Clinical Characteristics and Treatment Strategies in a Cohort of Patients with Tularemia: A Retrospective Multicenter Analysis of 65 Cases in Germany.

Background: In recent years, there has been a significant increase in cases of tularemia, a rare zoonotic disease caused by Francisella tularensis, in Europe. Methods: To investigate the epidemiological, clinical, and therapeutic characteristics of tularemia patients in Germany, we performed a retrospective evaluation of tularemia cases treated between 2010 and 2025 at selected treatment centers of the Permanent Working Group of Competence and Treatment Centers for High Consequence Infectious Diseases (STAKOB) at the Robert Koch Institute. Results: A total of 65 patients (median age: 48.5 years; 66.2% male) were identified. Most common manifestation was ulceroglandular (70.7%), followed by oropharyngeal (13.8%), pulmonary (10.8%), oculoglandular (7.7%), typhoidal (4.6%), and meningitic (4.6%). Serological confirmation of the diagnosis was achieved in all patients (90.8% ELISA, 46.2% Western blot). PCR-based direct pathogen detection was successful in 26.2%. Bloodstream infection was detected in 4.6%. Median incubation period was 7 days (IQR: 4-10), with fever being the most common symptom in 96.9% and lymphadenopathy in 46.2%. Median time to recovery was 56 days (IQR: 37-80) in patients diagnosed and treated early (≤3 weeks after symptom onset), compared to 84 days (IQR: 66-182) in patients with late diagnosis (>3 weeks after symptom onset; p = 0.015). Empirical therapy with beta-lactam antibiotics was initiated in 49.2% of cases. Following suspicion of tularemia, 96.9% received recommended treatment with fluoroquinolones, tetracyclines, or aminoglycosides. Conclusions: Delayed diagnosis and inappropriate initial therapy can significantly prolong disease courses and increase morbidity. Early treatment with effective antibiotics, considering the intrinsic beta-lactam resistance of Francisella tularensis, leads to faster recovery.