Health officials on April 28 confirmed the nation's first human bird flu case after a Colorado man who had been working on a commercial farm with infected poultry tested positive for an H5 virus.
Six things to know:
1. The Colorado man developed fatigue on April 20 after being exposed to poultry presumably infected with H5N1, according to the CDC. He reported wearing personal protective equipment while participating in depopulation activities. On April 27, the CDC confirmed a nasal specimen was positive for avian influenza A(H5) virus.
2. The man reported fatigue as his only symptom, which resolved after three days. He was treated with oseltamivir and was in isolation as of April 29.
3. Repeat testing since April 26 has been negative for influenza viruses. Health officials have not been able to confirm whether the positive test was from an actual infection, or "a result of transient surface contamination of the individual's nasal passage" after being exposed to the virus. Health officials "are assuming this is an infection and taking actions to contain and treat."
4. The CDC said specimens from close contacts of the patient and others who participated in depopulation activities at the same facility have tested negative for influenza viruses. All individuals exposed to the infected poultry are being monitored for symptoms for 10 days, the CDC said April 29. The agency did not say how many individuals were exposed to the poultry.
5. The CDC issued recommendations on testing and treating A(H5N1) bird flu for clinicians and public health workers in an April 29 health advisory. It said clinicians should consider the possibility of infection if patients exposed to potentially infected birds show symptoms of respiratory illness. The guidance said exposed patients who develop flu-like symptoms should be treated with oseltamivir, zanamivir or baloxavir as soon as possible.
6. The CDC has tracked the health of more than 2,500 people with exposure to infected birds since it started monitoring H5N1 outbreaks among wild birds in late 2021. This marks the only detected human case in the U.S., and the risk remains low to the general public.