In the area of prevention, there is a very extensive literature and a continuing evaluation of the necessity of prophylaxis against infective endocarditis in patients with various valvular or endocardial lesions. Tables 4 and 5 show the latest American Heart Association guidelines for prophylaxis of infective endocarditis (18). Note that post-procedure antibiotics are no longer recommended. These prophylaxis guidelines are not meant to apply to all oral-dental procedures but to procedures that are likely to lead to bleeding and bacteremia, such as extraction or scaling and root planing. In the area of urological and gastrointestinal procedures, high risk for bacteremia is also the concern.
Prophylaxis is complex and much debated because of the concerns of the larger dental and medical community about the possible adverse effects of the use of antibiotics in their outpatients and the use of antibiotics before various procedures. The research un-
derpinnings of the need for prophylaxis are not complete. It appears that prophylaxis is very clearly indicated in the prosthetic valve patient (19). However, the effectiveness of the prophylaxis given (antibiotics) may not entirely be related to killing of the microorganisms by the antibiotic. There may be effects on organism adherence. Microorganisms that are causing bacteremia must adhere to the native or prosthetic valve and form a colony there in order to cause infective endocarditis. There are very complex mechanisms by which organisms adhere to native or prosthetic valves (20).
Because it would be unethical to return to a situation of zero prophylaxis, it may be impossible to complete our knowledge about the necessity of prophylaxis once and for all. It would not be ethical to have the no-therapy arms of the study, which would be necessary for such a determination.
It is possible, due to the changes in oral flora that are present in the elderly, that prophylaxis needs may change in the future. For instance, the overwhelming presence of streptococci in the mouths of many people may change to other organisms as they age (21). The new predominant oral organism after antibiotics, dentures, or implantations may be S. aureus, lactobacilli, yeast, or still other organisms (21).
There also may be increased prophylaxis required for the elderly for a variety of inhospital procedures. As much as possible, we should base prophylaxis on the true rates of bacteremia in the elderly who undergo various in-hospital procedures. However, the study of such rates of bacteremia is difficult. Bacteremia with some oral procedures has been carefully studied (22). Often it is necessary to proceed with prophylaxis in the absence of full knowledge about risks. The risk of reaction to the antibiotic given in prophylaxis is usually low compared with the risk of bacteremia and infective endocarditis resulting from the procedure. Ongoing studies and evaluation of the various needs for prophylaxis need to continue.
The overall prevention of infective endocarditis still depends not only on prophylactic antibiotics or other measures but on care to avoid unnecessary bacteremia in the elderly. Bacteremia from dental procedures and oral diseases can ultimately be prevented only by good dental and oral care, usually initiated by the patients themselves. Good dental care and self-care are probably associated with a lower risk of bacteremia due to dental sources (22). In addition, ignored skin problems are a frequent source of bacteremia in the elderly, which can only be avoided by the person's own careful care of their skin and attention to periodic skin infections such as boils, which will arise throughout the person's life. In a recent review, Kjerulf and colleagues have pointed out the need not only for earlier detection of infective endocarditis and earlier antibiotic therapy, but the need for educating patients who already have cardiac disease or cardiac valve prostheses (23). The patient's own vigilance for reducing the risk of infective endocarditis or for being aware of the early symptoms and signs of this infection may become one of the patient's best protective mechanisms. In addition, there is need to develop further early diagnostic tests that are able to detect the presence of infective endocarditis (23). Overall, it is to be expected that infective endocarditis will become an ever more important infection in the elderly. The older patient will continue to benefit from the astute clinician's attention to the clinical manifestations, to the latest diagnostic tests and criteria, to ongoing improvements in therapy, and to the prevention of infective endocarditis.
1. Bayer, A. S., Ward, J. I., Ginzton, L.E., et al. (1994) Evaluation of new criteria for the diagnosis of infective endocarditis. Am. J. Med. 96, 211-219.
2. Osler, W. (1885) Gulstonian lectures on malignant endocarditis. Lancet 1, 415.
3. Korzeniowski, O. M. and Kaye, D. (1992) Endocarditis, in Infectious Diseases (Gorbach, S.L., Bartlett, J.G., and Blacklow, N.R., eds.), W.B. Saunders Co., Philadelphia, PA, pp. 548-555.
