in addition to marine mammals and domestic cats have also died from the virus.
What are Michigan researchers learning in regards to the outbreak?
In the case of H5N1 in cows, scientists and animal health experts here in Michigan And across the country are working to know a known disease in a brand new species.
Transmission of the H5N1 avian influenza virus to dairy cows was first confirmed in Texas in March 2024 and has not occurred since Spread to fifteen additional US states, most recently California.
The virus affects milk production and poses significant risks to other bird species, particularly domestic poultry and a few mammals. The CDC has also confirmed this mild cases in humans and a deadly in Louisiana in January 2025.
Diagnostician at Michigan State University and people of the USDA National Network of Animal Health Laboratories provide rapid diagnostics to discover infected flocks and monitor the virus in wild birds and mammals to manage the spread.
Based on sequencing of circulating viruses, we found that a particular virus strain or H5N1 genotype, B3.13, is circulating in cows and poultry. Subtle changes within the virus's genetic makeup over time point to a single one Spillover event. This means the virus was likely transmitted from wild birds to a cow in Texas after which spread from cow to cow. We also know that there’s a separate H5N1 genotype, D1.1, that’s currently circulating in wild birds and domestic poultry.
Researchers at our College of Veterinary Medicine are working with federal and state officials and farmers to seek out out How long do cows produce infectious milk?. The goal is to know how cows turn into infected inside and between herds so we are able to higher contain the spread.
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Why is it called bird flu when other animals also get it?
Influenza viruses affect many animals including people, Pigs, dogs And Horses.
There are 4 forms of influenza viruses: A, B, C, and D, broadly defined by the species they’ll infect. Avian influenza viruses are considered influenza A viruses. Interestingly, it’s influenza D viruses that primarily infect cattle. But the H5N1 virus currently circulating in dairy cows is similar influenza A virus seen in the continuing outbreak in birds.
This is especially concerning because this has only happened with influenza A viruses associated with human pandemics.
However, avian influenza viruses flow into in wild birds normally don’t cause significant illness. While many avian influenza viruses can infect poultry, the virus is classed as either highly pathogenic or low pathogenic based on its behavior in these hosts. It is significant to notice that this classification doesn’t necessarily indicate how easily it spreads or how likely the virus is to leap to other species.
The strain currently in circulation is classified as highly pathogenic bird fluor HPAI, based on the high mortality it causes in domestic poultry. One of the various unusual features of the present outbreak is the high mortality amongst wild birds; As a result, we now have seen many species of young carnivores and scavengers infected with the virus.
Infection in other species often requires contact with a considerable amount of virus or a weakened or underdeveloped immune system. These are typically “Dead-end innkeepers.” They turn into infected, but play no role within the spread of the virus because either the animal dies or it’s infected but not infectious.
The current outbreak was HPAI H5N1 running since 2021. The outbreak is notable for its duration, wide geographical spread and weird impacts even on non-poultry species. It has caused significant illness and death in wild birds like geese and geese, as well Mammals exposed to infected bird carcasses like cats and skunks.
However, if the USDA unexpectedly confirmed that H5N1 was the explanation for significant disease in dairy cows The virus was first detected in US dairy cattle in early 2024.
What does the virus do to cattle?
Most cows infected with H5N1 recuperate on their very own without treatment. Symptoms include fever and lethargy. In addition, lactating cows experience reduced appetite and a big decrease in milk production, as is the case with the virus concentrates within the mammary glands and milk.
There are three reasons to be concerned in regards to the ongoing H5N1 outbreak in dairy cows:
First, the decline in milk production and the contagiousness of the virus pose challenges for farmers in controlling the infection and lead to economic losses. In addition to production losses, there are additional labor and provide costs to administer the outbreak within the herd, including separation and supportive care of sick cows. Workers must also wear personal protective equipment to forestall the virus from spreading to healthy animals and protect themselves from possible infection.
Second, dairy cows produce large amounts of the virus of their milk, which is very contagious. While pasteurization kills the virus, raw milk stays a serious infection risk. Significant variety of wild mammals and domestic cats on dairy farms died from the virus after consuming raw milk. It also poses a risk to dairy employees.
The virus has also spread from dairy farms to poultry farms. leading to high bird mortality. are experts explore the likelihood that clothing, shoes, trucks, equipment and other items which have been contaminated with raw milk containing the virus can result in accidental and fatal exposure of poultry.
Third, prolonged circulation in cattle increases the danger of the virus adapting to mammals. including people.
To monitor this risk, all H5N1-positive samples are sent to the USDA for genetic sequencing to discover mutations that would increase the virus's ability to contaminate mammals and to offer necessary details about how the virus spreads inside and spread between populations.
How can we manage H5N1 in the longer term?
Biosecurity for poultry and dairy farms is more necessary than ever. Biosecurity measures include limiting the number of tourists to farms and facilities; disinfection tools, shoes and equipment; avoiding contact between infected and uninfected species; and isolating sick animals.
These measures play a very important role in each containing the virus and keeping it away from other animals, properties and folks.
image credit : theconversation.com