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C L Strand

Publications and source records attributed to C L Strand.

At least 19 recordsLinked to original sources
PubMed1998

Blood culture contamination: a College of American Pathologists Q-Probes study involving 640 institutions and 497134 specimens from adult patients.

OBJECTIVE: To examine clinical and laboratory practices associated with contamination of blood culture specimens from adults. DESIGN AND SETTING: A College of American Pathologists Q-Probes quality improvement study involving prospective evaluation of adult blood culture contamination rates in 640 institutions. MAIN OUTCOME MEASURE: Proportion of contaminated blood cultures. RESULTS: A total of 497134 blood cultures were studied. The median adult inpatient blood culture contamination rate was 2.5% (central 80th percentile=0.9%-5.4%) by laboratory assessment. There was no significant difference in contamination rates between inpatient and outpatient cultures (P=.273). The median contamination rate by clinical assessment (2.1%) was significantly lower (P=.005), primarily because of a lower proportion of cultures with coagulase-negative Staphylococcus that were interpreted as contaminants when only one of multiple specimens was positive. Specimen collection variables associated with significantly lower contamination rates included use of a dedicated phlebotomy service (P=.039), use of tincture of iodine for skin disinfection (P=.036), and application of an antiseptic to the top of the collection device before inoculation (P=.018). Teaching institutions and high numbers of occupied beds were demographic factors associated with higher contamination rates for inpatients but not for outpatients. Culture parameters associated with higher contamination rates included microbial growth from a single specimen, isolation of certain microbial species (eg, coagulase-negative Staphylococcus), and longer time to detect growth in culture. Contamination rates were not significantly affected by the type of blood culture method used, specimen volume, or use of a double-needle collection procedure. CONCLUSIONS: There is wide variation in blood culture contamination rates among institutions. Three specimen collection factors and three culture variables were identified as having a significant effect on blood culture contamination.

Adult↗
PubMed1993

Effect of iodophor vs iodine tincture skin preparation on blood culture contamination rate.

OBJECTIVE: To determine if iodine tincture is a more effective skin antiseptic for blood culture collection than povidone-iodine, an iodophor. DESIGN: Pairwise comparisons across phases. In phases 1 and 3, blood culture skin preparation was performed with the iodophor; in phases 2 and 4, skin preparation was performed with iodine tincture. SETTING: Emergency department of a large urban teaching hospital. PATIENTS: All adult patients seen in the emergency department who had blood cultures collected because a systemic bacterial infection was suspected. MAIN OUTCOME MEASURE: The blood culture contamination rate for the iodophor and iodine tincture skin preparations. RESULTS: A total of 8467 blood cultures were collected during the study, and 421 (4.97%) were classified as contaminated. The contamination rate for the blood cultures collected using the iodophor was 6.25%, and the contamination rate for the cultures using iodine tincture was 3.74%; this difference is statistically significant (P < .00001). CONCLUSIONS: The effectiveness of the skin antiseptic may be an important factor in determining contamination rate in blood culturing. If these results are confirmed by others, then institutions that have a high blood culture contamination rate when using an iodophor for skin preparation should consider changing to iodine tincture.

Anti-Infective Agents, Local↗
PubMed1992

A blood culture study comparing the new Bactec high-volume resin media with hypertonic media.

A blood culture study comparing the performance of the new high-volume Bactec resin media to hypertonic medium was conducted in adult patients seen in the emergency department. Twenty milliliters of blood was divided equally among three media: hypertonic (NR8A), aerobic high-volume resin (HV26), and anaerobic high-volume resin (HV27). During a 5.5-month period, 2,724 blood cultures were collected; there were 417 (15.3%) positive cultures, of which 233 (8.6%) yielded pathogens and 184 (6.8%) contaminants. For the 257 isolates recovered from 233 cultures yielding pathogens, the isolation rates were: NR8A-194 (75.5%), HV26-204 (79.4%), and HV27-189 (73.5%). We conclude that in this emergency department patient population, the rate and speed of recovery of pathogenic microorganisms is comparable in high-volume resin media and the hypertonic medium but that the high-volume resin media still has a definite advantage over standard nonradiometric media in adults because high-volume blood cultures (20 mL) can be performed using a two-bottle collection set rather than a three-bottle set.

Bacteremia↗
PubMed1991

Solitary blood cultures as a quality assurance indicator.

