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An outbreak of staphylococcus aureus sternal wound infections in patients undergoing coronary artery bypass (CABG) surgery
Abstracts EVALUATION OF THE VIVO HANDWASHING MACHINE. Gopal, P. Dague.* Carl T. Hayden VA Medical Center, Phoenix,
V. AZ.
The new VIVO handwashing machine was evaluated on 71 hospital personnel over a two-month period. Handwashing was performed under controlled conditions in the VIVO machine as well as manually using ordinary non-medicated soap and chlorhexidine. Pre- and post-cultures were obtained from the hands by the sterile closed bag technique of Larson et al. The table below summarizes the bacteriologic results of the study. Mean
Bacterial
Counts
for Each Group Prewash
Group Soap - Hand Soap Machine Chlorhex - Hand Chlorhex - Machine
Sample NlUllb.3 46 43 38 59
Postwash
% Mean Count 197 173 144 183
151 115 20 25
Change +ll% -14% -84% -71%
Statistical Analysis indicated that when using soap the VIVO machine was more effective than manual handwashing. However, using chlorhexidine, Ihe VIVO machine was just as effective as manual handwashing. Further, the VIVO machine was found to be very acceptable and convenient for usage in a hospital setting.
AN OUTBREAK OF STAPHYLOCOCCUS AUREUS STERNAL WOUND INFECTIONS IN PATIENTS UNDERGOING CORONARY ARTERY BYPASS (CABG) SURGERY. J. McLeod,* L. Nicolle, S. Parker, A. Maniar, M. McGill, A. Yassi. Health Sciences Centre. Winnipeg, Manitoba. Canada. From May 5, 1988 to June 2, 1988, 5 (33%) of 15 patients with elective CABG procedures using saphenous vein grafts and/or internal mammary artery grafts (in one case cephalic artery grafts were used) developed S. aureus sternal wound infections from 8 to 21 days post-operatively. Prospective surgical wound surveillance from January 1, 1987 to May 4, 1988 identified 0 S. aurcus wound infections in 170 cases. Outbreak investigation identilied 16 (57%) of 28 staff as nasal S. ouI‘eus carriers with 4 staff member isolates with phage types similar to 3 patients. In a case control study other factors associated with infection included duration of operation over 4 hours (p=O.O6) and prolonged time between prophylactic antimicrobials and incision (p=O.OS). The outbreak coincided with a time of excessive temperature and humidity in the operating theatres. The outbreak was terminated after exclusion and treatment of epidemiologically linked staff S. aureus carriers, optimizing prophylactic antimicrobial dosing, and improved ettyirotimental control. This outbreak documents the occurrence of multiple factors contributing to a marked increase in surgical wound infections. The importance of maintaining optimal environmental control in the operating theatres is also demonstrated.
113
NOSOCOMIAL ADULT VARICELLA IN A LARGE TEACHING HOSPITAL. A. Maroney,* A. Toledo, J. Sclva, S. Forlcnza. Nassau County Medical Center, East Meadow, NY. In November 1988, two cases of culture posinve primary nosocomial varicella infcclion occurred in 2 chronically hospitalized adult patients in a large teaching hospital. The cases were separated geographically and in time. An investigation was conducted to determine a possible link between the two cases and the source of these nosocomial infections. Efforts also focused on minimizing further spread of this pathogen to other susceptible hosts. Case 1 was an 84-year-old women hospitalized on the Alternate Level of Care Unit on the 1 lth floor, while case 2 was a 39-year-old pregnant woman hospitalized on the maternity unit on the 3rd floor. When reported to infection control, both patients were placed on strict isolation. Investigation included determining the immune status of all exposed hospital employees and patients, identifying any immunosuppressed contacts who might require Zostcr Immune Globulin, attempting to identify the source of infection in each case and investigating a possible link between the two cases. Despite intensive investigation, no common link could be identilied. No index case could be identified for case 1, and all patient contacts were immune and without overt immunosuppression. Case 2 had shared a room with a patient who developed Herpes roster during her hospitalization. Of 43 staff members, one was nonimmune and furloughed during the incubation period. Invcstigalion of 54 patient contacts revealed two maternity palients with negative histories, both of whom were seronegative. Neither exposed patients, nor staff members developed varicella infection during the period of intensive follow-up. A failure to report and isolate the