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L C McDonald

Publications and source records attributed to L C McDonald.

At least 19 recordsLinked to original sources
PubMed2001

Quinupristin-dalfopristin-resistant Enterococcus faecium on chicken and in human stool specimens.

BACKGROUND: The combination of the streptogramins quinupristin and dalfopristin was approved in the United States in late 1999 for the treatment of vancomycin-resistant Enterococcus faecium infections. Since 1974, another streptogramin, virginiamycin, has been used at subtherapeutic concentrations to promote the growth of farm animals, including chickens. METHODS: To determine the frequency of quinupristin-dalfopristin-resistant E. faecium, we used selective medium to culture samples from chickens purchased in supermarkets in Georgia, Maryland, Minnesota, and Oregon and stool samples from outpatients. RESULTS: Between July 1998 and June 1999, samples from 407 chickens from 26 stores in four states were cultured, as were 334 stool samples from outpatients. Quinupristin-dalfopristin-resistant E. faecium was isolated from 237 chicken carcasses and 3 stool specimens. The resistant isolates from stool had low-level resistance (minimal inhibitory concentration [MIC], 4 microg per milliliter; resistance was defined as a MIC of at least 4 microg per milliliter). The resistant isolates from chickens in general had higher levels of resistance (MICs ranging from 4 to 32 microg per milliliter; MIC required to inhibit 50 percent of isolates, 8 microg per milliliter). CONCLUSIONS: Quinupristin-dalfopristin-resistant E. faecium contaminates a large proportion of chickens sold in U.S. supermarkets. However, the low prevalence and low level of resistance of these strains in human stool specimens suggest that the use of virginiamycin in animals has not yet had a substantial influence. Foodborne dissemination of resistance may increase, however, as the clinical use of quinupristin-dalfopristin increases.

Animal Feed↗
PubMed2001

Correlates of antibiotic use in Taiwan hospitals.

OBJECTIVE: To determine factors that correlate with increased antibiotic use among adult inpatients in Taiwan. DESIGN: Retrospective survey of medical records. SETTING: 14 acute-care hospitals (8 regional hospitals, 6 medical centers) in Taiwan. PARTICIPANTS: A systematic probability sample from each hospital, totaling 663 adult inpatients who were discharged or had died in early 1999. MEASUREMENTS: Infectious disease physicians at the 14 hospitals collected data from medical records regarding patient demographics, hospitalization, discharge diagnosis, and antibiotics received. RESULTS: A total of 447 (67%) patients received antibiotics for an overall rate of 813 antibiotic-days (number of days patients received each antibiotic)/1,000 patient-days. Both the proportion of beds in intensive care units ([ICUs] Pearson correlation coefficient [r], 0.67; 95% confidence interval [CI 95], 0.36-0.89; P<.01) and the proportion of patients admitted to surgical services (r, 0.66; CI 95, 0.20-0.88; P=.01) correlated with the mean patient rate of antibiotic-days/hospital-day (MPAUD). In contrast, we found no correlation between the proportion of patients who received antibiotics and the MPAUD. Using multiple linear regression, medical center status was the only independent predictor for increased MPAUD (regression coefficient [b], 0.15; CI 95, 0.05-0.24; P<.01). There was no correlation between pooled rates of antibiotic-days/hospital-day and any hospital demographic factors. First-generation cephalosporin (39%) and aminoglycoside (24%) use accounted for the majority of antibiotic-days. CONCLUSIONS: Antibiotic use is greater in medical centers than in regional hospitals and appears to be independent of surgical case mix or the proportion of ICU beds. Determination of multiple, independent measures of antibiotic use may be necessary to understand the relation between antibiotic use and resistance in hospital.

Adolescent↗
PubMed2001

Emergence of reduced susceptibility and resistance to fluoroquinolones in Escherichia coli in Taiwan and contributions of distinct selective pressures.

