Tularemia (rabbit fever) serious symptoms causes treatment
Tularemia, also known as “rabbit fever,” is a rare bacterial disease that can cause significant concern due to its ability to spread from animals to humans, particularly rabbits, rodents, and blood-feeding insects. Although it is not a common infection, its seriousness lies in the fact that it often begins with mild flu-like symptoms such as fever and fatigue, but may progress in some cases to more severe complications if it is not diagnosed and treated in a timely manner.The presentation of tularemia varies depending on the route of infection. It may appear as skin ulcers, swollen lymph nodes, or even respiratory symptoms when the bacteria are inhaled. Because of this wide range of manifestations, early understanding of the disease and awareness of its causes and transmission routes are essential for prevention and reducing potential risks.In this article from Dalili Medical, we will take a comprehensive look at tularemia, covering its causes, symptoms, methods of diagnosis, as well as treatment options and prevention strategies.
What is tularemia (rabbit fever)?
Tularemia, also known as “rabbit fever,” is a rare but potentially serious bacterial infection caused by Francisella tularensis. It is a zoonotic disease, meaning it spreads from animals to humans, most commonly from rabbits and rodents. Infection can occur through tick or deer fly bites, direct contact with infected animals, ingestion of contaminated food or water, or in rare cases, inhalation of airborne bacteria.
Symptoms usually begin with a sudden fever, skin ulcers, and swollen lymph nodes, but the clinical picture can vary widely depending on how the bacteria enter the body. With early diagnosis, tularemia is highly treatable using appropriate antibiotics.
Is tularemia dangerous?
Yes, tularemia can be dangerous if left untreated. However, it is also a curable disease in most cases when diagnosed early and treated properly with antibiotics.
Is tularemia contagious between humans?
❌ No, tularemia is not usually spread from person to person.
Infection typically occurs through:
- Contact with infected animals
- Bites from infected insects (ticks and deer flies)
- Consumption of contaminated food or water
What is the incubation period?
Symptoms usually appear within 3 to 5 days after exposure, but in some cases, it may take up to 14 days.
Which animals commonly transmit tularemia?
The main animal reservoirs include:
- Wild rabbits (most commonly associated)
- Rodents such as mice, rats, and squirrels
- In rare cases, domestic pets like cats and dogs
Can tularemia be completely cured?
Yes, most patients recover fully, especially when treatment is started early. Antibiotics are highly effective in treating the infection.
Is there a vaccine for tularemia?
❌ No, there is currently no widely available vaccine for the general public.
Can pets transmit the disease?
Rarely. Cats and dogs may become infected if they hunt or come into contact with infected animals, but transmission to humans is uncommon.
How long does tularemia last?
Without complications, symptoms may last around three weeks. With proper antibiotic treatment, recovery is usually complete.
Antibiotic therapy typically lasts 10–21 days, depending on severity.
Most common form of tularemia
The most common form is ulceroglandular tularemia, characterized by:
- A skin ulcer at the infection site
- Painful swelling of nearby lymph nodes
Animals most affected by tularemia
Tularemia can affect several animal species, but some are more commonly involved:
- Wild rabbits (most well-known and highly susceptible)
- Rodents (mice, rats, squirrels, and field animals)
- Domestic rabbits (less common but possible)
- Small wild carnivores (like foxes, when they eat infected prey)
- Rare aquatic-associated rodents (such as beavers)
- Pets (rare cases in cats and dogs)
Types of tularemia
Tularemia is classified based on how the bacteria enter the body:
- Ulceroglandular tularemia (most common)
- Skin ulcer at infection site
- Painful lymph node swelling
- Fever and fatigue
- Glandular tularemia
- Swollen lymph nodes without visible skin ulcer
- High fever and general illness
- Oculoglandular tularemia
- Infection through the eye
- Eye redness, pain, discharge
- Swollen lymph nodes near face/neck
- Oropharyngeal tularemia
- From contaminated food or water
- Severe sore throat, difficulty swallowing
- Abdominal pain, nausea, diarrhea
- Pneumonic tularemia (most severe form)
- Caused by inhalation of bacteria
- Cough, chest pain, shortness of breath
- High fever; can be life-threatening
- Typhoidal tularemia
- General systemic infection
- High fever, fatigue, muscle pain
- No clear local symptoms, harder to diagnose
Causes of tularemia
The disease is caused by the bacterium Francisella tularensis, one of the most infectious bacteria known.
