Human risk of contracting bird flu is very low, says the CDC
Those most at risk of contracting bird flu are people in close contact with infected animals, such as dairy or poultry workers.
A new variant of the bird flu has infected a dairy worker in Nevada, marking the state’s first human case of the H5N1 avian influenza.
The worker was exposed to the D1.1 strain after working with infected dairy cattle in Churchill County, the Central Nevada Health District confirmed Monday.
The new genotype was first confirmed on Jan. 31 in dairy cattle and is not the same strain that has been triggered a nationwide egg shortage and price hikes in recent months.
There are no additional confirmed human cases in Nevada and no evidence that humans can transmit the virus to other humans, the state’s health district said. Officials are monitoring the symptoms of the infected worker and the other farm staff who have been offered testing, antiviral medication and personal protective equipment.
The U.S. Department of Agriculture confirmed last week that the new variant had infected dairy herds in the state after previously only appearing in wild birds since late 2023 or early 2024. Up until last month, the B3.13 strain made up all bird flu cases in dairy herds.
What is the D1.1 bird flu variant?
The D1.1 variant is a strain of the H5N1 avian influenza that has previously only been reported in wild birds. The variant has recently infected dairy cattle and humans, including the Nevada adult and a 13-year-old girl in Canada.
The D1.1 strain poses a low health risk to the general public though people regularly exposed to birds, poultry or cows are at a higher risk, according to the U.S. Centers for Disease Control and Prevention.
The strain is common among the starlings that migrate through Nevada in the winter and might have carried the virus into the state, the Nevada Department of Agriculture shared on Facebook last March.
Has anyone died from the D1.1 bird flu strain?
A Louisiana patient who was older and chronically ill died after contracting the D1.1 strain, marking the only reported U.S. human death from the bird flu, the Louisiana Department of Public Health confirmed on Jan. 6.
The adult, who health officials did not identify, was exposed to the virus from a backyard flock, according to the department. They were over 65 and had underlying health issues, officials said.
The version of the virus also hospitalized a 13-year-old girl with a history of mild asthma, according to the New England Journal of Medicine.
Since 2003, there have been 950 human cases of bird flu outside the U.S. with 464 of them resulting in death, according to data from the World Health Organization.
Most human cases of bird flu involve mild symptoms like eye infections.
When did bird flu start?
The H5N1 avian influenza has been reported globally since 1997 though it previously solely presented in wild birds until recent years.
How to avoid bird flu?
The most effective way to avoid contracting bird flu is to prevent sources of exposure, health experts say.
This includes avoiding direct contact with wild birds and all animals that are either infected or presumably infected with the virus.
Is it safe to eat eggs or drink milk?
Eggs and chicken meat are considered safe to eat, according to the U.S. Department of Agriculture, which routinely monitors farms for bird flu and euthanizes chickens if the virus is detected on a farm. Beef is also safe to consume as long as it’s cooked to proper temperatures.
Though the commercial milk supply is tested regularly to confirm it is safe, the USDA recommends avoiding raw milk, which has been shown in some cases to contain the virus. There have been no confirmed cases contracted by drinking unpasteurized milk.
Contributing: Karen Weintraub,
