Journal of Antimicrobial Chemotherapy doi:10.1093/jac/dkl299 Guidelines for the prevention of endocarditis: report of the Working Party of the British Society for Antimicrobial Chemotherapy—authors ’ response

Sir, Working Party guidelines were produced to update infective endocarditis (IE) prophylaxis guidelines based on current best evidence.1 Three major studies2–4 have failed to demonstrate a causative link between dental treatment and IE. As detailed in the guidelines, the risk of IE due to normal daily activities such as brushing of teeth or chewing is considerably greater than from a single dental procedure,5 therefore even if prophylaxis were assumed to be 100 % effective the overall benefit is negligible. This would also apply to moderate risk cardiac lesions. Of course, some cases of IE will occur following dental procedures6 but they may not be directly related. Indeed the use of prophylaxis has not decreased the incidence of IE7 and there are continued reports of failed prophylaxis.8 We agree with Dr Shanson’s9 observation that oral strepto