Fourth human case of H5N1 bird flu linked to U.S. dairy cow outbreak confirmed

This was reported by the Centers for Disease Control and Prevention (CDC). HE identified a case of human infection with highly pathogenic avian influenza virus (HPAI) A(H5) (“bird flu H5”) in the US state of Colorado.

This This is the fourth case linked to an ongoing outbreak of A(H5N1) virus in dairy cows in several states, and the first in Colorado.. Previous cases were reported in Texas (1) and Michigan (2). As in the previous cases, the person dairyman where cows tested positive for the A(H5N1) virus. Human Only ocular symptoms were reportedreceived treatment with oseltamivir and he recovered. The Centers for Disease Control and Prevention (CDC) is closely monitoring influenza surveillance systems, particularly in affected states, and there were no signs of unusual flu activity in peopleeven with syndromic observation.

Based on the information available at this time, this infection does not change CDC’s current human health risk assessment. of H5N1 bird flu in the US population, the agency consider it low. However, this development highlights the importance of recommended precautions for people exposed to infected animals. People who have close or prolonged unprotected contact with infected birds or other animals (including livestock) or with environments contaminated by infected birds or other animals are at increased risk of infection.

BACKGROUND OF THE CASE

A dairy farm worker who was under surveillance for occupational exposure to cattle infected with the H5N1 virus reported symptoms to state health officials. Test results were inconclusive in the state. Samples sent to the CDC for additional testing tested positive for influenza A(H5). The state was then notified of the results. The influenza virus neuraminidase (N in subtype) designation is awaiting genetic sequencing at the Centers for Disease Control and Prevention (CDC). HE Attempts are underway to sequence the virus in a clinical sample. and will be available within one to two days if successful. Additional genetic analysis will look for any changes in the virus that could alter the agency’s risk assessment.

ACTIVITIES OF THE CDC

This case was identified because the state implemented CDC-recommended strategies for testing and tracing exposed individuals. In addition to enhanced and targeted surveillance, CDC also: conducted multiple calls with state and local health departments to enhance preparedness, took steps to improve the supply of personal protective equipment (PPE) for farm workers, issued interim guidance updated to protect workers who work with dairy cows, conducted multiple calls with groups representing farm workers, and initiated a targeted digital campaign in affected counties to reach farm workers with information about preventing avian influenza and what to do if they develop symptoms.

CDC RECOMMENDATIONS

People should avoid close, prolonged, or unprotected exposure to sick or dead animalsincluding wild birds, poultry, other domestic birds and other wild or domestic animals (including cows).

People should also Avoid unprotected exposure to animal waste, bedding, unpasteurized (“raw”) milk or materials. who have touched or been near birds or other animals suspected or confirmed to have the A(H5N1) virus.

Following these recommendations is important to reduce individual risk and contain the overall public health risk.