United States: The oppressive heat recently posed a significant challenge for agricultural laborers as they sought to shield themselves from chickens recently afflicted by avian influenza in Colorado, leading to five individuals contracting the virus, as reported by the US Centers for Disease Control and Prevention.
State health authorities identified the infections last week, marking the most considerable concentration of human cases in the nation since the bird flu outbreak commenced over two years ago.
These human infections are a substantial concern for public health officials because they elevate the probability that the virus could mutate to facilitate person-to-person transmission, potentially triggering a human pandemic. Since April 2022, a total of 10 human infections have been documented, according to reports by Iowa Capital Dispatch.
However, the virus detected in the Colorado laborers does not exhibit such a mutation, explained Dr. Nirav Shah, principal deputy director for the CDC, during a Tuesday call with journalists. It is believed that each worker was infected by egg-laying hens as they endeavored to cull a flock of approximately 1.8 million in the state’s northeastern region.
It is a standard practice to exterminate entire flocks when they are infected by highly pathogenic avian influenza—which rapidly infects and kills poultry—to prevent the virus’s transmission to other flocks.
The Colorado workers handled the chickens, placed them into containers holding dozens at a time, and euthanized them with carbon dioxide, according to Dr. Julie Gauthier, executive director for field operations for the US Department of Agriculture’s Animal and Plant Health Inspection Service, as per Iowa Capital Dispatch.
Typically, the workers don protective suits, goggles, gloves, and boots and use respirators to safeguard against pathogens.
However, the outdoor temperature during the operation was around 100 degrees, and the temperature inside the facility was likely even higher. Massive fans circulated air to cool the interior, which also dispersed potentially virus-laden debris such as feathers.
“The challenge of wearing all that gear in such heat, you can imagine,” Gauthier noted, “and it was exacerbated by those fans pushing the air—making it difficult to keep the goggles and N95 respirators in place.”
The virus infecting the flock is akin to one that has affected dairy cattle in 13 states, Shah mentioned. Colorado has had the highest number of infected herds, with at least 37. Shah suggested that the virus might have been transferred to the egg-laying flock from one of these herds.
Highly pathogenic avian influenza has been disseminated by wild birds and has intermittently wreaked havoc on US poultry flocks since January 2022. According to CDC data, approximately 99 million birds from infected flocks have been culled, as reported by Iowa Capital Dispatch.
Federal officials believe that the virus was transmitted from wild birds to Texas dairy cattle in December. Since then, it has spread to herds in other states, likely due to the movement of infected cattle. It is thought to have spread locally to other herds and poultry flocks via humans and their equipment, including farm workers and veterinarians.
Colorado accounts for seven of the ten known human infections in the United States resulting from interactions with sick birds and cattle. The state recorded the first-ever infection of a poultry worker in April 2022. Earlier this month, a Colorado dairy worker was also infected.
The workers recently infected exhibited mild symptoms of conjunctivitis and respiratory illness.