Avian Influenza

Lancaster County Emergency Management Division

 Lancaster County Health Advisory Council 

Important Information: Avian Influenza (Bird Flu) 1/29/2025

What it is:

Avian Influenza (Bird flu) is an influenza type A virus that infects wild birds (i.e. ducks, gulls, and shorebirds) and domestic poultry (chickens, turkeys, ducks, and geese). Avian Influenza subtypes may also be divided into two other groups based upon their ability to cause severe disease in poultry: 

a. Low Pathogenic Avian Influenza (LPAI) infection naturally occurs in wild birds and can be spread to domestic birds, but it normally causes no signs of infection or only minor symptoms in infected birds. 

b. High Pathogenic Avian Influenza (HPAI) infection generally spreads more rapidly than LPAI and causes a higher avian death rate.

What it does:

Bird flu spreads in several ways:

  • Direct Contact: Birds can pass the virus to each other through close contact. 
  • Contaminated Surfaces: Equipment, materials, and even people can carry the virus from place to place. 
  • Feces and Secretions: The virus is found in bird droppings and fluids from the nose, mouth, and eyes. Contact with infected feces is the most common way birds get sick. 
  • Wild Birds: Ducks and other wild birds can bring the virus to domestic flocks by contaminating the environment with their droppings. 
  • Airborne Dust: In poultry houses, the virus can spread through dust and bird secretions. (Can travel from barn to barn or from flocks in field to poultry housing.) 
  • Egg Shells: The virus can be on the outer surface of fresh eggs, making egg transfer a possible risk. 
  • Farm-to-Farm Spread: The virus usually spreads between farms through contaminated equipment, clothing, or vehicles—not through the air. 
  • Farmers and workers who work with infected animals (cattle/ poultry) or their byproducts including raw milk. 
  • Drinking or accidentally inhaling raw milk containing bird flu virus may lead to illness. In addition, touching your eyes, nose, or mouth with unwashed hands after touching raw milk with bird flu virus may also lead to infection

What are the signs to be aware of in birds?

Bird flu symptoms vary depending on the type of infection.

Mild Cases (LPAI - Low Pathogenic Avian Influenza)Birds may eat less, sneeze or cough, and lay fewer eggs.
Severe Cases (HPAI - Highly Pathogenic Avian Influenza)Birds can become seriously ill and may show signs like:
  • Sudden death
  • Weakness and loss of appetite
  • Drop in egg production or misshapen eggs
  • Swelling or purple discoloration
  • Nasal discharge, coughing, and sneezing
  • Lack of coordination
  • Diarrhea


Are pet birds, family flocks and backyard chickens at risk for contracting Avian Influenza?

Bird owners should be aware of avian influenza (bird flu), but the risk to indoor pet birds is generally low. Here’s what you need to know:

  • Risk factors: Pet birds, backyard chickens/family flocks are at higher risk if they have outdoor exposure, contact with wild birds, or are housed with birds from unknown sources (such as live bird markets). 
  • Prevention: Keep pet birds indoors or in a secure, covered aviary to prevent contact with wild birds. Keep chickens in a secure coop or enclosed run to prevent contact with wild birds. Change shoes and wash hands before and after handling birds. Do not share equipment with other bird owners unless disinfected. Do not feed or touch wild birds. Drinking pasteurized milk which has been shown not to carry live Avian Flu virus. 
  • Symptoms to watch for: If your bird seems sick—showing signs like lethargy, loss of appetite, sneezing, decreased egg production or diarrhea—contact a veterinarian immediately. 
  • If an outbreak occurs: Follow guidance from local health and agriculture officials and avoid handling sick or dead wild birds. While pet birds/family flocks are at lower risk than poultry, proper care and hygiene can help keep them safe.

Avian Influenza and Human Health:

  • Can People Get Bird Flu?  Most human cases of bird flu (H5N1) happen after close, direct contact with infected poultry. CDC has multiple surveillance systems that are used year-round to monitor key flu indicators. This data is reviewed comprehensively each week. Taken together, as of January 24, 2025, these systems currently show no indicators of unusual flu activity in people, including avian influenza A(H5N1) viruses.
  • Symptoms in humans: Bird flu symptoms can include: 
    • Fever, cough, sore throat, and muscle aches 
    • Diarrhea, pneumonia, and other breathing problems 
    • Some strains can cause eye infections (conjunctivitis)
  • How do I know If I’ve been exposed? In Pennsylvania, poultry farms and live bird markets are regularly tested for bird flu. If a positive case is found, the facility owners are notified.
  • What should I do if exposed? If you've been around sick birds, monitor your health for 10 days. Watch for symptoms like fever, cough, chills, eye discharge, muscle aches, or diarrhea. Contact your healthcare provider if these symptoms persist.

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