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Biomedical subjects

S N Banerjee

Publications and source records attributed to S N Banerjee.

At least 37 records · Page 2Linked to original sources
PubMed1998

Risk factors for early recurrent Clostridium difficile-associated diarrhea.

Recurrence is a common sequela of Clostridium difficile-associated diarrhea (CDD) and may increase morbidity, costs, and treatment-related antimicrobial resistance. Because recurrent CDD (RCDD) frequently occurs very soon after an initial episode, our goal was to determine the risk factors for early RCDD (occurring < or = 45 days after the initial episode). We conducted a case-control study, comparing 13 patients with early RCDD (case patients) with 46 patients who had only one CDD episode (control patients) at Centre Hospitalier Angrignon (Québec) during January 1993 through November 1994. Risk factors for early RCDD included a history of chronic renal insufficiency, a white blood cell count of > or = 15 x 10(3)/mm3, and community-acquired diarrhea with the first CDD episode. For seven of eight case patients, C. difficile strains from the first and second CDD episodes were identical, suggesting that relapse is more common than reinfection. These results suggest that treatments should be directed at preventing relapses in patients at high risk for early RCDD.

Adult↗
PubMed1998

Tick-borne relapsing fever in the northwestern United States and southwestern Canada.

Records from 182 cases of tick-borne relapsing fever (TBRF) were reviewed. In confirmed cases, there was febrile illness, and spirochetes were identified on peripheral blood preparations. In probable cases, there were clinical features of TBRF and either the same exposure as a confirmed case or serological (indirect fluorescent antibody test and western blotting [WB]) evidence of infection with Borrelia hermisii. Sera also were tested for antibody to Borrelia burgdorferi. We identified 133 confirmed and 49 probable cases of TBRF. A Jarisch-Herxheimer reaction was reported in 33 (54.1%) of 61 cases for which this information was available. Most patients who had antibodies to B. hermsii were serologically positive for B. burgdorferi, and WB demonstrated false positivity of testing for B. burgdorferi. Thirty-five (21%) of 166 cases were unreported to public health authorities. In 52 cases, there were more than two relapses before the diagnosis. This study demonstrates that TBRF is underrecognized and underreported and may be falsely identified as Lyme disease.

Adolescent↗
PubMed1998

Increased bloodstream infection rates in surgical patients associated with variation from recommended use and care following implementation of a needleless device.

OBJECTIVE: To determine if an apparent increase in bloodstream infections (BSIs) in patients with central venous catheters (CVCs) was associated with the implementation of a needleless access device. DESIGN: Retrospective cohort study using a derived CVC-days factor for estimating appropriate denominator data. SETTING: A 350-bed urban, acute, tertiary-care hospital. METHODS: BSI surveillance data were obtained, and high-risk areas for BSIs were determined. A random 5% sample of medical records was used to estimate CVC days, and a cohort study was conducted to compare BSI rates before and during needleless device use. A survey was conducted of nursing needleless-device practices. RESULTS: The surgical intensive-care unit (SICU), the medical intensive-care unit, and the solid organ transplant unit (OTU) were identified as high-risk units. Using existing surveillance BSI data and the estimated CVC days, the catheter-related BSI rates in the high-risk surgical patients were significantly higher during the needleless-device period compared with the preneedleless-device period (SICU, 9.4 vs 5.0/1,000 CVC days; OTU, 13.6 vs 2.2/1,000 CVC days). A survey of the nurses revealed that 60% to 70% were maintaining the needleless devices correctly. CONCLUSION: We observed a significant increase in the BSI rate in two surgical units, SICU and OTU, associated with introduction of a needleless device. This increase occurred shortly after the needleless device was implemented and was associated with nurses' unfamiliarity with the device, and needless-device use and care practices different from the manufacturer's recommendations.

Catheterization, Central Venous↗
PubMed1998

Line-associated bloodstream infections in pediatric intensive-care-unit patients associated with a needleless device and intermittent intravenous therapy.

