American authorities have stepped up efforts to stop the spread of the H5N1, or bird flu, outbreak in dairy cows. As of right now, 33 herds across eight states have been affected, and the outbreak has contaminated the nation's milk supply.
Only one farm worker in Texas has tested positive for H5N1, and although scientists and health officials maintain that there is still little risk to the public, many doubts remain.
Why is avian flu or H5N1 a concern?
The extension of the range of mammals susceptible to infection by the virus that normally infects birds is reflected in the rise of bird flu among dairy cattle.
Researchers are watching for alterations in H5N1 that may indicate the virus is modifying to more easily transmit among people. People who have been into intimate touch with wild birds or poultry have contracted the virus, which can be lethal. It has been on the list of viruses that could cause a pandemic for a long time, so any spread to new mammal species is cause for alarm.
The bird flu variant that is infecting cattle is the same one that has been killing various animal species and infecting wild birds and poultry flocks worldwide for over two years. The virus was probably spread by eating sick or dead birds.
What is the extent of the livestock bird flu outbreak?
Although the exact extent is still unknown, a number of recent events imply that it might exist in more herds than are officially recorded.
The U.S. Food and Drug Administration announced on April 23 that it has found H5N1 particles in the milk supply. According to tests, the milk is safe and the remaining viruses were destroyed throughout the pasteurization process. U.S. health experts advise against consuming unpasteurized milk and believe that people cannot become ill from drinking pasteurized milk because early testing has not shown any live viruses in milk samples.
Authorities have discovered that the virus can exist in cows that do not exhibit symptoms of infection, and the milk from those cows does not exhibit symptoms of infection, such as thickening and becoming yellow.
The US government is mandating that dairy animals traveling between states undergo avian flu testing in an effort to control the outbreak.
When did the outbreak of bird flu begin?
Although fresh research indicates the outbreak may have started late last year, U.S. officials had assumed it was a recent outbreak.
Following the April 21 release of raw genetic data by the U.S. Department of Agriculture into a public database, a group of evolutionary biologists headed by Dr. Michael Worobey of the University of Arizona assembled the genetic codes of the virus.
By monitoring the virus's alterations as it traveled among herds, the team was able to map the outbreak. In an interview on April 24, Worobey stated that, according to their study, the dairy cattle outbreak was caused by a single instance of transmission from a bird to a cow in late 2023, most likely in December.
The spread of H5N1: How?
There is evidence of wild bird-to-cow, cow-to-cow, cow-to-poultry, and one incidence of cow-to-human transmission, though it is still unknown how the virus is spreading. No proof of human-to-human transmission is found.
Scientists believe the virus is being transmitted to animals during the milking process, either by touch with contaminated equipment or by virus that becomes aerosolized during cleaning processes, because to the high viral load in milk and mammary glands.
It is unknown if the virus can spread by respiratory droplets that contaminate the airway, as flu viruses usually do when they infect people.
Is there a human avian flu vaccine?
The United States is well-stocked with antivirals that may be used to treat human illnesses in addition to bird flu vaccines that are matched to the strain that is presently circulating. A significant pandemic or epidemic would require a significant increase in U.S. resources.
Sanofi, GlaxoSmithKline, and CSL Seqirus, the providers of flu vaccines, have stated that they are keeping an eye on avian flu and are prepared.
