Highly Pathogenic Bird Flu Now in Almost a Quarter of U.S. States

Bird flu has been found in backyard flocks in Kansas and Illinois, the United States Department of Agriculture's (USDA) Animal and Plant Health Inspection Service (APHIS) has confirmed.

The highly infectious and lethal strain of avian flu has now been discovered in both commercial poultry flocks and backyard flocks in 12 states in the U.S.

The USDA said on Saturday that samples from the backyard mixed-poultry flock from Franklin County, Kansas, had been tested at the Kansas State Veterinary Diagnostic Laboratory, while samples from the Illinois flock were tested at the University of Illinois Veterinary Diagnostic Laboratory.

The agency added that APHIS is working closely with state animal health officials in both states to respond to the infections. The USDA added that state officials had quarantined the affected premises, and birds from the properties will be depopulated to prevent the spread of the disease and to ensure they will not enter the food system.

The virus has also been detected in wild birds in a number of states, with detections causing the closure of bird exhibits and aviaries in Florida.

Despite the fact that bird flu has now been detected in the backyard and commercial flocks in almost a quarter of U.S. states, including New York, Connecticut, Iowa, Indiana, Maine, Michigan, and Kentucky, the Centers for Disease Control and Prevention (CDC) maintained that the virus does not present a threat to public health.

The CDC said that since 2002 there have been just four detections of bird flu making the rare leap to humans in the United States. Avian flu in humans can potentially cause severe respiratory disease with a high mortality rate.

Professor Peter Barlow, chair of immunology and infection at the School of Applied Sciences at Edinburgh Napier University, previously tod Newsweek: "Transmission [to humans] can occur where individuals who have prolonged close contact with infected birds can become infected themselves."

The CDC added that this normally happens when infected birds shed the virus in bodily fluids such as saliva, mucus, and feces. Human infection happens when these fluids get into a person's eyes, nose or mouth as droplets, or become mixed with dust and are inhaled.

Even though human infection most often occurs when a person has unprotected contact with infected birds or surfaces contaminated with the virus, the CDC said that rare infections have been identified where direct contact is not known to have occurred.

Barlow said: "The advice from the CDC is that the most effective way of preventing avian influenza in humans is to avoid sources of exposure. Animal workers should also follow the guidance provided by CDC on the use of personal protective equipment."

Mark Jit, professor of vaccine epidemiology at the London School of Hygiene & Tropical Medicine, told Newsweek: "This is a big worry for poultry farmers in the affected states because it could lead to many birds dying of flu, and others needing to be culled to stop the spread.

"If anyone does get infected with highly pathogenic avian flu it is unfortunately bad news for that person because it tends to cause very severe illness in humans too."

Jit added that as the virus doesn't transmit easily between humans it is unlikely to lead to a large outbreak, although there have been a few documented cases of transmission between close contacts like household members.

A stock image of chickens in a commercial flock. Bird flu has been detected in commercial and backyard flocks in 12 states. tawatchaiprakobkit/GETTY