A case of highly pathogenic avian influenza (HPAI) A(H5), commonly known as “H5 bird flu,” has been confirmed in Colorado. According to the Centers for Disease Control and Prevention, this is the fourth human case linked to an ongoing multistate outbreak of avian flu in dairy cows and the first case reported in Colorado. Previous cases have been identified in Texas and Michigan.
The affected individual, a worker on a dairy farm where cows tested positive for the A(H5N1) virus, reported only eye symptoms. After receiving treatment with oseltamivir, the individual has fully recovered.
The CDC says that it ash been monitoring influenza surveillance systems and has not observed any unusual influenza activity in humans, including through syndromic surveillance.
The infected dairy workers were monitored due to their exposure to H5N1 virus-infected cattle, and they reported symptoms to state health officials. Initial testing at the state level was inconclusive. However, specimens sent to the CDC confirmed the presence of influenza A(H5).
The CDC conducts genetic sequencing to determine the virus’s neuraminidase (N) designation. Results from additional genetic analysis, which may reveal any changes impacting the virus’s risk assessment, are expected within 1-2 days.
The state identified this case by implementing the CDC’s recommended monitoring and testing strategies for exposed individuals. The CDC has undertaken several actions to address this situation, including holding numerous calls with state and local health departments to enhance preparedness, improving supplies of personal protective equipment (PPE) for farmworkers, updating interim recommendations for worker protection, including those working with dairy cows, conducting calls with groups representing farmworkers, and launching targeted paid digital outreach in affected counties to inform farmworkers about bird flu prevention and steps to take if they develop symptoms.
The public is advised to avoid close, prolonged, or unprotected exposure to sick or dead animals, including wild birds, poultry, other domesticated birds, and livestock. Additionally, unprotected exposure to animal feces, bedding, unpasteurized milk, or materials contaminated by infected animals should be avoided.
Interim recommendations for preventing, monitoring, and public health investigation of A(H5N1) virus infections in people have been updated. The CDC has also revised recommendations for worker protection and using PPE.
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