What to know
- Presentation Day/Time: Wednesday, April 23, 9:00–10:25 am
- Presenter: Dennis Wang, MD, MPH, EIS officer assigned to the National Center for Immunization and Respiratory Diseases, Coronavirus and Other Respiratory Viruses Division
What did we do?
- During an outbreak of highly pathogenic avian influenza A(H5) in dairy cattle, officials in Tulare County, California identified multiple dairy farm workers with influenza A(H5) infection. From October–November 2024, we prospectively evaluated the durations of influenza A(H5) symptoms and viral RNA detection.
What did we find?
- Seven workers with presumptive influenza A(H5) had repeat testing; all were Hispanic males aged 18 years or older. All reported ocular, five reported constitutional, two reported respiratory, and one reported gastrointestinal symptoms.
- On initial influenza A(H5) testing conducted a median of two days after symptom onset, conjunctival swabs were positive for seven, nasal/oropharyngeal swabs for three, and nasopharyngeal swabs for none.
- All initiated oseltamivir a median of three days after symptom onset, and six initiated oseltamivir before re-testing; none were hospitalized.
- On the first repeat test, collected a median of five days after symptom onset, results were negative for six; one had a positive conjunctival swab three days after symptom onset, and a negative one two days later.
- Symptoms were reported for a median of 10 days; ocular and constitutional symptoms were reported for a median of six days.
Why does it matter?
- Viral detection duration was usually under a week, while symptom duration was longer among these antiviral-treated individuals. Additional data may inform recommendations around discontinuation of isolation prior to full clinical resolution, particularly for mild influenza A(H5) cases with ocular symptoms.
Abstract Category: Avian Flu