A new and highly virulent virus, known as D1.1, has been identified in cows across the United States, causing significant concern among health officials and agricultural authorities. According to the latest data from the U.S. Department of Agriculture (USDA), a total of 957 confirmed cases of cattle infections have been reported in 16 states. Of particular note are the 36 new infections detected in California and Nevada within the past month alone.
Alarmingly, D1.1 has demonstrated the potential to pose a threat to human health as well. Among the 67 documented cases of avian flu in humans in the U.S. since April 2024, only one patient was found to be infected with the D1.1 strain, and tragically, this individual, located in Louisiana, succumbed to the illness earlier this year. Health officials have disclosed that the patient, who was over the age of 65 and had underlying health conditions, had been in contact with a backyard flock.
In a separate incident, a 13-year-old girl from British Columbia, Canada, was admitted to the intensive care unit after testing positive for the same D1.1 strain in November. Unlike the Louisiana patient, the British Columbia teenager’s exposure to the virus remains unknown.
Despite these concerning developments, the Centers for Disease Control and Prevention (CDC) have sought to reassure the public, emphasizing that the risk of widespread transmission among humans is currently low and that there is no evidence of human-to-human spread of the virus.
In response to the outbreak, the USDA issued a federal mandate for the collection and testing of raw milk samples nationwide to detect the presence of avian flu. This initiative, known as the National Milk Testing Strategy, aims to enhance surveillance of the milk supply and dairy herds across the country, providing valuable insights into the spread of the virus.
The USDA underscored that the discovery of D1.1 in dairy cows does not alter their eradication strategy for avian flu, highlighting the efficacy of the National Milk Testing Strategy in monitoring and managing the outbreak. The agency has announced plans to release a detailed technical brief on their findings and make the sequence data publicly available in the near future.
This report was contributed by Youri Benadjaoud for ABC News, shedding light on the unprecedented detection of a secondary form of avian flu in U.S. dairy cows for the first time, marking a significant milestone in the ongoing battle against the outbreak.
