Analysis of the frequency of bacteraemia of dental origin implicated in infective endocarditis in patients requiring valve surgery.

Understanding the frequency of bacteraemia of dental origin that is implicated in severe infective endocarditis (IE) will further our understanding of the disease's pathoaetiology and help us take steps to reduce its prevalence. A total of 78 patients from the Royal Papworth Hospital, Cambridge, who had valve surgery due to IE (as confirmed by the Modified Duke Criteria) were included. Case notes were retrospectively reviewed for microorganisms that were implicated in the bacteraemia and IE. Associated factors were also recorded to determine whether they were different if a dental or non-dental pathogen was inoculated. A dental pathogen was implicated in 24 of the patients with IE; 20 had non-dental pathogens, and 30 were culture negative. This was not deemed statistically significant (p=0.54). Of the associated factors, only smoking was statistically significant with a greater proportion of non-smokers having bacteraemia of dental origin (p=0.03). No other associated factor was appreciably different based on the aetiology of the microorganism. Our results indicate that dental pathogens are not more likely to cause severe IE. We therefore advocate the stance adopted by the current national guidance on the judicious prescription of antibiotic prophylaxis for IE with regard to dental procedures.