Q J Med 2015; 108:337–338 doi:10.1093/qjmed/hcu123 Advance Access Publication 2 June 2014
Case report A canine bug in a human heart F. KOCI1, A. SEKAR2, L. PACIFICO1 and A. ESPOSITO3 From the 1Division of Cardiology, 2Department of Medicine and 3Division of Infectious diseases, Department of Medicine, Saint Vincent Hospital & University of Massachusetts Medical School, MA 01608, USA Address correspondence to F. Koci. email: [email protected].
Learning Point for Clinicians Absence of obvious vegetations on echocardiography does not rule out a pacemaker infection as low virulence bacteria like Staphylococcus intermedius can produce small biofilms that are not readily detected by echocardiography. Pacemaker infections can be hard to manage conservatively and may require complete removal of hardware for eradicating the infection.
Introduction The use of cardiovascular electronic devices has increased significantly in the last decade. Despite antibiotic prophylaxis and aseptic precautions, recent data point to a disturbing trend of device related infections. These are challenging cases requiring prolonged hospitalization and treatment. Staphylococcus aureus is most frequently implicated in permanent pacemaker infections (PPM) infections.1 Initially, all coagulase positive staphylococci were identified as S. aureus, until Hajek established the unique identity of S. intermedius. Staphylococcus intermedius is a predominantly coagulase positive zoonotic organism, although it has been reported causing various human infections.2
Case report A 58-year-old gentleman with a history of first PPM implantation more than 30-years presented with
fever and chills. Review of systems was positive for headaches. He revealed that his neighbor’s dog had licked a fresh cut wound on his hand a few weeks earlier. His PPM was initially placed in 1981 for an episode of sustained sinus arrest and revised in 1994, 2005 and 2011. Initial examination showed a fever of 103.1 F. Skin revealed two incision scars on his chest wall with no tenderness, erythema or warmth over the pacemaker site. Labs revealed a WBC count of 12 900 with 26% bandemia. Two sets of blood cultures drawn 48 h apart grew S. intermedius in 2 of 4 bottles. Chest X-ray, CT spine and urine analysis did not reveal a source of infection. Transthoracic and subsequently a transesophageal echocardiogram (TEE) did not reveal any vegetations or masses in the leads or valves. He was initially treated with vancomycin which was changed to cefazolin once sensitivity was available. He remained afebrile and blood cultures drawn after antibiotic initiation were negative. He received a 6 week course of daptomycin for presumed endocarditis. Five days after completing treatment, he presented with a fever of 105.0 F. Blood cultures grew S. intermedius sensitive to cefazolin. Fevers resolved after initiating cefazolin and blood cultures 3 days later were negative. Repeat TEE was not diagnostic for infection. He was transferred to a specialized center where his entire pacemaker system was removed. No obvious vegetations or masses were noted in the lead
! The Author 2014. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For Permissions, please email: [email protected]
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F. Koci et al.
wires or the generator pocket. He was discharged home on antibiotics without need for a new pacemaker placement. Cultures from the wires tips were negative. Nine months after completing antibiotics he remains afebrile and a 30 day event monitor revealed no arrhythmias.
clinical presentation illustrates the importance of maintaining low thresholds towards PPM infection induced by low virulence bacteria. A comprehensive reevaluation of the indications for PPM placement/revision in accordance with recent guidelines is an important step needed to reduce the incidence of these life threatening conditions.5
Discussion
Conflict of interest: None declared.
Pacemaker infection is a rare, but life-threatening situation. The estimated rate of PPM infection varies from 0.13% to 12.6%.3 Lack of revealing lead vegetations on TEE does not exclude PPM infection especially in cases of low virulence bacteria capable of forming small biofilms or vegetations attached to leads that are not readily detected by TEE. Some staphylococci can grow on the plastic sheath of the pacemaker wire producing a slimy amorphous material that may play a role in the maintenance of colonization.4 This may explain why lead infections are difficult to manage conservatively and require complete removal of the device.5 Staphylococcus intermedius is a zoonotic organism commonly found in the oral cavity of dogs and other canines.6 Analyzing the specific biochemical characteristics of isolates has ensured the accurate diagnosis of S. intermedius infection. This is the first report of a pacemaker lead infection caused by S. intermedius. Secondary seeding of the device by the organism was likely transmitted from the saliva of his neighbor’s dog. This rare
References 1. Sohail MR, Uslan DZ, Khan AH, Friedman PA, Hayes DL, Wilson WR, et al. Management and outcome of permanent and implantable cardioverter-defibrillator infections. J Am Coll Cardiol 2007; 49:1851–9. 2. Theodoros K, Sotirios T. Staphylococcus intermedius is not only a zoonotic pathogen, but may also cause skin abscesses in humans after exposure to saliva. Int J Infect Dis 2010; 14:e838–41. 3. Klug D, Vaksmann G, Jarwe´ M, Wallet F, Francart C, Kacet S, et al. Pacemaker lead infection in young patients. Pacing Clin Electrophysiol 2003; 26:1489–93. 4. Peters G, Saborowski F, Locci R, Pulverer G. Investigations on staphylococcal infection of transvenous endocardial pacemaker electrodes. Am Heart J 1984; 108:359–65. 5. Larry MB, Andrew EE, Christopher CE, Bradley P, Matthew E. Update on cardiovascular implantable electronic device infections and their management: a scientific statement from the American Heart Association. Circulation 2010; 121:458–77. 6. Hajek V. Staphylococcus intermedius, a new species isolated from animals. Int J Syst Bacteriol 1976; 26:401–8.
