A recent bird flu outbreak at a commercial egg-laying facility in Weld County, Colorado, has led to the infection of five workers, marking the largest bird flu outbreak among U.S. workers to date, according to federal health officials. The outbreak is linked to industrial fans and improper use of protective equipment during the mass culling of 1.8 million chickens infected with the H5N1 influenza virus.
Federal health officials reported that the virus spread while workers were attempting to euthanize the infected chickens using carbon dioxide. Temperatures inside the barns exceeded 104 degrees Fahrenheit, making the use of personal protective equipment (PPE) difficult. This exposure led to mild symptoms in the infected workers, including fever, chills, coughing, and eye infections. They were treated with Tamiflu, and none required hospitalization.
The virus, which initially spread from wild birds to poultry, has been detected in various states since December. In early July, a dairy worker in northeastern Colorado contracted the virus, suggesting the transmission from cattle to chickens. Officials are working to determine the exact route of transmission to the Weld County poultry farm.
Approximately 160 workers were involved in the culling process, and 60 were tested for bird flu. So far, 55 have tested negative, though testing continues. The CDC has deployed a 10-person team to monitor the situation and recommend improved safety measures.
The U.S. Department of Agriculture (USDA) and the Centers for Disease Control and Prevention (CDC) have emphasized that the risk to the general public remains low, with no significant virus mutations observed. The USDA has distributed PPE, including 300,000 gloves and 150,000 N95 masks, to mitigate further risk.
In response to the outbreak, Colorado Governor Jared Polis issued a disaster emergency. The USDA has outlined steps to contain the virus, including the four D’s of outbreak control: diagnosis, depopulation, disposal, and decontamination. All infected birds must be euthanized and disposed of properly to prevent further spread.
The outbreak underscores the need for stringent biosecurity measures and effective use of PPE in preventing virus transmission. Officials are investigating more humane and effective methods for mass culling of infected birds, amidst criticism from animal welfare groups. Current methods, including ventilation shutdown and carbon dioxide gassing, have faced opposition due to concerns about their humaneness.
While the USDA continues to explore vaccine options for poultry, the primary goal remains the rapid eradication of the virus upon detection. The CDC and USDA are monitoring the situation closely and remain prepared to handle any future outbreaks with preemptive measures and stockpiled supplies.