For patients with suspected bacteremia, at least two separate blood cultures are recommended to achieve maximum sensitivity and to properly interpret results. Since a single blood collection may signify an improper procedure with serious consequences if the diagnosis of blood stream infection is missed, we investigated this problem with studies at three teaching hospitals (A, B, and C) and by a survey of 38 other hospitals. The incidence of solitary blood cultures ranged from 1 to 99% (median 26%) at the surveyed institutions. Among the cases investigated at hospitals B and C, between 10 and 30% of solitary blood cultures were not clinically indicated, while most of the others were caused by the physician not knowing that one culture was insufficient or by failure to complete the diagnostic plan. Focused concurrent intervention at hospital B was associated with reductions in solitary blood cultures from 40.0 to 24.6% (p = 0.045) and a decline in those not indicated from 38.1 to 12.5% (p = 0.192). Global educational efforts at hospital A were associated with a decrease in solitary blood culture rates from 52 to 37% (p = 0.016). These results show that blood culture practice varies widely among institutions in spite of consensus recommendations for proper specimen collections. We estimate that, nationwide, up to 18,000 etiologic diagnoses of bacteremia are missed annually because of this problem. Monitoring institutional solitary blood cultures is recommended as a test utilization indicator and as the basis for improving blood culture practice.

Bacteremia↗
PubMed1990

Role of the microbiology laboratory in the diagnosis of opportunistic infections in persons infected with human immunodeficiency virus.

Patients with defects in the immune system caused by infection with human immunodeficiency virus are predisposed to a variety of opportunistic infections, many of which can be diagnosed by conventional or special microbiological procedures. This article reviews the laboratory diagnosis of bloodstream, lower respiratory tract, gastrointestinal tract, and central nervous system infections in persons infected with human immunodeficiency virus. Laboratories serving health care facilities in which a large number of patients with human immunodeficiency virus infection are cared for should consider enhancing the detection of the specific pathogens affecting these patients by the use of special procedures, including blood culture methods for mycobacteria and fungi, examination of induced sputum for Pneumocystis carinii, and modified acid-fast stains on feces to identify Cryptosporidium and Isospora belli.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Evaluation of a new blood culture medium for mycobacteria.

This study evaluates the sensitivity and detection time of a new radiometric broth (BACTEC 13A medium, Johnston Laboratories, Towson, MD) designed for direct blood culturing for Mycobacteria. A total of 1,848 blood specimens were cultured in parallel by a new method in which blood was directly inoculated into 13A medium and a comparative method involving lysis-centrifugation and inoculation of 7H11 agar and 7H12 broth media. There were 65 blood cultures with positive results (64 Mycobacterium avium-intracellulare and 1 Mycobacterium tuberculosis) from 43 patients. For the direct inoculation and lysis-centrifugation methods, the recovery rates were 96.9% and 98.5%, respectively, and the mean times to detection were essentially the same (23.6 and 23.8 days, respectively). Thus, the direct-inoculation technique using 13A medium showed performance equivalent to the lysis-centrifugation method. Also, the direct method has the advantage of elimination of the time-consuming manual manipulations that are required by lysis-centrifugation methods.

Bacteriological Techniques↗
PubMed1987

Evaluation of the automated leukocyte differential count in emergency department patients.

This study compares the results of the leukocyte three-part differential count as determined by the Coulter S-Plus IV in 104 consecutive patient samples from the emergency department with results obtained by conventional visual differential. A high rate (40%) of instrument rejection was found, reflecting the high prevalence of disease and hematologic abnormalities in the patient population. No clinically significant abnormality went undetected, demonstrating that the automated leukocyte three-part differential is effective as a screening test in the emergency department patient population.

Emergency Service, Hospital↗
PubMed1987

Reliability of blood cultures collected from intravascular catheter versus venipuncture.

This is a study of 130 matched venipuncture and intravascular blood cultures collected from 53 patients. In 99 cultures (76.1%), both the venipuncture and the catheter specimens were negative. There were six matched cultures yielding significant isolates: in three both the venipuncture and intravascular specimens were positive; in two only the intravascular specimen was positive; and in one only the venipuncture specimen was positive. Twenty-five cultures were positive from the intravascular specimen only, and 23 of these were classified as contaminated cultures. Thus, the contamination rate was significantly higher in the intravascular catheter blood culture specimens (P less than 0.001). These results indicate that blood culture specimens should not be routinely collected from intravascular catheters unless collection by venipuncture is impossible.

Blood Specimen Collection↗
PubMed1985

Septicemia secondary to urinary tract infection with colony counts less than 10(5) CFU/mL.

This study evaluates the importance of low-colony-count bacteriuria (less than 10(5) CFU/mL) in septicemia originating from urinary tract infections. In a 14-month period, 260 episodes of septicemia occurred. No clinical or microbiologic evidence for a source other than the urinary tract was evident in 68 (26.2%) cases. Of these 68 patients, 13 (19.1%) had colony counts less than 10(5) CFU/mL, and 6 of the 13 had colony counts less than 10(4) CFU/mL. Nine of the infections were community acquired and four were nosocomial. None of the nosocomial cases were associated with an indwelling catheter; four of the 13 patients were receiving chemotherapy and/or steroid therapy. These data support the thesis that some cases of septicemia in patients other than acutely dysuric women, can be caused by UTIs with low colony counts.

Adult↗
PubMed1983

Evaluation of the BACTEC resin blood-culture medium.

