Bloodstream Infection Surveillance Research Articles

Computer Algorithms To Detect Bloodstream Infections

We compared manual and computer-assisted bloodstream infection surveillance for adult inpatients at two hospitals. We identified hospital-acquired, primary, central-venous catheter (CVC)-associated bloodstream infections by using five methods: retrospective, manual record review by investigators; prospective, manual review by infection control professionals; positive blood culture plus manual CVC determination; computer algorithms; and computer algorithms and manual CVC determination. We calculated sensitivity, specificity, predictive values, plus the kappa statistic (kappa) between investigator review and other methods, and we correlated infection rates for seven units. The kappa value was 0.37 for infection control review, 0.48 for positive blood culture plus manual CVC determination, 0.49 for computer algorithm, and 0.73 for computer algorithm plus manual CVC determination. Unit-specific infection rates, per 1,000 patient days, were 1.0-12.5 by investigator review and 1.4-10.2 by computer algorithm (correlation r = 0.91, p = 0.004). Automated bloodstream infection surveillance with electronic data is an accurate alternative to surveillance with manually collected data.

Nosocomial bloodstream infections in a neonatal intensive care unit.

A study was performed to assess the incidence density of, and to identify the risk factors associated with, nosocomial bloodstream infection (BSI) in a neonatal intensive care unit (NICU) in Athens. Twenty-four of 105 patients developed nosocomial BSI (22.9%). The incidence density of BSI was 10.9 per 1000 patient-days. A multivariate model showed that only two factors were significantly and independently responsible for nosocomial BSI: central venous catheter use and umbilical catheter use. Results showed that the incidence density rate was high and the factors that had most influence on the development of nosocomial BSI were associated with the treatment received by neonates during their stay in the NICU. Therefore, surveillance of nosocomial BSI and strategies such as infection control, nursery design and staffing should be implemented to reduce the incidence of these infections. This effort should be multidisciplinary, involving staff who insert and maintain intravascular catheters, and healthcare managers who allocate resources.

Bloodstream infection surveillance in a cancer centre: a prospective look at clinical microbiology aspects

A prospective clinical and microbiological surveillance study was conducted during a 26-month period to evaluate consecutive malignancy or post-bone marrow transplant patients with positive blood cultures. The study included 859 episodes of bloodstream infection (BSI) in 719 patients. There were 6.9 BSI episodes/1000 patient-days. Overall mortality was 25%. The median age of patients was 43 years, with 71% of episodes occurring in patients aged > 18 years. Patients with underlying haematology malignancies accounted for 38.2% of the episodes. An indwelling central vein catheter was present in 61% of episodes. BSI origin was unknown in 27% of episodes, associated with other sites in 49.6%, and catheter-related in 23.4%. There were 638 concomitant infection sites, of which the most common were pulmonary (28.4%), urinary tract (14.8%), and non-surgical skin or soft tissue (9.7%). In total, 1039 microorganisms were isolated within 48 h of the first blood culture, of which Gram-negative bacilli accounted for 56%. Among Klebsiella pneumoniae and Escherichia coli isolates, 37.8% and 8.9%, respectively, produced extended-spectrum beta-lactamases. High rates of ceftazidime resistance were detected among Acinetobacter spp. (40%) and Enterobacter spp. (51.2%). E. coli and K. pneumoniae were isolated frequently from haematology patients, and Enterobacter spp. from solid tumour patients. E. coli, K. pneumoniae and Pseudomonas aeruginosa were isolated more often from neutropenic than from non-neutropenic patients. Oxacillin resistance was detected in 18.7% of Staphylococcus aureus isolates. It was concluded that continuous multidisciplinary surveillance of BSI is warranted in this high-risk group of patients in order to develop strategies for antimicrobial resistance control and treatment of infectious complications.

Incidence and nature of epidemic nosocomial infections.

