Health officials in New York are reporting at least three probable cases of tularemia, also known as "rabbit fever," on Long Island. The Suffolk County Department of Health stated that laboratory testing is required to confirm the diagnoses, a process that can take several weeks.
Tularemia is a rare but potentially serious illness caused by the bacterium Francisella tularensis. According to the Centers for Disease Control and Prevention (CDC), it is commonly transmitted through tick and deer fly bites that have fed on infected animals, such as rabbits, hares, muskrats, and rodents. The disease does not spread from person to person.
Humans can also contract tularemia by handling the skin of infected animals, inhaling dust or aerosols contaminated with the bacteria, or drinking contaminated water. Hunters who skin and eviscerate infected animals are at particular risk of contamination through direct contact with tissues.
Symptoms and Diagnosis
Symptoms of tularemia can vary depending on the mode of infection and range from mild to life-threatening. All forms of the illness include a fever that can reach up to 104 degrees Fahrenheit. The incubation period typically spans three to five days after exposure but can extend up to three weeks. Initial symptoms often mimic a severe flu, including sudden fever, chills, headache, body aches, and fatigue. What distinguishes tularemia is often the presence of a sore or ulcer at the site of infection, accompanied by swollen and painful lymph nodes nearby.
Specific forms of the illness include oculoglandular tularemia, which affects the eyes and nearby lymph glands, and oropharyngeal tularemia, which can result from ingesting contaminated food or water and may cause a sore throat, mouth ulcers, and swollen neck lymph glands. The most severe form, pneumonic tularemia, occurs when infected dust or aerosols are inhaled, leading to cough, chest pain, and difficulty breathing. This severe form can also develop if other types of tularemia are left untreated and the bacteria spread to the lungs.
Diagnosing tularemia can be challenging due to its rarity and the similarity of its symptoms to other common illnesses. Confirmation requires a combination of laboratory testing and specific clinical or epidemiological criteria.
Prevention and Treatment
Tularemia is treatable with commonly used antibiotics. Historically, a vaccine was available for laboratory workers who handle the bacteria, but it is currently under review by the Food and Drug Administration and is not widely accessible in the U.S.
To prevent infection, the CDC recommends using EPA-registered insect repellents containing DEET, picaridin, or other approved active ingredients when outdoors. Wearing long pants, long sleeves, and long socks can provide protection against ticks and deer flies, and prompt removal of attached ticks is advised.
Individuals should avoid mowing over sick or dead animals. When hunting, trapping, or skinning animals, wearing gloves is essential, and game meat should be thoroughly cooked before consumption.
Tularemia cases are relatively uncommon, with fewer than 200 reported annually in the U.S. between 2019 and 2023, according to CDC data. The illness is more common in males and typically occurs between May and September.