Tularemia: An Overlooked Zoonotic Disease

Tularemia is a re-emerging zoonotic disease caused by Francisella tularensis, Gram-negative, facultative intracellular bacterium classified under Category A bioterrorism agent and endemic presence in various regions of the Northern Hemisphere. It affects over 100 animal species and poses a serious threat to human health. Transmission occurs through arthropod vectors, direct animal contact, ingestion of contaminated materials and aerosol inhalation (Troha et al., 2022). The pathogenesis involves evasion of immune responses through inhibition of phagosome-lysosome fusion and inflammasome activation, facilitating intracellular survival and dissemination (Celli and Zahrt, 2013). Clinical presentations in humans and animals vary depending on the route of infection, with ulceroglandular, pneumonic, typhoidal and oropharyngeal forms being most common. Gross pathological lesions include pulmonary congestion, splenomegaly, hepatomegaly and enlarged lymph nodes. Histopathologically, affected organs exhibit multifocal necrosis, lymphoid depletion, granulomatous inflammation and necrotizing pneumonia. Tularemia remains underdiagnosed, especially in developing countries like India (Buettcher et al., 2024). Global distribution and increasing incidence of tularemia are driven by climate change, expanding vector habitats and human-wildlife interactions. Laboratory diagnosis requires biosafety level 3 containment for culture, while serological and molecular methods such as MAT, ELISA and PCR are commonly employed. A One Health approach integrating human, veterinary and environmental health sectors is essential for surveillance, early detection and outbreak preparedness. Strengthening interdisciplinary collaboration by enhancing awareness, diagnostics and vaccination research in addressing this overlooked zoonotic disease.