A subcutaneous infection mimicking necrotizing fasciitis due to Butyricimonas virosa

Introduction: Butyricimonas virosa is a Gram-negative rod who was first identified in rat faces in 2009. Since then only six human infections have been described in literature of which five bacteremia and one bone abscess. We report a clinical case of a subcutaneous infection mimicking necrotizing fasciitis due to B. virosa. Patient and methods: A 78-year-old man was referred to our hospital because of a wound infection at the surgical site with suspicion of necrotizing fasciitis. Treatment consisted of immediate surgical exploration with obtainment of intra-operative specimens for microbiologic examination, 15 d of negative pressure wound therapy (NPWT) and antibiotic treatment with piperacillin-tazobactam (12 d) plus vancomycin (9 d). Results: Surgical exploration did not show necrotising fasciitis but a subcutaneous infection mimicking necrotising fasciitis. The results of the intra-operative specimens revealed the presence of B.virosa and Finegoldia magna. Cultures taken during the NPWT replacements became negative and the patient was able to leave the hospital after 18 d. Conclusions: Considering there was no necrotizing infection present it may have been possible to safely close the wound sooner. However, it is difficult to differentiate between an actual necrotizing fasciitis and a subcutaneous infection mimicking necrotizing fasciitis. Therefore further studies on effective assessment tools to diagnose necrotizing fasciitis, such as the (modified) laboratory risk indicator for necrotizing fasciitis (LRINEC) score and enhanced computed tomography (CT), could be helpful.