Nosocomial bloodstream infections continue to be a major cause of morbidity and mortality. Approximately 8% of all nosocomial infections reported in the United States are primarily bloodstream infections. These infections prolong hospital length of stay, increase mortality, and raise the overall cost of healthcare. A contaminated infusate administered through a central venous catheter is one of the commonly identified causes of nosocomial bacteremia. In most cases, contamination of the infusate occurs extrinsically during manipulation of the fluid before its administration to the patient. Failure to use aseptic technique and poor hand washing often are the cause. In addition to improved staff education, surveillance for nosocomial bloodstream infections continues to be the cornerstone of prevention.

Medicine Ward Patients in a Large Teaching Hospital: A High-Risk Population for Catheter-Associated Bloodstream Infections?

BACKGROUND: Infection control surveillance for catheter-associated bloodstream infections (CA-BSIs) is often focused in intensive care units (ICUs), where national benchmark data is available. Limited data on CA-BSI rates are available for non-ICU areas. Increasing acuity among non-ICU patients with central venous catheters (CVCs) raised the need to evaluate these areas. OBJECTIVE: To determine the CA-BSI rate in selected non-ICU medical wards over a 13-month period. METHODS: An infection control specialist performed active surveillance for CA-BSIs on four medical wards (A, B, C, D) from April 2002 to April 2003. CA-BSI was defined using NNIS definitions. CVC days were obtained from an electronic report based on nurses' CVC charting. Type of CVC and CA-BSI microbiology was documented. RESULTS: The general medicine wards each average 5–10 admissions/day. Each ward has separate nursing staff. A medical director, nurse manager, and interns/residents are shared between wards A & B and between wards C & D. The mean monthly CVC days for the 13-month period was 141 (range 77-215) per ward. Device utilization ratios for the four wards were 0.21, 0.25, 0.19, 0.24, respectively. Forty-two episodes of CA-BSI were identified. The mean CA-BSI rate in Ward A was 5.3/1000 CVC days (n=9); Ward B: 8.0/1000 CVC days (n=16); Ward C: 4.3/1000 CVC days (n=7); and Ward D: 4.9/1000 CVC days (n=10). CA-BSI organisms were: polymicrobial, 12% (n=5); Enterococcus spp., 24% (n=10); Coagulase-negative staphylococci, 24% (n=10); Staphylococcus aureus, 7% (n=3); other gram-positive, 2% (n=1); Pseudomonas aeruginosa, 2% (n=1); Escherichia coli, 2% (n=1); Proteus mirabilis, 2% (n=1); other gram-negative, 10% (n=4); Candida albicans, 12% (n=5), and other Candida, 2% (n=1). Patients with CA-BSI had the following catheters: tunneled, 5% (n=2); non-tunneled, 83% (n=35); and implanted port, 7% (n=3). Two patients had more than one type of CVC. CONCLUSION: Non-ICU medical wards in our study had device utilization ratios that were considerably lower than medical ICUs, but CA-BSI rates were comparable to medical ICUs nationally. Studies of catheter utilization rates and knowledge of CVC care and insertion on medical wards should be performed. Interventions usually focused on ICU personnel may be indicated to prevent CA-BSI on medical wards.

Central Line-Associated Bloodstream Infection Surveillance and Reduction Strategies across the Continuum of Care of a Tertiary-Care Pediatric Institution

Central Line-Associated Bloodstream Infection Surveillance and Reduction Strategies across the Continuum of Care of a Tertiary-Care Pediatric Institution

Central Line-Associated Bloodstream Infection Surveillance and Reduction Strategies across the Continuum of Care of a Tertiary-Care Pediatric Institution