Main transmission routes include:
- Contact with infected animals (especially during handling, hunting, or skinning rabbits and rodents)
- Tick and deer fly bites
- Inhalation of contaminated dust or aerosols (rare but possible)
- Consumption of contaminated food or water
- Consumption of contaminated food or water
Drinking unclean or untreated water
Eating food contaminated with bacteria - Entry of bacteria through the skin or eyes
Through small cuts or scratches
Or by touching the eyes after exposure to a contaminated source
Third: Factors that increase the risk of infection
Handling wild animals or hunting
Living in rural or forested areas
Exposure to insect bites (ticks and flies)
Poor hygiene or lack of proper sterilization practices
Symptoms of Tularemia (Rabbit Fever)
Tularemia symptoms vary depending on how the bacteria enter the body—whether through the skin, eyes, respiratory system, or digestive system.
First: General symptoms
Usually appear within 3 to 5 days after infection and include:
Sudden high fever
Chills and shivering
Severe headache
Extreme fatigue
Muscle and joint pain
Loss of appetite
Second: Symptoms according to infection type
1. Skin form (Ulceroglandular) – most common
Small ulcer at the site of infection
Swollen and painful nearby lymph nodes
Local redness or inflammation
2. Glandular form
Painful swelling of lymph nodes
No obvious skin ulcer
3. Ocular form
Redness and pain in the eye
Discharge and inflammation
Swelling of lymph nodes in the face or neck
4. Respiratory form (Pneumonic) – most dangerous
Dry or productive cough
Chest pain
Difficulty breathing
High fever
5. Gastrointestinal form
Abdominal pain
Nausea and vomiting
Diarrhea
Sore throat
Third: Advanced cases symptoms
If not treated early, the following may occur:
Severe weakness
Significant weight loss
Worsening health condition
Serious complications in the lungs or blood (rare)
Diagnosis of Tularemia (Rabbit Fever)
Diagnosing tularemia can sometimes be difficult at the early stage because its symptoms resemble common illnesses such as influenza or other bacterial infections. Therefore, diagnosis relies on a combination of medical history, clinical examination, and laboratory tests.
First: Medical history (most important step)
The doctor asks about possible exposure, such as:
Handling wild animals, especially rabbits and rodents
Exposure to tick or fly bites
Hunting, slaughtering, or animal handling work
Drinking unsafe water or living in contaminated rural areas
✔ This information is essential for suspecting tularemia.
Second: Clinical examination
The doctor may observe:
High fever
Skin ulcers in some types
Painful lymph node swelling
Eye or throat inflammation depending on infection type
Respiratory signs in pulmonary cases
Third: Laboratory tests
1. Blood tests
Increased white blood cells
Elevated inflammatory markers (CRP, ESR)
⚠️ Not sufficient alone for diagnosis
2. Serology (antibody tests)
Measures antibodies against Francisella tularensis
Used to confirm infection
May require two samples over time
3. Bacterial culture
Samples may be taken from:
Blood
Skin ulcers
Lymph nodes
Attempt to isolate the bacteria in the lab
⚠️ Requires specialized laboratories due to safety concerns
4. PCR test
✔ Most accurate and fastest test
Detects bacterial genetic material directly
Useful for early or advanced diagnosis
Fourth: Imaging tests (if needed)
Used especially in respiratory or advanced cases, such as:
Chest X-ray
CT scan
✔ To assess lung or lymph node involvement
Complications and harms of Tularemia (Rabbit Fever)
Tularemia may begin with mild flu-like symptoms such as fever and fatigue, but if not diagnosed and treated early, it can lead to serious complications depending on the route and severity of infection.
1. Severe infections and general deterioration
Persistent high fever
Severe weakness and fatigue
Loss of appetite and weight loss
Rapid health decline if untreated
2. Painful lymph node swelling
Visible and painful swelling in the neck, armpit, or groin
Abscess formation (pus collections)
Sometimes requires medical drainage intervention
3. Skin complications
Deep skin ulcers at the site where the bacteria entered the body
Slow wound healing
Possible secondary bacterial infection
4. Respiratory system complications (most dangerous)
In pulmonary cases:
Severe pneumonia
Shortness of breath and breathing difficulty
Chest pain
In severe cases, it may progress to respiratory failure
5. Systemic spread of infection (sepsis)
Bacteria entering the bloodstream
Very high fever
Low blood pressure and circulatory collapse
Can be life-threatening if not treated promptly
6. Eye complications (ocular form)
Severe eye inflammation
Persistent pain and discharge
Temporary vision impairment
Swelling of nearby lymph nodes
7. Digestive system complications
If infection is transmitted through food or water:
Severe diarrhea
Abdominal pain
Vomiting and dehydration
Treatment of Tularemia (Rabbit Fever) with Medications
Tularemia is a bacterial infection, so treatment mainly depends on antibiotics. There are no alternative drugs or home remedies capable of eliminating the bacteria. Early treatment greatly increases the chances of recovery and reduces complications.