A survey of 1,203 Escherichia coli isolates from 44 hospitals in Taiwan revealed that 136 (11.3%) isolates were resistant to fluoroquinolones and that another 261 (21.7%) isolates had reduced susceptibility. Resistance was more common in isolates responsible for hospital-acquired (mostly in intensive care units) infections (17.5%) than in other adult inpatient (11.4%; P = 0.08) and outpatient isolates (11.9%; P > 0.1). Similarly, reduced susceptibility was more common in isolates responsible for hospital-acquired infections (30.9%) than in other adult inpatient (21.0%; P = 0.04) and outpatient (21.4%; P = 0.06) isolates. Isolates from pediatric patients were less likely to be resistant (1.3 versus 12.0%; P < 0.01) but were nearly as likely to have reduced susceptibility (17.7 versus 21.9%; P > 0.1) as nonpediatric isolates. There was an inverse relationship in the proportion of isolates that were resistant versus the proportion that had reduced susceptibility among isolates from individual hospitals (R = 0.031; P < 0.05). In an analysis of isolates from two hospitals, all 9 resistant strains possessed double point mutations in gyrA and all 19 strains with reduced susceptibility strains had single point mutations; no mutations were found among fully susceptible strains. Risk factors for resistance included underlying cancer (odds ratio [OR], 83; 95% confidence interval [CI(95)], 7.3 to 2,241; P < 0.001), exposure to a quinolone (OR, undefined; P = 0.02), and exposure to a nonquinolone antibiotic (OR, 20; CI(95), 2.2 to 482; P < 0.001); underlying cancer was the only independent risk factor (OR, 83; CI(95), 8.6 to 807; P < 0.001). There were no significant associations between any of these factors and reduced susceptibility. Whereas acute and chronic quinolone use in cancer patients is a major selective pressure for resistance, other undetermined but distinct selective pressures appear to be more responsible for reduced susceptibility to fluoroquinolones in E. coli.

Adolescent↗
PubMed2001

Controlled comparison of BacT/ALERT FAN aerobic medium and BATEC fungal blood culture medium for detection of fungemia.

Yeasts are an increasingly common cause of nosocomial bloodstream infections. Methods for their detection are many; controlled comparisons are few. The vented FAN aerobic blood culture medium has been shown to be superior to the standard BacT/ALERT aerobic medium for the detection of fungemia as well as bacteremia. The BACTEC selective fungal medium (FM) (BD Biosciences, Sparks, Md.) allowed detection of more episodes of fungemia than did a resin-containing medium with equal volumes of blood cultured. Therefore, we compared vented FAN to FM for the ability to recover fungi from the blood of patients who were at increased risk of having fungemia. From 5,109 cultures processed for which both FAN and FM bottles were adequately filled, fungi were recovered from 87 cultures. Of these, 47 were detected with both bottles, 12 were detected with FAN only, and 28 were detected with FM only (P < 0.05). FAN was the first bottle positive for 36 of the 47 cultures for which both bottles yielded the same fungus, whereas the FM bottle was the first bottle positive for 11 cultures (P < 0.001). A total of 54 episodes of fungemia were identified, with 40 detected by both media, 4 detected only by FAN, and 10 detected only by FM (P value, not significant). We conclude that the vented FAN aerobic bottle is comparable to the FM bottle for detection of episodes of yeast infection but has the added benefit of detecting bacteria.

Aerobiosis↗
PubMed2001

Use and abuse of surgical antibiotic prophylaxis in hospitals in Taiwan.