BACKGROUND: Central line–associated bloodstream infections (CBSIs) are the most common type of device-related, healthcare-associated infection across the care continuum at Columbus Children's Hospital (CCH). CBSIs result in prolongation of hospitalization, morbidity, and mortality at CCH and nationally. OBJECTIVE: To demonstrate the value of CBSI surveillance across the care continuum and of interdisciplinary collaboration to identify and implement interventions to reduce the risk of occurrence. METHODS: In 1990, CCH became a member of the Centers for Disease Control and Prevention's (CDC) National Nosocomial Infection Surveillance System (NNIS). Surveillance began in the pediatric intensive care unit (PICU) and the neonatal intensive care unit (NICU). The other inpatient units and Home Parenteral Nutritional (HPN) Program were added in 1994, followed by CCH's Homecare (HC) in 2000. Infection control practitioners (ICPs) conduct surveillance in all inpatient units utilizing NNIS criteria. Nutritional Support Services collects HPN data; HC collects data based upon Infection Control Committee (ICC)–approved criteria. Epidemiology assists with interpretation, analysis, and recommendations for these areas. Meetings occur regularly to identify opportunities for improvement and to ensure consistent practice in all settings. RESULTS: Rates are expressed as the number of CBSI/1000 central line days. The following are a comparison of rates from 2000 and 2003 year to day by site or service: Hospital-wide (6.5 versus 4.9, p = 0.015); PICU (7.8 versus 5.5, p = 0.150); NICU (10.5 versus 6.3, p = 0.006); HC Private Duty Nursing (4.0 versus 1.9, p = 0.273); HC Pharmacy Only (2.0 versus 1.7, p = 0.360); HPN patients served by CCH HC (9.0 versus 5.6, p = 0.093), and those served by other HCs (3.8 to 8.0, p = 0.178). CONCLUSIONS: 1) CBSI surveillance across the care continuum is essential. 2) Interdisciplinary collaboration maximizes identification of opportunities to improve. 3) Direct observation of healthcare workers' practice with feedback and standardized policy/practice is essential. 4) Feedback to other HC companies caring for our patients is necessary. 5) Administrative, Medical Staff, and ICC support is critical. 6) An organizational culture of patient safety is required. 7) In 2003, an IV Access Taskforce identified interventions including a budget-approved IV Access Team.

Prospective surveillance for primary bloodstream infections occurring in Canadian hemodialysis units.

Bloodstream infections are a major cause of morbidity and mortality in patients receiving long-term hemodialysis. We wanted to determine the incidence of hemodialysis-related bloodstream infections in Canadian centers participating in the Canadian Nosocomial Infection Surveillance Program. Prospective surveillance for hemodialysis-related bloodstream infections was performed in 11 centers during a 6-month period. Bloodstream infections were defined by published criteria. Hemodialysis denominators included the number of dialysis procedures, the number of patient-days on dialysis, and the frequencies of different types of vascular access. There were 184 bloodstream infections in 133,158 dialysis procedures (1.4 per 1,000) and 316,953 patient-days (0.6 per 1,000). Hemodialysis access through arteriovenous (AV) fistulae was associated with the lowest risk for bloodstream infection (0.2 per 1,000 dialysis procedures). The relative risk for infection was 2.5 with AV graft access, 15.5 with cuffed and tunneled central venous catheter (CVC) access, and 22.5 with uncuffed CVC access (P < .001). There was marked variation among the 11 centers in the means of vascular access used for hemodialysis. Significant variation in infection rates was observed among the centers when controlling for types of access. There was a hierarchy of risk of hemodialysis-related bloodstream infection according to type of vascular access. There was significant variation in the type of vascular access being used among the Canadian hemodialysis centers, and also variation in access-specific infection rates between centers.

Surveillance of hemodialysis-associated primary bloodstream infections: the experience of ten hospital-based centers.

To determine baseline rates of primary bloodstream infection (BSI) among a large pool of patients receiving hemodialysis using standardized surveillance tools and methodology. Prospective, descriptive analysis of primary BSI rates. Ten hospital-based hemodialysis centers in Connecticut. All patients receiving long-term hemodialysis in the participating facilities. A total of 158 BSIs occurred during 142,525 dialysis sessions within a 12-month study period. Of the BSIs, 15.2% occurred in patients with fistula or graft access and 84.8% in patients with central venous catheter access (P < .001). Rates per 100 patient-years in centers ranged from 0 to 30.8, with a mean of 16.6. Rates per 1,000 dialysis sessions ranged from 0 to 2.1, with a mean of 1.1. Coagulase-negative staphylococci and Staphylococcus aureus (including methicillin-resistant S. aureus) accounted for 61% and Klebsiella or Enterobacter species for 14.6% of infections. Of the patients, 63.3% received vancomycin, 24.7% received cefazolin, and 41.7% received aminoglycosides. Rates declined in the second 6 months of the study from 1.4 to 0.8 infections per 1,000 dialysis sessions (P < .001). Primary BSI rates varied widely among participating centers and declined during the study period. BSIs were strongly associated with central venous catheter access. Further studies are needed to determine the reasons for variance in rates between centers and among various types of hemodialysis access.