First: Main antibiotics (first-line treatment)
1. Gentamicin
✔ One of the most important and powerful treatments
Given by injection (intramuscular or intravenous)
Used in moderate to severe cases
Duration: usually 7–10 days
2. Streptomycin
✔ Classic traditional treatment for tularemia
Given via intramuscular injection
Highly effective in killing the bacteria
Advantages:
Fast and strong effect
Often used in severe cases
Second: Alternative antibiotics
1. Doxycycline
Taken orally
Used for mild to moderate cases
Suitable for outpatient treatment
Duration: 14–21 days
2. Ciprofloxacin
Oral or intravenous antibiotic
Common alternative for non-severe cases
Advantages:
Easy to use
Effective in many cases
3. Chloramphenicol
Used in special cases
Especially when complications like meningitis occur
Third: Hospital treatment (severe cases)
In advanced or pulmonary cases, the patient may need:
Intravenous antibiotics
Monitoring of breathing and vital signs
Oxygen or fluid support if needed
Treatment of complications such as pneumonia or sepsis
Fourth: Supportive treatment
May include:
Antipyretics (e.g., paracetamol)
Pain relievers
IV fluids for dehydration
Anti-nausea or anti-diarrheal medications if needed
Fifth: Treatment duration
Mild cases: 10–14 days
Moderate to severe cases: 7–10 days (injectable therapy) with follow-up
Duration may vary depending on severity and response
Sixth: Important notes
Treatment must be done under medical supervision only
Do not delay starting antibiotics
Stopping treatment early may cause relapse
Some cases require hospital admission
Surgical interventions in Tularemia (Rabbit Fever)
Although tularemia is primarily treated with antibiotics, surgery may be needed in some cases to manage complications—not to treat the infection itself.
1. Incision and drainage of abscess
✔ Most common procedure
Used when pus collects in lymph nodes
The doctor makes a small incision to drain pus
Then the area is cleaned and disinfected
When used:
Painful or enlarged abscess
Abscess not responding to medication
2. Lymph node excision
✔ Less common
Complete removal of the infected lymph node
When used:
Severe persistent swelling
Chronic or recurrent infection
3. Wound and ulcer debridement
✔ Used in advanced skin cases
Removal of dead or infected tissue
Cleaning the ulcer to prevent spread
Benefit:
Faster healing
Reduced risk of secondary infection
4. Respiratory surgery (very rare)
May include drainage of fluid around the lungs
Only in exceptional severe cases
Used when drug therapy fails
5. Emergency surgery in sepsis (very rare)
Not for tularemia itself
Used only for severe tissue complications or widespread abscesses
When is surgery needed?
Surgery is not a primary treatment and is only used when:
Large abscess formation occurs
Antibiotics fail
Severe localized complications develop
Tissue damage is present
Prevention of Tularemia (Rabbit Fever)
Prevention focuses on avoiding exposure to the bacteria and reducing contact with infected sources.
First: Avoid contact with infected animals
Stay away from wild animals such as:
Rabbits
Rodents (mice, squirrels)
Do not touch sick or dead animals
Wear gloves when handling animals or hunting
Wash hands thoroughly after contact
Second: Safe hunting and slaughter practices
Wear protective gloves when handling animal meat
Avoid direct contact with blood or tissues
Clean tools thoroughly after use
Dispose of animal remains safely
Third: Protection from insect bites (ticks and flies)
Use insect repellent on skin and clothing
Wear long sleeves and pants in rural or forest areas
Check the body after outdoor exposure
Remove ticks properly if found
Fourth: Safe drinking water
Avoid untreated water from rivers or open wells
Boil or disinfect water when necessary
Maintain clean water sources
Fifth: Personal hygiene
Wash hands regularly with soap and water
Clean and cover wounds immediately
Avoid touching eyes, mouth, or face after animal contact
Sixth: Protection in high-risk occupations
Such as farms, hunting, or laboratories
Use protective equipment
Follow biosafety guidelines
Regularly disinfect tools and surfaces
Seventh: Safe handling of animal carcasses
Do not handle dead animals without protection
Use proper tools and protective clothing
Dispose of or bury carcasses safely
Eighth: Awareness and early detection
Seek medical help if symptoms appear such as:
Sudden fever
Swollen lymph nodes
Skin ulcers after animal or insect exposure
Always inform the doctor about exposure history to help diagnosis