Most people exposed to tularemia who become sick generally do so within two to 10 days. Several types of tularemia exist, and which type you get depends on how and where the bacteria enter the body. Most commonly, they enter through skin or mucous membranes, but they can also be inhaled or eaten. Each type of tularemia has its own set of symptoms.
This is by far 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
People with glandular tularemia have the same signs and symptoms of ulceroglandular tularemia, except no skin ulcers.
This form affects the eyes and may cause:
- Eye pain
- Eye redness
- Eye swelling and discharge
- An ulcer on the inside of the eyelid
Usually caused by eating poorly cooked wild animal meat or drinking contaminated water, this form affects the digestive tract. Signs and symptoms include:
- Sore throat (pharyngitis)
- Mouth ulcers
More common in the elderly and in people with typhoidal tularemia, this causes signs and symptoms typical of pneumonia:
- Chest pain
- Difficulty breathing
Other forms of tularemia also can spread to the lungs.
This rare and serious form of the disease usually causes:
- High fever
- Extreme exhaustion
- Vomiting and diarrhea
- Enlarged spleen (splenomegaly)
- Enlarged liver (hepatomegaly)
When to see a doctor
If you think you may have been exposed to tularemia — especially if you've been bitten by a tick or handled a wild animal in an area where tularemia is found and have developed fever, skin ulcers or swollen glands — see a doctor as soon as possible. If you test positive for the disease, you'll need to start antibiotic treatment right away.
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, insects and fish 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 number 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 160 F (71.1 C) for pork and ground meat and game meat, 145 F (62.8 C) for farm-raised steaks and roasts — 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
In the United States, people living in or visiting areas of Arkansas, Missouri and Oklahoma may be at greater risk because of the concentration of ticks in those areas.
Having certain hobbies or occupations
The following can increase your risk of developing tularemia:
- Hunting and trapping. Because hunters handle wild animals, are exposed to 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. They are more likely to develop pneumonic tularemia, one of the least common and most deadly forms of the disease. 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, 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. Signs and symptoms of bacterial meningitis include high fever, severe headache, stiff neck and sensitivity to light. If not treated promptly, bacterial meningitis can cause brain damage and even death.
- Irritation around the heart (pericarditis). This is swelling and irritation of the pericardium, the thin membrane that surrounds the heart. Mild pericarditis often improves without treatment, but more-serious cases may require antibiotic therapy.
- Bone infection (osteomyelitis). Tularemia bacteria sometimes spread to the bones, leading to pain, decreased range of motion in nearby joints, and sometimes to skin redness, tenderness or open sores in the affected areas.
Attempts to develop a tularemia vaccine have not been successful so far. If you work in a high-risk occupation or live in an area where tularemia is present, these measures may help reduce your chance of infection:
Protect yourself from insects. Most people get tularemia though tick bites. If you spend time in tick-infested areas, wear long-sleeved shirts and long pants, tuck your pants into your socks, and use a broad-brimmed hat to help protect your face and neck. Even bundled up, you'll need to check your skin and clothing often for ticks.
Use an insect repellent, but follow the manufacturer's directions carefully. Products containing DEET are still considered the most effective against ticks, although oil of lemon eucalyptus or natural insecticides may offer some protection. Use the lowest concentration of repellent for the circumstances, apply it in moderation, and wash it off at the end of the day. Don't use repellents containing DEET on infants younger than 2 months. Check yourself for ticks often and remove them immediately if you find any.
- Take care when gardening. Home gardeners and professional landscapers should consider wearing a face mask when excavating the soil, clearing weeds or brush, or mowing lawns.
- Handle animals carefully. If you hunt or handle wild rabbits or hares, wear gloves and protective goggles, and wash your hands thoroughly with soap and hot water after touching the animal. Cook all wild meat thoroughly, and avoid skinning or dressing any animal that appeared ill.
- Protect your pets. Livestock and pets can contract tularemia if they eat part of a diseased rabbit or are bitten by an infected tick. To help keep your pets safe, avoid letting them outside unsupervised, provide them with flea and tick protection, and don't let them come in close contact with wild or dead animals.