Histoplasmosis is caused by a fungus (Histoplasma capsulatum) found primarily in the areas drained by the Mississippi and Ohio rivers. Both humans and animals can be affected. The disease is transmitted to humans by airborne fungus spores from soil contaminated by pigeon and starling droppings (as well as from the droppings of other birds and bats). The soil under a roost usually has to have been enriched by droppings for two years or more for the disease organism to reach significant levels. Although almost always associated with soil, the fungus has been found in droppings (particularly from bats) alone, such as in an attic.

Infection occurs when spores, carried by the air are inhaled - especially after a roost has been disturbed. Most infections are mild and produce either no symptoms or a minor influenza-like illness. On occasion the disease can cause high fever, blood abnormalities, pneumonia and even death. In some areas, including portions of Illinois, up to 80 percent of the population show evidence of previous infection. Outbreaks of histoplasmosis have occurred in Central Illinois.

The National Institutes of Health (NIH) has reported a potentially blinding eye condition - presumed ocular histoplasmosis syndrome (OHS) - that probably results from the fungus. NIH estimates that 4 percent of those exposed to the disease are at risk of developing OHS.

Yes.

Worldwide, bats are a major predator of night-flying insects, including pests that cost farmers billions of dollars annually. Throughout the tropics, seed dispersal and pollination activities by bats are vital to rain forest survival. In addition, studies of bats have contributed to medical advances including the development of navigational aids for the blind. Unfortunately, many local populations of bats have been destroyed and many species are now endangered.

Pigeon droppings appear to be the most important source of the disease fungus Cryptococcus Neoformans in the environment. The fungus is typically found in accumulations of droppings around roosting and nestling sites, for example, attics, cupolas, ledges and water towers. It has been found in as many as 84 percent of samples taken from old roosts. Even when old and dry, bird droppings can be a significant source of infection.

Like histoplasmosis, most cryptococcosis infections are mild and may be without symptoms. Persons with weakened immune systems, however, are more susceptible to infection. The disease is acquired by inhaling the yeast-like cells of the organism. Two forms of cryptococcosis occur in humans. The generalized form begins with a lung infection and spreads to other areas of the body, particularly the central nervous system, and is usually fatal unless treated. The cutaneous (skin) form is characterized by acne-like skin eruptions or ulcers with nodules just under the skin. The cutaneous form is very rare, however, without generalized (systemic) disease. Outbreaks (multiple cases at a location) of cryptococcosis infections have not been documented.

Most of the recent human rabies cases in the United States have been caused by rabies virus from bats. Awareness of the facts about bats and rabies can help people protect themselves, their families, and their pets. This information may also help clear up misunderstandings about bats.

When people think about bats, they often imagine things that are not true. Bats are not blind. They are neither rodents nor birds. They will not suck your blood--and most do not have rabies. Bats play key roles in ecosystems around the globe from rain forests to deserts, especially by eating insects, including agricultural pests. The best protection we can offer these unique mammals is to learn more about their habits and recognize the value of living safely with them.

How can I tell if a bat has rabies?

Rabies can be confirmed only in a laboratory. However, any bat that is active by day, is found in a place where bats are not usually seen (for example, in a room in your home or on the lawn), or is unable to fly, is far more likely than others to be rabid. Such bats are often the most easily approached. Therefore it is best never to handle any bat.

Other diseases carried or transmitted by birds affect man to a lesser degree. Psittacosis is normally mild in man; however, serous illness can occur rarely. Pigeons and sparrows also have been implicated (also with many other species of birds) as reservoirs for encephalitis viruses such as Saint Louis encephalitis virus, which are carried by mosquitoes.

Bats are associated with a few diseases that affect people, such as rabies and histoplasmosis. Rabies is a dangerous, fatal disease, but only about 5 percent of bats submitted for testing are infected with rabies virus. In recent years, there has been increased concern about the risk of rabies transmission following contact with bats. If an injured or ill bat is found in or around a structure, it should be removed. If a bat has bitten or scratched a person or pet or is found in your home, capture the bat without touching it with your hands and without crushing it's head. If the bat is dead, refrigerate it (DO NOT freeze) and then contact your local health department immediately for instructions.

