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Biomedical subjects

S N Banerjee

Publications and source records attributed to S N Banerjee.

At least 19 recordsLinked to original sources

Bloodstream infection associated with needleless device use and the importance of infection-control practices in the home health care setting.

The influence of infection-control practices on bloodstream infection (BSI) risk was examined in a home health care setting in which three needleless devices were used consecutively. A case-control study and a retrospective cohort study were conducted. Risk factors for BSI included lower education level, younger age, having a central venous catheter (CVC) with multiple ports, or having a tunneled CVC. Among patients with a tunneled CVC, those at greatest risk had been allowed to shower rather than bathe and to get their exit site wet (P<.01). A high proportion (49%) of isolates were hydrophilic gram-negative bacteria, suggesting water sources of infection. In the cohort study, the BSI rate decreased as the frequency of changing the needleless device end cap increased from once weekly up to every 2 days, suggesting that the mechanism for BSI may involve contamination from the end cap. These findings may help to develop infection-control measures specific to home health care.

Adolescent

Fever and human immunodeficiency virus infection as sentinels for emerging mycobacterial and fungal bloodstream infections in hospitalized patients >/=15 years old, Bangkok.

To determine the etiology of bloodstream infections (BSIs) in hospitalized patients >/=15 years old in Thailand, prospectively enrolled, consecutive febrile (>/=38 degrees C) patients were admitted to one hospital during February-April 1997. After a patient history was taken and a physical examination was performed, blood was obtained for comprehensive culture and human immunodeficiency virus (HIV) testing. Of 246 study patients, 119 (48%) had BSIs, and 182 (74%) were infected with HIV. The 2 most common pathogens were Cryptococcus neoformans and Mycobacterium tuberculosis (30 and 27 patients, respectively). HIV-positive patients were more likely than HIV-negative patients to have mycobacteremia (57/182 vs. 0/64, P<. 0001), fungemia (38/182 vs. 2/64, P<.001), or polymicrobial BSIs (19/182 vs. 0/64, P<.002). Clinical predictors of BSIs included HIV infection, chronic diarrhea, lymphadenopathy, or splenomegaly. Mortality was higher among patients with than those without BSIs (P<. 001). Cohort-based microbiologic studies are critically important to diagnose emerging pathogens and to develop algorithms for empirical treatment of BSIs in developing countries.

Adolescent

Are US hospitals making progress in implementing guidelines for prevention of Mycobacterium tuberculosis transmission?

BACKGROUND: Outbreaks of tuberculosis (TB) in hospitals have occurred when the Centers for Disease Control and Prevention (CDC) guideline recommendations for preventing the transmission of Mycobacterium tuberculosis were not fully implemented. OBJECTIVE: To determine whether US hospitals are making progress in implementing the CDC guidelines for preventing TB. METHODS: In 1992, we surveyed all public (city, county, Veterans Affairs, and primary medical school-affiliated) US hospitals (n = 632) and 444 (20%) random samples of all private hospitals with 100 beds or more. In 1996, we resurveyed 136 random samples (50%) of all 1992 respondent hospitals with 6 or more TB admissions in 1991. RESULTS: Of the 1076 hospitals surveyed in 1992, 763 (71%) respondents returned a completed questionnaire. Among these, 536 (71%) of 755 reported having rooms that met CDC criteria for acid-fast bacilli isolation, ie, negative air pressure, 6 or more air exchanges per hour, and air directly vented to the outside. The predominant respiratory protective device for health care workers was nonfitted surgical mask and attending physicians were infrequently (50%) included in tuberculin skin-testing programs. In the 1996 resurvey, 103 (76%) of 136 respondents returned a completed questionnaire. Of these, 99 (96%) reported having rooms that met CDC criteria for acid-fast bacilli isolation. The N95 respiratory protective devices were predominantly used by health care workers, and attending physicians were increasingly (69%) included in the hospitals' tuberculin skin-testing programs. CONCLUSIONS: Most US hospitals are making progress in the implementation of CDC guidelines for preventing the transmission of M tuberculosis.

Centers for Disease Control and Prevention, U.S.

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

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

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

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

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

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.

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

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

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

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

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