OBJECTIVES: To determine risk factors for an increase in line-associated bloodstream infections (BSIs) in three pediatric intensive-care units at one hospital that recently had changed brands of needleless access device. DESIGN: Retrospective case-control studies; review of the units' infection control policies and procedures for accessing and replacing components of needleless access devices. SETTING: A community tertiary-care hospital's three pediatric intensive-care units. PATIENTS: Children in one of the three intensive-care units with a central venous catheter in place during January 1, 1995, through May 15, 1996, who developed laboratory-confirmed primary BSI. Children who had central venous catheters in place for >48 hours and who did not develop BSI were chosen randomly as controls. RESULTS: Eight patients met the case definition; they had 11 episodes of BSI. Multivariate analysis identified duration of catheterization and exposure to the IVAC first-generation needleless device as independent risk factors for BSI. Compared with patients from another pediatric intensive-care unit in which the IVAC device also was used but in which an increased BSI rate did not occur, patients from the unit with an increased BSI rate were more likely to receive intermittent (vs continuous) intravenous therapy through one or more lumens. In both units, the IVAC device valve component was replaced every 6 days, and the endcap used to cover the valve (when connected to an unused lumen) was replaced every 24 hours or after each access. The BSI rate returned to baseline after institution of a policy to replace the entire IVAC device, valve, and endcap every 24 hours. CONCLUSIONS: An increased risk of BSI was associated with use of the IVAC first-generation needleless device when replaced every 6 days. This increased risk may have been more pronounced in one pediatric intensive-care unit, because patients were more likely to receive intermittent intravenous therapy. Intermittent intravenous therapy or central venous catheter flushing practices may be important determinants of BSI risk.

Adolescent↗
PubMed1998

Tick-borne relapsing fever in British Columbia, Canada: first isolation of Borrelia hermsii.

The spirochete that causes tick-borne relapsing fever, Borrelia hermsii, was isolated in pure culture during 1995 and 1996 from three acutely ill human patients infected in southern British Columbia, Canada. The geographic area of exposure is a known focus of this disease dating back to 1930 when the first case was recognized in a human. Analyses of plasmid DNA, protein profiles, and reactivity with a species-specific monoclonal antibody identified the new isolates of spirochetes as B. hermsii, all of which were most similar to an isolate of this spirochete from northern California described previously. These are the first reported isolates of B. hermsii from Canada.

Adult↗
PubMed1997

Status of tuberculosis infection control programs at Texas hospitals, 1989 through 1991.

BACKGROUND: Paralleling the resurgence of tuberculosis (TB) in the United States, the reported number of persons with TB in Texas increased by 33% during 1985 through 1992, the third largest rise among all the states. This increase prompted us to survey hospitals in Texas to determine their degree of compliance with recommendations in the Centers for Disease Control and Prevention TB guidelines. METHODS: In April 1992, we mailed a voluntary questionnaire about TB infection control practices, health care worker tuberculin skin testing procedures, and Mycobacterium tuberculosis laboratory methods to a convenience sample of hospitals in Texas. RESULTS: Of 180 hospitals surveyed, 151 (83%) returned completed questionnaires. Of these, 90 (60%) were nonteaching community hospitals; 28 (19%) were teaching community hospitals; 13 (9%) were university-affiliated hospitals; and 20 (13%) were other hospitals. The number of hospitals to which patients with TB were admitted increased from 98 (65%) in 1989 to 122 (81%) in 1991. Respondent hospitals had a mean of 183 acute care beds (median 100, range 5 to 999), 6 acid-fast bacillus isolation rooms (median 2, range 0 to 57) and 7.5 admissions/year of patients with TB (median 2, range 0 to 202). Of hospitals responding to specific questions, 20% (27/137) admitted patients with multidrug-resistant TB, 18% (25/140) reported not having any acid-fast bacillus isolation rooms, and 28% (35/125) had no rooms meeting all of the Centers for Disease Control and Prevention criteria for acid-fast bacillus isolation (negative air pressure, > or = 6 air changes per hour, and air directly vented to the outside). The tuberculin skin test conversions among health care workers rose from 246 (0.6%) in 1989 to 547 (0.9%) in 1991. CONCLUSION: Although the number of Texas hospitals admitting patients with TB increased during 1989 through 1991, many facilities still did not have infection control practices consistent with the 1992 Centers for Disease Control and Prevention TB guidelines.

Centers for Disease Control and Prevention, U.S.↗
PubMed1997

Serratia marcescens outbreak associated with extrinsic contamination of 1% chlorxylenol soap.

