“A Dairy Worker Contracts a New Strain of Bird Flu”
In Nevada, a dairy worker has been infected with a new strain of avian flu, specifically the H5N1 variant, marking the state’s first human case of this influenza type. The individual was exposed to the D1.1 strain while working with infected dairy cattle in Churchill County, as confirmed by the Central Nevada Health District on Monday.
This new genotype was initially identified in dairy cattle on January 31 and differs from the strain responsible for causing a nationwide shortage of eggs and price increases in recent months. While there have been no other confirmed human cases in Nevada, health officials emphasize that there is no evidence of human-to-human transmission of the virus.
The infected worker and other farm staff are being closely monitored for symptoms and have been provided with testing, antiviral medication, and personal protective equipment. The U.S. Department of Agriculture has verified that this new variant has spread to dairy herds in the state, having previously been observed only in wild birds since late 2023 or early 2024. Until recently, the B3.13 strain accounted for all cases of bird flu in dairy herds.
What Is the D1.1 Bird Flu Variant?
The D1.1 variant of the H5N1 avian flu, previously seen only in wild birds, has now infected dairy cattle and humans, including the Nevada worker and a 13-year-old girl in Canada. While the D1.1 strain poses a low risk to the general population, individuals regularly exposed to birds, poultry, or cows are considered to be at higher risk, according to the U.S. Centers for Disease Control and Prevention.
It is believed that the strain may have been brought into the state by starlings migrating through Nevada in the winter. An adult in Louisiana, who was older and had chronic health conditions, succumbed to the D1.1 strain, marking the first reported human death from bird flu in the U.S. The virus also affected a 13-year-old girl with mild asthma.
Since 2003, there have been 950 reported human cases of bird flu outside the U.S., with 464 resulting in fatalities, according to the World Health Organization. Most cases involve mild symptoms, such as eye infections.
The Origins of Bird Flu and Prevention Measures
The H5N1 avian influenza has been documented globally since 1997, primarily in wild birds until recent years. Health experts recommend preventing exposure to the virus by avoiding direct contact with wild birds or animals suspected of carrying the infection.
While eggs, chicken meat, and beef are safe for consumption if properly cooked, the commercial milk supply is regularly tested to ensure its safety.
The SDA strongly advises against consuming raw milk due to instances where the virus has been detected in certain cases. There have not been any verified reports of individuals contracting the virus through the consumption of unpasteurized milk. This information was contributed by Karen Weintraub and was originally published on USA TODAY regarding the first human case of a new bird flu strain infecting a worker in Nevada.
