Differential features of Infective endocarditis caused by oral streptococci in the Reina Sofia University Hospital, Córdoba (Spain): 1987-2023 period.

Introduction and objectives: Infective endocarditis (IE) caused by oral streptococci is considered to be a 'more benign' IE than those caused by other microorganisms. Our aim is to analyse the changes in its incidence and its differential characteristics in our setting.

Methods: Observational, single-centre, prospective cohort study including all cases of IE diagnosed in our centre between 1987 and 2023. IE caused by oral streptococci were identified and their characteristicsand mortality were compared with those of other IE.

Results: Of 569 cases of IE, 104 (18.5%) were oral streptococcal IE, decreasing from 29.5% in 1987-1999 to 12.2% in 2000-2023 (p<0.001). The incidence of serious complications was lower in oral IE (65.3 vs. 78.9%; p=0.003), as was in-hospital mortality (14.4 vs. 29.9%; p=0.001).

Conclusions: Oral streptococcal IEs account for almost 20% of all IEs in our setting. They have a better prognostic clinical profile, with a lower incidence of serious complications, and their mortality is significantly lower than that of other IE. Their incidence seems to be decreasing in recent years.