Bird Flu, Cows, and Disease Threats
Terry H. Schwadron
April 29, 2024
Bird flu, which is blamed for prompting rising chicken prices at the supermarket over shortages, now has begun to spread among cows.
If Covid left you at all suspicious about whether governments are watching for transplantation of communicable disease among species, the cow reports apparently reflect danger ahead for others, including possibly for humans. Indeed, a dairy worker in Texas has reportedly caught it.
While I don’t see cows up close these days, the non-ending debates about lab leaks, natural trans-species contact from the wild, and the resistance in those early days of Covid to want to reckon with communicable disease that had leapt to human air travelers started ringing in my head.
The Washington Post reported last week that the federal agencies responsible for tracking and controlling a highly virulent bird flu are lagging in testing and sharing of results, creating delays that could allow the disease to spread. As it does, the issue is that the flu bug could develop the machinery needed to affect others, including humans.
Already, the experts who talked to The Post said not enough livestock herds are being tested and results are not being shared among agencies with competing missions to know how the H5N1 virus moves and the safety of milk.
Warning signs come from Katelyn Jetelina, who writes an infectious-disease newsletter, who basically said that scientific uncertainty is running into bureaucratic delay. A White House spokesman said its Office of Pandemic Preparedness and Response Policy — an office resurrected by the Biden administration after its elimination in the Donald Trump years — is busy coordinating developments among various agencies, adding that so far, commercial milk is considered safe.
Prepping for Trouble
Just last week, though, the Agriculture Department announced that lactating dairy cows must be tested for bird flu before moving across state lines, rather than leaving testing voluntary and limited to animals with designated symptoms.
Three agencies split responsibility for monitoring and containing the outbreak. Agriculture is looking at the virus in cows, the FDA oversees food safety, and the Centers for Disease Control and Prevention is monitoring risks to people.
The Post reported that it took the FDA two weeks to acknowledge that the agency was
testing milk on grocery store shelves, and only last week confirmed that viral particles had been found “in some of the samples” without providing details — like whether those fragments were dead or alive.
Investigators are trying to determine if the virus is being spread through milking equipment or through the air and contact. They also are studying how long livestock will shed virus in their milk once they have recovered from an infection, as well as risks and protocols for human exposure.
Clearly, the scientists involved say, more routine testing on herds and even other animals would reduce the risk of spreading the virus to other cattle and poultry farms — and the possibility of dairy workers contracting the illness.
In the last month, nearly three dozen livestock herds in eight states have been infected and the virus was tracked as it spread from dairy farms to poultry farms, affecting barn cats. Most cases were temporary. Epidemiologists fear that indicates cows can pass the virus to birds, and possibly other animals, broadening the potential for spread. It is unclear how long the virus has been around and whether it is found outside those states.
One virologist who studied 239 genetic sequences of the virus said they had come from a single source. Others said there was not enough information available to know about the movement of cows, feed sources or human contact.
Health and Business
Naturally, the Agriculture Department also is working with farmers about new dairy markets at the same time as worrying about illness spread. Identifying farms willing to share samples has been a problem, and the government now is testing unaffected herds as a precaution. It seems to be concentrated among lactating cows, which is prompting a look at milking equipment.
This strain of avian flu has been circulating for more than 20 years and the spread to cows is seen as significant, Avian flu has infected humans in Asia, but so far has not spread efficiently in people. As with other communicable disease, that changes with various mutations.
State health official tested 23 people so far. The single positive dairy worker in Texas recovered. Officially, the CDC says the risk to humans is low.
The risk to dairy farm business, however, is not so low, which could be one reason farmers are not eager to volunteer their herds for testing. Milk producers are waiting for detailed guidance to know how many tests may need to be performed on the nation’s eight million milk cows.
Of course, there are preparations for human testing should more tests prove positive. One wrinkle for human testing includes the big number undocumented farm workers who may not choose to have contact with a government increasingly eager to deport them.
Given the range of sensitivities still in place from Covid, it is only surprising that the potential dangers of bird flu hitting dairy farms and beyond is not a part of the daily barrage of political messaging we already are suffering.
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