HPAI H5N1 infection in indoor cats from dairy worker homes
The article titled "Highly Pathogenic Avian Influenza A(H5N1) Virus Infection of Indoor Domestic Cats Within Dairy Industry Worker Households — Michigan, May 2024" was published in the Morbidity and Mortality Weekly Report (MMWR) by the U.S. Centers for Disease Control and Prevention (CDC) on February 20, 2025. This report elucidates a public health investigation into instances of highly pathogenic avian influenza (HPAI) A(H5N1) virus infection identified in two exclusively indoor domestic cats residing in households of dairy workers in Michigan.
The investigation was instigated by the atypical presentation of respiratory and neurologic illness in these felines, which exhibited no known direct exposure to HPAI-infected agricultural settings. The report emphasizes that both cats were associated with dairy farm workers, who may have encountered HPAI A(H5N1) through their occupational exposures.
Although cat-to-human transmission cannot be entirely discounted, the predominant concern appears to be the occupational exposure of the owners to HPAI-infected livestock, which likely poses a more substantial risk for virus transmission.
