Tularemia: causes, forms, diagnosis, and prevention

Clinical features and routes of transmission

Symptoms depend on how the bacterium enters the body. Typical early signs include fever, fatigue and swollen lymph nodes. Distinct clinical presentations are recognized:

• Ulceroglandular: skin ulcer at the entry site plus regional lymphadenopathy.
• Glandular: swollen lymph nodes without an obvious skin lesion.
• Oculoglandular: eye inflammation after contamination.
• Oropharyngeal: sore throat and gastrointestinal complaints following ingestion of contaminated food or water.
• Pneumonic: primary lung infection after inhalation, or secondary spread to the lungs.
• Typhoidal: systemic illness with fever and malaise without localized signs.

Diagnosis and treatment

Diagnosis combines clinical suspicion with laboratory tests such as culture, serology and molecular methods (PCR). Because Francisella tularensis can be hazardous to laboratory staff, special precautions are used during culture. The disease is treatable; several classes of antibiotics are effective when given appropriately. Choice of agent and duration depend on disease severity and local guidelines, and treatment is usually guided by infectious-disease specialists.

History, epidemiology and public health

Tularemia occurs mainly in the temperate zones of the Northern Hemisphere, with sporadic cases and local outbreaks linked to animal reservoirs, insect bites (ticks, flies), contaminated water, or handling infected carcasses. Historically the bacterium and disease were described in the early 20th century and the organism bears the name of a researcher associated with those investigations. Certain subspecies or strains differ in geographic distribution and virulence, and the infection is considered notable for its low infectious dose in some forms.

Prevention and notable facts

Prevention focuses on avoiding exposure: use insect repellents and protective clothing in endemic areas, cook game meat thoroughly, avoid handling sick or dead animals without protection, and follow safe laboratory practices. Vaccination has been developed for high-risk groups and laboratory personnel in some settings but is not in routine civilian use. Because of its infectious properties, tularemia is monitored by public health authorities; suspected cases should be reported and managed promptly.