Tularemia – What it is, Causes, Symptoms and Antibiotic Treatments. Additionally, Tularemia is a rare infectious disease that typically attacks the skin, eyes, lymph nodes, and lungs. Tularemia – also called rabbit fever or cervical fly fever – is caused by the bacterium Francisella tularensis.
The disease mainly affects mammals, especially rodents, rabbits and hares, although it can also infect birds, sheep and domestic animals such as dogs, cats and hamsters. Tularemia spreads to humans through several routes, including insect bites and direct exposure to an infected animal.
Highly contagious and potentially fatal, Tularemia can usually be treated effectively with specific antibiotics if caught early.
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Causes: Tularemia doesnot occur naturally in humans and is not 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 via a single route, Tularemia has multiple modes of transmission. How you get the disease often determines the type and severity of symptoms. In general, you can get Tularemia through:
- Insect bites. Although a number of insects have Tularemia , ticks and deer flies are more likely to transmit the disease to humans. Tick bites cause a large percentage of ulceroglandular tularemia cases .
- Exposure to sick or dead animals. Glandular ulcer tularemia can also result from being handled or bitten by an infected animal, most often a rabbit or hare. Bacteria enter the skin through small cuts and abrasions or bites, 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. Soil bacteria can become airborne during gardening, construction or other activities that disturb the Earth. Inhaling the bacteria can lead to pneumonic tularemia . Laboratory workers working with Tularemia are also at risk of airborne infection.
- Contaminated food or water. Although uncommon, it is possible for Tularemia to eat undercooked meat from an infected animal or drink contaminated water. Signs include vomiting, diarrhea, and other digestive problems ( see Oropharyngeal Tularemia ). Heat kills F. tularensis, so cook meat to the right temperature – a minimum of 165 F (73.8 C) for ground beef and game meat – so it’s safe to eat.
Symptoms: Most people exposed to Tularemia who become ill usually do so within three to five days, although it can take up to 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.
Glandular Ulcer 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
Glandular Tularemia: People with Glandular Tularemia have the same signs and symptoms as Ulcer Glandular Tularemia , but without skin ulcers.
Oculoglandular Tularemia: This form affects the eyes and can cause:
- eye pain
- eye redness
- Eye swelling and discharge
- An ulcer on the inside of the eyelid
- light sensitivity
Oropharyngeal Tularemia: Usually caused by eating undercooked wild animal meat or drinking contaminated water, this form affects the mouth, throat, and digestive tract. Signs and symptoms include:
- Sore throat
- Mouth ulcers
- inflamed tonsils
- Swollen lymph nodes in the neck
Tularemia Pneumonia: This type of Tularemia causes typical signs and symptoms of pneumonia:
- Dry cough
- Chest pain
- Difficulty breathing
Other forms of Tularemia can also spread to the lungs.
Typhoid Tularemia: 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 have been bitten by a tick or handled a wild animal in an area where Tularemia is found and have developed a fever, skin ulcers or swollen glands – consult the doctor as soon as possible.
Risk Factors: While anyone of any age can develop Tularemia , participating in certain occupations or activities or living in certain areas poses a greater risk.
Living in or visiting certain areas: In Brazil, people living in or visiting areas of Arkansas, Missouri and Oklahoma may be at greater risk due to the concentration of ticks in these areas.
Having certain hobbies or occupations: The following may increase your risk of developing Tularemia :
- Hunting and traps. As hunters are exposed to the blood of wild animals and can eat their flesh, they are at risk for Tularemia .
- Gardening or landscaping. Gardeners and landscapers may also be at risk for Tularemia . It is possible that gardeners inspire bacteria that stir while working in the soil or when using mowers and weed cutters.
- Working in wildlife management or veterinary medicine. People who work with wildlife are at increased risk of Tularemia .
Complications: Without treatment, Tularemia can be fatal. Other possible complications include:
- Inflammation of the lungs (pneumonia). Pneumonia can lead to respiratory failure — a condition where 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 fatal infection of the fluid and membranes (meninges) that surround 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 severe cases may require antibiotic therapy.
- Bone infection (osteomyelitis). Tularemia bacteria sometimes spread to bones.
Testing and Diagnosis: Because it is rare and because it shares symptoms with other conditions , Tularemia can be difficult to diagnose. Doctors can check for F. tularensis in a blood or sputum sample that is cultured to encourage the bacteria to grow.
Tularemia can sometimes be identified by antibodies against the bacteria in a blood sample, but these do not develop until several weeks after infection. You are also likely to have a chest X-ray to look for signs of pneumonia.
Treatments: Tularemia can be effectively treated with antibiotics such as streptomycin or gentamicin, which are given by injection directly into a muscle or vein. Depending on the type of Tularemia being treated, doctors may prescribe oral antibiotics such as doxycycline (Oracea, Vibramycin, others).
You will also receive therapy for any complications, such as meningitis or pneumonia. In general, you should be immune to Tularemia after recovery from the disease , but some people may experience a recurrence or reinfection.
Prevention: There is currently no publicly available vaccine for Tularemia . If you work in a high-risk occupation or live in an area where Tularemia is present, these measures can help reduce your chances of infection:
- Protect yourself from insects. Most people in the United States get Tularemia through tick bites. If you spend time in thrush-infested areas, wear long-sleeved shirts and long pants, tuck your pants into your socks, and wear a wide-brimmed hat to help protect your face and neck. Even packaged, you will need to check your skin and clothing frequently for ticks. Use an insect repellent with 20 to 30 percent DEET, picaridin, or IR3535, but follow the manufacturer’s instructions carefully. Apply insect repellent sparingly and wash it off at the end of the day. Check for ticks frequently and remove them immediately if you find any.
- Be careful when gardening. Home gardeners and professional landscapers should consider wearing a face mask when digging soil, weeding, or brushing or mowing lawns.
- Handle animals carefully. If you hunt or hold wild rabbits or hares, wear gloves and 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 animals that look sick.
- Protect your pets. Cattle and pets can get Tularemia if they eat part of a sick rabbit or are bitten by an infected tick. To help keep your pets safe, avoid letting them outside unattended, provide flea and tick protection, and don’t let them come into contact with wild or dead animals.