The United States has notified the World Animal Health Organization (WOOH) the first H5N9 aviar flu outbreak in poultry in Corral, a new strain in the country and “highly pathogenic” whose presence was confirmed in mid -January in a Patos Farm in the Californian County of Merced, to a hundred miles southeast of the Bay of San Francisco
The inspection service of the Department of Agriculture (USDA), together with state officers of animal health and wildlife, “are carrying out exhaustive epidemiological investigations and reinforced surveillance,” the WOAH explained in a report of the event.
In that same farm, the most common aviar flu strain had also been detected, the H5N1, which is affecting hundreds of farms in the country in recent months, and that in that specific exploitation led to sacrifice almost 119,000 birds in December, As reported by the Reuters news agency.
The Agriculture Department describes avian flu as “a contagious viral disease of domestic and wild birds (…) and a great threat to the poultry industry, animal health, trade and economy worldwide.” Caused by the flu virus of type A, “it varies in gravity according to the strain and species.”
Highly pathogenic strains “are mortal for domestic poultry and can end entire damage in just a few days.”
These highly pathogenic strains have spread throughout the world in recent years, causing the sacrifice of hundreds of millions of birds, and also affecting dozens of mammal species, including cows in the United States, and people.
The H5N1 strain
The Centers for Disease Control and Prevention (CDC, in English) ensure that the H5N1 strain “is a specific group of avian flu virus that causes serious diseases with high mortality between infected corral birds.” Since 1997, he adds, “sporadic human infections have been notified (…) in 23 countries, with a proportion of lethality greater than 50%.”
However, since 2022 only a small number of human cases has been notified; Most human infections have occurred after unprotected exhibitions to infected birds.
Last year, sporadic human infections were notified in the United States for exposure to infected animals. “There is no sustained transmission tests from H5N1 from human to human in any country, and since 2007 a limited and not sustained transmission from human to human has not been notified worldwide,” he adds.
The H5N9 strain
The H5N9 strain is one of the nine subtypes of the aviar flu, and one of the most unusual. A study published in the National Library of Medicine ensures that it is “a highly pathogenic rearrange virus that originates from the H5N1, H7N9 and H9N2 subtypes.” He adds that “living bird markets represent a potential risk of public health and poultry industry.”
“It is not yet known if this H5N9 virus will cause human infections from its avian host,” he adds, “and will become a pandemic subtype.” “It is imperative to evaluate the risk of appearance of this virus,” he concludes, “with potential public health affectation.”
The first death in the United States
The United States notified at the beginning of the month the first death by Aviar flu in the country: a Louisiana person who had been hospitalized with serious respiratory symptoms, according to news agency.
The health authorities declared that the victim was over 65, suffered from other medical problems, and had been in contact with sick and dead birds in a flock of his backyard. A genetic analysis suggested that the virus had mutated inside the patient, which could have caused the most serious disease.
Since March, 66 confirmed cases of avian flu in humans have been notified in the United States. But the symptoms have been mild; Most have been detected in agricultural workers exposed to poultry or sick cows.
A avian flu death was not unexpected, according to virus experts. Since 2003, more than 950 cases of avian flu in humans have been confirmed worldwide, of which more than 460 have died, according to the World Health Organization.
“It is a serious threat and historically has been a deadly virus,” he told Jennifer Nuzzo, director of the Pandemics center at the Brown University School of Public Health. “This is nothing more than a tragic reminder of it,” he concluded.