:

• Type A and Type B: category J10.- (Influenza due to other identified influenza virus); and
• Novel Type A: category J09.- (Influenza due to certain influenza viruses).

There are codes that include influenza and manifestations, such as novel influenza A virus with respiratory manifestations (J09.X2). There are also “code also” instructions. Code Z23 (Encounter for Immunization) should be assigned when a patient is immunized.

In the Official Coding and Reporting Guidelines for ICD-10-CM, Chapter 10 provides additional guidance regarding the coding of influenza. The guidelines include this information:

• Code only confirmed cases of influenza due to certain identified influenza viruses. This is an exception to Section II.H (Uncertain Diagnoses).
• Confirmation does not require a positive lab test. Coding may be based on the provider’s diagnostic statement.
• If the provider states “suspected,” “possible,” or “probable” influenza or novel influenza, assign a code from category J11 (Influenza due to unidentified influenza virus).

On a personal note, I have an egg allergy, which is not severe. I have received egg-free flu shots in the past. This year, the egg-free immunization was difficult to get, and I had to wait for almost a month.

Next year, I will consider getting a regular flu shot, based on this year’s CDC guidance.