streptobacillus moniliformis bacteremia in a patient with reactive arthritis without a bite: a case report

Introduction: clinically, rat bite fever (rbf) is a condition caused by spirillum minus or streptobacillus moniliformis infections, following rat or any rodent bite. in the absence of a rat bite, this condition cannot be accurately diagnosed. here, we report the first case of rbf due to s. moniliformis but without a rat bite in china. case presentation: a77-year-oldwomanwith reactive arthritiswasadmitted to the hospitaldueto high fever. initially,wesuspected reactive arthritis with liver function deterioration. however,weisolated a bacteriumwhichwasconfirmedto be s. moniliformis using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (maldi-tof ms). subsequently, the patient was given targeted anti-infective treatment, which completely resolved the symptoms. the patient was discharged upon fully recovery. conclusions: rat bite fever infection caused by s. moniliformis may occur without actual rodent bite. maldi-tof ms may be applied to determine the diagnosis of rbf. difficulties in pathogen and clinical diagnosis highlight the need for discovering the complete exposure history and a greater understanding of this rare zoonotic infections.