The Texas dairy farm worker infected with H5N1 bird flu was not wearing respiratory or eye protection and had been exposed to cattle that appeared to have the same symptoms as those in a nearby farm with a confirmed outbreak of the virus, according to new details on the case released on Friday.
The details, reported online in the New England Journal of Medicine, underscore the risk to farm workers in the ongoing outbreak among U.S. dairy cattle and the need to wear protective gear to avoid infection.
The outbreak - the first in cattle - is so far known to have infected 36 dairy herds in nine states.
Infection by the bird virus is rare in humans, and the dairy worker's case, first reported in March, represents only the second known human infection in the United States.
It follows a worrisome spread of the virus in a variety of mammal species, raising concerns that widespread exposure of people could cause the virus to spread more easily among the population and spark a global pandemic.
The U.S. Centers for Disease Control and Prevention (CDC) in the report said the farm worker developed a serious infection in his right eye known as conjunctivitis, or pink eye, but had no signs of respiratory infection or fever.
The worker had not reported any contact with sick or dead birds or other animals, but did have close exposure with sick dairy cows, with symptoms such as decreased milk production, reduced appetite and lethargy.
The worker had been wearing gloves but no respiratory or eye protection.
The CDC is urging farmers, workers, and emergency responders to wear appropriate protective gear when in direct or close physical contact with sick birds, livestock, feces, raw milk or contaminated surfaces.
An analysis of the outbreak released on Thursday by the U.S. Department of Agriculture suggests the virus has been circulating in U.S. dairy cows for about four months before being reported on March 25.
Preliminary tests of milk, baby formula and other dairy products suggests they are safe to consume, according to the FDA.