BACKGROUND AND PURPOSE: A large proportion of antibiotics used in hospitals is for surgical prophylaxis. We determined the prevailing practices and factors associated with the misuse of surgical antibiotic prophylaxis in hospitals in Taiwan. METHODS: In a systematic survey of the medical records of 629 patients from 14 hospitals who underwent clean or clean-contaminated surgery from September 1998 through March 1999, data on the timing and duration of, and reasons for, antibiotic use were collected and analyzed. RESULTS: Overall, 578 (92%) patients received antibiotics perioperatively; in 499 (79%) cases, antibiotics were used for surgical prophylaxis. Only 302 (61%) patients received prophylaxis within 1 hour before surgery. More than 70% of patients received more than 3 days of postoperative antibiotic prophylaxis. The most commonly used antibiotics were first-generation cephalosporins and aminoglycosides. Factors independently associated with inappropriately timed prophylaxis included surgery performed at a hospital with a greater proportion of intensive care unit beds (conditional odds ratio [OR] = 1.14 per 1% increase, 95% confidence interval [CI95%] 1.06-1.23; p < 0.01), surgery duration of at least 1 hour (OR = 0.40, CI95% 0.24-0.67; p < 0.01), orthopedic surgery (OR = 0.59, CI95% 0.36-0.98; p = 0.041), and cardiothoracic surgery (OR = 2.07, CI95% 1.14-3.77; p = 0.02). Risk factors for more than 3 days of prophylaxis included surgical placement of prosthetic material (OR = 2.26, CI95% 1.10-4.64; p = 0.03), the number of antibiotics used (OR = 1.99 per antibiotic, CI95% 1.26-3.13; p < 0.01), surgery duration of at least 1 hour (OR = 3.07, CI95% 1.45-6.51; p < 0.01), neurosurgery (OR = 4.57, CI95% 2.24-9.31; p < 0.01), and the use of oral antibiotics together with intravenous drugs (OR = 20.72, CI95% 10.72-40.07; p < 0.01). CONCLUSIONS: The results of this survey indicate that inappropriate use of surgical antibiotic prophylaxis is common in hospitals in Taiwan. Our results identify several problem areas, including incorrect timing, duration, and use of oral antibiotics for surgical prophylaxis, that require targeted physician education and public health interventions.

Adolescent↗
PubMed2001

The use of antibiotics critical to human medicine in food-producing animals in Taiwan.

There are increasing public health concerns about antibiotics used in food-producing animals that may contribute to the development of resistance in human pathogens. Such resistance may be critical to human medicine when resistance develops to drugs that treat certain pathogens of which there is no good alternative therapy. We surveyed 10 farms, eight feed mills, and one animal drug distributor in Taiwan to determine the major antibiotics used in food-producing animals, and the extent of use of five drugs that may select for resistance to antibiotics that are critical for human medicine. The five animal drugs, and the resistance of human drug/class they may select for, included avoparcin (vancomycin/glycopeptides), avilomycin (ziracin/envirninomycins), enrofloxacin (ciprofloxacin/fluoroquinolones), virginiamycin (quinupristin and dalfopristin combination/streptogramins), and kanamycin (gentamicin/aminoglycosides). Tetracyclines were the class of antibiotic that was most widely used in the greatest amounts. Over the past 12 months, the number of farms, chicken feed mills, and pig feed mills, that have respectively reported the use of avoparcin was 1 (10%), 5 (63%), 0; avilomycin 0, 0, 3 (50%); enrofloxacin 4 (40%), 1 (13%), 3 (50%); virginiamycin 2 (20%), 5 (63%), 0; and kanamycin 3 (30%), 1 (13%), 1 (17%). We conclude that although the most commonly used antibiotics (ie tetracyclines) have little effect on human medicine, there is a widespread use of antibiotics that may select for critical forms of resistance in human pathogens in food-producing animals.

Animal Diseases↗
PubMed2000

A hospital-based prevalence survey of bloodstream infections in febrile patients in Malawi: implications for diagnosis and therapy.

The etiology of bloodstream infections (BSIs) in febrile (> or =37.5 degrees C) adults (> or =18 years old) in one Malawi hospital were determined during August and September 1997. After clinical evaluation, blood was drawn for comprehensive culture, human immunodeficiency virus (HIV) type 1 testing, and malaria smear. Of 233 patients, 173 (74%) were HIV-1 infected, and 70 (30%) had BSI. BSI pathogens included 25 (33%) Streptococcus pneumoniae and 21 (28%) Mycobacterium tuberculosis. Nine patients (4%) had malaria parasitemia. BSIs were more likely in HIV-1-positive than in -negative patients (62/173 vs. 8/60, P<.01). Clinical predictors of BSI included HIV-1 infection and altered mental status. Mortality among inpatients with BSI was higher than among those without BSI (P<.001). In conclusion, S. pneumoniae and M. tuberculosis are frequent causes of BSI in febrile adults. Similar surveys, performed periodically in developing countries, may assist in the identification of clinical predictors of BSI and in planning appropriate therapy.

