Infective endocarditis

Infective endocarditis is an infection of the inner surface of the heart, usually the valves. Symptoms may include fever, small areas of bleeding into the skin, heart murmur, feeling tired, and low red blood cell count. Complications may include valvular insufficiency, heart failure, stroke, and kidney failure.Ultrasound showing infectious endocarditisUltrasound showing infectious endocarditisUltrasound showing infectious endocarditisUltrasound showing another case of infectious endocarditis Infective endocarditis is an infection of the inner surface of the heart, usually the valves. Symptoms may include fever, small areas of bleeding into the skin, heart murmur, feeling tired, and low red blood cell count. Complications may include valvular insufficiency, heart failure, stroke, and kidney failure. The cause is typically a bacterial infection and less commonly a fungal infection. Risk factors include valvular heart disease including rheumatic disease, congenital heart disease, artificial valves, hemodialysis, intravenous drug use, and electronic pacemakers. The bacteria most commonly involved are streptococci or staphylococci. Diagnosis is suspected based on symptoms and supported by blood cultures or ultrasound. There is also a noninfective form of endocarditis. The usefulness of antibiotics following dental procedures for prevention is unclear. Some recommend them in those at high risk. Treatment is generally with intravenous antibiotics. The choice of antibiotics is based on results of blood cultures. Occasionally heart surgery is required. The number of people affected is about 5 per 100,000 per year. Rates, however, vary between regions of the world. Males are affected more often than females. The risk of death among those infected is about 25%. Without treatment it is almost universally fatal. Many microorganisms can cause infective endocarditis. These are generally isolated by blood culture, where the patient's blood is drawn and any growth is noted and identified. The term bacterial endocarditis (BE) commonly is used, reflecting the fact that most cases of IE are due to bacteria; however, infective endocarditis (IE) has become the preferred term. Staphylococcus aureus followed by Streptococci of the viridans group and coagulase negative Staphylococci are the three most common organisms responsible for infective endocarditis. Other Streptococci and Enterococci are also a frequent cause of infective endocarditis. HACEK group of microorganisms and fungi are seen less frequently in North America. The viridians group include S. oralis, S. mitis, S. sanguis, S. gordonii and S. parasanguis. The primary habitats for these organisms are oral cavity and upper respiratory tract. These bacteria are present in the normal oral flora and enter the bloodstream usually by dental surgical procedures (tooth extractions) or genitourinary manipulation; as such, dental surgeons must fully carry out protective and preventive measures. In some countries e.g. the USA, high risk patients may be given prophylactic antibiotics such as penicillin or clindamycin for penicillin allergic patients prior to dental procedures. Prophylactics should be bactericidal rather than bacteriostatic. Such measures are not taken in certain countries e.g. Scotland due to the fear of antibiotic resistance. Because bacteria is the most common cause of infective endocarditis (especially Streptococci), antibiotics such as penicillin and amoxycillin (for beta lactamase bacteria) are used in prophylaxis.