Runs Over a Roe Deer and Contracts Tularemia: The Strange Case of a Hunter That Highlights the Risks of Handling Wildlife

The case, published in The Lancet Infectious Diseases, is an exceptional example of an exposure route of particular interest to people who work with or engage in activities involving wildlife: contact between open wounds and the blood, tissues and fluids of a potentially infected animal.

A roe deer crashes through the windscreen and causes facial injuries

The accident occurred when a roe deer (Capreolus capreolus) was initially hit by another vehicle and thrown into the car driven by the patient. The animal crashed through the windscreen, and the man suffered several facial injuries, caused both by broken glass and by the impact with the deer itself.

The circumstance that later acquired medical significance was that the wounds were exposed to blood, body fluids, material from internal organs and soil during the accident. This sequence is relevant because Francisella tularensis, the bacterium responsible for tularemia, can enter the body through skin lesions or mucous membranes after contact with contaminated material.

Photograph taken on the day of the accident showing facial exposure to deer blood, other deer body fluids and soil. (B) Photograph taken on day 24 after the accident; the lower arrow indicates cervical swelling near the left mandibular angle and the upper arrow indicates a periorbital lesion. (C) Contrast-enhanced axial cervical computed tomography performed on day 30 after the accident; the arrow indicates an abscess representing multiple left-sided periparotid and intraparotid lesions.

Fever developed eight days later

The patient did not immediately develop the disease. Eight days after the accident, he began to experience fever, a lesion near his left eye and progressive swelling of the neck on the same side. Four days later, an ultrasound scan showed inflammation of the cervical lymph nodes, although no collection of pus was yet visible.

The patient was initially treated with amoxicillin, but the course of the disease was not as expected. The swelling continued to increase. One month after the accident, imaging tests showed that the process had progressed to form several abscesses in the parotid gland area and nearby tissues. Surgical drainage was also required.

The bacterium was found in the pus from the abscesses

The diagnosis came from analysing the material obtained during drainage. PCR detected specific DNA from Francisella tularensis, and subsequent tests identified the subspecies F. tularensis subsp. holarctica. Serology also supported the diagnosis. It should not be stated that a sample from the roe deer proved that the animal was infected. The available microbiological evidence concerns the patient. The authors consider exposure to the roe deer to be the explanation for the infection, given the extraordinary coincidence between contact with the animal’s fluids and the subsequent onset of the disease.

Amoxicillin failed to halt the infection

The initial treatment also provides an important lesson. Amoxicillin belongs to the beta-lactam group of antibiotics, against which F. tularensis has intrinsic resistance. The initial treatment therefore failed to control the infection. Once the microorganism had been identified, doctors changed the treatment to ciprofloxacin, initially administered intravenously and subsequently orally for 21 days.

The response was favourable. Three months later, the abscesses had disappeared and the patient was in good general health, although he still felt a slight tightness in his face.

What is tularemia, or “hare fever”?

Tularemia is an infectious disease caused by the bacterium Francisella tularensis.

The popular name “hare fever” comes from its well-known association with lagomorphs, especially hares, which are a classic source of infection. But the disease is not exclusive to rabbits and hares. F. tularensis can infect numerous animal species and reach humans through different routes. In Europe, the reference subspecies is F. tularensis subsp. holarctica. German scientific literature indicates that this is the known subspecies responsible for the disease in humans and animals in Germany.

Transmission can occur through contact with infected animals or their tissues, bites from certain arthropods, inhalation of contaminated material, or consumption of contaminated water or food.

A disease that also affects hunters

Handling wild animals is a recognised route of exposure. Skinning, gutting or handling game with wounds on the hands can facilitate entry of the bacterium, while splashes to the eyes or mucous membranes are another possible entry point.

German scientific literature has documented outbreaks associated with handling hares during hunting activities. In an outbreak investigated in Bavaria in 2018, 12 of the 41 participants in a hunting outing developed antibodies against F. tularensis. The infection occurred among people who were present while the hares were being processed, and the risk was particularly high among those directly involved in that task. In addition, the bacterium was isolated from one of the four hares analysed. This episode shows that the risk associated with handling wildlife is not merely theoretical.

The roe deer is not the only game species that may be involved

Although hares are probably the best-known example, tularemia has a broad host range. Studies of the disease in Europe describe infections associated with different wild mammals and various vectors. In Germany, the epidemiology of the disease is closely linked to wildlife and to environmental conditions that favour the circulation of F. tularensis.

