Introduction

Tularemia is a rare, infectious disease commonly seen in Europe and is fatal when left untreated. The disease is generally transmitted from contaminated water or infected insects.¹ It begins with flu-like symptoms and later develops into a more severe disease characterised by skin ulcers, conjunctivitis and sometimes pneumonia.² Current treatment options for tularemia are limited to different types of antibiotic therapy. 

Due to limited knowledge and understanding of tularemia, the disease is commonly misdiagnosed as any common bacterial infection.³ Because of this, patients receive the incorrect treatment, allowing the disease to progress, which increases the patients’ risk of developing severe symptoms and possibly even death.  

It is important to increase awareness about tularemia and its symptoms to ensure that patients are treated for the disease immediately. Here, we present a brief overview of tularemia, including its transmission to humans, common symptoms, diagnosis, standard therapies and information on how to prevent the disease. 

What is tularemia?

Tularemia, also called ‘rabbit fever’, is a rare disease caused by a specific type of bacteria called Francisella tularensis.¹ This bacterium is highly infectious and can be harmful at low counts. It is categorised as a class A bioterrorism agent. This means it can be used as a biological weapon to cause death and disease in humans, which emphasises how damaging it can be.³

As of 2020, there were 641 confirmed tularemia cases in Europe.² The disease is most commonly found in the northern hemisphere, particularly Europe and Canada.⁴ However, tularemia infection has not been found to happen in the United Kingdom, Iceland and Ireland, according to the European Centre for Disease Prevention and Control, and most frequently occurs in Sweden and Finland. Tularemia cases generally increase during the summer and early spring, and are more common in individuals assigned male at birth (AMAB) than in individuals assigned female at birth (AFAB).⁵

How is tularemia transmitted?

Tularemia can be transmitted to humans from animals, contaminated food or water and dust through various routes such as:¹

• Eating/drinking food or water which is contaminated with the bacteria
• Direct transmission from infected animals 
• Bites from animals which have the bacteria (i.e. mosquitoes and ticks) 
• Inhaling dust contaminated by the bacteria

As a result, the likelihood of becoming infected increases in people handling meat or animals such as sheep, farmers, laboratory workers and veterinarians.⁵ It is important to be careful if you fit into one of these categories and take precautions to prevent transmitting the disease, which we discuss later in this article. 

The most common method of transmission varies between regions. Drinking contaminated water from rivers, streams, etc. is the most common route of infection in some regions. However, mosquito bites are the main cause of tularemia in Finland and Sweden.⁶ 

What are the symptoms of tularemia?

Tularemia symptoms may differ depending on the route of transmission. In the early stages of the disease (3-5 days), tularemia patients will experience symptoms similar to the common flu.² Unfortunately, this can lead to misdiagnosis and fatal consequences. After this, patients will develop more severe symptoms like skin ulcers and conjunctivitis.² In severe cases, patients may develop pneumonia or meningitis, both of which are extremely life-threatening.²  A list of tularemia symptoms is provided below: 

• Fever
• Nausea and vomiting
• Chills
• Fatigue
• Skin ulcers
• Swollen lymph nodes
• Conjunctivitis 
• Respiratory issues
• Pneumonia 
• Meningitis 

In one case, a 13-year-old individual AMAB was bitten by an insect and initially experienced fever, nausea, swollen lymph nodes and ulceration after being admitted to the hospital. Due to these nonspecific symptoms, the patient was misdiagnosed and treated with antibiotics for common skin infections. The patient’s health got progressively worse. His ulcers grew larger, lymph nodes became more swollen, and fever became enhanced, and professionals suspected the patient may have cat scratch disease, a different infection with similar symptoms. It wasn’t until five weeks after the patient’s disease progressively deteriorated that he was finally diagnosed with tularemia and received appropriate antibiotic treatment.³ 

This is one of many cases where patients have been misdiagnosed and underlines the importance of correctly diagnosing a patient to treat the disease as early as possible, ensuring that the disease doesn’t progress into an irreversible, dangerous state. 

How is tularemia diagnosed?