Adolescent↗
PubMed2000

Determining the significance of coagulase-negative staphylococci isolated from blood cultures at a community hospital: a role for species and strain identification.

OBJECTIVES: To determine the degree to which species identification or strain relatedness assessment of successive blood culture isolates of coagulase-negative staphylococci (CNS) may improve the clinical diagnosis of bloodstream infection (BSI). SETTING: 400-bed community hospital. DESIGN: Prospective laboratory survey during which all CNS blood culture isolates obtained between mid-August 1996 and mid-February 1997 (study period) were saved and later identified to the species level; selected isolates were genotyped using pulsed-field gel electrophoresis at the Centers for Disease Control and Prevention (CDC). Retrospective review of medical records of 37 patients with multiple cultures positive for CNS. RESULTS: During the study period, 171 patients had blood cultures positive for CNS; 130 had single positive cultures and 41 had > or =2 positive cultures. Of these 41, 23 (62%) were from patients with signs and symptoms of BSI according to CDC surveillance definitions. Species identification and strain clonality of CNS isolates from patients with > or =2 positives revealed 3 (13%) of the 23 patients did not have a consistent CNS species, and another 3 (13%) did not have a consistent genotype in the > or =2 positive cultures, suggesting that CNS from these patients probably were contaminants. Thus, species identification and strain clonality assessment reduced by 27% the number of patients with BSI diagnosed based on the presence of symptoms and > or =2 positive blood cultures. CONCLUSIONS: Routine species identification and selected strain genotyping of CNS may reduce the misinterpretation of probable contaminants among patients with > or =2 positive blood cultures.

Adolescent↗
PubMed2000

Comparison of BACTEC MYCO/F LYTIC and WAMPOLE ISOLATOR 10 (lysis-centrifugation) systems for detection of bacteremia, mycobacteremia, and fungemia in a developing country.

In less-developed countries, studies of bloodstream infections (BSI) have been hindered because of the difficulty and costs of culturing blood for bacteria, mycobacteria, and fungi. During two study periods (study period I [1997] and study period II [1998]), we cultured blood from patients in Malawi by using the BACTEC MYCO/F LYTIC (MFL), ISOLATOR 10 (Isolator), Septi-Chek AFB (SC-AFB), and Septi-Chek bacterial (SC-B) systems. During study period I, blood was inoculated at 5 ml into an MFL bottle, 10 ml into an Isolator tube for lysis and centrifugation, and 10 ml into an SC-B bottle. Next, 0.5-ml aliquots of Isolator concentrate were inoculated into an SC-AFB bottle and onto Middlebrook 7H11 agar slants, chocolate agar slants, and Inhibitory Mold Agar (IMA) slants. During study period II, the SC-B and chocolate agar cultures were discontinued. MFL growth was detected by fluorescence caused by shining UV light (lambda = 365 nm) onto the indicator on the bottom of the bottle. During study period I, 251 blood cultures yielded 44 bacterial isolates. For bacteremia, the MFL was similar to the Isolator concentrate on chocolate agar (34 of 44 versus 27 of 44; P, not significant [NS]), but more sensitive than the SC-B bottle (34 of 44 versus 24 of 44; P = 0.05). For both study periods combined, 486 blood cultures yielded 37 mycobacterial and 13 fungal isolates. For mycobacteremia, the sensitivities of the MFL and Isolator concentrate in the SC-AFB bottle were similar (30 of 37 versus 29 of 37; P, NS); the MFL bottle was more sensitive than the concentrate on Middlebrook agar (30 of 37 versus 15 of 37; P = 0.002). For fungemia, the MFL bottle was as sensitive as the SC-B bottle or Isolator concentrate on chocolate agar or IMA slants. We conclude that the MFL bottle, inoculated with just 5 ml of blood and examined under UV light, provides a sensitive and uncomplicated method for comprehensive detection of BSI in less-developed countries.

