A dairy employee in Nevada has contracted a novel strain of bird flu that is distinct from the variant that has been prevalent in U.S. livestock since the previous year, according to federal health authorities.
This case was classified as mild, with the primary symptom being redness and irritation of the eyes, which is a common reaction linked to bird flu associated with cattle. Fortunately, the individual did not require hospitalization and has since made a full recovery, as reported by the Centers for Disease Control and Prevention (CDC).
This recently identified strain has been detected in over a dozen individuals who had exposure to poultry; however, this marks the first documented case linked to infected cows. The exposure for the Nevada worker occurred at a farm located in Churchill County.
CDC representatives have stated that there are no indications that this virus has transmitted from this individual to others, reaffirming that the overall risk to the public remains low.
The bird flu that is currently affecting animals and some humans is identified by scientists as Type A H5N1 influenza, which has multiple strains. In March, a variant referred to as B3.13 was confirmed after it was transmitted to cattle late in 2023. This strain has impacted 962 cattle herds across 16 states, with California bearing the brunt of the infections.
The new strain, designated D1.1, was detected in Nevada dairy cows on January 31, having shown up in milk samples as part of a monitoring initiative that started in December.
This finding indicates that the virus has made multiple transitions from wild birds to cattle, raising concerns about the potential for widespread infection and the challenges in managing these illnesses among animals and the people who work with them.
In the past year, there have been at least 68 reported cases of bird flu infections in the United States, according to CDC records, with most cases occurring among individuals who had close interactions with cows or poultry.
The majority of these infections were caused by the B3.13 variant. Initially, the CDC indicated that the D1.1 strain had been observed only in Louisiana and Washington state, but recent evidence suggests that last year, D1.1 may have infected 15 individuals across five states—namely Iowa, Louisiana, Oregon, Washington, and Wisconsin—all connected to poultry.
The D1.1 strain has been associated with the first reported death in the U.S. linked to bird flu, as well as a severe case in Canada. A Louisiana resident died in January after experiencing severe respiratory issues connected to interactions with wild and backyard birds. Meanwhile, a teenage girl in British Columbia was hospitalized for an extended period due to an infection traced back to poultry.
Even though the risk to the general population remains low, the CDC cautions that bird flu presents a heightened risk for individuals who have close or prolonged contact with infected animals, including cows and various birds. Such individuals are urged to utilize protective gear and adhere to safety measures to mitigate risks.
