University of Illinois Extension

Public Health and Safety Issues

Directory of  Zoonoses

Tick-borne Diseases

Ticks can be carriers of several diseases including Babesiosis, Ehrlichiosis, Lyme Disease, and Rocky Mountain Spotted Fever. The best way to avoid infection is to prevent tick bites. When you are out in the woods or tall grass, wear long-sleeved shirts, long pants, socks, and closed-toed shoes. Wearing light-colored clothing makes it easier to spot ticks.

For additional protection, apply a tick-repellent containing DEET or permethrin. Carefully follow the instructions provided by the manufacturer when using these products. When using DEET, apply the lowest concentration necessary. Apply DEET to clothing and use sparingly on skin, avoiding contact with the eyes, mouth, or open cuts. Permethrin may be applied to clothing or camping gear but should not be applied to skin. For more information, visit the CDC's Insect Repellent Use and Safety site.

Conduct a thorough tick check of clothes, body, and head. Be aware that some ticks are extremely small - about the size of a small pinhead. If you find a tick, carefully remove it using tweezers. Grasp the tick as close as possible to the point of attachment and gently pull it from the skin. Be careful not to crush the tick in the removal process and make sure that the mouthparts of the tick are completely removed. Do not pull the tick off with your bare fingers. If tweezers are not available, use a tissue as a barrier between your fingers and the tick. Do not try to remove the tick by burning it off or covering it with petroleum jelly.

Removed ticks can be stuck to tape and disposed of in the trash. Wash the bite site with hot, soapy water for at least 20 seconds and apply an antibiotic ointment. See your doctor if you develop a rash or flu-like symptoms. These diseases can be treated with antibiotics, but quick diagnosis and treatment is critical. Delayed treatment can result in more severe, long-term effects in some cases. The Illinois Department of Public Health provides very good information about ticks.

For detailed information about each of the diseases please reference the websites given below.

Mosquito-borne Diseases

Mosquitoes can be carriers of several diseases including California Encephalitis and West Nile Virus. The best way to avoid infection is to prevent mosquito bites. When outdoors, wear long-sleeved shirts and long pants. Wear insect repellent when in areas heavily infested with mosquitoes and around your home in the evenings when working in your garden or relaxing on your patio. Burning citronella candles near patios and decks and using outdoor fans on porches can help keep mosquitoes away.

The Illinois Department of Public Health provides a wealth of information about mosquitoes and disease at:

For detailed information about each of the diseases please reference the websites given below.

West Nile Virus

Parasitic Diseases

Many diseases are caused by parasites such as protozoans, mites, or parasitic worms. To reduce the risk of infection, thoroughly wash your hands with hot, soapy water for at least 20 seconds after handling animals or meat or after being outdoors and thoroughly cook meat to the appropriate temperature. For information, read the HealthBeat Safe Food Handling fact sheet.

The USGS National Wildlife Health Center has developed a valuable reference about safely eating game meat as part of their publication Disease Emergence and Resurgence: The Wildlife-Human Connection. Download Chapter 5: "Is This Safe to Eat?"


Giardiasis is caused by the protozoan Giardia lamblia. Both wild mammals (beaver, muskrat) and waterfowl can be carriers. People can become infected by ingesting contaminated water or from hand-to-mouth contact after handling an infected animal. Symptoms include abdominal cramps, bloating, diarrhea, and weight loss. To prevent infection, wear gloves when processing hunted or trapped animals and wash hands thoroughly with hot, soapy water for at least 20 seconds after handling wildlife.

For more information about giardiasis, visit:

Raccoon Roundworm (Baylisascaris)

The raccoon roundworm (Baylisascaris procyonis) is a parasitic worm that inhabits the intestines of raccoons. Infected raccoons rarely show signs of infection. The eggs of the worm are shed in raccoon feces. Larvae develop within the egg within 30 days. If fully developed larvae are ingested by an animal other than a raccoon, the larvae penetrate the intestinal wall of the host and travel throughout the body (larval migrans). Many animals other than raccoons, including rabbits, mice, and woodchucks, can become infected. These infected species often have trouble with motor coordination, walk with the head tilted, or go blind, making them more susceptible to predation or starvation.

The larvae of raccoon roundworm can also infect people and pets. Neurological signs, blindness, and death can occur. Any raccoon feces found in yards where children or pets are present should be removed immediately. When disposing of the feces, wear gloves, double bag the feces, and place in the garbage. Thoroughly wash hands in hot, soapy water for at least 20 seconds when finished. To prevent infection, do not feed raccoons, keep raccoons as pets, or handle young raccoons. Raccoons should not be relocated to avoid spreading the disease. Orphaned raccoons under the care of a wildlife rehabilitator should be quarantined during fecal testing, wormed, and any bedding material should be burned. Larvae in eggs remained alive after three weeks submerged in cleaning solutions, including 100 percent bleach solutions and isopropyl alcohol.