Clinical microbiological case: chronic disseminated candidiasis unresponsive to treatment

Clinical microbiological case: chronic disseminated candidiasis unresponsive to treatment

International surveillance of bloodstream infections due to Candida species: frequency of occurrence and in vitro susceptibilities to fluconazole, ravuconazole, and voriconazole of isolates collected from 1997 through 1999 in the SENTRY antimicrobial surveillance program.

A surveillance program (SENTRY) of bloodstream infections (BSI) in the United States, Canada, Latin America, and Europe from 1997 through 1999 detected 1,184 episodes of candidemia in 71 medical centers (32 in the United States, 23 in Europe, 9 in Latin America, and 7 in Canada). Overall, 55% of the yeast BSIs were due to Candida albicans, followed by Candida glabrata and Candida parapsilosis (15%), Candida tropicalis (9%), and miscellaneous Candida spp. (6%). In the United States, 45% of candidemias were due to non-C. albicans species. C. glabrata (21%) was the most common non-C. albicans species in the United States, and the proportion of non-C. albicans BSIs was highest in Latin America (55%). C. albicans accounted for 60% of BSI in Canada and 58% in Europe. C. parapsilosis was the most common non-C. albicans species in Latin America (25%), Canada (16%), and Europe (17%). Isolates of C. albicans, C. parapsilosis, and C. tropicalis were all highly susceptible to fluconazole (97 to 100% at < or =8 microg/ml). Likewise, 97 to 100% of these species were inhibited by < or =1 microg/ml of ravuconazole (concentration at which 50% were inhibited [MIC(50)], 0.007 to 0.03 microg/ml) or voriconazole (MIC(50), 0.007 to 0.06 microg/ml). Both ravuconazole and voriconazole were significantly more active than fluconazole against C. glabrata (MIC(90)s of 0.5 to 1.0 microg/ml versus 16 to 32 microg/ml, respectively). A trend of increased susceptibility of C. glabrata to fluconazole was noted over the three-year period. The percentage of C. glabrata isolates susceptible to fluconazole increased from 48% in 1997 to 84% in 1999, and MIC(50)s decreased from 16 to 4 microg/ml. A similar trend was documented in both the Americas (57 to 84% susceptible) and Europe (22 to 80% susceptible). Some geographic differences in susceptibility to triazole were observed with Canadian isolates generally more susceptible than isolates from the United States and Europe. These observations suggest susceptibility patterns and trends among yeast isolates from BSI and raise additional questions that can be answered only by continued surveillance and clinical investigations of the type reported here (SENTRY Program).

Effectiveness of surveillance of central catheter-related bloodstream infection in an ICU in Korea.

To determine whether surveillance and infection control interventions decrease the incidence of catheter-related (CR) bloodstream infections (BSIs) in Korea. A medical-surgical intensive care unit (ICU) of a university hospital in Korea. The CR infection rate of the intervention period was compared to that of historical controls for a 4-month period. All patients with a central venous catheter in the intensive care unit (ICU) from October 1998 to January 1999. Active infection control programs were initiated during the intervention period. Data collected included patient characteristics, risk factors of CR infection, and the microbiology laboratory results. Laboratory-proven CR infection rates were compared between the intervention group and control group. 304 catheters were inserted into 248 patients. The intervention group and the control group showed similar characteristics, but more patients in the intervention group received steroid therapy, and subclavian insertion was more common in the intervention group. CR BSI occurred in 1.3 per 1,000 catheter-days in the intervention group and 4.2 in the control group (binomial test, P=.14). CR infections were associated with the duration of ICU admission by multivariate logistic regression. The data suggested that an active infection surveillance and control program could reduce the rate of CR

Group B streptococci causing neonatal bloodstream infection: Antimicrobial susceptibility and serotyping results from SENTRY centers in the Western Hemisphere

