Dental consultation in initially unknown-source Staphylococcus aureus bacteremia : a retrospective single-center cohort study

Abstract

Background/Objectives: Identifying the source of Staphylococcus aureus bacteremia (SAB) is central to therapeutic management, but data on dental consultation in initially unknown-source SAB are scarce. We characterized its use, timing, and diagnostic yield, and described the underlying clinical findings and management recommendations through structured re-adjudication. Methods: Exploratory retrospective single-center cohort study of adult inpatients with blood-culture-confirmed SAB during 2025, classified at baseline as having an alternative-presumed-source or initially unknown-source SAB. A possible dental focus was defined as a dental condition exhibiting clinical signs of active infection at structured intraoral examination—regardless of whether the active infectious component arose on an acute or, more frequently, on a chronic structural substrate. In the absence of microbiological or molecular confirmation of an odontogenic origin, such findings were interpreted as a possible portal of entry in initially unknown-source patients and as concurrent oral pathology in patients with an alternative-presumed-source. Transesophageal echocardiography (TEE) and infective endocarditis were analyzed as contextual variables; infective endocarditis was extracted as documented by the treating team and was not centrally readjudicated against the modified Duke criteria. Results: Of 72 eligible patients, 53 (73.6%) had an alternative-presumed-source and 19 (26.4%) an initially unknown-source SAB. TEE was performed in 54 (75.0%) and infective endocarditis was diagnosed in nine (12.5%) patients, with similar rates in both subgroups. Dental consultation was requested in 17 patients (23.6%), including six of 19 with initially unknown-source SAB (31.6%); a possible dental focus was identified in five of six consulted unknown-source patients (83.3%; 95% CI 43.6–97.0) versus four of 11 alternative source patients (36.4%). This estimate reflects the yield among consultation-selected patients and is not generalizable to the wider unknown-source population. Cardiac and dental evaluation jointly contributed to source clarification in six of 19 unknown-source patients (31.6%). Structured re-adjudication by a blinded dental specialist showed findings dominated by chronic structural dental disease with active inflammatory components rather than classical acute odontogenic infection; active dental treatment was recommended in 11 of 17 patients (64.7%), including all unknown-source patients. Conclusions: Dental consultation was performed infrequently in SAB, yet among consultation-selected unknown-source patients it frequently identified clinically suspected oral foci and prompted concrete management, complementing echocardiographic evaluation. Given the exploratory single-center design and the absence of microbiological confirmation of an odontogenic origin, these findings should be interpreted as hypothesis-generating and warrant prospective evaluation with predefined dental criteria and linkage to bacteremia-relevant clinical outcomes.