Days after discovering a deadly and contagious strain of bird flu in a Lancaster County avian operation, Don Rank spoke with a farmer who was candid about the anxiety he feels every time a wild bird flies over his chicken houses.
Any wild bird that passes over its head can become infected, and contaminated droppings can transmit the disease to their flock, said Rank, deputy chief of the Lancaster County Farmer’s Office.
“There are a lot of unknowns. There are a lot of ducks flying overhead, and any of them can carry them,” Rank said.
In fact, scientists say they believe the virus — a strain of highly dangerous bird flu contagious in poultry — made its way to the United States via migratory wild waterfowl from Europe.
Now, although most of the spring waterfowl migratory season is coming to a close in Pennsylvania, local experts believe the virus has likely spread and spreads within a number of the state’s native bird species throughout the year.
This means that local poultry farmers must continue to be vigilant to limit exposure of their flocks to wild birds.
“We don’t know when that will come before this particular outbreak is resolved,” said Andrew de Salvo, a wildlife veterinarian with the State Game Commission.
It is not closely monitored
As of Tuesday, the virus has been detected in only eight wild birds in Pennsylvania — two bald eagles, five hooded Merganser ducks and a red duck, according to Game Commission officials.
None of the birds have been discovered in Lancaster County.
The closest bird was a dead bald eagle discovered in neighboring Chester County, the state’s first bird to contract the virus, which was confirmed in mid-March. Others are found in northwestern Pennsylvania, specifically Clarion, Crawford and Finango counties.
Just eight wild birds might seem a few, de Salvo said, but the confirmed numbers are likely deceptive.
“Monitoring the health of our wildlife is not uniform across the Commonwealth,” he said in an email, explaining that it is very difficult to spot sick birds in remote areas. “It’s very biased as to where people live because they often call us to report sick/dead wildlife.”
For a more accurate assessment of cases of wild bird flu, de Salvo pointed to the numbers recorded nationwide, including hundreds of infections along the east coast.
As of Wednesday, highly pathogenic avian influenza has been detected in at least 899 wild birds in 34 states, according to figures from the US Centers for Disease Control and Prevention.
Once again, de Salvo provided a point of view when it came to issues in Pennsylvania.
If we do not test birds in an area, this does not mean that the disease is not present. “It is much more accurate to assume that the disease is present in wild birds throughout the Commonwealth,” he said.
Waterfowl are among the species considered highly vulnerable to the current outbreak of bird flu, and recent migrations through the region have put agriculture officials on high alert.
Experts said bird flu is most commonly spread when healthy birds come into contact with bodily fluids from other infected birds, both wild and domestic.
This type of contact has likely occurred between domestic wild birds since the current strain of bird flu was first confirmed in the United States in December, according to a pair of Millersville University biologists.
For example, a duck infected with the virus could have defecated in a water source used by other birds, spreading the infection, according to Eric Rendok, an assistant professor of biology at the university who specializes in virology.
Or that a predator such as a bald eagle could hunt and consume an infected bird that migrates through the area, becoming ill in the process, said Aaron Haines, associate professor of conservation biology who specializes in wildlife management.
“The eagles are here all year round, feeding on the waterfowl,” he said. “I think there is potential for it to continue spreading within our native birds here.”
Agriculture officials said this is a problem for poultry and egg farmers, because infected wild birds can fly over and land on chicken houses and other facilities. There it can infect poultry directly – including chickens, ducks, geese, quail, pheasants, guinea fowl and turkey. Or wild birds can secrete bodily fluids that contaminate farmers’ clothing and equipment, and the virus is later transmitted to poultry animals.
Wild birds are more powerful
Because of these threats, experts have encouraged farmers and backyard poultry farmers to increase biosecurity measures to protect their flocks. They include restricting unnecessary access to farms; Clean farm-related clothing and equipment regularly; not to share equipment with other farms; Intensification of disinfection of personnel and vehicles on farms.
However, as of Thursday afternoon, the virus had been found in flocks at six poultry operations in Lancaster County, requiring the destruction of 3,825,800 birds – a mixture of egg, meat and fowl layers. Nationwide, the disease has infected 247 flocks in 29 states, affecting 35.52 million commercial or backyard poultry birds, according to the USDA.
Most of these birds have been killed primarily in an effort to limit the spread of the virus. It is also believed that killing birds is more humane than letting poultry suffer from influenza.
“You’re going to have severe respiratory conditions,” Rendock said, referring to the poultry disease.
In birds, symptoms include poor coordination, diarrhea, nasal secretions, lack or abnormal egg-laying, lack of energy, lack of appetite, and even sudden death.
However, Haines said wild birds appear to be more “strong” or better able to handle the disease, which means symptoms may be less severe, allowing them to move around more easily during infection.
That’s likely already the case, according to Shaun Murphy, an ornithologist on the Game Commission.
It’s right there on our landscapes,” Murphy said.
Emphasizing this point, Murphy has named a few species of native wild birds known to be susceptible to disease, including predators such as red-tailed hawks, great-horned owls, bald eagles, and Cooper’s hawks.
“There are a lot of these who are here throughout the year,” he said.
If there is any good news, many experts said, it is that many migratory waterfowl have already disappeared from the area, and temperatures are beginning to rise.
“The transmission of the disease should decrease as the density of the birds decreases, plus this virus cannot survive for long at room temperature or higher,” said veterinarian de Salvo.
Rednock added that the humid summer air will make it difficult for airborne virus droplets to travel
He said that humidity and changing temperatures will have little effect on transmission through direct contact with body fluids such as the feces of infected birds.
“I think that could be a factor that could keep it going through the summer,” Rednock said.
Dan Ardia, professor of biology at Franklin and Marshall Colleges, agrees, especially when it comes to infections in poultry houses, where the climate is at least somewhat controlled and birds are often crammed and crowded, causing stress that can lower the immune system.
“Housing conditions, they don’t change from year to year, from month to month,” Ardea said.
In rare cases, humans have contracted bird flu, but experts, including those at the CDC, have said this outbreak poses a low risk to people.
Earlier this spring, UNHCR officials said people should use caution while handling wild birds.
“Always observe wildlife from a safe distance. Avoid contact with surfaces that may be contaminated with feces from wild or domestic birds. Do not handle wildlife unless you are hunting, hunting, or otherwise authorized,” officials said, adding that Even those licensed to handle wildlife should wear personal protective equipment.
Previously, commission officials asked people who encounter sick or dead wild birds to report them at 610-926-3136.
“Hopefully, we’ll be in a better place in late summer,” Di Salvo said. “But it’s too early to say.”