Adult↗
PubMed1999

Unrecognised Mycobacterium tuberculosis bacteraemia among hospital inpatients in less developed countries.

BACKGROUND: Nosocomial transmission of Mycobacterium tuberculosis is a global public-health concern. Although early clinical recognition of M. tuberculosis in hospital inpatients is critical for effective infection control, such recognition may be difficult in patients with HIV infection. To find out whether M. tuberculosis bacteraemia frequently goes unrecognised, we did a prospective blood-culture survey in an infectious-diseases hospital in Thailand and a general hospital in Malawi. METHODS: Consecutive febrile (> or = 37.5 degrees C axillary or > or = 38.0 degrees C orally) hospital inpatients (aged > or = 18 years) were enrolled; blood was obtained for mycobacterial culture and HIV testing. Simple diagnostic tests, such as chest radiographs and sputum smears, were ordered by clinicians as deemed necessary, and were carried out with existing local resources. FINDINGS: Of 344 patients enrolled, 255 (74%) were HIV infected, the median age was 33 years (range 18-87), and 208 (61%) were male. 34 (10%) patients had M. tuberculosis bacteraemia; five of these patients were already on antituberculosis therapy. Only HIV-infected patients had M. tuberculosis bacteraemia. Of the 29 patients with M. tuberculosis bacteraemia who were not already receiving antituberculosis therapy, 13 (45%) had an abnormal chest radiograph or a positive sputum smear. 16 (55%) patients had no additional diagnostic test results to indicate M. tuberculosis infection; 18 (81%) of these had a cough. INTERPRETATION: In less developed countries where both M. tuberculosis and HIV infections are prevalent, M. tuberculosis bacteraemia may frequently go unrecognised among febrile hospital inpatients.

Adolescent↗
PubMed1999

Seasonal variation of Acinetobacter infections: 1987-1996. Nosocomial Infections Surveillance System.

To determine whether nosocomial infections due to Acinetobacter species have increased over the past 10 years and whether infections continue to have a pronounced seasonal variation, we analyzed infections reported by hospitals in the National Nosocomial Infections Surveillance System that performed adult and pediatric intensive care unit surveillance from 1987 through 1996. Overall, 3447 nosocomial acinetobacter infections were reported during 5,596, 156 patient-days. There was a yearly median of 7.2 infections (range, 5.0-10.5) per 10,000 patient-days and a downward trend in the rate of acinetobacter infections overall (P<.05) and of 2 major types of infection (P<.05): bloodstream infections (yearly median, 1.6 per 10, 000 central venous catheter-days; range, 1.3-2.9) and pneumonia (yearly median, 7.6 per 10,000 ventilator-days; range, 6.5-12.0). Throughout this period, average rates were significantly higher during July-October than during November-June for acinetobacter infections overall (8.0 vs. 5.2; P<.01) and for bloodstream infections (2.0 vs. 1.2; P<.01) and pneumonia (9.7 vs. 6.6; P<.01).

Acinetobacter Infections↗
PubMed1999

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↗
PubMed1999

Immune determinants of organism and outcome in febrile hospitalized Thai patients with bloodstream infections.