Bats with rabies have been identified in most areas of the state. In recent years, bats have been the most common animal identified with rabies in the state.

The incidence of histoplasmosis being transmitted from bat droppings to humans is not thought to be high. Nevertheless, fresh bat droppings (unlike fresh bird dropping) can contain the histoplasmosis fungus. Bat droppings do not need to come into contact with soil to be a source of the disease.

If you are bitten by a bat--or if infections material (such as saliva) from a bat gets into your eyes, nose, mouth, or a wound--wash the affected area thoroughly and get medical advice immediately. Whenever possible, the bat should be captured and sent to a laboratory for rabies testing.

People usually know when they have been bitten by a bat. However, because bats have small teeth which may leave marks that are not easily seen, there are situations in which you should seek medical advice even in the absence of an obvious bite wound. For example, if you see a bat around an unattended child, or near a mentally impaired or intoxicated person, seek medical advice and have the bat tested.

People cannot get rabies just from seeing a bat in an attic, in a cave, or at a distance. In addition, people cannot get rabies from having contact with bat guano (feces), blood, or urine, or from touching a bat on its fur (even though bats should never be handled!)

Bird or bat roosts can harbor parasites that may invade buildings. Although these parasites can bite and irritate, they are unlikely to transmit diseases to humans. The northern fowl mite and chicken mite are usually the main culprits. Other parasites that may cause problems inside buildings include the pigeon nest bug and the bat bug (both are related to the bed bug), soft ticks, biting lice and the pigeon fly. Although most parasites associated with bird or bat roosts die quickly after the birds or bats leave, some may live for several weeks.

Droppings, feathers, food and dead birds under a roosting area can breed flies, carpet beetles and other insects that may become major problems in the immediate area. These pests may fly through open windows or crawl through cracks to enter buildings. If birds or bats are discouraged from roosting around buildings, most of the parasites associated with them will soon die. If the pests are a problem after birds or bats have been excluded, the roost area may be treated with a residual insecticide appropriately labeled by the U.S. Environmental Protection Agency for control of fleas, ticks, mites and similar pests.

If you think your pet or domestic animal has been bitten by a bat, contact a veterinarian or your health department for assistance immediately and have the bat tested for rabies. Remember to keep vaccinations current for cats, dogs, and other animals.

Teach children never to handle unfamiliar animals, wild or domestic, even if they appear friendly. "Love your own, leave other animals alone" is a good principle for children to learn.

Wash any wound from an animal thoroughly with soap and water and seek medical attention immediately.

Have all dead, sick, or easily captured bats tested for rabies if exposure to people or pets occurs.

Prevent bats from entering living quarters or occupied spaces in homes, churches, schools, and other similar areas where they might contact people and pets.

Be a responsible pet owner by keeping vaccinations current for all dogs, cats, and ferrets, keeping your cats and ferrets inside and your dogs under direct supervision, calling animal control to remove stray animals from your neighborhood, and consider having your pets spayed or neutered.

In February 1995, the aunt of a 4-year-old girl was awakened by the sounds of a bat in the room where the child was sleeping. The child did not wake up until the bat was captured, killed, and discarded. The girl reported no bite, and no evidence of a bite wound was found when she was examined. One month later the child became sick and died of rabies. The dead bat was recovered from the yard and tested--it had rabies.

This case demonstrates several points:

This child's infection with rabies was most likely the result of a bat bite. Children sleep heavily and may not awaken from the presence of a small bat. A bat bite can be superficial and not easily noticed.

The bat was behaving abnormally. Instead of hiding, the bat was making unusual noises and was having difficulty flying. This strange behavior should have led to a strong suspicion of rabies.

If the bat had been submitted for rabies testing a positive test would have led to life-saving anti-rabies treatment.