source of infection of case 2 was responsible for this occurrence of nosocomial varicella. No index case was identified for case 1. Corrective action included intensive education of al1 medical and nursing personnel regarding proper identitication. isolation and immediate reporting of all varicella-zoster infected patients to infection control. A policy requiring a routine history of varicella infection in all patients admitted to the maternity ward was implemented. The occurrence of case 2 following room sharing only with a patient with Herpes roster merits further consideration of isolation precautions in patients with Herpes z~srer infection. AVIAN PSITTACOSIS OUTBREAK IN A GERIATRIC WING OF A TERTIARY CARE HOSPITAL. D. Robson,* H. Frederick, G. Spearman, G. Harding. St. Boniface General Hospital, Winnipeg, Manitoba, Canada. Two of six birds that were parl of a pet therapy program on two extended care units (ECU) for geriatric inpatients, developed symptoms of dyspnea. ruffled feathers and loss of appetite. The index case was sent to a veterinary hospital and a diagnosis of psittacosis was made. An antibiotic was prescribed and the bird was sent back to the ECU. The bird was isolated and treatment initiated but it died the following day. Post mortem examination confirmed Chlamydia psittaci infection. The rest of the birds were sacrificed md pathologic examination showed all were infected with Chlamydia. All exposed patienrs and staff were monitored for signs and symptoms of respiratory infection for four weeks. The three individuals who developed symptoms had serological tests done. No evidence of chlamydiaI infection was found. As a result of the avian outbreak, a review of the infection control practices in use in the pet therapy program revealed the following deficiencies: 1) Prophylactic antibiotics not added to the bird food; 2) Cage not made of appropriate material: 3) Cage not washed routinely: 4) Mixing birds from different wards. Pet therapy programs can be a beneficial treatment tool, however. this outbrc;lk reinforces the need for Infection Control Guidclines for such programs.
V. AZ.
The new VIVO handwashing machine was evaluated on 71 hospital personnel over a two-month period. Handwashing was performed under controlled conditions in the VIVO machine as well as manually using ordinary non-medicated soap and chlorhexidine. Pre- and post-cultures were obtained from the hands by the sterile closed bag technique of Larson et al. The table below summarizes the bacteriologic results of the study. Mean
Bacterial
Counts
for Each Group Prewash
Group Soap - Hand Soap Machine Chlorhex - Hand Chlorhex - Machine
Sample NlUllb.3 46 43 38 59
Postwash
% Mean Count 197 173 144 183
151 115 20 25
Change +ll% -14% -84% -71%
Statistical Analysis indicated that when using soap the VIVO machine was more effective than manual handwashing. However, using chlorhexidine, Ihe VIVO machine was just as effective as manual handwashing. Further, the VIVO machine was found to be very acceptable and convenient for usage in a hospital setting.
AN OUTBREAK OF STAPHYLOCOCCUS AUREUS STERNAL WOUND INFECTIONS IN PATIENTS UNDERGOING CORONARY ARTERY BYPASS (CABG) SURGERY. J. McLeod,* L. Nicolle, S. Parker, A. Maniar, M. McGill, A. Yassi. Health Sciences Centre. Winnipeg, Manitoba. Canada. From May 5, 1988 to June 2, 1988, 5 (33%) of 15 patients with elective CABG procedures using saphenous vein grafts and/or internal mammary artery grafts (in one case cephalic artery grafts were used) developed S. aureus sternal wound infections from 8 to 21 days post-operatively. Prospective surgical wound surveillance from January 1, 1987 to May 4, 1988 identified 0 S. aurcus wound infections in 170 cases. Outbreak investigation identilied 16 (57%) of 28 staff as nasal S. ouI‘eus carriers with 4 staff member isolates with phage types similar to 3 patients. In a case control study other factors associated with infection included duration of operation over 4 hours (p=O.O6) and prolonged time between prophylactic antimicrobials and incision (p=O.OS). The outbreak coincided with a time of excessive temperature and humidity in the operating theatres. The outbreak was terminated after exclusion and treatment of epidemiologically linked staff S. aureus carriers, optimizing prophylactic antimicrobial dosing, and improved ettyirotimental control. This outbreak documents the occurrence of multiple factors contributing to a marked increase in surgical wound infections. The importance of maintaining optimal environmental control in the operating theatres is also demonstrated.
