Dozens of Colorado dairy farm workers monitored for bird flu symptoms
The Colorado Department of Public Health and Environment confirmed Friday that approximately 70 dairy farm workers are currently being monitored for possible symptoms of avian flu.
The 70 workers were recently exposed to the virus while employed at two Colorado dairy farms. Neither the farms or the workers have not been identified.
None of the workers are reporting symptoms of infection at this time, a CDPHE spokesperson confirmed. The agency will coordinate testing for any of the workers who do report symptoms and ensure flu antiviral drugs are available to them.
The U.S. Department of Agriculture first detected bird flu in a Colorado dairy herd on April 25.
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The second Colorado herd tested positive Wednesday.
The virus was first discovered in a Texas dairy herd in late March. One person from that Texas farm became mildly symptomatic. That is, to this point, the only person to become ill due to the virus's transmission to dairy herds. That person is the first to contract this particular strain of the virus from another mammal, per the World Health Organization. The first person to contract it directly from birds was an inmate working at a commercial poultry facility near Montrose two years ago.
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Highly Pathogenic Avian Influenza (HPAI) H5N1 highly contagious and often deadly in birds, and can be easily transmitted between domestic poultry and wild birds.
"It is important to note that "highly pathogenic" refers to severe impact in birds, not necessarily in humans," according to the Federal Food and Drug Administration.
The potential is there, however, for pandemic levels of bird fly. According to the results a 2023 study, severe infections can cause human death at a high rate. In tests, a dozen laboratory monkeys inhaled an aerosol dose of the virus. Four of the six unvaccinated monkeys developed acute respiratory disease and died. The six vaccinated monkeys became ill but survived.
"Human infections with avian influenza viruses can happen when virus gets into a person's eyes, nose or mouth, or is inhaled," as stated by the Center for Disease Control and Prevention. "This can happen when virus is in the air (in droplets, small aerosol particles, or possibly dust) and deposits on the mucus membranes of the eyes or a person breathes it in, or possibly when a person touches something contaminated by viruses and then touches their mouth, eyes or nose."
In the latest count, 42 dairy herds in nine states have tested positive. The federal government's testing on the commercial milk supply has found "fragments" of the virus in milk after it was pasteurized. Thus, the USDA declared the nation's milk supply to be safe, and pointed out higher risks to consumers who drink or cook with untreated raw milk.
Still, the USDA is regularly conducting tests for the virus. It has also issued an order requiring the testing of any lactating dairy cattle that cross state lines.
The USDA is offering up to $28,000 in support to each of the 42 dairy farms and their workers. The funds can be used to provide personal protective equipment for the workers; enhanced biosecurity for other workers such as feed truck drivers, milk haulers and veterinarians; increased veterinary costs to dairy operators; and heat treatment systems (similar to pasteurization) used to deactivate the virus in milk that is disposed of by the dairy farms.
The USDA is also taking steps to make funding available to compensate dairy farmers for the loss of milk production attributable to the virus. The effect of bird flu on the health of the dairy cattle is moderate. The cows exhibits decreasing appetite and lower milk production, but rebound with treatment.
"I have seen many infected cows and they look dull and depressed, similar to how humans feel during a viral infection," wrote a veterinarian and epidemiologist at Colorado State University, Jason Lombard.
How the disease has been transmitted to dairy cattle has not been confirmed.
Bird flu has proven fatal to several cats on dairy farms in Texas, New Mexico and Ohio that tested positive for bird flu, according to the American Veterinary Medical Association.