New strains of bird flu wipe out the Mississippi poultry flock.

A new strain of highly pathogenic avian influenza known as H7N9 is being kept for breeding on poultry farms in Mississippi.

The discovery of new strains came when researchers reported potentially positive developments separately. Exposure to human seasonal influenza may provide some degree of immunity to H5N1 avian influenza.

The new strain found in Noxevy County, Michigan, was confirmed on March 12, with about 46,000 birds all either killed or euthanized after the infection spread. USDA's Animal and Plant Health Testing Services and Mississippi Animal Health Commission. None of the birds were in the food supply.

Authorities did not say how the birds were infected, but federal wildlife agents had been identifying a less pathogenic version of the H7N9 virus in wild birds for several years. The version seen in chickens may be circulating in wild birds, but most researchers believe it is probably a fatal attribute after being caught up in a Noksevi chicken surgery.

And if that's the case, “My money is probably in the local spread, my money is one thing,” said Richard Webby, an infectious disease expert at St. Jude Children's Research Hospital in Memphis, Tennessee.

Webby said most avian flu outbreaks follow that pattern. The low-pathogenic version is introduced into commercially available poultry and becomes highly pathogenic when inside.

Since March 2024, the introduction of H5N1, avian influenza virus that has infected dairy cows, commercial poultry, pet cats, wildlife and wild birds, has been a notable exception to this trend.

Veterinarian and former USDA researcher John Colsland agreed with Webby and noted that it houses breeder broiler: chickens grown and maintained for breeding purposes rather than for meat.

This is important because breeders live for months, if not years.

He said that when the hypopathogenic virus “occasionally enters a flock of broiler meat, the birds don't get sick, it becomes a massacre.” But when the breeder picks up the virus, “The virus can be recreated for weeks… this may have happened in Mississippi.”

However, according to USDA Rulesroutine and regular testing of breeding birds against hypopathogenic avian influenza is required. H7N9 outbreak in 2017 It occurred along the Mississippi Flyway probably from late February, but was reported only in March. An outbreak summary report suggests that the virus was introduced through wild birds.

In this case, as suspected, it was thought to have started as a “low road” and became a “high road” when it was commercially operated.

Nevertheless, experts said that if they are wrong and a highly pathogenic virus is circulating in wild birds, it will start to appear in other states and sites as well.

“Time will see how troublesome it can be this time,” Korsland said.

Experts say that the key to preventing these types of occurrence, or at least going beyond them, is wildlife monitoring.

Agency such as the USDA, the US Fish and Wildlife Service, the US Geological Survey Wildlife Health Center, and the National Marine and Atmospheric Administration have departments responsible for sampling wild birds and other animals for infectious diseases. The information they collect is used by agriculture and public health authorities to determine where and how to enhance biosecurity or keep an eye on it.

If I didn't have that information, I'd say it Angela Rasmussena virologist with vaccine and infectious disease tissue at the University of Saskatchewan, Canada. “We're flying blind.”

The positive news that came out this week: International Team Researchers found it Ferrets exposed to the common seasonal human influenza (H1N1) before exposure to H5N1 will acquire some degree of immunity from seasonal influenza.

Ferrets who were not exposed to seasonal influenza prior to infection with H5N1 had high levels of virus in respiratory tissue and had detectable viruses in the heart, spleen, liver and intestine.

In contrast, those who had previously exposed to seasonal influenza had the virus only in the respiratory system, but at fairly low levels.

“The biggest take home message for our data is that previous human seasonal virus infections can provide some degree of protection against the fatality of avian influenza,” says Sheema Rakdawala, a microbiologist at Emory University in Atlanta and one of the researchers.

Webby, a researcher at St. Jude, said the study supports other studies that examined the potential protection of prior exposure to influenza viruses.

“It certainly plays a role in regulating H5N1 disease in humans,” he said, but not the only factor. “After all, many people suffer from severe seasonal H1N1 infections every year despite being more immunized to the virus from previous H1N1 exposure.”

However, this finding may help explain why the virus is commonly associated with mild illnesses in infected people these days. 70 people in the US have been infected since March 2024. One person died. (Four people were hospitalized, including a deceased Louisiana patient).

Before last year, the virus was believed to have killed about 50% of infected people.

Rasmussen said the concern now is that if H5N1 mutates and becomes more susceptible to infection among people, it is young children, old and compromised people who are most likely to be affected. Children under the age of 5 are less likely to be exposed to seasonal human influenza viruses than school-age children and adults, and are more susceptible to harms from viruses such as H5N1.

She further stated, “As far as we know, we know what population level of immunity is from such viruses that circulate in birds and livestock.

It is not clear how seasonal influenza vaccines will affect this protection.

“Seasonal vaccines do not provide the same variety of immune responses as natural infections, and rarely provide the same level of protection,” says Cakdawala, who is testing the issue in the lab.