For more information about raccoon roundworms:

Sarcoptic Mange

Sarcoptic mange is caused by the Sarcoptes scabiei mite. Many mammals, including humans, cats, and dogs, can become infected with the mite. In humans, the mite causes intense itching, but the infection is short, lasting a few days to a few months. Pets become infested with a different kind of scabies mite. If your pet is infested with scabies (mange), and has close contact with you, the mite can get under your skin and cause itching and skin irritation. However, the mite dies in a couple of days and does not reproduce. A veterinarian can treat domestic pets. In wild animals, the infection is more severe. Coyotes, foxes, and squirrels can all be infected with the mite. Infected animals excessively scratch and chew at the skin, and have patches of missing fur and dry, thickened skin. The disease causes weakness and emaciation in infected wildlife and eventually leads to death.

For more information about sarcoptic mange, read the CDC's fact sheet.


Toxoplasmosis is caused by the protozoan Toxoplasma gondii. The definitive hosts for this protozoan are wild and domestic cats. Infected domestic cats may become depressed and lose their appetite or die suddenly with no obvious signs of illness. Other animals and people can become infected if they accidentally ingest food, water, or soil that has been contaminated by infected tissue or cat feces. The parasite multiples in the intestines of the intermediate host and spreads throughout the body. There are typically no symptoms after infection has occurred. However, the disease can be severe or fatal. Pregnant women can pass the parasite on to their fetus, and should not be around cat feces during pregnancy.

For more information about toxoplasmosis:

Viral Diseases

Avian Influenza (Bird Flu)

The strain of avian influenza that infects humans (Asian H5N1) has not yet been identified in the United States. Other strains of avian influenza that do not infect people are found in North America. Migratory waterfowl are the natural reservoir for the human-infecting Asian H5N1 strain, but domestic ducks and chickens can also become infected. Transmission to humans has been documented in other countries, with some fatalities.

To learn more about avian influenza, visit:

Hantavirus (Hantavirus Pulmonary Syndrome)

Hantavirus is carried by deer mice (genus Peromyscus) and other wild mice and rats and does not usually cause disease in the host. The common house mouse (Mus musculus) is not a carrier of this disease. Humans can become infected with hantavirus when they breathe in air-borne droplets containing the virus. The virus becomes air-borne when mice feces or nesting material are stirred up. Within one to five weeks of exposure, infected individuals may experience fever, fatigue, and muscle aches. Hantavirus can be fatal, and medical treatment should be sought immediately. The virus is not contagious. The virus is more common in the southwestern United States. There have only been two reported cases of Hantavirus in Illinois.

For more information about hantavirus:


Rabies is caused by a single stranded RNA virus. The virus can infect any mammal - people, domestic animals, and wildlife. In Illinois, the dominant wildlife carriers of rabies are bats and striped skunks. Transmission of rabies occurs through contact with saliva from infected animals. Rabies can cause muscle spasms, seizures, paralysis, increased salivary production (foaming at the mouth), and aggressive behavior. Affected wildlife often lose their fear of humans in the advanced stages of the disease. The disease is almost 100 percent fatal if not treated. If bitten by an animal (wildlife or domestic animal) seek medical treatment immediately. For those not previously vaccinated against rabies, treatment will include a combination of human rabies immune globulin (HRIG) and vaccine, recommended for both bite and non-bite exposures.

Preventing exposure is the best strategy for animals and humans. Pets should be vaccinated for rabies. When trapping wild animals, take precautions not to get bitten or scratched. If possible, hire a Nuisance Wildlife Control Operator (NWCO) to trap wildlife for you. NWCOs, wildlife rehabilitators, and other professionals that regularly have contact with wildlife should receive the rabies vaccine. If bitten by a bat or other wild animal, contact a local health department to have the bat tested for rabies. Contact a local Animal Control agency if you need assistance capturing the bat. Do not damage the animal's head; the brain will be needed for testing.

For more information about rabies:

Fungal Diseases


Histoplasmosis is caused by the fungus Histoplasma capsulatum. Birds and bats serve as the hosts for this fungus. The fungus lives in soil that has been contaminated with decaying bird or bat droppings, particularly underneath well-established bird or bat roosts. People and other animals can become infected when they inhale the fungal spores from disturbed soil. People that become infected can experience a mild respiratory infection. Individuals with chronic illnesses are more susceptible to serious illness. Heavily contaminated environments may cause severe respiratory infections and death.

For more information about histoplasmosis:

For information about cleaning up contaminated sites, read the HealthBeat fact sheet Health Hazards Associated with Bird and Bat Droppings.

Bacterial Diseases


Leptospirosis is caused by bacteria and can infect people, domestic animals, and wildlife. Infection in humans is usually caused by exposure to water that has been contaminated by the urine of infected animals. Symptoms are flu-like. People often display symptoms two days to four weeks after exposure. Cases of Leptospirosis are rare in Illinois.

For more information about leptospirosis:


Tularemia is caused by the bacterium Francisella tularensis. Transmission occurs through the bite of an infected flea or tick or through contact with the body fluids of contaminated animals such as rabbits, beavers, muskrats, squirrels, deer, and birds. Carnivores can carry the bacteria in their mouths or on their claws if they kill or eat infected prey. Domestic cats can transmit the disease to people in this way. Symptoms of the disease are usually mild and mimic flu-like symptoms, but Tularemia can be life threatening if not treated. Antibiotics are effective in treating the disease. To protect against Tularemia, wear insect repellent, do not let your cat outdoors unsupervised, and wash hands thoroughly with hot, soapy water for at least 20 seconds after handling wildlife.

For more information about tularemia: