91AV

Guidance for Personnel Working with Birds at 91AV

What is histoplasmosis?

Histoplasmosis is an infectious disease of the lungs caused by a fungus, Histoplasma capsulatum. The infection can sometimes spread to other parts of the body. Droppings from chickens, pigeons, starlings, blackbirds, and bats support the growth of the fungus. Birds are not themselves infected with it because of their high body temperatures, but they do carry it on their feathers. Histoplasma capsulatum may also be found in the soil, particularly soil which has been enriched with bird or bat droppings.

How is histoplasmosis spread?

People get histoplasmosis by breathing air which contains small spore forms of the organism. Spores become airborne when contaminated soil is disturbed. Commonly such individuals have been exposed to environmental sites where birds had previously roosted or have hobbies or professions which expose them to bird roosts or bat habitats. After breathing in air containing the organism, it causes infection in the lungs. The infection may spread by the blood stream to involve other parts of the body. Dissemination of disease is most frequently seen in immunocompromised individuals.

Who is at risk for infection?

Persons whose occupations involve contact with the soil, in particular with soil enriched with bird and bat droppings, are at high risk of acquiring infection. They include:

• Farmers and poultry keepers, especially when cleaning silos, chicken coops, and pigeon roosts
• Gardeners and horticulturists using poultry manure as fertilizer
• Construction and other workers in earth-moving operations
• Workers who monitor bird populations
• Workers who have contact with bats or bat caves

Others who may be at risk include archaeologists, geologists, and medical laboratory technicians who handle cultures of the organism.

Is histoplasmosis infection serious?

Most histoplasmosis infections are easily overlooked because they either produce mild symptoms or none at all. However, histoplasmosis can be severe and produce an illness similar to tuberculosis. More severe disease usually occurs in patients with diseases which impair their body's ability to fight infections. In such cases, histoplasmosis may spread from the lungs to involve other parts of the body; the infection is progressive and usually fatal if left untreated.

How can I protect myself?

Prevention of histoplasmosis relies on avoiding exposure to dust in a contaminated environment. Before anyone cleans chicken coops or other contaminated soil, spraying with water is advisable to reduce dust. Decontamination with 3% formaldehyde has been shown to be effective; however, such solutions should be used with caution since this chemical may cause adverse health effects following inhalation, ingestion, or skin or eye contact. Persons working in contaminated areas should use protective clothing such as gloves and coveralls. They should also use a respirator equipped with a high efficiency particulate air (HEPA) filter that is capable of filtering particles down to two microns in size. For major clean-up operations of prolonged exposure, a powered air purifying or supplied air respirator may be necessary.

What are the signs of histoplasmosis infection?

Histoplasmosis causes a spectrum of illness, and the symptoms vary depending on the type of infection, the underlying health of the patient, and the extent of exposure. Symptoms of the infection appear within 5 to 18 days after exposure, most commonly in 10 days. In the healthy individual, H. capsulatum may cause no symptoms or may cause a flu-like illness with fever, cough, chest pain, and fatigue. In some healthy individuals histoplasmosis may cause joint pain, muscle pain, and painful red lumps on the arms or legs. In patients with pre-existing lung disease or who are immunocompromised, histoplasmosis leads to more severe symptoms and lung infection.

What do I do if an exposure or injury occurs?

Exposure to aerosols, bites or scratches involving animals or injuries from objects contaminated with body fluids from animals require immediate first aid and medical attention. Notify your supervisor! Then, contact the University Police Department at 593-2611 or dial 911.