Key points:

• A second strain of bird flu, D1.1, has been detected in U.S. dairy cows for the first time, leading to respiratory symptoms.
• This detection occurred in Nevada cattle and may increase public health risks given its association with severe human cases.
• The USDA confirmed nearly 957 cattle infections across 16 states and is conducting further investigations.
• Experts express concerns over the potential spread of the virus and its implications for human health and food safety.
• Despite the rising concern, the CDC maintains that the overall risk to the public remains low.

The emergence of a new strain of bird flu, formally identified as D1.1, has been confirmed in U.S. dairy cows, marking a significant health concern for both animal and public safety. The U.S. Department of Agriculture (ABC News) reported that this strain, previously identified in wild birds, was detected in several dairy herds in Nevada, where it has been linked to respiratory symptoms such as coughing, sneezing, and reduced milk production.

This finding follows a concerning trend of the H5N1 virus impacting not only avian species but also livestock. Until recently, the primary strain affecting dairy cows in the U.S. was B3.13, with over 950 confirmed cattle infections documented nationwide (CBS News).

The D1.1 strain has significant implications, having previously caused severe illness in humans, including a recent fatality in Louisiana attributed to exposure from a backyard flock of sick birds. It has also left a Canadian teenager hospitalized (Forbes). Health officials report that out of the 67 confirmed human cases since 2024, a substantial number were linked to exposure to infected dairy cows.

The CDC continues to monitor the situation, stating that the risk to the general public remains low (Salon). Nevertheless, concerns grow about the potential for this virus to undergo genetic changes that could increase transmissibility between humans. Agriculture health experts stress the importance of biosecurity measures in preventing the further spread of the virus within livestock populations and protecting at-risk human populations.

A shift in the trends of bird flu infections is indicated by the discovery that D1.1 has now infected dairy cows, raising questions about the virus's long-term implications for livestock management and food safety. The USDA is implementing additional testing and surveillance measures alongside state departments to manage the outbreak effectively.

The long-term effects of this outbreak remain uncertain, but experts have urged increased awareness and vigilance within both agricultural and healthcare sectors. As the situation develops, many look to federal agencies for a coordinated response to this evolving health threat.

To learn more about the ongoing public health response and safety measures regarding bird flu, refer to the detailed reports from ABC News, Forbes, CBS News, and Salon.