Scot.
moo. J., 1977, 22:
13
GROUP B STREPTOCOCCAL ENDOCARDITIS
T. M. S. Reid Department of Bacteriology, Medical School, Aberdeen University
Summary. A retrospective study of group B streptococcal endocarditis during 1965-74 in Aberdeen General Hospitals revealed that group B streptococci now principally affect patients in the older age groups with or without a history of antecedent heart disease. Despite recent reports of increased group B infections in obstetric and perinatal practice there were no cases of post-puerperal endocarditis. Although aortic valve involvement would appear to be increasing, group B streptococci still show a marked predilection for the mitral valve. N 1940 Lancefield group B streptococci were recognised as causative agents in the pathogenesis of post-puerperal endocarditis often superimposed on apparently normal heart valves in young subjects (Hill & Butler, 1940; Rosenthal & Stone, 1940; Ramsay & Gillespie, 1941). With the advent of the antibiotics and improved standards of obstetric and gynaecological care this disease entity has become increasingly rare. In view of the recent resurgence of interest in group B streptococci as major pathogens in obstetric and neonatal practice (Reid, 1975), it is timely to assess the present status of these underrated and often unrecognised organisms in bacterial endocarditis.
I
Materials, methods and results The records of 14 cases of group B streptococcal endocarditis during the period 1965-74 in Aberdeen General Hospitals were reviewed. The diagnosis was established only if a group B streptococcus was isolated from 2 or more blood cultures in a patient with a heart murmur and otherwise unexplained fever. Bacteriological isolation and antibiotic sensitivity testing were performed as previously described (Reid, 1975). A detailed analysis of the 14 cases is shown in Table 1. Discussion A review of bacterial endocarditis in Aberdeen General Hospitals during the period 1945-64 led Hughes and Gauld (1966) to delineate 2 distinct groups; a younger group suffering from rheumatic heart disease with a pre-
ponderance of Streptococcus viridans infection and a contrasting older group often lacking evidence of antecedent heart disease and in general infected with more virulent organisms. It would appear that with increasing mean age the chronic rheumatic heart disease group also showed a propensity to infection with organisms other than Streptococcus viridans such as the group B streptococcus. During their 20-year study, however, only 2 possible cases of group B endocarditis were noted in contrast to 14 cases in the 10 years now reported. Group B streptococci appear predominantly to affect the mitral valve, but an increasing tendency for aortic valve involvement, first noted by Duma et al. (1969), is evident and may become more common in the future as the population with its high incidence of atherosclerotic heart disease ages. The tricupsid valve involvement in Case 1 is testimony to the virulence of the group B streptococcus (Vilde et al., 1974). The concept that infection can involve normal endocardium in the absence of valve abnormalities (Geraci & Martin, 1954) is illustrated in Case 2 where, as Angrist and Oka (1963) demonstrated experimentally, transient group B streptococcal bacteraemia has seeded an ageing endocardium 'stressed' by intercurrent illness. The risk of exposure of a 'stressed' endocardium to virulent organisms such as group B streptococci emanating from foci of biliary, gastrointestinal or urinary disease would appear to be increasing due to the ageing population with its attendant multiple pathologies. This
Reid
Table I. Group B streptococcal endocarditis Underlying Age disease
Associated disease
M
7S
Ischaemic heart disease
Diverticulitis
2
F
71
3
M
72
4
F
7S
Maturity onset Died None diabetic. Chronic osteomyelitis of foot Rheumatic heart Maturity onset (1) Ampicillin Recovered disease diabetic (2) Ampicillin + Streptomycin Congenital heart (1) Penicillin-l-Streptomycin Recovered disease (2) Penicillin+ Probenecid
S
F
61
6
F
32
Rheumatic heart disease
7
M
62
8
F
82
9
F
62
Atherosclerotic heart disease Rheumatic heart disease Rheumatic heart disease
10
F
11
M
75 8S
12
F
69
13
M
73
14
F
60
Case Sex
Treatment
Outcome
(1) Tetracycline (2) Gentamicin (3) Penicillin
Died
Affected Valves Tricuspid Aortic Pericarditis left ventricular softening Aortic Mitral Mitral
(I) Penicillin + Streptomycin Recovered Aortic (2) Penicillin + Probenecid Penicillin + Streptomycin Recovered Mitral
(1) Penicillin -l-Streptornycin Recovered Mitral (2) Ampicillin + Probenecid Aortic (1) Penicillin + Probenecid Recovered Mitral
Aortic valve disease Rheumatic heart Maturity onset disease diabetic Rheumatic heart disease
(I) Tetracycline (2) Penicillin + Ampicillin None Ampicillin
Died Died
Mitral Aortic Mitral
Died
Aortic
(1) Penicillin Recovered Mitral (2) Cloxacillin + Probenecid Penicillin + Streptomycin Recovered Mitral Aortic (1) Cephaloridine+ Streptomycin Recovered Mitral (2) Novobiocin (3) Erythromycin