OBJECTIVES: To determine risk factors for Serratia marcescens infection or colonization, and to identify the source of the pathogen and factors facilitating its persistence in a neonatal intensive-care unit (NICU) during an outbreak. DESIGN: Retrospective case-control study; review of NICU infection control policies, soap use, and handwashing practices among healthcare workers (HCWs); and selected environmental cultures. SETTING: A university-affiliated tertiary-care hospital NICU. PATIENTS: All NICU infants with at least one positive culture for S marcescens during August 1994 to October 1995. Infants who did not develop S marcescens infection or colonization were selected randomly as controls. RESULTS: Thirty-two patients met the case definition. On multivariate analysis, independent risk factors for S marcescens infection or colonization were having very low birth weight (< 1,500 g), a patent ductus arteriosus, a mother with chorioamnionitis, or exposure to a single HCW. During January to July 1995, NICU HCWs carried their own bottles of 1% chlorxylenol soap, which often were left standing inverted in the NICU sink and work areas. Cultures of 16 (31%) of 52 samples of soap and 1 (8%) of 13 sinks yielded S marcescens. The 16 samples of soap all came from opened 4-oz bottles carried by HCWs. DNA banding patterns of case infant, HCW soap bottle, and sink isolates were identical. CONCLUSIONS: Extrinsically contaminated soap contributed to an outbreak of S marcescens infection. Very-low-birth-weight infants with multiple invasive procedures and exposures to certain HCWs were at greatest risk of S marcescens infection or colonization.

Anti-Infective Agents, Local↗
PubMed1994

Ceftazidime resistance among selected nosocomial gram-negative bacilli in the United States. National Nosocomial Infections Surveillance System.

To examine temporal trends in ceftazidime resistance, susceptibility data reported to the National Nosocomial Infections Surveillance system during 1987-1991 were analyzed among nosocomial Enterobacter species, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Linear increases in resistance were observed for Enterobacter species and K. pneumoniae. One hospital experienced a dramatic rise from 1.0% in 1987-1989 to 40% in 1990-1991 (P < .001) in ceftazidime resistance among K. pneumoniae isolates. No increase was observed during this period for P. aeruginosa. Logistic regression analysis confirmed these trends (or the lack thereof) for Enterobacter species and P. aeruginosa; for K. pneumoniae, ceftazidime resistance was found to be increasing among isolates from teaching hospitals and intensive care units. Ceftazidime resistance is an emerging problem that has the potential for dramatic increases. Selective pressures for the development of ceftazidime resistance need to be identified and addressed.

Ceftazidime↗
PubMed1994

Clinical evaluation of Tc-99m cystine. A new renal radiopharmaceutical.

Tc-99m cystine has been proved to be a good renal agent in animals. Its clinical evaluation has not been reported. In this study, Tc-99m cystine is used for evaluation of renal function in normal subjects and patients with chronic renal failure as well as in renal transplant patients. The results are compared with similar studies using Tc-99m DTPA and Tc-99m GHA. The clearance values also are compared with I-131 OIH. The results show that Tc-99m cystine has good radiopharmaceutical characteristics suitable for evaluation of both renal function as well as morphology.

Cystine↗
PubMed1994

Clinical evaluation of Tc-99m cystine. A new renal radiopharmaceutical.

Tc-99m cystine has been proven to be a good renal agent in animals, but its clinical evaluation has not been reported. In this study, Tc-99m cystine was used for evaluation of renal function in normal subjects and patients with chronic renal failure as well as in renal transplant patients. The results are compared with similar studies that used Tc-99m DTPA and Tc-99m GHA. The clearance values also have been compared with I-131 OIH clearance. The results show that Tc-99m cystine has good radiopharmaceutical characteristics suitable for evaluation of both renal function as well as morphology.

Cystine↗
PubMed1994

Evaluation of Alamar colorimetric MIC method for antimicrobial susceptibility testing of gram-negative bacteria.

The Alamar (Alamar Biosciences, Inc., Sacramento, Calif.) colorimetric antimicrobial susceptibility testing method is a new approach to the determination of broth microdilution MICs. The method uses a color indicator to detect growth of microorganisms within the wells of a microdilution tray. The color changes can be read visually or with a fluorometer. The system contains growth and sterility control wells and 20 antimicrobial agents per MIC tray with eight twofold dilutions for each antimicrobial agent. We tested 186 multiresistant, gram-negative bacterial isolates against 33 antimicrobial agents and compared the results to those obtained by agar dilution. Categorical agreement for all agents was 90.9% and ranged from 78.2% for ampicillin-sulbactam to 98.1% for amikacin. Percent agreement for MIC results (within +/- 1 log2 dilution) was 91.0% for all agents and ranged from 69.1% for gentamicin to 97.9% for ciprofloxacin. Most of the disagreements were with the penicillins and cephalosporins for beta-lactamase-producing strains. The Alamar MIC system is very easy to read visually and appears to be a satisfactory addition to currently used MIC determination methods.

Agar↗
PubMed1993

Two percent sodium chloride is required for susceptibility testing of staphylococci with oxacillin when using agar-based dilution methods.

