Histoplasmosis is a fungal disease mainly affecting the lungs of persons infected with it (although it can spread throughout the body). The disease is normally found throughout the central and eastern United States. The causative agent is a soil organism dispersed through the air when soil is disturbed. It is often found in bird or bat droppings. In a Kansas City study, children that lived in buildings on which pigeons roosted or nested had a histoplasmosis infection rate three times higher than that of children living where there were no pigeons.3 In Delaware, Ohio, 384 students and faculty became ill when the school children cleaned up a school yard where pigeons and blackbirds had roosted. Clinical illness occurred in 40% of the entire student and faculty population. One adult was ill for six weeks. The entire school building was contaminated because the fungal spores had entered the air ventilating system.3 Pigeons and starlings are especially associated with histoplasmosis.

Biology of the Pest Species Involved. Pigeons are found throughout the U.S. and many parts of the world. Adult pigeons are about 11 inches long and weigh about 13 ounces. They vary in color from gray to white, tan, or blackish, with an iridescent green head. Pigeons inhabit roofs, ledges, attics, and many kinds of ornate architectural features of buildings. They may live 3 to 4 years. Starlings are stocky, short-tailed birds about the size of a robin. At a distance they may look entirely black, but actually have light-colored speckles on their feathers. Starlings make nests in tree cavities, birdhouses, and almost any available holes, nooks, or crannies in buildings. In the fall and winter, flocks of starlings may become huge, containing thousands of birds. They may fly 15 to 30 miles each day between roosting sites and feeding sites. The house sparrow, or English sparrow, is the most common and numerous of all birds. It is a small, stocky bird with a reddish brown upper body and gray belly. The male has a distinctive black throat. Nests of house sparrows are usually built in or on buildings and may consist of a messy conglomeration of twigs, grass, straw, paper, or almost anything else. House sparrows are extremely quick breeders and can build to extremely high numbers within a single season.

Control Options and Health Effects from Non-use of Pesticides. Control of birds in the school environment mostly consists of sanitation (removing food, water, and harborage), exclusion, and habitat alteration. However, bird problems highlight the need for an on-going pest control program. A traditional pest control contract will go a long ways toward keeping pest birds out of school buildings because pest control technicians can monitor/reduce bird problems before they get out of hand. Only rarely (especially in light of a health threat from histoplasmosis) will bird population reduction be necessary. No one wants to kill birds. However, that option must be maintained. In such cases, chemical frightening agents (in bait form which inadvertently kill some of the affected birds) may be carefully used to lower/eliminate pest bird populations - only according to label directions - and, only after appropriate coordination with local wildlife officials. In addition, under rare circumstances, personnel from the USDA Wildlife Services department can assist local officials with bird problems by applying pesticidal baits for bird control at the affected site.

If chemical agents are not available to pest control or wildlife services personnel for the removal of pest birds in/around schools, then successful elimination of the birds -- and their associated health risks -- may be difficult. Pesticides should be considered as rare, but important "public health tools" in the removal of birds. Failure to have such tools available may ultimately lead to children being exposed to pest birds and their ectoparasites, and possible liability on the school's part for not having provided a safe, pest-free environment.

References
1. Timm RM, Marsh RE: Vertebrate pests. In: Mallis A, ed. Handbook of Pest Control. 8th ed. University Park, Pennsylvania: Mallis Handbook and Technical Training Company, 1997:955-1019.

2. Benenson AS, ed: Control of Communicable Diseases Manual. 16th ed. Washington, DC: American Public Health Association, 1995.

3. Weber WJ: Health Hazards from Pigeons, Starlings, and English Sparrows. Fresno, California: Thomson Publications, 1979.

4. Caul EO, Sillis M: Chlamydiosis. In: Palmer SR, Soulsby L, Simpson DIH, eds. Zoonoses: Biology, Clinical Practice, and Public Health Control. Oxford: Oxford University Press, 1998:53-65.

5. Goddard J: Physician's Guide to Arthropods of Medical Importance. 3rd ed. Boca Raton, FL: CRC Press, 2000.

ABOUT THE AUTHOR:
Jerome Goddard holds a Ph.D. in medical entomology from Mississippi State University. He is a public health entomologist and a Clinical Assistant Professor of Preventive Medicine at the University of Mississippi Medical Center in Jackson, Mississippi. Dr. Goddard has written a medical entomology textbook, "Physician's Guide to Arthropods of Medical Importance" which is now in its Third Edition and is used by physicians worldwide. In addition, Dr. Goddard has written two other books on medically important pests, three book chapters, and 80 scientific articles. He has been a visiting professor in the Department of Dermatology at the Mayo Clinic, as well as a member of a National Institute of Health panel convened to study the future of tick taxonomy in the U.S. In 1999, he testified before a congressional committee on the public health benefits of pesticides.

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