~~--~.------~. _ - ~ - _ . _ - - - - -
change in age and causative agent in bacterial endocarditis is further compounded by the virtual disappearance in Britain of florid rheumatic fever in young adults. Traditional reasons for the persisting mortality (30%) from infective endocarditis are delay in diagnosis due to bizarre presentation in the elderly, inadequate or initially inappropriate therapy and mechanical factors such as valve rupture and heart failure. These coupled with the greater virulence of the group B streptococcus would appear to explain the fatalities in the series. The association between group B streptococcal infection and diabetes mellitus, particularly of the maturity-onset type previously described by Eickhoff et al. (1964), is con14
firmed. All three cases in this series were controlled by oral hypoglycaemic agents and diet, and ketoacidosis was not a feature of their illness. The uniform sensitivity of group B streptococci to benzyl penicillin enables rational treatment to be commenced immediately, dosages being controlled by monitoring serum levels where required. Recommended antibiotics are. 1. Empirical-Benzyl penicillin + aminoglycoside a combination which is effective against enterococci by virtue of the marked in vivo synergy (Sapico et al., 1971). 2. Following laboratory identification of group B-benzyl penicillin.
Group B Streptococcal Endocarditis
A C K NOW LED GEM E N T S. I wish to thank Professor A. Macdonald and Dr H. G. Smylie for their helpful criticism and advice during this study.
REFERENCES
Angrist, A. A., Oka, M. (1963). Pathogenesis of bacterial endocarditis. Journal of the American Medical Association, 183, 249 Duma, R. J., Weinberg, A. N., Medrek, R. F., Kunz, L. J. (1969). Streptococcal infections. A bacteriological and clinical study of streptococcal bacteremia. Medicine, 48, 87
Hughes, P., Gauld, W. R. (1966). Bacterial endocarditis: a changing disease. Quarterly Journal of Medicine, 35, 511 Ramsay, A. M., Gillespie, M. (1941). Puerperal infection associated with haemolytic streptococci other than Lancefield's group A. Journal of Obstetrics and Gynaecology of the British Empire, 48, 569 Reid, T. M. S. (1975). Emergence of group B streptococci in obstetric and perinatal infections. British Medical Journal, 2,533
Eickhoff, T. L., Klein, J. 0., Daly, A. K., Ingall, M., Finland, M. (1964). Neonatal sepsis and other infections due to group B beta-hemolytic streptococci. New England Journal of Medicine, 271, 1221
Rosenthal, A. H., Stone, F. M. (1940). Puerperal infection with vegetative endocarditis. Report of sulfanilamide therapy in two fatal cases due to streptococcus haemolyticus group Band C. Journal of the American Medical Association, 114, 840
Geraci, J. E., Martin, W. J. (1954). Antibiotic therapy of bacterial endocarditis. VI. Subacute enterococcal endocarditis. Clinical, pathologic and therapeutic consideration of 33 cases. Circulation, 10, 173
Sapico, F. L., Keys, T. F., Hewitt, W. L. (1972). Experimental enterococcal endocarditis. II Study of in vivo synergism of penicillin and streptomycin. American Journal of the Medical Sciences, 263, 128
Hill, A. M., Butler, H. M. (1940). Haemolytic streptococcal infections following childbirth and abortion. Clinical features with special reference to infections due to streptococci of groups other than A. Medical Journal of Australia, 1, 293
Vilde, J-L., Roujeau, .r.c., Bure, A., Ver Liac, F., Bastin, R. (1974). Infections graves et septicemies a streptocoque du group B chez I'adulte. A propos de quatre observations dont une endocardite tricuspidienne compliquee de glomerulonephrite. Semaine des Hopitaux de Paris, 50, 355
15
moo. J., 1977, 22:
13
GROUP B STREPTOCOCCAL ENDOCARDITIS
T. M. S. Reid Department of Bacteriology, Medical School, Aberdeen University
Summary. A retrospective study of group B streptococcal endocarditis during 1965-74 in Aberdeen General Hospitals revealed that group B streptococci now principally affect patients in the older age groups with or without a history of antecedent heart disease. Despite recent reports of increased group B infections in obstetric and perinatal practice there were no cases of post-puerperal endocarditis. Although aortic valve involvement would appear to be increasing, group B streptococci still show a marked predilection for the mitral valve. N 1940 Lancefield group B streptococci were recognised as causative agents in the pathogenesis of post-puerperal endocarditis often superimposed on apparently normal heart valves in young subjects (Hill & Butler, 1940; Rosenthal & Stone, 1940; Ramsay & Gillespie, 1941). With the advent of the antibiotics and improved standards of obstetric and gynaecological care this disease entity has become increasingly rare. In view of the recent resurgence of interest in group B streptococci as major pathogens in obstetric and neonatal practice (Reid, 1975), it is timely to assess the present status of these underrated and often unrecognised organisms in bacterial endocarditis.