4. Terpenning, M. S., Buggy, B. P., and Kauffman, C. A. (1987) Infective endocarditis: clinical features in young and elderly patients. Am. J. Med. 83, 626-634.
5. Fisher, E. A., Fisher, L. L., Fuster, V., et al (1998) Infective endocarditis: New perspectives on an old disease. Infect. Dis. Clin. Pract. 7, 12-24.
6. Cantrell, M. and Yoshikawa, T. T. (1984) Infective endocarditis in the aging patient. Gerontology 30, 316-326.
7. Yoshikawa, T. T. (1987) Antimicrobial therapy: special considerations, in Aging and Clinical Practice: Infectious Diseases. Diagnosis and Treatment (Yoshikawa, T. T., Norman, D., eds.), Igaku-Shoin, New York, pp. 32-54.
8. Terpenning, M. S. and Dominguez, B. L. (1994) Endocarditis of oral origin (abstr.), in Proceedings of the International Association for Dental Research, March 9-13, Seattle, WA.
9. Hamada, S. and Slade, H. D. (1980) Biology, immunology and cariogenicity of Streptococcus mutans. Microbiol. Rev. 44, 331-336.
10. Durack, D. T., Lakes, A. S., Bright, D. K., et al, and the Duke Endocarditis Service (1994) New criteria for diagnosis of infective endocarditis: Utilization of specific echocardiography findings. Am. J. Med. 96, 200-209.
11. von Reyn, C. F., Levy, B. S., Arbeit, R. D., et al. (1981) Infective endocarditis: an analysis based on strict case definitions. Ann. Intern. Med. 94, 505-518.
12. Schulz, R., Werner, G. S., Fuchs, J. B., et al. (1996) Clinical outcome and echocardiography findings of native and prosthetic valve endocarditis in the 1990s. Eur. Heart J. 17, 281-288.
13. Daniel, W. G., Mugge, A., Grote, J., et al. (1993) Comparison of transthoracic and transesophageal echocardiography for detection of abnormalities of prosthetic and bioprosthetic valves in the mitral and aortic positions. Am. J. Cardiol. 71, 210-215.
14. Wilson, W. R., Karchmer, A. W., Dajani, A. S., et al. (1995) Antibiotic treatment of adults with infective endocarditis due to streptococci, enterococci, staphylococci, and HACEK microorganisms. JAMA 274, 1706-1713.
15. Terpenning, M. S. (1992) Infective endocarditis, in Clinics in Geriatric Medicine (Yoshikawa, T. T., ed.), vol. 8, W. B. Saunders Co., Philadelphia, PA, pp. 903-912.
16. Heinle, S., Wilderman, N., Harrison, J. K., et al and the Duke Endocarditis Service (1994) Value of transthoracic echocardiography in predicting embolic events in active infective endocarditis. Am. J. Cardiol. 74, 799-801.
17. Schünemann, S., Werner, G. S., Schulz, R., et al. (1997) Embolische komplikationem bei bakterieller endokarditis. Z. Kardiol. 86, 1017-1025.
18. American Heart Association Guidelines for the Treatment of Infective Endocarditis (1990) JAMA 264, 2929, adapted to 1999.
19. Santinga, J. T., Kirsh, M., and Fekety, F. R. (1984) Factors affecting survival in prosthetic valve endocarditis. Review of the effectiveness of prophylaxis. Chest 85, 471-481.
20. Jones, G. (1977) The attachment of bacteria to the surfaces of animal cells, in Microbial Interactions: Receptors and Recognition (Reissig, J. L., ed.), Chapman and Hall, New York, pp. 139-176.
21. Loesche, W. J., Schork, A., Terpenning, M. S., et al. (1995) Factors which influence levels of selected organisms in saliva of older individuals. J. Clin. Microbiol. 33, 2550-2557.
22. Hockett, R. N., Loesche, W. J., and Sodeman, T. M. (1977) Bacteraemia in asymptomatic human subjects. Arch. Oral Biol. 22, 91-98.
23. Kjerulf, A., Trede, M., and Aldershvile, J. (1998) Bacterial endocarditis at a tertiary hospital-How do we improve diagnosis and delay of treatment? Cardiology 89, 79-86.
24. Dajani, A. S., Bisno, A. L., Chung, K. J. et al. (1990) Prevention of bacterial endocarditis. Recommendations by the American Heart Association. JAMA 264, 2919.
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