Lancaster County has gone a month with no new confirmed cases of bird flu at any of its many poultry farms, giving experts reason to believe an ongoing outbreak has slowed.
To date, the highly contagious strain of bird flu has resulted in the deaths of more than 3.8 million domestic birds in the county, as well as disruptions to poultry operations in flu-related quarantine areas.
“Certainly things are moving in a very positive direction, both in Pennsylvania and nationally,” said Chris Herr, executive vice president of the PennAg Industries Association. “I’d like to think we’ve come out of the woods on this, but I’m not naïve enough to say that.”
State Department of Agriculture officials said they could not predict when the current outbreak would end or even say it was waning, but added that “the decline in new cases is encouraging.”
The last new case of bird flu in Lancaster County was discovered May 10 in a laying flock. It was the last of eight commercial flocks – a combination of ducks and chickens, both meat birds and layers – infected since mid-April.
The county’s 3.8 million birds are among nearly 40 million birds affected by the virus nationwide, according to the U.S. Department of Agriculture. As of Friday, the virus had infected birds in 369 commercial or backyard poultry flocks in 36 states since winter, according to the USDA.
These infections are due to a strain of bird flu which has been described as highly pathogenic, meaning it is highly contagious and usually fatal to poultry.
The disease is most often spread when healthy birds come into contact with body fluids secreted by infected birds, either through direct bird-to-bird contact or on contaminated surfaces, equipment, vehicles or clothing. used by humans.
Experts have said infected wild birds flying from farm to farm are largely responsible for the spread.
Spring migrations across the county are mostly over now, Herr said, which could significantly reduce, but not eliminate, the number of wild birds that could spread the disease.
“But they will come back in the fall,” Herr said, fearing further migration could trigger a second wave of the outbreak.
In addition to the decrease in the number of migratory birds prone to the virus, the increase in summer temperatures could have slowed the spread of the virus.
“It doesn’t do well in warmer temperatures,” Herr said.
He also thanked local poultry farmers for their efforts to slow the spread of influenza, particularly their continued and strengthened use of biosecurity practices – on-farm precautions intended to limit human-caused transmission.
“I think there’s never been a higher level of biosecurity,” Herr said.
Those precautions developed, at least in part, from lessons learned from previous avian flu outbreaks, state Department of Agriculture officials said.
When birds sick with influenza are discovered on a farm, poultry and egg farmers usually have to euthanize their entire flocks as part of a government-mandated attempt to curb the spread to neighboring farms.
In Lancaster County, this resulted in the depopulation of millions of birds at the eight infected properties, four of which have since been cleared of their infection status.
The virus has continued to spread in places outside the county with cases confirmed as recently as Thursday in Colorado, Indiana and Washington.
Pennsylvania had a confirmed case as recently as June 2 in neighboring Berks County. During this outbreak, Berks and Lancaster counties are the only ones in the state to see confirmed cases of the flu in domestic poultry, according to the USDA.