Copyright of QJM: An International Journal of Medicine is the property of Oxford University Press / USA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
Case report A canine bug in a human heart F. KOCI1, A. SEKAR2, L. PACIFICO1 and A. ESPOSITO3 From the 1Division of Cardiology, 2Department of Medicine and 3Division of Infectious diseases, Department of Medicine, Saint Vincent Hospital & University of Massachusetts Medical School, MA 01608, USA Address correspondence to F. Koci. email: [email protected].
Learning Point for Clinicians Absence of obvious vegetations on echocardiography does not rule out a pacemaker infection as low virulence bacteria like Staphylococcus intermedius can produce small biofilms that are not readily detected by echocardiography. Pacemaker infections can be hard to manage conservatively and may require complete removal of hardware for eradicating the infection.
Introduction The use of cardiovascular electronic devices has increased significantly in the last decade. Despite antibiotic prophylaxis and aseptic precautions, recent data point to a disturbing trend of device related infections. These are challenging cases requiring prolonged hospitalization and treatment. Staphylococcus aureus is most frequently implicated in permanent pacemaker infections (PPM) infections.1 Initially, all coagulase positive staphylococci were identified as S. aureus, until Hajek established the unique identity of S. intermedius. Staphylococcus intermedius is a predominantly coagulase positive zoonotic organism, although it has been reported causing various human infections.2
Case report A 58-year-old gentleman with a history of first PPM implantation more than 30-years presented with
fever and chills. Review of systems was positive for headaches. He revealed that his neighbor’s dog had licked a fresh cut wound on his hand a few weeks earlier. His PPM was initially placed in 1981 for an episode of sustained sinus arrest and revised in 1994, 2005 and 2011. Initial examination showed a fever of 103.1 F. Skin revealed two incision scars on his chest wall with no tenderness, erythema or warmth over the pacemaker site. Labs revealed a WBC count of 12 900 with 26% bandemia. Two sets of blood cultures drawn 48 h apart grew S. intermedius in 2 of 4 bottles. Chest X-ray, CT spine and urine analysis did not reveal a source of infection. Transthoracic and subsequently a transesophageal echocardiogram (TEE) did not reveal any vegetations or masses in the leads or valves. He was initially treated with vancomycin which was changed to cefazolin once sensitivity was available. He remained afebrile and blood cultures drawn after antibiotic initiation were negative. He received a 6 week course of daptomycin for presumed endocarditis. Five days after completing treatment, he presented with a fever of 105.0 F. Blood cultures grew S. intermedius sensitive to cefazolin. Fevers resolved after initiating cefazolin and blood cultures 3 days later were negative. Repeat TEE was not diagnostic for infection. He was transferred to a specialized center where his entire pacemaker system was removed. No obvious vegetations or masses were noted in the lead
! The Author 2014. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For Permissions, please email: [email protected]
338
F. Koci et al.
wires or the generator pocket. He was discharged home on antibiotics without need for a new pacemaker placement. Cultures from the wires tips were negative. Nine months after completing antibiotics he remains afebrile and a 30 day event monitor revealed no arrhythmias.
clinical presentation illustrates the importance of maintaining low thresholds towards PPM infection induced by low virulence bacteria. A comprehensive reevaluation of the indications for PPM placement/revision in accordance with recent guidelines is an important step needed to reduce the incidence of these life threatening conditions.5
Discussion
Conflict of interest: None declared.
Pacemaker infection is a rare, but life-threatening situation. The estimated rate of PPM infection varies from 0.13% to 12.6%.3 Lack of revealing lead vegetations on TEE does not exclude PPM infection especially in cases of low virulence bacteria capable of forming small biofilms or vegetations attached to leads that are not readily detected by TEE. Some staphylococci can grow on the plastic sheath of the pacemaker wire producing a slimy amorphous material that may play a role in the maintenance of colonization.4 This may explain why lead infections are difficult to manage conservatively and require complete removal of the device.5 Staphylococcus intermedius is a zoonotic organism commonly found in the oral cavity of dogs and other canines.6 Analyzing the specific biochemical characteristics of isolates has ensured the accurate diagnosis of S. intermedius infection. This is the first report of a pacemaker lead infection caused by S. intermedius. Secondary seeding of the device by the organism was likely transmitted from the saliva of his neighbor’s dog. This rare
References 1. Sohail MR, Uslan DZ, Khan AH, Friedman PA, Hayes DL, Wilson WR, et al. Management and outcome of permanent and implantable cardioverter-defibrillator infections. J Am Coll Cardiol 2007; 49:1851–9. 2. Theodoros K, Sotirios T. Staphylococcus intermedius is not only a zoonotic pathogen, but may also cause skin abscesses in humans after exposure to saliva. Int J Infect Dis 2010; 14:e838–41. 3. Klug D, Vaksmann G, Jarwe´ M, Wallet F, Francart C, Kacet S, et al. Pacemaker lead infection in young patients. Pacing Clin Electrophysiol 2003; 26:1489–93. 4. Peters G, Saborowski F, Locci R, Pulverer G. Investigations on staphylococcal infection of transvenous endocardial pacemaker electrodes. Am Heart J 1984; 108:359–65. 5. Larry MB, Andrew EE, Christopher CE, Bradley P, Matthew E. Update on cardiovascular implantable electronic device infections and their management: a scientific statement from the American Heart Association. Circulation 2010; 121:458–77. 6. Hajek V. Staphylococcus intermedius, a new species isolated from animals. Int J Syst Bacteriol 1976; 26:401–8.
Copyright of QJM: An International Journal of Medicine is the property of Oxford University Press / USA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
