Tularemia

Tularemia (too-lah-REE-me-uh), sometimes called rabbit fever or deerfly fever, is an infection caused by bacteria that can spread from wild animals to humans.

Tularemia bacteria enter the body through the mucous membranes * , the skin, the lungs, or the digestive system. Seven different forms of the disease exist:

People cannot catch tularemia from one another. Most cases in the United States occur when someone gets a bite from a tick, fly, or mosquito that has previously bitten an infected rabbit or deer. If a person is in contact with infected animals, the bacterium may be able to enter that person's body through small cuts on the skin. Hunters contract tularemia from handling carcasses or from eating undercooked, contaminated meat. In rare cases, people may breathe in bacterial spores that have been released into the air from the soil where the bacteria live. Drinking contaminated water is another rare but possible way to contract the disease.

Tularemia affects people of every age, sex, and race. In spring and summer months, it occurs most often in children who become infected when playing outside. In fall and winter, hunters are more likely to contract the infection.

Symptoms of tularemia depend on the form of the disease. Most infected people have a red spot at the site of the insect bite or the cut where the bacterium entered the body. This spot may become an ulcer.

Other signs and symptoms appear within 1 to 14 days (most frequently in 2 to 5 days) and may come on suddenly. They can include extreme tiredness, muscle aches, fever, headache, sweating, chills, and weight loss. Lymph nodes * in the groin and armpits may become swollen.

People who contract tularemia from inhaled bacteria usually have pneumonia-like symptoms, such as a dry cough, shortness of breath, or discomfort in the chest area. This form can progress to shock and respiratory failure * .

People who drink contaminated water or eat contaminated meat may experience nausea (NAW-zee-uh) and vomiting, pain in the abdomen, diarrhea, sore throat, and sometimes gastrointestinal * bleeding.

Doctors use blood tests to check for tularemia. Some tests look for antibodies * to the F. tularensis bacterium. Doctors may also look for evidence of the bacterium in the blood, fluid from the nose and mouth, and lymph nodes. If the person has symptoms of pneumonia, the doctor will also order a chest x-ray.

Tularemia responds well to antibiotics, and most people can receive treatment at home. Because tularemia is not contagious, people who have it do not have to be isolated.

In more severe cases, when the disease attacks the lungs or other organs, people may require hospitalization and closer monitoring.

Most people who receive treatment recover from tularemia, but the septic and pneumonic forms of the disease can be life-threatening. Symptoms of tularemia can last for several weeks. Most people do not experience any lasting damage from the disease and may develop some degree of immunity * to it.

Complications of tularemia can include pneumonia, meningitis * , osteomyelitis * , kidney problems, lung abscesses * , pericarditis (inflammation of the sac surrounding the heart), shock, and, rarely, death. Approximately 1.4 percent of all cases in the United States are fatal.

In the past, laboratory workers at risk for contracting tularemia due to frequent contact with laboratory animals received vaccinations against the disease. That vaccine was unavailable for public use in the United States as of 2015. The U.S. Food and Drug Administration was, however, continuing its review of a potential vaccine for use by the general public.

The best way to avoid contracting tularemia is to prevent tick and insect bites by using repellent and by wearing light-colored clothing that covers the arms and legs. Another prevention measure is to avoid contact with certain wild animals, such as rabbits. Experts recommend that hunters wear rubber gloves when handling animals and that they cook all meat thoroughly. In addition, people should avoid swimming in or drinking water that might be contaminated.

See also Bacterial Infections • Bioterrorism Agents: Overview • Meningitis • Osteomyelitis • Pneumonia • Tick-Borne Illnesses: Overview • Zoonoses: Overview

* mucous membranes are the thin layers of tissue found inside the nose, ears, cervix (SER-viks) and uterus, stomach, colon and rectum, on the vocal cords, and in other parts of the body.

* shock is a serious condition in which blood pressure is very low and not enough blood flows to the body's organs and tissues. Untreated, shock may result in death.

* lymph nodes (LIMF) are small, bean-shaped masses of tissue containing immune system cells that fight harmful microorganisms. Lymph nodes may swell during infections.

* respiratory failure is a condition in which breathing and oxygen delivery to the body are dangerously altered.

* gastrointestinal (gas-tro-in-TEStih-nuhl) means having to do with the organs of the digestive system, the system that processes food. It includes the mouth, esophagus, stomach, intestines, colon, and rectum and other organs involved in digestion, including the liver and pancreas.

* antibodies (AN-tih-bah-deez) are protein molecules produced by the body's immune system to help fight specific infections caused by microorganisms, such as bacteria and viruses.

* immunity (ih-MYOON-uh-tee) is the condition of being protected against an infectious disease. Immunity often develops after a germ has entered the body.

* meningitis (meh-nin-JY-tis) is an inflammation of the meninges, the membranes that surround the brain and the spinal cord. Meningitis is most often caused by infection with a virus or a bacterium.

* osteomyelitis (ah-stee-o-my-uh-LYE-tis) is a bone infection that is usually caused by bacteria. It can involve any bone in the body, but it most commonly affects the long bones in the arms and legs.

* abscesses (AB-seh-sez) are localized or walled-off accumulations of pus caused by infection that can occur anywhere within the body.