To diagnose tularemia, a patient’s symptoms are recorded, particularly the occurrence of fever, headaches and ulcers.⁵ Next, their medical history is taken, along with their travel history, such as: 

• Ingestion of outdoor water
• Engagement in outdoor activities such as hunting
• History of insect bites 

Next, biological samples, such as blood or skin from an ulcer, are taken to identify the bacteria. Laboratory tests are done to identify F. tularensis bacteria, and if the bacteria are present, the patient is diagnosed with tularemia.⁵

Standard therapies for tularemia

Currently, the main treatment for tularemia is antibiotic therapy, and no vaccine is available to treat or prevent the disease.⁷ Antibiotic therapy is always used to treat the disease, despite the patients’ symptoms. Different classes of these antibiotics may be used depending on the patient and the route of transmission. For example: 

• Aminoglycosides:  A class of antibiotics, such as streptomycin and gentamicin, is the most common treatment. These antibiotics are injected into the patient’s muscles or veins ⁵
• Tetracyclines: Another class of antibiotics, such as doxycycline, is also used to treat the disease, although less commonly. These drugs are taken orally 
• Fluoroquinolones: Another class of antibiotics has been approved to treat tularemia. An example of this is ciprofloxacin

If left untreated, between 5% to 15% of patients will die from the disease. Following successful antibiotic treatment, the death rate declines to 2%. However, many who do survive are left with lung damage, kidney damage and muscle loss, and relapse, where the disease returns, occurs frequently.^2,5 

Although antibiotics are effective in treating tularemia, they can be toxic to patients, particularly to pregnant women and children.⁷ This, along with high relapse rates, highlights the urgency to find new treatment methods for tularemia.^8,9 

How to manage tularemia symptoms? 

If you are experiencing tularemia symptoms, it is crucial to go to the doctor and receive a correct diagnosis immediately. If you are prescribed medicine, take the entire course as per your doctor’s instructions until the course is finished. You must not stop taking your antibiotics early, as this may cause the disease to return. 

It is important to get plenty of rest and stay hydrated while you are recovering. If you are experiencing flu-like symptoms or joint pain, check with your healthcare provider before taking any additional medication. 

How can I prevent tularemia?

According to the Centres for Disease Control and Prevention, there are many ways to reduce your risk of developing tularemia, including: 

• Using insect repellents to prevent insect bites 
• Wear long clothing whilst hiking
• Remove ticks immediately with tweezers
• Check the ground to ensure you don't run over dead animals when mowing or landscaping 
• Wear gloves when handling and hunting animals, and properly cook animals if you intend to eat them

FAQs 

Do I need to go to a hospital to be treated for tularemia?

Most of the time, patients can complete a course of antibiotics at home. However, hospitalisation and intensive care may be necessary in more severe cases, such as when pneumonia has set in. This underlines the importance of getting a diagnosis and the correct treatment as soon as possible. 

Is tularemia resistant to antibiotics? 

Antibiotic resistance is when the bacteria no longer respond to treatments and can continue to survive during treatment. In general, this is a growing issue, and something to be cautious about, but this is rare for tularemia.⁹ However, due to incorrect treatment or if the course of antibiotics is incomplete, the disease may return or take longer to go away. 

How long is the treatment course for tularemia? 

The symptoms of tularemia can vary depending on the patient and route of transmission, and the treatment options will differ depending on this. Therefore, the duration of treatment is generally between 10 and 21 days, but can be longer in severe cases. 

What are the side effects of tularemia treatment? 

Depending on the treatment you receive, the side effects may differ. Common antibiotic side effects include headaches, dizziness, changes to your vision, and ringing in your ears. It is important to check with your doctor which side effects are specific to the antibiotics you are taking, and tell your doctor immediately if you notice any of these side effects. 

Summary

In summary, tularemia is a disease which is often overlooked, causing larger issues for patients and increasing the severity of the disease. The correct diagnosis and treatment of tularemia are crucial to prevent life-threatening situations.

Once diagnosed, there are effective treatment options, which may differ depending on the type of tularemia infection and the patient being treated. Despite this, the disease commonly returns,  and it can be harmful to children and pregnant women. Further research must be done into new treatment options for the disease. 

The take-home message is that the general public and healthcare professionals must be more aware of tularemia, its symptoms and the risk it carries. If you are experiencing symptoms of tularemia, contact your doctor immediately and inform them of any exposures you have had to bites, animals or contaminated water.