Tularemia

The symptoms of tularemia usually develop 3 – 5 days after exposure to the bacterium. The signs and symptoms of the disease include the following [7]:

• Fever accompanied by chills
• Development of conjunctivitis
• Unexplained weight loss
• Pain in muscles along with experiencing stiffness in joints
• Headache 
• Difficulty in breathing
• Sweating

These are some of the common signs and symptoms experienced. However, symptoms may be different for different forms of tularemia. For example, in case of pneumonic tularemia, individuals suffer from cough, difficulty in breathing and shortness of breath. In case of typhoidal tularemia, in addition to above mentioned symptoms, individuals also experience pneumonia, enlarged spleen and liver, extreme exhaustion and vomiting along with diarrhea.

It often gets difficult to diagnose tularemia, the reason being that the disease shares some common signs and symptoms with other diseases. The following tests are carried out to diagnose the disease condition [8]:

• Blood tests: Blood tests and culture are done for identifying the causative bacterium. Serology tests would also be required in order to measure the immune response to infections.
• Chest X-ray: This is done to check for signs of pneumonia.
• In addition to blood tests and chest X-ray, polymerase chain reaction (PCR) test is also carried out from sample of an ulcer.

• Antibiotics form the preliminary basis of treatment regime. Various antibiotics such as gentamicin or streptomycin are administered for treating the condition of tularemia [9]. These antibiotics may either be given intravenously or orally. Based on the type of tularemia that has set in, different types of antibiotics may also be given.
• In case of accompanying complications, affected individuals may also receive additional therapy for the same. After an attack of tularemia, individuals may develop immunity against it. However, there have been many instances, when individuals may suffer from recurrent bouts of the disease [10].

When treatment is not given, then the disease turns fatal in about 5% cases. However, when promptly treated, the condition can successfully resolve. The mortality rate is higher in individuals suffering from typhoidal tularemia. In addition to delay in diagnosis and typhoidal tularemia, there are several other factors that increase the chances of mortality in individuals. These include renal failure and elevated levels of creatine kinase [6].

Humans are not directly infected by the bacteria that cause tularemia. But, it spreads to humans by the mammals infected by Francisella tularensis. The following are the ways through which humans get infected through the bacterium [2]:

• Insect bites or mosquito bite
• Direct exposure to infected animals and or insects
• Consumption of contaminated water or improperly cooked meat
• Breathing in dust or soil containing the bacterium can cause pneumonic tularemia [3]

Tularemia is a common occurrence in the western and southern regions of the US. It has been estimated that annually, 200 cases of tularemia are reported to occur in the US. In the past, the condition occurred more frequently during the winter months. However, the incidence pattern has changed and frequency of tularemia has increased during warm weather. Statistics have revealed that, during the years 1990 – 2000, about 56% cases were reported in areas of Oklahoma, Arkansas, South Dakota and Missouri [4].

For the bacteria to cause an infection, it must first gain entry into the human body. This primarily occurs through insect bites or through inhalation. Once it enters the body, there is development of an ulcer at the site of wound or bite. It takes about 2 to 4 days for the ulcer to develop. In cases, when the bacteria enter the body through inhalation, it spreads through the lymph nodes causing infection. The infection that occurs, produces an inflammatory response that particularly involves the neutrophils, local macrophages and fibrin [5].

The following measures can be taken to prevent attack of tularemia:

• Insect bites are the most common route for transmission of the bacterium. Individuals are advised to wear long sleeved clothing when they visit tick infected areas.
• During gardening, individuals are advised to wear face mask while working with the soil.
• It is necessary to wear gloves and other protective clothing while handling wild animals such as rabbits, or hares.
• It is also necessary to protect the pets from insect bites or prevent them from feeding on diseased animals. This would prevent them from contracting the bacteria and developing tularemia.
• Several attempts have been made to prepare the tularemia vaccine; however, attempts were not successful [11].

Tularemia is also known as deer fly fever. It primarily affects the mammals such as hares, rodents and rabbits. In certain cases, it can also affect the reptiles, fishes and birds. Humans are affected through insect bites or when they are directly exposed to infected animals. It is a highly infectious disease, though rare, but extremely fatal. If diagnosed in the early stages, it can be successfully treated with antibiotics [1].

• Definition: Tularemia is an infectious disease which is common amongst the wild rodents. Humans can get infected through contact with tissues of infected animals. The condition is also known as deer fly fever. Tularemia is a common occurrence in parts of North America and Northern Eurasia. 
• Cause: Tularemia is caused by the bacterium Francisella tularensis. The bacteria primarily infect the rodents and wild animals, which is later on transmitted to the humans. Humans can get infected by the bacteria through insect bites, consumption of contaminated water or undercooked meat of diseased animal, breathing in infected plant material or soil and direct contact with the bacteria during handling animals.
• Symptoms: The common symptoms of tularemia include fever, chills, muscle aches, stiffness in the joints, sweating, breathing difficulty and weight loss. When the lungs are affected, individuals can develop pneumonia and can experience chest pain as well. Affected individuals get exhausted easily and also experience shortness in breath.
• Diagnosis: Blood tests and blood culture will help to identify the causative organisms. Sputum culture would also aid in diagnosis of tularemia. In addition, chest X-ray would also provide useful insight about pneumonia and other associated complications.
• Treatment: Antibiotics are given for treatment of tularemia. Depending on severity of the condition, antibiotics are administered either orally or intravenously.

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