I
Materials, methods and results The records of 14 cases of group B streptococcal endocarditis during the period 1965-74 in Aberdeen General Hospitals were reviewed. The diagnosis was established only if a group B streptococcus was isolated from 2 or more blood cultures in a patient with a heart murmur and otherwise unexplained fever. Bacteriological isolation and antibiotic sensitivity testing were performed as previously described (Reid, 1975). A detailed analysis of the 14 cases is shown in Table 1. Discussion A review of bacterial endocarditis in Aberdeen General Hospitals during the period 1945-64 led Hughes and Gauld (1966) to delineate 2 distinct groups; a younger group suffering from rheumatic heart disease with a pre-
ponderance of Streptococcus viridans infection and a contrasting older group often lacking evidence of antecedent heart disease and in general infected with more virulent organisms. It would appear that with increasing mean age the chronic rheumatic heart disease group also showed a propensity to infection with organisms other than Streptococcus viridans such as the group B streptococcus. During their 20-year study, however, only 2 possible cases of group B endocarditis were noted in contrast to 14 cases in the 10 years now reported. Group B streptococci appear predominantly to affect the mitral valve, but an increasing tendency for aortic valve involvement, first noted by Duma et al. (1969), is evident and may become more common in the future as the population with its high incidence of atherosclerotic heart disease ages. The tricupsid valve involvement in Case 1 is testimony to the virulence of the group B streptococcus (Vilde et al., 1974). The concept that infection can involve normal endocardium in the absence of valve abnormalities (Geraci & Martin, 1954) is illustrated in Case 2 where, as Angrist and Oka (1963) demonstrated experimentally, transient group B streptococcal bacteraemia has seeded an ageing endocardium 'stressed' by intercurrent illness. The risk of exposure of a 'stressed' endocardium to virulent organisms such as group B streptococci emanating from foci of biliary, gastrointestinal or urinary disease would appear to be increasing due to the ageing population with its attendant multiple pathologies. This
Reid
Table I. Group B streptococcal endocarditis Underlying Age disease
Associated disease
M
7S
Ischaemic heart disease
Diverticulitis
2
F
71
3
M
72
4
F
7S
Maturity onset Died None diabetic. Chronic osteomyelitis of foot Rheumatic heart Maturity onset (1) Ampicillin Recovered disease diabetic (2) Ampicillin + Streptomycin Congenital heart (1) Penicillin-l-Streptomycin Recovered disease (2) Penicillin+ Probenecid
S
F
61
6
F
32
Rheumatic heart disease
7
M
62
8
F
82
9
F
62
Atherosclerotic heart disease Rheumatic heart disease Rheumatic heart disease
10
F
11
M
75 8S
12
F
69
13
M
73
14
F
60
Case Sex
Treatment
Outcome
(1) Tetracycline (2) Gentamicin (3) Penicillin
Died
Affected Valves Tricuspid Aortic Pericarditis left ventricular softening Aortic Mitral Mitral
(I) Penicillin + Streptomycin Recovered Aortic (2) Penicillin + Probenecid Penicillin + Streptomycin Recovered Mitral
(1) Penicillin -l-Streptornycin Recovered Mitral (2) Ampicillin + Probenecid Aortic (1) Penicillin + Probenecid Recovered Mitral
Aortic valve disease Rheumatic heart Maturity onset disease diabetic Rheumatic heart disease
(I) Tetracycline (2) Penicillin + Ampicillin None Ampicillin
Died Died
Mitral Aortic Mitral
Died
Aortic
(1) Penicillin Recovered Mitral (2) Cloxacillin + Probenecid Penicillin + Streptomycin Recovered Mitral Aortic (1) Cephaloridine+ Streptomycin Recovered Mitral (2) Novobiocin (3) Erythromycin
