Mycobacterium avium complex (MAC), the causative agent of avian tuberculosis is found world-wide in soil and droppings of infected birds. Persons infected with MAC may develop lymphadenitis & pulmonary disease similar to tuberculosis or more severe disseminated disease. Transmission of MAC occurs primarily through aerosolization and inhalation of the agent in dried bird droppings and contaminated soil.

Cryptococcus neoformans is a fungus frequently found in pigeon droppings and in soil in many parts of the world. Disease in humans usually presents as chronic meningitis; infection of the lungs, kidneys, prostate and bone may also occur. Immunodeficient persons have increased susceptibility to cryptococcosis and disseminated MAC infection and should consult with their personal physician before working with birds.

Histoplasmosis (Histoplasma capsulatum) is a fungal disease that is spread to people by breathing in dust contaminated with the fungus from pigeon or bat droppings. Fungal spores are found in the environment, especially in areas with bird and bat droppings. Birds do not get sick from exposure to histoplasmosis. Infections in humans is rare. People who do become sick tend to develop pneumonia-like symptoms within 1–3 weeks after exposure. People with weak immune systems should avoid activities such as disturbing material where there are bird or bat droppings, cleaning chicken coops, exploring caves, and cleaning, remodeling, or tearing down old buildings.

Erysipelas is a bacterial infection of chickens that is transmitted through direct contact with animals, tissues and droppings. The risk of infection increases if persons have unprotected cuts or abrasions on their hands. Disease in humans may present as cellulitis, bacteremia, endocarditis, encephalitis, and arthritis.

Ornithosis, also known as psittacosis, parrot fever and avian chlamydiosis is a bacterial disease caused by Chlamydophila psittaci and is found in parrots, parakeets, turkeys, geese, ducks, pigeons and other birds. Birds may become ill or show no symptoms of disease. Chlamydophila psittaci infections in people usually result in flu-like symptoms and respiratory disease with occasional complications. Infection in pregnant women has been associated with infectious abortion. Transmission is usually by inhalation of dried droppings, secretions and feather dust of infected birds.

Salmonellosis, cryptosporidiosis and campylobacterosis are acquired by contact and accidental ingestion of fecal material or consumption of undercooked meat and egg products from infected birds. Birds infected with these diseases may have diarrhea and discolored droppings, but some birds may show no symptoms of disease. Free-ranging or wild-caught animals are more likely to carry these infections than those raised and housed in a laboratory setting. Any animal with diarrhea should be suspect of having a zoonotic disease. Humans affected by these diseases typically have gastrointestinal symptoms including diarrhea that is often bloody, abdominal pain, and nausea, with or without vomiting, and can also have fever.

Escherichia coli are bacteria that naturally occur in the gastrointestinal tract of animals and people. Some types of E. coli are harmful and can cause disease especially in people with compromised immune systems. E. coli infections can result from accidental ingestion of fecal material or consumption of contaminated, undercooked foods. Infected birds usually do not show any signs, but people infected with harmful E. coli can have severe symptoms such as bloody diarrhea and even kidney failure.

West Nile virus, eastern equine encephalitis virus, and other related arboviruses do infect poultry and other birds but transmission to people is via the bite of an infected mosquito and not by contact with infected birds.

Wild, migratory birds may be implicated in the spread of Lyme disease in the U.S. as ticks carrying the causative agent. Borrelia burgdorferi, have been found attached to their skin. This disease is transmitted to people after a bite from an infected tick. Symptoms include a skin rash known as erythema migrans, fever, headache, and fatigue. If not treated, the disease can progress to affect the joints, the heart and the nervous system.

Individuals with exposure to birds and avian environments may develop allergic reactions to avian proteins (allergens). Approximately 20-30 percent of individuals working with laboratory animals will develop an allergic reaction to animal proteins and 5-10 percent of individuals will develop asthma. Personnel may be exposed to allergens through inhalation and contact with skin, eyes and mucous membranes. Animal allergens may be present in dander, feathers, skin, urine, saliva, serum and any contaminated feed or bedding materials. Risk factors for developing an allergic reaction include history of previous allergies to animals.

Symptoms of zoonotic bird diseases may include:

• Allergic reactions (nasal discharge and congestion, conjunctivitis, tearing and eye itching, skin redness, rash or hives, lower airway symptoms [coughing, wheezing, shortness of breath]).
• Lymphadenitis: inflamed or enlarged lymph nodes
• Pulmonary disease: shortness of breath, difficulty breathing, coughing up mucus, headache
• Fever, chest pains, shortness of breath, weight loss, cough
• Headache, neck stiffness, fever, malaise, nausea, vomiting, sensitivity to light, confusion, and altered behavior
• Arthritis: pain, swelling, stiffness, redness and warmth, limited movement
• Endocarditis: fever, chills, sweating, fatigue, weight loss, loss of appetite, muscle or joint aches and pains, shortness of breath with activity, swelling of the feet, legs, or abdomen
• Red streaks, burning, tenderness, itchiness, fevers, chills, shivering, fatigue, and headaches
• Fever, headache, rash, loss of appetite, vomiting, neck and back pain, muscle aches, chills, fatigue, upper and lower respiratory symptoms and cough
• Gastroenteritis: vomiting, diarrhea (may be bloody), loss of appetite, abdominal pain

Revision History

07-2025 v.1