Most people exposed to tularemia who become sick generally do so within three to five days, although it can take as long as 14 days. Several types of tularemia exist, and which type you get depends on how and where the bacteria enter the body. Each type of tularemia has its own set of symptoms.

Ulceroglandular tularemia

This is the most common form of the disease. Signs and symptoms include:

• A skin ulcer that forms at the site of infection — usually an insect or animal bite
• Swollen and painful lymph glands
• Fever
• Chills
• Headache
• Exhaustion

Glandular tularemia

People with glandular tularemia have the same signs and symptoms of ulceroglandular tularemia, but without skin ulcers.

Oculoglandular tularemia

This form affects the eyes and may cause:

• Eye pain
• Eye redness
• Eye swelling and discharge
• An ulcer on the inside of the eyelid
• Sensitivity to light

Oropharyngeal tularemia

Usually caused by eating poorly cooked wild animal meat or drinking contaminated water, this form affects the mouth, throat and digestive tract. Signs and symptoms include:

• Fever
• Throat pain
• Mouth ulcers
• Vomiting
• Diarrhea
• Inflamed tonsils
• Swollen lymph nodes in the neck

Pneumonic tularemia

This type of tularemia causes signs and symptoms typical of pneumonia:

• Dry cough
• Chest pain
• Difficulty breathing

Other forms of tularemia also can spread to the lungs.

Typhoidal tularemia

This rare and serious form of the disease usually causes:

• High fever
• Extreme exhaustion
• Vomiting and diarrhea
• Enlarged spleen (splenomegaly)
• Enlarged liver (hepatomegaly)
• Pneumonia

Tularemia doesn't occur naturally in humans and isn't known to pass from person to person. However, tularemia occurs worldwide, especially in rural areas, because many mammals, birds and insects are infected with F. tularensis. The organism can live for weeks in soil, water and dead animals.

Unlike some infectious diseases that spread from animals to people through a single route, tularemia has several modes of transmission. How you get the disease usually determines the type and severity of symptoms. In general, you can get tularemia through:

• Insect bites. Although a number of insects carry tularemia, ticks and deer flies are most likely to transmit the disease to humans. Tick bites cause a large percentage of cases of ulceroglandular tularemia.
• Exposure to sick or dead animals. Ulceroglandular tularemia can also result from handling or being bitten by an infected animal, most often a rabbit or hare. Bacteria enter the skin through small cuts and abrasions or a bite, and an ulcer forms at the wound site. The ocular form of tularemia can occur when you rub your eyes after touching an infected animal.
• Airborne bacteria. Bacteria in the soil can become airborne during gardening, construction or other activities that disturb the earth. Inhaling the bacteria can lead to pneumonic tularemia. Laboratory workers who work with tularemia also are at risk of airborne infection.
• Contaminated food or water. Although uncommon, it's possible to get tularemia from eating undercooked meat of an infected animal or drinking contaminated water. The signs include vomiting, diarrhea and other digestive problems (oropharyngeal tularemia).

Heat kills F. tularensis, so cook meat to the right temperature — a minimum of 165 F (73.8 C) for ground meat and game meat — to make it safe to eat.

Although anyone of any age can develop tularemia, engaging in certain occupations or activities or living in certain areas pose a greater risk.

Living in or visiting certain areas

Tularemia has been reported in the United States, Canada, Mexico, Japan and Europe. In the United States, it's most common in the south-central states, the Pacific Northwest and parts of Massachusetts, including Martha's Vineyard.

Having certain hobbies or occupations

The following can increase your risk of developing tularemia:

• Hunting and trapping. Because hunters are exposed to wild animal blood and may eat their flesh, they're at risk of tularemia.
• Gardening or landscaping. Gardeners and landscapers may also be at risk of tularemia. It's possible that gardeners inhale bacteria that are stirred up while working the soil or when using mowers and weed trimmers.
• Working in wildlife management or veterinary medicine. People who work with wildlife are at increased risk of tularemia.

Left untreated, tularemia can be fatal. Other possible complications include:

• Inflammation of the lungs (pneumonia). Pneumonia can lead to respiratory failure — a condition in which the lungs don't take in enough oxygen, don't release enough carbon dioxide or both.
• Infection around the brain and spinal cord (meningitis). Meningitis is a serious and sometimes life-threatening infection of the fluid and membranes (meninges) surrounding the brain and spinal cord.
• Irritation around the heart (pericarditis). This is swelling and irritation of the pericardium, the thin membrane that surrounds the heart. Mild pericarditis may improve without treatment, but more-serious cases may require antibiotic therapy.
• Bone infection (osteomyelitis). Tularemia bacteria sometimes spread to the bones.