Epidemiological and clinical predictors of murine typhus in hospitalized patients in central israel: association with urban construction

Abstract

Murine typhus (MT), caused by Rickettsia typhi, is a zoonotic disease with a nonspecific clinical presentation, making diagnosis challenging. During 2022-2023, we observed in our hospital a rise in MT cases, prompting an investigation into clinical predictors and epidemiological factors, including potential links to a light rail system constructed in the hospital's vicinity. We conducted a retrospective case-control study of hospitalized febrile patients tested for rickettsial disease at the Wolfson Medical Center in central Israel (2022-2023). Cases were defined by positive R. typhi PCR or serology. Controls had negative testing for R. typhi (PCR and/or serology), with or without an alternative diagnosis, based on predefined criteria. Clinical, laboratory, and epidemiological data were analyzed, and residential proximity to the light rail construction site was assessed. Among 46 febrile patients tested for rickettsial disease, 18 were diagnosed with MT. Compared to controls, MT patients more frequently reported animal exposure and presented with headache, thrombocytopenia, bandemia, elevated liver enzymes, and increased LDH. Notably, MT patients lived significantly closer to the light rail system construction site than controls (mean 291.3 m vs. 836.2 m from the rail line, p = 0.022), with a 22% decrease in MT likelihood per additional 100 m distance. MT remains an important cause of febrile illness. Key diagnostic clues include animal exposure and specific laboratory markers. Our findings suggest an association between urban construction and MT, likely due to disrupted Rattus species habitats. Awareness of these risk factors may aid early diagnosis and treatment.

Keywords: Animal exposure; Murine typhus; Rickettsia; Urban construction; Zoonoses.