Objective: Group B streptococcal infection is a common cause of neonatal sepsis. Surveillance of antimicrobial susceptibility and serotype frequencies of invasive group B streptococci is important to ensure the effectiveness of therapeutic regimens and to guide vaccine development. Study Design: Prospective surveillance of neonatal bloodstream infection was performed at all Western Hemisphere sites participating in the SENTRY Program. From January 1997 through December 1999, a total of 122 isolates of bloodstream infections with group B streptococci were collected and sent to the University of Iowa for antimicrobial susceptibility testing and serotyping. Results: No isolates were resistant to penicillin. More than 25% of isolates from US hospitals and 14% of isolates from Canadian hospitals were erythromycin resistant. Seven percent of isolates from the United States and Canada were resistant to clindamycin. No clindamycin or erythromycin resistance was found among isolates from Latin America. Clindamycin and erythromycin resistance was most frequent among serotype V strains. Conclusions: No emerging resistance to penicillin was noted among bloodstream infection isolates of group B streptococci from a broad geographic area; erythromycin and clindamycin resistance was found in the United States and Canada and appeared most frequently among serotype V strains. (Am J Obstet Gynecol 2000;183:859-62.)

Bloodstream infections due to Candida species: SENTRY antimicrobial surveillance program in North America and Latin America, 1997-1998.

An international program of surveillance of bloodstream infections (BSI) in the United States, Canada, and Latin America detected 306 episodes of candidemia in 34 medical centers (22 in the United States, 6 in Canada, and 6 in Latin America) in 1997 and 328 episodes in 34 medical centers (22 in the United States, 5 in Canada, and 7 in Latin America) in 1998. Of the 634 BSI, 54.3% were due to Candida albicans, 16.4% were due to C. glabrata, 14.9% were due to C. parapsilosis, 8.2% were due to C. tropicalis, 1.6% were due to C. krusei, and 4.6% were due to other Candida spp. The percentage of BSI due to C. albicans decreased very slightly in the United States between 1997 and 1998 (56.2 to 54.4%; P = 0.68) and increased in both Canada (52.6 to 70.1%; P = 0.05) and Latin America (40.5 to 44. 6%; P = 0.67). C. glabrata was the second most common species observed overall, and the percentage of BSI due to C. glabrata increased in all three geographic areas between 1997 and 1998. C. parapsilosis was the third most prevalent BSI isolate in both Canada and Latin America, accounting for 7.0 and 18.5% of BSI, respectively. Resistance to fluconazole (MIC, >/=64 microgram/ml) and itraconazole (MIC, >/=1.0 microgram/ml) was observed infrequently in both 1997 (2.3 and 8.5%, respectively) and 1998 (1.5 and 7.6%, respectively). Among the different species of Candida, resistance to fluconazole and itraconazole was observed in C. glabrata and C. krusei, whereas isolates of C. albicans, C. parapsilosis, and C. tropicalis were all highly susceptible to both fluconazole (98.9 to 100% susceptible) and itraconazole (96.4 to 100% susceptible). Isolates from Canada and Latin America were generally more susceptible to both triazoles than U.S. isolates were. Continued surveillance appears necessary to detect these important changes.

Evaluation of an antiseptic triple-lumen catheter in an intensive care unit.

To evaluate a decrease in catheter-related bloodstream infection rate in patients with antiseptic triple-lumen catheters in an intensive care unit. Retrospective review of surveillance records, patient medical records, laboratory and microbiological reports, and antibiotic administration records. Patients admitted to the intensive care unit with triple-lumen catheters. A subset of one entry per patient was extracted from 2 yrs of primary bloodstream infection surveillance data. Data collection included risk factors, laboratory and microbiological data, and insertion sites and dates of all intravascular catheters present during triple-lumen catheterization. The catheter-related bloodstream infection rate was 5.4 and 11.3 per 1000 catheter days in antiseptic and nonantiseptic triple-lumen catheter groups, respectively (p = .06). By multivariate analysis using a Cox Proportional Hazards Model, the antiseptic triple-lumen catheters were associated with a significant reduction in catheter-related bloodstream infection (p = .03). Model expansion to include intrajugular site was significant by a likelihood ratio test [2(log likelihood diff) = 4.26 P<.05 chi2(1)] The use of antiseptic triple-lumen catheters may substantially reduce catheter-related bloodstream infections in an intensive care population and may be subsequently associated with a decrease in length of stay.

International surveillance of blood stream infections due to Candida species in the European SENTRY program: species distribution and antifungal susceptibility including the investigational triazole and echinocandin agents

The SENTRY Antimicrobial Surveillance Program, an international study of blood stream infections (BSIs), detected 170 episodes of candidemia in 20 European medical centers (13 nations) between January and December, 1997. Twenty-three percent of the candidal BSI occurred in patients hospitalized in an intensive care unit, 21% in patients in an internal medicine service, 13% in patients in a surgical service, and 9% in patients in an oncology service. Overall, 53% of the BSI were attributable to Candida albicans followed in prevalence by C. parapsilosis (21%), C. glabrata (12%), C. tropicalis (6%), C. famata (2%), C. krusei (1%), and C. inconspicua (1%). As observed previously in Canada and Latin America, C. parapsilosis and not C. glabrata, was the most common non- albicans species causing yeast BSI in Europe. The proportion of these candidemias attributable to C. albicans varied widely from 0–100% among the 20 European centers. Among the different species of Candida, resistance to fluconazole (MIC, ≥ 64 μg/mL) and itraconazole (MIC, ≥ 1.0 μg/mL) was observed with C. glabrata and C. krusei and was observed more rarely among other species (e.g., C. inconspicua). Isolates of C. albicans, C. parapsilosis, C. tropicalis, and C. guilliermondii were all highly susceptible to both fluconazole and itraconazole. Furthermore, the investigational triazoles (BMS-207147, Sch 56592, and voriconazole) and an echinocandin (MK-0991) all demonstrated potent in vitro activity (MIC 90s, 0.5, 0.5, 1.0, and 2.0 μg/mL, respectively) against these isolates. Continued surveillance at an international level will be important to monitor trends in species distribution and antifungal susceptibility among invasive strains of Candida.

Nosocomial bloodstream infections in United States hospitals: a three-year analysis.

Nosocomial bloodstream infections are important causes of morbidity and mortality. In this study, concurrent surveillance for nosocomial bloodstream infections at 49 hospitals over a 3-year period detected >10,000 infections. Gram-positive organisms accounted for 64% of cases, gram-negative organisms accounted for 27%, and 8% were caused by fungi. The most common organisms were coagulase-negative staphylococci (32%), Staphylococcus aureus (16%), and enterococci (11%). Enterobacter, Serratia, coagulase-negative staphylococci, and Candida were more likely to cause infections in patients in critical care units. In patients with neutropenia, viridans streptococci were significantly more common. Coagulase-negative staphylococci were the most common pathogens on all clinical services except obstetrics, where Escherichia coli was most common. Methicillin resistance was detected in 29% of S. aureus isolates and 80% of coagulase-negative staphylococci. Vancomycin resistance in enterococci was species-dependent--3% of Enterococcus faecalis strains and 50% of Enterococcus faecium isolates displayed resistance. These data may allow clinicians to better target empirical therapy for hospital-acquired cases of bacteremia.

Trends in species distribution and susceptibility to fluconazole among blood stream isolates of Candida species in the United States

National surveillance of blood stream infections (BSI) attributable to Candida spp. has been limited to date. Recent studies have suggested an increase in the proportion of BSI attributable to non- Candida albicans species and have also raised concerns regarding the emergence of antifungal resistance among Candida spp. The increased utilization of broad-spectrum antifungal agents and the recognition of Candida spp. as prominent pathogens with the potential for developing antifungal resistance, emphasize the need for ongoing surveillance of antifungal susceptibility patterns. In this investigation trends in species distribution and susceptibility to fluconazole among BSI isolates of Candida spp. referred to our laboratory by United States hospitals were evaluated over the 7-year period from 1992 to 1998. A total of 1579 BSI isolates from more than 50 medical centers were processed. Overall, C. albicans accounted for 52% of isolates followed by C. glabrata (18%), C. parapsilosis (15%), C. tropicalis (11%), and C. krusei (2%). The proportion of BSI isolates that were C. albicans ranged from 45% in 1992 to 60% in 1998. Among the non- C. albicans isolates, C. glabrata succeeded C. parapsilosis as the most common species beginning in 1995. Overall, the susceptibility of all Candida species ( C. albicans plus all other species) to fluconazole remained stable (MIC 90, 16 μg/mL). The fluconazole MIC 90 for C. albicans was 0.5–2.0 μg/ml for all years studied except 1995 (8.0 μg/mL) and was 1.0 μg/mL overall. The present study suggests a continued prominent role of C. albicans as a cause of BSI, and a constant level of susceptibility of Candida BSI isolates to fluconazole over 7 years. These data should serve as a baseline for future surveillance efforts for anti-fungal agents tested against yeast BSI isolates.

