Antibacterials for the prophylaxis and treatment of bacterial endocarditis in children

Although the overall incidence of infective endocarditis in the paediatric population is considered to be low, over the last 20 years a rising trend in infective endocarditis has been observed among children. This could be due to several reasons including the availability of improved diagnostic techniques, use of continuous central venous catheters and cardiac implants increasing the risk of infection, and the survival of a greater number of infants with congenital heart disease as a result of improved medical management. The predominant causative organisms of paediatric endocarditis include staphylococci and streptococci. There is increased concern surrounding the emergence of endocarditis in children caused by methicillin-resistant Staphylococcus aureus and drug resistant strains of Streptococcus pneumoniae. The treatment approach to paediatric endocarditis is similar to that for adult patients with endocarditis because of similarities in disease pathogenesis and aetiology. The therapeutic goal is to achieve sterilisation of the cardiac vegetations. The choice of antibacterial is dependent upon the susceptibility profile of the causative organism. Vancomycin or gentamicin is recommended for enterococcal endocarditis, according to guidelines from the American Heart Association. For staphylococcal endocarditis in patients with no prosthetic valve, oxacillin or nafcillin with or without gentamicin is the treatment of choice. In the case of endocarditis caused by methicillin-resistant S. aureus, vancomycin is commonly used in patients with no prosthetic valve and a combination of vancomycin, gentamicin and rifampicin (rifampin) for patients with prosthetic material. Cefazolin or ceftriaxone is the treatment of choice for penicillin allergic paediatric patients with endocarditis caused by viridans streptococci. While there have been no major changes in endocarditis therapy for the last decade, the current focus is on the recognition of multiple-drug resistant pathogens and the use of newer agents such as quinupristin/dalfopristin in the treatment of resistant bacterial endocarditis. Prophylactic antibacterial therapy is recommended for procedures thought to be associated with the occurrence of bacteraemia involving organisms commonly associated with endocarditis. These include dental extractions and oral, respiratory tract, genitourinary, gastrointestinal or oesophageal procedures. Prophylactic antibacterials recommended by the American Heart Association during genitourinary and gastrointestinal surgical procedures in high risk patients include ampicillin + gentamicin or vancomycin + gentamicin in high risk patients with penicillin allergy. Ampicillin has been recommended for prophylaxis of bacterial endocarditis in children undergoing oral, respiratory tract or oesophageal procedures. In the case of penicillin allergy in these patients, cephalosporins, clindamycin, azithromycin or clarithromycin have been recommended. The general consensus is that antibacterial prophylaxis during dental procedure is unnecessary, and in fact propagates bacterial resistance.