By Jessica Domel
Multimedia Reporter

The U.S. Department of Agriculture (USDA) is urging backyard and commercial poultry raisers to ensure they’re following proper biosecurity measures to reduce the spread of the deadly highly pathogenic avian influenza (HPAI).

HPAI has been confirmed in 309 commercial flocks and 427 backyard flocks in 47 states, including Texas.

More than 57.8 million birds have been affected.

“HPAI is a type A influenza virus that’s specific to birds,” Michael Bodenchuk, Texas state director of USDA’s Animal and Plant Health Inspection Service (APHIS) Wildlife Services, said.

HPAI can be deadly, especially to domestic poultry like chickens and turkeys.

It can be spread through bird-to-bird contact or indirectly through contaminated materials.

“This particular strain of the virus that’s circulating now in wild birds is very pathogenic to chickens. It causes mortality often within 48 hours,” Bodenchuk told the Texas Farm Bureau Radio Network. “On the other hand, many wild birds don’t exhibit any symptoms of that. Waterfowl, ducks in particular, may be carrying the virus but not be affected by it.”

According to the Texas Animal Health Commission (TAHC), the movement of humans, birds and equipment, along with exposure to migratory waterfowl, increases the risk for the introduction of HPAI into a backyard or commercial flock.

That’s one of the reasons why APHIS has been working with hunters and other agencies to track the spread of HPAI through wild birds.

In 2022, APHIS confirmed HPAI in 190 wild birds in Texas. That’s not the total number of wild birds that were infected with HPAI. It’s the number of positives APHIS detected through its surveillance program, which is ongoing.

Three positives have been detected so far in calendar year 2023.

“Our surveillance strategies are based on wild bird, wild waterfowl surveillance, but there are also a number of mortality events or morbidity events where birds are sick that are also investigated,” Bodenchuk said. “One-hundred-ninety-three cases in this surveillance year, which runs from June through May, is just part of what’s actually out in the environment.”

Of the 193 total positive detections from 2022 through Jan. 20, 2023, four cases were in captive, wild birds.

The rest of the positive detections were found in hunter-harvested wild birds—the majority of which, at 140, were teal.

The majority of the positive cases were confirmed in October, November and December.

“That’s when the hunting season occurs, and those are the best birds to use as sentinels for it. So, that’s when the positives are going to show up,” Bodenchuk said. “Outside of the hunting season, the cases that you see are really those mortality or morbidity events.”

The strain of HPAI that is circulating now is a Eurasian strain.

Bodenchuk said he does not expect the virus to impact waterfowl or wild bird hunting because most waterfowl appear not to be affected by it.

“In fact, that’s why they serve as good sentinels because they don’t get sick. They continue to fly around,” Bodenchuk said. “Sick birds don’t tend to migrate, so if these birds were impacted, they wouldn’t be migrating. We do not expect that it’s going to impact huntable numbers, but we have a concern about it impacting the poultry industry. That’s why we’re doing the surveillance in wild birds—to get a handle on how much is out there in the environment.”

If a wild bird carrying HPAI comes into contact with equipment that is used in backyard or commercial poultry operations, it may spread the deadly disease to that flock.

A wild bird landing in a backyard that comes into contact with a backyard poultry flock may also directly infect those birds.

That’s why APHIS is encouraging all poultry raisers to increase their biosecurity.

“There’s always a concern for the poultry industry and wildlife vectored diseases, and biosecurity is the number one way of maintaining poultry health,” Bodenchuk said. “APHIS has a webpage, Defend the Flock, that talks about biosecurity issues that backyard poultry producers, organic poultry producers and those raising poultry outdoors can reference to gain biosecurity suggestions for their farms.”

Suggestions include: keeping visitors to a minimum, washing your hands before and after coming into contact with live poultry, using disposable shoe covers, cleaning and disinfecting tools, looking for signs of illness and reporting sick birds right away.

TAHC recommends creating barriers between poultry and wild birds, as well.

Texans can report dead poultry at 1-800-550-8242.

HPAI symptoms include: sudden death without clinical signs; lack of energy and appetite; decreased egg production or soft-shelled or misshapen eggs; swelling of head, comb, eyelid, wattles and hocks; purple discoloration of wattles, comb and legs; nasal discharge, coughing and sneezing; incoordination; and diarrhea.

Many wild birds will not show symptoms of HPAI. For some species, like eagles and hawks, often the only sign of HPAI infection is death.

“The reason we’re using ducks, and in particular, puddle ducks like teal, mallards and pintails as a surveillance tool is because they don’t get sick, and they don’t show the symptoms, yet they carry the virus,” Bodenchuk said. “Other wild birds may be susceptible to HPAI, raptors in particular. Hawks and falcons are very susceptible to this. So, if you see one of those, they’re either healthy and don’t have it, or if they get the virus they die.”

The wild ducks that do have HPAI most likely won’t have any symptoms.

The U.S. Fish and Wildlife Service recommends hunters take a few precautions to ensure they don’t infect a poultry flock after handling waterfowl.

“Clearly, don’t clean your ducks in the chicken coop. Don’t leave the remains around for birds to get access to. Use gloves when you’re cleaning the birds, and wash your clothes before you go to feed the chickens,” Bodenchuk said. “Those kind of common sense rules for duck hunters who may have backyard birds are pretty important.”

One of the concerns is the virus will mutate.

“While we may be able to tackle or at least outlast this particular virus, there’s a very real possibility that other viruses will come up in the future. So, there’s a need for continual monitoring in the wild bird population so that we have an idea of what’s out there, how pathogenic it might be to poultry, how pathogenic it might be to wild birds and how to respond,” Bodenchuk said. “It’s easier to develop biosecurity measures for poultry producers than it is to address a disease in a wild population.”

Bodenchuk said they believe the virus will be circulating for another year or two.

“Whether it’s at this high level that mandates this widespread surveillance or not, I don’t know,” Bodenchuk said.

Although it is rare, avian influenzas have jumped to humans in the past. According to the Centers for Disease Control and Prevention, there may be no symptoms, mild illness or severe illness.

Symptoms may include: eye redness, upper respiratory issues, pneumonia, cough, sore throat, runny or stuffy nose, head and body aches, fatigue, shortness of breath and difficulty breathing.

As a general precaution, CDC recommends avoiding direct contact with wild birds whenever possible, avoiding unprotected contact with poultry that look sick or have died and refraining from touching surfaces that may have been contaminated with saliva, mucous or feces from wild or domestic birds.

If contact cannot be avoided, the CDC recommends wearing protective equipment like gloves, an N95 respirator or well-fitted face mask and eye protection.

Avoiding touching your mouth, nose and eyes after contact with birds or surfaces that may be contaminated. Wash your hands thoroughly after contact and change your clothes before contact with healthy domestic poultry and after handling wild birds.

Additional details on HPAI and biosecurity is available at aphis.usda.govdefendtheflock.