Unusual increase in tularemia incidence in Alsace, Northeastern France in 2024

Abstract

Tularemia is a bacterial zoonosis endemic to the Northern Hemisphere, transmitted through various modes and presenting with diverse clinical manifestations. In recent years, the number of notifications (tularemia is a reportable disease in France) have increased and the spectrum of clinical forms have changed. We conducted a retrospective study of tularemia incidence diagnosed in 2024 at two major hospitals in Alsace, a small region of Northeastern France. This study included 10 cases (7 men and 3 women; mean age = 52 years) reported in 2024. Clinical forms comprised six ulceroglandular or glandular cases, two oropharyngeal forms, and two pleuropulmonary forms including a fatal case in a 73-year-old immunocompromised patient.. Three patients reported recent tick bites, while two others had frequent tick exposure. In 9 of the 10 cases, tularemia was not initially suspected by primary care physicians, leading to delayed diagnosis, inappropriate treatment, and complications. Nationwide, 150 cases were reported in 2024, including 33 from the Northeastern region, of which 10 were our cases. Compared to other regions of France, cases in Alsace showed a higher proportion associated with tick-related transmission. Our findings reveal a peak in tularemia incidence in Alsace in 2024. Primary care physicians often failed to recognize tularemia, resulting in delayed treatment and complications-even in cases with typical glandular forms. Tularemia is an increasing zoonosis that may be under recognized among general practitioners. There is a need for increased awareness and education among healthcare providers and the public.

Keywords: France; Outcome; Primary care; Tick-borne diseases; Tularemia; Zoonosis.