The incubation period fits the accident

The onset of symptoms eight days after the accident is also compatible with tularemia. A study of an outbreak that occurred during a hare hunt in Germany reports that the incubation period is usually several days, although it can vary considerably depending on the route and dose of exposure.

Therefore, the fact that the patient appeared to be well during the first week does not rule out a link between the accident and the subsequent infection.

Swollen lymph nodes, a characteristic sign

The manifestations of tularemia depend largely on how the bacterium enters the body. When it enters through a skin wound, an ulceroglandular form may develop, characterised by a lesion at the entry point and involvement of nearby lymph nodes. When the entry point is ocular, an oculoglandular form may occur. Oropharyngeal, respiratory and systemic forms also exist. Some can follow a severe course.

The German patient presented precisely a combination compatible with an infection acquired through facial wounds and involving the lymph nodes in the cervical region.

Spain recorded 445 cases of tularemia between 2015 and 2024

The German case is relevant in Spain because tularemia is also present in the country. Data from the National Epidemiological Surveillance Network analysed by the Carlos III Health Institute recorded 445 cases between 2015 and 2024. The years 2019 and 2024 accounted for approximately 80% of all cases recorded during that decade, with 187 cases in 2019 and 169 in 2024.

The sex distribution also shows a marked male predominance: 337 of the 445 cases occurred in men, compared with 106 women and two cases in which sex was not recorded.

In 2024, 169 cases were reported, all locally acquired according to the national table, involving 135 men and 34 women.

Castile and León accounts for a large part of the problem

The epidemiology in Spain shows a highly uneven geographical distribution.

The sharp increase in 2019 was associated with a major outbreak in Castile and León. Between 2018 and 2022, this autonomous community accounted for 210 of the 227 cases recorded in Spain as a whole, according to the analysis published by the Carlos III Health Institute.

In 2024, Castile and León was once again the autonomous community with the highest number of cases and the highest notification rate. This makes certain areas of the Meseta, and particularly Castile and León, a territory of special interest from the standpoint of monitoring this zoonosis.

Tularemia does not mean there is a generalised danger in touching a roe deer

The German case is exceptional and should not be interpreted as meaning that running over or touching a roe deer normally entails a risk of tularemia. What made that situation particularly dangerous was the combination of several factors:

• The animal suffered severe trauma.
• Its body struck the driver directly.
• The windscreen caused open wounds.
• The injuries were exposed to blood and tissue.
• There was contact with fluids from internal organs.
• And the patient subsequently developed an infection compatible with that exposure.

This is very different from coming across a roe deer, observing one, or even having occasional contact without wounds.

Gloves and protection during butchering

The case shows that game animals should be handled with appropriate protective measures, especially when there is any suspicion of disease or when the animal has abnormal lesions. Wearing gloves reduces direct contact between the skin and the animal’s tissues. Wounds or cuts on the hands should be properly covered, and fluids or biological material must be prevented from reaching the eyes, mouth or nose.

In the case of suspected animals, German health recommendations also include measures to prevent the formation of dust or aerosols during handling and the use of respiratory and eye protection.

A zoonosis worth remembering when fever follows the handling of game

For a hunter, one of the key lessons of the case is epidemiological. Anyone who develops fever, a skin lesion and swollen lymph nodes after handling wildlife should tell their doctor about the contact with animals. Information about the exposure may be decisive in directing the diagnosis towards an uncommon disease that might otherwise initially be confused with other infections.

The German case shows precisely how an exposure apparently linked to a traffic accident ultimately proved to be an infection with Francisella tularensis.

An unusual case that leaves a very specific warning

The man did not become infected simply by “running over a roe deer”. The decisive circumstance was much more specific: his wounds were exposed to biological material from the animal and he subsequently developed tularemia. The scientific publication in The Lancet Infectious Diseases makes the episode an exceptional clinical case, but its message goes beyond the accident.

Tularemia continues to circulate in Europe and in Spain. For those who handle game animals, prevention involves something as basic as protecting the hands, eyes and airways when circumstances warrant it, and taking extra care with hygiene after handling a carcass.

The roe deer that crashed through that windscreen does not show that this species poses a habitual health danger. It does, however, remind us of a reality well known to veterinary medicine and epidemiology: wildlife can act as a source of pathogens, and some infections may appear several days after apparently forgotten contact.