~~--~.------~. _ - ~ - _ . _ - - - - -
change in age and causative agent in bacterial endocarditis is further compounded by the virtual disappearance in Britain of florid rheumatic fever in young adults. Traditional reasons for the persisting mortality (30%) from infective endocarditis are delay in diagnosis due to bizarre presentation in the elderly, inadequate or initially inappropriate therapy and mechanical factors such as valve rupture and heart failure. These coupled with the greater virulence of the group B streptococcus would appear to explain the fatalities in the series. The association between group B streptococcal infection and diabetes mellitus, particularly of the maturity-onset type previously described by Eickhoff et al. (1964), is con14
firmed. All three cases in this series were controlled by oral hypoglycaemic agents and diet, and ketoacidosis was not a feature of their illness. The uniform sensitivity of group B streptococci to benzyl penicillin enables rational treatment to be commenced immediately, dosages being controlled by monitoring serum levels where required. Recommended antibiotics are. 1. Empirical-Benzyl penicillin + aminoglycoside a combination which is effective against enterococci by virtue of the marked in vivo synergy (Sapico et al., 1971). 2. Following laboratory identification of group B-benzyl penicillin.
Group B Streptococcal Endocarditis
A C K NOW LED GEM E N T S. I wish to thank Professor A. Macdonald and Dr H. G. Smylie for their helpful criticism and advice during this study.
REFERENCES
Angrist, A. A., Oka, M. (1963). Pathogenesis of bacterial endocarditis. Journal of the American Medical Association, 183, 249 Duma, R. J., Weinberg, A. N., Medrek, R. F., Kunz, L. J. (1969). Streptococcal infections. A bacteriological and clinical study of streptococcal bacteremia. Medicine, 48, 87
Hughes, P., Gauld, W. R. (1966). Bacterial endocarditis: a changing disease. Quarterly Journal of Medicine, 35, 511 Ramsay, A. M., Gillespie, M. (1941). Puerperal infection associated with haemolytic streptococci other than Lancefield's group A. Journal of Obstetrics and Gynaecology of the British Empire, 48, 569 Reid, T. M. S. (1975). Emergence of group B streptococci in obstetric and perinatal infections. British Medical Journal, 2,533
Eickhoff, T. L., Klein, J. 0., Daly, A. K., Ingall, M., Finland, M. (1964). Neonatal sepsis and other infections due to group B beta-hemolytic streptococci. New England Journal of Medicine, 271, 1221
Rosenthal, A. H., Stone, F. M. (1940). Puerperal infection with vegetative endocarditis. Report of sulfanilamide therapy in two fatal cases due to streptococcus haemolyticus group Band C. Journal of the American Medical Association, 114, 840
Geraci, J. E., Martin, W. J. (1954). Antibiotic therapy of bacterial endocarditis. VI. Subacute enterococcal endocarditis. Clinical, pathologic and therapeutic consideration of 33 cases. Circulation, 10, 173
Sapico, F. L., Keys, T. F., Hewitt, W. L. (1972). Experimental enterococcal endocarditis. II Study of in vivo synergism of penicillin and streptomycin. American Journal of the Medical Sciences, 263, 128
Hill, A. M., Butler, H. M. (1940). Haemolytic streptococcal infections following childbirth and abortion. Clinical features with special reference to infections due to streptococci of groups other than A. Medical Journal of Australia, 1, 293
Vilde, J-L., Roujeau, .r.c., Bure, A., Ver Liac, F., Bastin, R. (1974). Infections graves et septicemies a streptocoque du group B chez I'adulte. A propos de quatre observations dont une endocardite tricuspidienne compliquee de glomerulonephrite. Semaine des Hopitaux de Paris, 50, 355
15