113
NOSOCOMIAL ADULT VARICELLA IN A LARGE TEACHING HOSPITAL. A. Maroney,* A. Toledo, J. Sclva, S. Forlcnza. Nassau County Medical Center, East Meadow, NY. In November 1988, two cases of culture posinve primary nosocomial varicella infcclion occurred in 2 chronically hospitalized adult patients in a large teaching hospital. The cases were separated geographically and in time. An investigation was conducted to determine a possible link between the two cases and the source of these nosocomial infections. Efforts also focused on minimizing further spread of this pathogen to other susceptible hosts. Case 1 was an 84-year-old women hospitalized on the Alternate Level of Care Unit on the 1 lth floor, while case 2 was a 39-year-old pregnant woman hospitalized on the maternity unit on the 3rd floor. When reported to infection control, both patients were placed on strict isolation. Investigation included determining the immune status of all exposed hospital employees and patients, identifying any immunosuppressed contacts who might require Zostcr Immune Globulin, attempting to identify the source of infection in each case and investigating a possible link between the two cases. Despite intensive investigation, no common link could be identilied. No index case could be identified for case 1, and all patient contacts were immune and without overt immunosuppression. Case 2 had shared a room with a patient who developed Herpes roster during her hospitalization. Of 43 staff members, one was nonimmune and furloughed during the incubation period. Invcstigalion of 54 patient contacts revealed two maternity palients with negative histories, both of whom were seronegative. Neither exposed patients, nor staff members developed varicella infection during the period of intensive follow-up. A failure to report and isolate the source of infection of case 2 was responsible for this occurrence of nosocomial varicella. No index case was identified for case 1. Corrective action included intensive education of al1 medical and nursing personnel regarding proper identitication. isolation and immediate reporting of all varicella-zoster infected patients to infection control. A policy requiring a routine history of varicella infection in all patients admitted to the maternity ward was implemented. The occurrence of case 2 following room sharing only with a patient with Herpes roster merits further consideration of isolation precautions in patients with Herpes z~srer infection. AVIAN PSITTACOSIS OUTBREAK IN A GERIATRIC WING OF A TERTIARY CARE HOSPITAL. D. Robson,* H. Frederick, G. Spearman, G. Harding. St. Boniface General Hospital, Winnipeg, Manitoba, Canada. Two of six birds that were parl of a pet therapy program on two extended care units (ECU) for geriatric inpatients, developed symptoms of dyspnea. ruffled feathers and loss of appetite. The index case was sent to a veterinary hospital and a diagnosis of psittacosis was made. An antibiotic was prescribed and the bird was sent back to the ECU. The bird was isolated and treatment initiated but it died the following day. Post mortem examination confirmed Chlamydia psittaci infection. The rest of the birds were sacrificed md pathologic examination showed all were infected with Chlamydia. All exposed patienrs and staff were monitored for signs and symptoms of respiratory infection for four weeks. The three individuals who developed symptoms had serological tests done. No evidence of chlamydiaI infection was found. As a result of the avian outbreak, a review of the infection control practices in use in the pet therapy program revealed the following deficiencies: 1) Prophylactic antibiotics not added to the bird food; 2) Cage not made of appropriate material: 3) Cage not washed routinely: 4) Mixing birds from different wards. Pet therapy programs can be a beneficial treatment tool, however. this outbrc;lk reinforces the need for Infection Control Guidclines for such programs.