Increased surveillance and further testing for avian influenza have confirmed no signs of the disease following inconclusive screening results from a Wicomico County, Md., commercial poultry flock during the week of Dec. 10, according to the Maryland Department of Agriculture.

Out of an abundance of caution following the inconclusive result in early December, the decision was made to depopulate the suspect flock of 40,000 birds on Maryland's eastern shore. Avian influenza is not a food safety or human health concern, but it is a very serious issue for the poultry business because of its impact on bird health, the department said.

Additional testing from the U.S. Department of Agriculture's National Veterinary Services Laboratory confirmed negative test results for the suspect flock, and screenings of nearby farms were also all negative.

“We are all relieved by the negative test result, and I am proud of the rapid and collaborative response to this event,” Maryland Secretary of Agriculture Joe Bartenfelder said. “This has demonstrated that our department is prepared to work with federal, state and industry partners to protect the chicken industry, which is a vital part of Delmarva’s economy.”

Avian influenza is a viral disease that can affect bird species throughout the world. The disease can vary from mild to severe, depending on the virus strain involved. The most severe strain is called highly pathogenic avian influenza, which is characterized by high, fast-moving fatality rates (more than 75%) within infected flocks. Low-pathogenic avian influenza (LPAI) virus strains occur naturally in wild migratory waterfowl and shorebirds without causing illness. LPAI can infect domestic poultry, creating little or no signs of illness, but can reduce bird performance.