Understanding tularaemia’s origins, symptoms, treatment, and its presence in Europe. Tularaemia, also known as rabbit fever or deer fly fever, is a rare but potentially serious bacterial disease caused by the bacterium Francisella tularensis. This zoonotic disease can affect various mammals and birds, including rodents, hares, and rabbits. The Swedish public health authority Folkhalsomyndigheten has reported 208 cases from 14 different regions of Sweden as of September 16th, with numbers expected to rise due to the disease’s particular prevalence in the month of September in the Nordic nation.
Origins of Tularaemia
Tularaemia was first identified in the United States in 1911, during an outbreak in Tulare County, California, hence its name. Since then, it has been reported in many parts of the world, with varying frequencies. The causative agent, Francisella tularensis, is a highly infectious and resilient bacterium that can survive for weeks in water, soil, and even dead animal tissues. This resilience makes it challenging to eradicate from environments where it is established.
Causes of Tularaemia
Tularaemia is primarily caused by the bacterium Francisella tularensis, which is a highly infectious and intracellular pathogen. This bacterium has several subspecies, and the most common ones responsible for human infections are F. tularensis tularensis and F. tularensis holarctica. The disease can be contracted through various routes, including direct contact with infected animals or their tissues, inhalation of contaminated aerosols, ingestion of contaminated food or water, and insect bites from vectors like ticks and deer flies.
The bacterium is exceptionally hardy and can persist in the environment, making it a formidable pathogen in both urban and rural settings. Tularaemia is considered a zoonotic disease, as it primarily affects animals such as rabbits, hares, rodents, and birds, and can be transmitted to humans through close contact or exposure to infected animals or their habitats.
Symptoms of Tularaemia
Tularaemia can manifest in several forms, depending on the route of infection. The most common forms of tularaemia and their associated symptoms include:
Ulceroglandular Tularaemia: This is the most common form and typically occurs when the bacterium enters the body through a break in the skin, such as a cut or scratch. Symptoms may include a painful ulcer at the site of infection, swollen lymph nodes, fever, chills, fatigue, and headache.
Glandular Tularaemia: Similar to ulceroglandular tularaemia, this form results in swollen lymph nodes and flu-like symptoms but does not involve a skin ulcer.
Oculoglandular Tularaemia: This form occurs when the bacterium enters the eye, causing eye redness, irritation, and swelling of the lymph nodes near the eye.
Oropharyngeal Tularaemia: Ingesting contaminated food or water can lead to oropharyngeal tularaemia. Symptoms include sore throat, mouth ulcers, abdominal pain, vomiting, diarrhoea, and swollen lymph nodes.
Pneumonic Tularaemia: The inhalation of airborne F. tularensis particles can lead to pneumonic tularaemia, which can cause severe respiratory symptoms such as cough, chest pain, and difficulty breathing. This form is the most severe and can be fatal if not treated promptly.
Treatment of Tularaemia
Early diagnosis and prompt treatment with antibiotics are essential to successfully manage tularaemia. Commonly used antibiotics include streptomycin, gentamicin, and ciprofloxacin. The choice of antibiotic and duration of treatment depend on the severity of the infection and the patient’s overall health.
It is crucial to seek medical attention if you suspect you have tularaemia, as delayed treatment can lead to complications and worsen the outcome. Additionally, healthcare workers should take precautions when handling a patient with suspected tularaemia, as it is highly contagious.
Tularaemia in Europe
Tularaemia has been reported in various European countries such as the aforementioned cases in Sweden, with varying levels of prevalence. In Europe, the disease is primarily associated with hares and rabbits, and hunters, veterinarians, and others who handle or consume these animals are at higher risk of infection.
Some other European countries where tularaemia has been reported include Finland, Norway, and the Czech Republic. The bacterium’s presence in these regions is often linked to the presence of specific vectors, such as ticks and deer flies, which can transmit the disease to humans.
To prevent tularaemia in Europe, individuals in high-risk professions should take precautions, such as wearing gloves when handling animals, using insect repellent to prevent tick and fly bites, and practicing proper food hygiene when handling or consuming wild game.
Conclusion
Tularaemia is a bacterial disease caused by Francisella tularensis, with various forms and symptoms depending on the mode of transmission. Early diagnosis and appropriate antibiotic treatment are essential for a successful outcome. In Europe, tularaemia is a rare but present threat, particularly among those who come into contact with infected animals. Vigilance, proper precautions, and public health measures are essential to prevent and control tularaemia in this region.