A fourth human case of H5 bird flu in the US has been confirmed in Colorado involving a dairy farm worker.

RT’s Three Key Takeaways:

  1. Fourth Case Confirmed: A fourth human case of H5 bird flu in the US was identified in Colorado, involving a dairy farm worker who reported only eye symptoms and has since recovered.
  2. Risk Assessment: Despite the new case, the CDC maintains that the overall risk to the US general public remains low.
  3. Precautionary Measures: The CDC emphasizes the importance of avoiding close, prolonged, and unprotected exposure to infected animals and environments, recommending specific precautions for people working with livestock and poultry.

A human case of highly pathogenic avian influenza (H5 bird flu) virus infection in the United States has been identified in the state of Colorado, marking the fourth case associated with an ongoing multistate outbreak of A(H5N1) in dairy cows and the first in Colorado. 

Previous cases were reported in Texas and Michigan. As with previous cases, the person is a worker on a dairy farm where cows tested positive for A(H5N1) virus. The person reported eye symptoms only, received oseltamivir treatment, and has recovered. 

Based on the information available at this time, this infection does not change the Centers for Disease Control and Prevention’s (CDC) current H5N1 bird flu human health risk assessment for the US general public, which the agency considers to be low. 

Case Background

A dairy worker who was being monitored because of their work exposure to H5N1 virus-infected cattle reported symptoms to state health officials. Testing results were inconclusive at the state. Specimens forwarded to CDC for additional testing were positive for influenza A(H5). The state was then notified of the results. 

The designation of the influenza virus neuraminidase (the N in the subtype) is pending genetic sequencing at CDC. Additional genetic analysis will look for any changes to the virus that could alter the agency’s risk assessment.

CDC Recommendations

This case was detected through the state’s implementation of the CDC’s recommended monitoring and testing strategies in exposed persons. 

The CDC notes in a release that it has been watching influenza surveillance systems, particularly in affected states, and there has been no sign of unusual influenza activity in people, including in syndromic surveillance.

However, the CDC says this development underscores the importance of recommended precautions in people with exposure to infected animals. People with close or prolonged, unprotected exposures to infected birds or other animals (including livestock), or to environments contaminated by infected birds or other animals, are at greater risk of infection.

The CDC recommends: 

  • People should avoid close, long, or unprotected exposures to sick or dead animals, including wild birds, poultry, other domesticated birds, and other wild or domesticated animals (including cows).
  • People should also avoid unprotected exposures to animal poop, bedding (litter), unpasteurized milk, or materials that have been touched by, or close to, birds or other animals with suspected or confirmed A(H5N1) virus.
  • CDC has interim recommendations for prevention, monitoring, and public health investigations of A(H5N1) virus infections in people. CDC also has updated recommendations for worker protection and use of personal protective equipment. 

Photo 109376391 | Dairy Cows © Patrick Tappe | Dreamstime.com