LA County Department of Public Health

Bats and Disease

The two most common diseases associated with bats in the United States are rabies and histoplasmosis.	Have an encounter with a bat in LA County? Call Public Health for rabies exposure consultation 213-989-7060 8-5pm after hours 213-240-7941 (Physician on Call)
Rabies is a fatal disease caused by the rabies virus. People can become infected when bitten by an infected bat, or when saliva of an infected bat comes in contact with the eyes, nose, mouth or an open wound. Bat bites are very small. Some bat bites cause only minor pain. A wound from a bat bite can easily go unnoticed. Therefore if there is the possibility of contact with a bat, a physician or the Department of Public Health should be consulted to evaluate the risk of rabies. Any suspected bite should be washed with soap and water immediately and prompt medical attention sought. If a person was likely exposed to the rabies virus, symptoms can be prevented with a series of rabies vaccinations given in the upper arm over a few weeks, and one dose of immune globulin given in the site of exposure. This is called ‘rabies post-exposure prophylaxis’ or rabies PEP. Because rabies is such a serious disease, rabies PEP is needed after any bat bite unless the bat tests negative for rabies. If it is needed after a bat incident, rabies PEP should be started as soon as possible (i.e within 1-3 days). Symptoms of rabies from bats usually start 30-90 days after the bite. If symptoms occur, the disease is nearly always fatal. Histoplasmosis is a disease caused by the fungus Histoplasma capsulatum. It can be anywhere there is a large amount of bat droppings (guano). People can become infected if they breathe in the fungal spores. Symptoms are similar to pneumonia (including trouble breathing and coughing) and should be treated early to avoid severe disease. The risk of contracting histoplasmosis from bat guano is no different from the risk associated with bird droppings. Professional services should be sought to clean up areas with large amounts of droppings.

Veterinary Public Health

The two most common diseases associated with bats in the United States are rabies and histoplasmosis.