Tularemia is a disease that infect animals as well as humans and it is also known as rabbit fever. It is caused by small, rod shaped non motile bacterium Francisella tularensis. The bacterium is typically spread through:
1. Insect bites (e.g. ticks, mosquitoes)
2. Handling infected animals (e.g. rabbits, hares)
3. Consuming contaminated food or water
4. Inhalation of contaminated dust or aerosols
5. Direct contact with infected tissues or bodily fluids.
People who work with infected animals or in environments where the bacterium is common (e.g. hunters, agricultural workers) are at a higher risk of exposure to tularemia.


The symptoms of tularemia can vary depending on how the bacterium entered the body, but common symptoms include:
1. Fever
2. Chills
3. Fatigue
4. Muscle aches
5. Headache
6. Dry cough
7. Skin ulcers or swelling at the site of infection
8. Swollen lymph nodes
9. Conjunctivitis (red, sore eyes)
10. Pneumonia (in severe cases)
Symptoms can appear anywhere from 1 to 14 days after exposure to the bacterium and can range from mild to severe. If left untreated, tularemia can be serious and potentially fatal, so prompt diagnosis and treatment are important.


Pathogenesis


The pathogenesis of tularemia involves the infection and replication of the bacterium Francisella tularensis in the host organism. Here is a general overview of the process:
1. Initial infection: The bacterium can enter the body through various routes such as insect bites, handling infected animals, inhalation of contaminated dust or aerosols, or direct contact with infected tissues or bodily fluids.
2. Bacterial replication: Once inside the host, the bacterium replicates and spreads to nearby tissues and organs, causing inflammation and tissue damage.
3. Immune response: In response to the infection, the host's immune system activates and produces various cytokines and immune cells to fight the bacterium.
4. Tissue damage and symptoms: As the bacterium continues to replicate and spread, it causes tissue damage and the release of toxins, leading to the symptoms of tularemia.
5. Complications: In severe cases, the bacterium can spread to the bloodstream and cause a systemic infection, leading to sepsis and potentially fatal complications.
It is important to note that the course of tularemia can vary depending on the route of infection, the virulence of the strain, and the host's immune response. Early diagnosis and treatment with antibiotics can help to minimize the severity of the disease and improve the outcome.


Diagnosis


Diagnosis of tularemia is typically based on a combination of the patient's symptoms, medical history, and laboratory tests. The following methods may be used to diagnose tularemia:
1. Physical examination: The doctor will examine the patient and look for signs of infection, such as skin ulcers, swollen lymph nodes, or conjunctivitis.
2. Medical history: The doctor will ask the patient about their recent activities and any potential exposure to infected animals or contaminated environments.
3. Blood tests: Blood tests can be used to detect the presence of the bacterium or antibodies against it, or to identify any changes in the body's normal functioning that may indicate infection.
4. Cultures: Culturing the bacterium from a sample of infected tissue (e.g. skin ulcer, sputum) can confirm the diagnosis of tularemia.
5. Serological tests: Serological tests, such as the enzyme-linked immunosorbent assay (ELISA), can detect antibodies against the bacterium in the patient's blood.
6. Imaging tests: Imaging tests, such as chest X-rays or computed tomography (CT) scans, can be used to look for signs of infection in the lungs or other organs.
It is important to seek prompt medical attention if you suspect you have been exposed to tularemia or if you develop symptoms of the disease. Early diagnosis and treatment can improve the outcome of the disease and reduce the risk of complications.




Treatment


Tularemia can be treated with antibiotics, and early diagnosis and treatment can lead to a full recovery. The specific type of antibiotics and length of treatment depend on the severity of the disease and the specific strain of the bacterium causing the infection. Some commonly used antibiotics for tularemia include:
1. Streptomycin
2. Gentamicin
3. Tetracycline
4. Chloramphenicol
5. Fluoroquinolones (e.g. ciprofloxacin)
In severe cases of tularemia, hospitalization may be necessary to receive intravenous antibiotics and supportive care. In addition to antibiotics, supportive measures such as rest, hydration, and pain management may also be recommended.
It is important to complete the full course of antibiotics even if you start feeling better, as this can help to prevent the development of antibiotic-resistant strains of the bacterium and ensure that the infection is fully treated. If tularemia is not treated, it can lead to serious and potentially fatal complications.