Tularemia: a re-emerging zoonosis

Tularemia, caused by Francisella tularensis, presents cycles of re-emergence in the Northern Hemisphere. In 2024-2025, increased incidence has been documented in Central Europe (Austria: 117 cases; Slovenia: 38 cases; France: 150 cases) and Spain (Castile and León: 206 cases) while the United States reported 220 cases in 2024. These data, combined with advances in molecular diagnostics and therapeutics, underscore the need for updated clinical knowledge. Tularemia is classified as a Category A bioterrorism agent by the CDC due to its extraordinary virulence; as few as 10 bacterial cells can establish infection, and untreated cases carry 30% mortality. Clinical manifestations range from localized forms (ulceroglandular, glandular) to systemic presentations with risk of progression without treatment. Diagnostic advances include PCR and culture-independent whole genome sequencing. The 2025 CDC guidelines establish fluoroquinolones and doxycycline as first-line therapeutic options. Despite over seven decades of research, no licensed human vaccine exists, and disease control depends on preventive measure. This review provides an updated synthesis of the microbiological, epidemiological, clinical, and therapeutic aspects of tularemia, with emphasis on early diagnosis given the organism's epidemic potential.