The need to add NaCl to agar media to ensure accuracy of results when testing staphylococci with oxacillin was investigated. The results of four antimicrobial susceptibility testing methods (agar and broth dilution, E test, and disk diffusion) in which the growth medium contained 0, 2, 4, or 5% NaCl were compared with the results of a hybridization assay using a mec gene probe. We tested 223 strains of staphylococci, 128 of which were mec gene positive. A total of 7 of the 128 positive strains were coagulase-negative staphylococci with 24-h oxacillin MICs of < or = 2 micrograms/ml. Ninety-five isolates were mec gene negative, including seven strains of Staphylococcus aureus with oxacillin MICs of > or = 4 micrograms/ml. The oxacillin MICs for mec gene-positive, oxacillin-resistant strains of staphylococci increased two- to fourfold with the addition of NaCl to the test medium, while the MICs for mec gene-negative strains did not change in the presence of added salt. Very major error rates for the agar dilution and E test methods in the absence of salt ranged from 18.2 to 20.2%. Major error rates for mec gene-negative S. aureus isolates were > 17% for all test methods when 4 or 5% NaCl was added to the test medium. The addition of 2% NaCl to Mueller-Hinton agar for testing of oxacillin resulted in very major error rates of < 1% for the agar dilution and E test methods although the major error rates for the two methods with added NaCl were 8.5 and 6.9%, respectively. The disk diffusion test did not perform well in this study, showing essential error rates of > or = 18.3%. We recommended the addition of 2% NaC1 to Mueller-Hinton agar when testing staphylococci with oxacillin by either the agar dilution or E test method. NaC1 should not be added for the disk diffusion test.

Culture Media↗
PubMed1991

Secular trends in nosocomial primary bloodstream infections in the United States, 1980-1989. National Nosocomial Infections Surveillance System.

More than 25,000 primary bloodstream infections (BSIs) were identified by 124 National Nosocomial Infections Surveillance System hospitals performing hospital-wide surveillance during the 10-year period 1980-1989. These hospitals reported 6,729 hospital-months of data, during which time approximately 9 million patients were discharged. BSI rates by hospital stratum (based on bed size and teaching affiliation) and pathogen groups were calculated. In 1989, the overall BSI rates for small (less than 200 beds) nonteaching, large nonteaching, small (less than 500 beds) teaching, and large teaching hospitals were 1.3, 2.5, 3.8, and 6.5 BSIs per 1,000 discharges, respectively. Over the period 1980-1989, significant increases (p less than 0.0001) were observed within each hospital stratum, in the overall BSI rate and the BSI rate due to each of the following pathogen groups: coagulase-negative staphylococci, Staphylococcus aureus, enterococci, and Candida species. In contrast, the BSI rate due to gram-negative bacilli remained stable over the decade, in all strata. Except for small nonteaching hospitals, the greatest increase in BSI rates was observed in coagulase-negative staphylococci (the percentage increase ranged between 424% and 754%), followed by Candida species (219-487%). In small nonteaching hospitals, the greatest increase was for S. aureus (283%), followed by enterococci (169%) and coagulase-negative staphylococci (161%). Our analysis documents the emergence over the last decade of coagulase-negative staphylococci as one of the most frequently occurring pathogens in BSI.

Bacteremia↗
PubMed1991

The National Nosocomial Infections Surveillance System: plans for the 1990s and beyond.

The National Nosocomial Infections Surveillance (NNIS) System is an ongoing collaborative surveillance system among the Centers for Disease Control (CDC) and United States hospitals to obtain national data on nosocomial infections. This system provides comparative data for hospitals and can be used to identify changes in infection sites, risk factors, and pathogens, and develop efficient surveillance methods. Data are collected prospectively using four surveillance components: hospital-wide, intensive care unit, high-risk nursery, and surgical patient. The limitations of NNIS data include the variability in case-finding methods, infrequency or unavailability of culturing, and lack of consistent methods for post-discharge surveillance. Future plans include more routine feedback of data, studies on the validity of NNIS data, new components, a NNIS consultant group, and more rapid data exchange with NNIS hospitals. Increasing the number of NNIS hospitals and cooperating with other agencies to exchange data may allow NNIS data to be used better for generating benchmark nosocomial infection rates. The NNIS system will continue to evolve as it seeks to find more effective and efficient ways to measure the nosocomial infection experience and assess the influence of patient risk, changes in the delivery of hospital care, and changes in infection control practices on these measures.

Centers for Disease Control and Prevention, U.S.↗