A study to determine the value of the BACTEC resin-containing medium, 16B, used in conjunction with radiometric detection of bacteremia using three media was conducted. During a six-month period, 2,104 blood-culture sets consisting of the four media (6B, 7C, 8B, and 16B) were collected. There were 158 significant positive cultures (excluding contaminants) that yielded 168 pathogenic isolates. The data were divided into two patient groups: patients receiving antibiotics and patients not receiving antibiotics. In contrast to previous studies, there was no significant difference in the detection rate of significant positive cultures by the different media in either group of patients. However, in patients receiving antimicrobial therapy, 41 of 55 significant positive cultures (74.5%) were detected by 16B medium, while 34 of 55 (61.8%) were detected by 6B medium. Although this difference is not statistically significant, this trend suggests that 16B medium may be useful in these patients. However, the isolation rate of significant positive cultures is the same for the resin medium and the hypertonic aerobic medium for both groups of patients. Thus, it is possible that the hypertonic medium is as efficacious as resin-containing media in blood culturing.

Adult↗
PubMed1982

Nosocomial Pseudomonas aeruginosa urinary tract infections.

Two separate outbreaks of Pseudomonas aeruginosa urinary tract infections (UTIs) were associated with cystoscopy or transurethral prostate resection. The first outbreak was identified after routine bacteremia surveillance demonstrated four cases of P aeruginosa septicemia in a three-month period. A six-month retrospective review of the microbiology records identified 14 cases of P aeruginosa UTI associated with urologic surgery instrumentation. The outbreak terminated after the implementation of two major control measures: (1) replacement of hexachlorophene solution with an iodophor solution for preparing patients and cleaning instruments before disinfection, and (2) weekly gas sterilization of cystoscopy instruments. The second outbreak, consisting of 11 cases of P aeruginosa UTI after transurethral resection of the prostate gland, occurred in a 187-bed community hospital. All available patient isolates were serotype 011, and culture of a rubber adaptor attached to the resectoscope also yielded growth of that serotype. The outbreak promptly terminated when the rubber adaptor was sterilized between cases.

Aged↗
PubMed1982

Routine subcultures shown to be unnecessary in radiometric detection of bacteremia using three media.

A study to determine the necessity of routine blind subcultures when using the radiometric BACTEC-460 instrument for detection of bacteremia was conducted. In the first phase, blind subcultures were performed on day 10 of incubation; in the second phase, blind subcultures were performed on day 4; in the final phase the subculture was performed on day one. During the study, 6,208 blood cultures from 2,455 patients were inoculated into three different culture media. There were 454 microbial isolates recovered, including 269 presumed pathogenic isolates. The single significant discrepancy between blind subculture and radiometric detection was a case of Staphylococcus epidermidis septicemia in which the organism was detected 48 hours earlier by blind subculture. There were no cultures in which significant bacterial isolates were detected by blind subcultures but not radiometrically. Thus, under the conditions of this study, routine blind subcultures are not necessary when using the BACTEC radiometric system for detection of bacteremia.

Adult↗
PubMed1982

Evaluation of the antimicrobial removal device when used with the BACTEC blood culture system.

A study to determine the value of the Antimicrobial Removal Device (ARD) used in conjunction with radiometric detection of bacteremia using three media was conducted. During a 12-month period, 622 duplicate ARD/BACTEC blood-culture sets were collected. There were 88 positive cultures that yielded 68 pathogenic isolates and 28 probable contaminant isolates. When all patients were considered, 31 pathogenic isolates were detected by both systems, 25 pathogenic isolates were detected faster or only by the BACTEC system, and 12 pathogenic isolates were detected faster or only when the ARD was employed. This difference is statistically significant (P less than 0.05). Thus, the standard BACTEC blood-culture system using three different media was superior to the same BACTEC system using ARD-processed blood specimens. When only patients receiving antimicrobial therapy were considered, there were more pathogenic isolates detected from unprocessed blood than from blood processed in the ARD; however, this difference was not statistically significant. In conclusion, there appears to be no advantage to using the ARD system in conjunction with the three-bottle BACTEC blood-culture system.

Adult↗
PubMed1981

Propionibacterium acnes central nervous system shunt infection. Commercial blood culture medium-dependent isolation of the bacterium.

A 58-year-old woman had a central nervous system shunt infection and septicemia caused by Propionibacterium acnes. During a two-year period, many Becton-Dickinson blood cultures (18 of 39) were positive for P. acnes, but all BACTEC blood cultures (15) were negative. Parallel cultures in the two commercial media performed simultaneously on the same blood samples several times resulted in a positive Becton-Dickinson culture and a negative BACTEC culture. This case reemphasizes that some bacterial isolates may not be detected when using only one commercial blood culture medium. Thus, if many blood cultures are negative for patients who have clinical features suggestive of septicemia, other types of blood culture media should be inoculated.

Bacterial Infections↗