Rabies
As with other mammals including skunks, raccoons, fox, and domestic dogs, bats can carry rabies. Rabies is a viral disease that affects the nervous system of mammals including humans and is the most important public health problem concerning bats.
Rabies is usually transmitted by the bite of an animal, but in a few rare cases may be transmitted from the saliva of an infected mammal into the eyes, nose, mouth, or wound of another mammal. Because rabies is a fatal disease, all wild mammals should be viewed from a distance and treated as “wild animals.”
Typically, a wild animal will not attack a human unless cornered or provoked. Occasionally, a bat may be found on the ground or spotted hanging in a tree or bush. In either circumstance do not try to pick the bat up. Any bat that appears to be “acting abnormal” should be treated with caution and left alone.
If a bat is in an area where it must be removed, then you should wear a pair of leather gloves and pick the bat up with a long-handled shovel. If it appears to be alive, then move the bat to an area where there will be no pet or human traffic. Try to place the bat up in a bush or crook of a tree branch, with the goal of getting the bat off the ground, out of reach of children and pets. If the bat is dead, then bury it deep enough in the ground so pets cannot dig it up.
Because rabies can only be confirmed in a laboratory, under any circumstances where human contact is suspected, the bat should be collected (see Nuisance Bats in Homes or Buildings). Your local health department will be able to send the animal off for rabies testing.
If a bat bites you, collect the animal to have it tested for rabies, wash the area with soap and water, and immediately seek medical advice. If you find a bat in a child’s room or in a room where an individual is asleep, collect the bat to be tested for rabies, and seek medical advice.
Generally, people know when a bat has bitten them, but because bats have small teeth there may be occasions where the individual may not be aware of the contact.
Histoplasmosis
Histoplasmosis is a microscopic fungus that occurs in soil and in the droppings of birds and bats. This is an airborne disease that causes flu-like symptoms including a dry cough, fever, and body aches. While histoplasmosis is generally not debilitating, severe cases may become life threatening.
The most likely situation where a homeowner could come into contact with this disease is if they have a large colony of bats living in their attic. Guano piles may be present in such situations and should be treated with caution.
After excluding the bats from the attic (see Nuisance Bats in Homes and Buildings), the guano piles should be removed without further distributing the guano or dusty particles. Workers should wear a properly-fitted respirator capable of filtering particles as small as two microns in diameter.
Parasites
External parasites infect bats but do not typically pose a human health problem, primarily because of a lack of physical contact between bats and humans. In addition, many of the parasites are fairly host specific. Some parasites that infect bats are those we might encounter on a hike such as chiggers, ticks, and fleas; others include mites and parasitic flies.