International surveillance of bloodstream infections due to Candida species: frequency of occurrence and antifungal susceptibilities of isolates collected in 1997 in the United States, Canada, and South America for the SENTRY Program. The SENTRY Participant Group.

An international program of surveillance of bloodstream infections (BSIs) in the United States, Canada, and South America between January and December 1997 detected 306 episodes of candidemia in 34 medical centers (22 in the United States, 6 in Canada, and 6 in South America). Eighty percent of the BSIs were nosocomial and 50% occurred in patients hospitalized in an intensive care unit. Overall, 53.3% of the BSIs were due to Candida albicans, 15.7% were due to C. parapsilosis, 15.0% were due to C. glabrata, 7.8% were due to C. tropicalis, 2.0% were due to C. krusei, 0.7% were due to C. guilliermondii, and 5.8% were due to Candida spp. However, the distribution of species varied markedly by country. In the United States, 43.8% of BSIs were due to non-C. albicans species. C. glabrata was the most common non-C. albicans species in the United States. The proportion of non-C. albicans BSIs was slightly higher in Canada (47.5%), where C. parapsilosis, not C. glabrata, was the most common non-C. albicans species. C. albicans accounted for 40.5% of all BSIs in South America, followed by C. parapsilosis (38.1%) and C. tropicalis (11.9%). Only one BSI due to C. glabrata was observed in South American hospitals. Among the different species of Candida, resistance to fluconazole (MIC, > or = 64 microg/ml) and itraconazole (MIC, > or = 1.0 microg/ml) was observed with C. glabrata and C. krusei and was observed more rarely among other species. Isolates of C. albicans, C. parapsilosis, C. tropicalis, and C. guilliermondii were all highly susceptible to both fluconazole (99.4 to 100% susceptibility) and itraconazole (95.8 to 100% susceptibility). In contrast, 8.7% of C. glabrata isolates (MIC at which 90% of isolates are inhibited [MIC90], 32 microg/ml) and 100% of C. krusei isolates were resistant to fluconazole, and 36.9% of C. glabrata isolates (MIC90, 2.0 microg/ml) and 66.6% of C. krusei isolates were resistant to itraconazole. Within each species there were no geographic differences in susceptibility to fluconazole or itraconazole.

National Surveillance of Nosocomial Blood Stream Infection Due to Candida albicans: Frequency of Occurrence and Antifungal Susceptibility in the SCOPE Program

Surveillance of nosocomial blood stream infections (BSI) in the USA between April 1995 and June 1996 revealed that Candida was the fourth leading cause of nosocomial BSI, accounting for 8% of all infections. Fifty-two percent of 379 episodes of candidemia were due to Candida albicans. In vitro susceptibility studies using the 1997 National Committee for Clinical Laboratory Standards reference method demonstrated that 92% of C. albicans isolates were susceptible to 5-fluorocytosine and 90% were susceptible to fluconazole and itraconazole. Geographic variation in susceptibility to fluconazole and itraconazole was observed. Isolates from the Northwest and Southeast regions were more frequently resistant to fluconazole (13.3–15.5%) and to itraconazole (17.2–20.0%) than those from the Northeast and Southwest regions (2.9–5.5% resistant to fluconazole and itraconazole). Continued surveillance for infections caused by C. albicans and other species of Candida among hospitalized patients is recommended.