Opportunistic infections (OI) and the human immunodeficiency virus (HIV) cause significant morbidity and mortality in developing countries. Immune cell and cytokine profiles may be related to the type and course of OI and to the OI-HIV interaction. Examining cell-specific cytokine production ex vivo has only recently become feasible. In Thailand, 53 febrile, hospitalized adults were enrolled in a study of the immune correlates of bloodstream infections (BSI). On site, blood cells were stimulated ex vivo. Cell-surface antigens and eight intracellular cytokines were subsequently analyzed using flow cytometry to determine associations with mortality and the organism causing the BSI. By logistic regression analysis, the percentage of CD3(+) CD16/56(+) cells making tumor necrosis factor alpha (TNF-alpha) (P = 0.033) and the percentage of CD3(-) CD16/56(+) cells (NK) (P = 0.032) were related to HIV positivity. Lymph node enlargement with HIV infection and the percentage of CD3(+) CD16/56(+) making TNF-alpha were predictive of death. A lower percentage of CD3(+) CD8(+) lymphocytes making interleukin-8 (IL-8) (P = 0.005), fewer monocytes expressing CD14 (P = 0.009), and the percentage of CD3(+) CD8(+) cells producing gamma interferon (P = 0. 011) were associated with blood culture positivity and the causative organism. For every one point decrease in the percentage of CD3(+) CD8(+) cells making IL-8, the likelihood of a positive culture increased 23%; for every one point decrease in the percentage of monocytes expressing CD14, the likelihood of a positive culture increased by 5%. Only a few immune cell types and three of their related cytokines were significantly associated with HIV disease outcome or the BSI organism. These cell types did not include CD3(+) CD8(-) cells (a surrogate for CD4(+) cells), nor did they involve cytokines associated with a type I to type II cytokine shift, which might occur with advancing HIV infection. These associations support the premise that CD8(+) and CD16/56(+) lymphocytes play significant roles in HIV and type I infections.

AIDS-Related Opportunistic Infections↗
PubMed1999

Controlled clinical comparison of bioMérieux VITAL and BACTEC NR-660 blood culture systems for detection of bacteremia and fungemia in adults.

A total of 9,446 blood cultures were collected from adult patients at three university-affiliated hospitals. Of these, 8,943 cultures were received with both aerobic bottles filled adequately; 885 yielded 1,016 microorganisms, including 622 isolates (61%) that were the cause of sepsis, 337 isolates (33%) that were contaminants, and 57 isolates (6%) that were indeterminate as the cause of sepsis. With the exception of Staphylococcus aureus, which was recovered more often from VITAL aerobic bottles, more pathogenic microorganisms were recovered from BACTEC NR6 (aerobic) bottles than from VITAL aerobic bottles. Growth of pathogenic microorganisms was detected earlier in VITAL aerobic bottles. A total of 8,647 blood cultures were received with both anaerobic bottles filled adequately; 655 yielded 740 microorganisms, including 486 isolates (66%) that were the cause of sepsis, 215 isolates (29%) that were contaminants, and 39 isolates (6%) that were indeterminate as the cause of sepsis. More pathogenic microorganisms were recovered from VITAL anaerobic bottles than from BACTEC NR7 (anaerobic) bottles. Growth of pathogenic microorganisms was detected earlier in VITAL anaerobic bottles. In 8,500 sets all four bottles were received adequately filled. When paired aerobic and anaerobic bottle sets (systems) were compared, more pathogenic microorganisms (again with the exception of S. aureus) were recovered from the BACTEC system. For the 304 septic episodes (253 unimicrobial and 51 polymicrobial), significantly more were detected by the BACTEC system. We conclude that VITAL requires modification to improve recovery of pathogenic microorganisms to make it competitive with other commercially available blood culture systems.

Adult↗
PubMed1999

Surveillance of antibiotic resistance in Taiwan, 1998.

For the first national surveillance of antibiotic resistance in Taiwan, we collected in 1998 from 22 hospitals (6 medical centers, 15 regional hospitals, and 1 local hospital) 3,211 isolates in all parts of the country. Besides 50 random successive isolates from inpatients, each hospital was requested to collect 25 isolates each from positive blood cultures, hospital-acquired infections, outpatients and the pediatric department. We re-speciated all the submitted specimens and determined their antibiotic susceptibility patterns. The most common isolates were Enterobacteriaceae (Escherichia coli, Klebsiella pneumoniae), Staphylococcus aureus, and Pseudomonas aeruginosa. Among hospital-acquired infections, Acinetobacter spp. were among those which accounted for over 10% of the isolates. The oxacillin resistance of S. aureus was 82% in isolates from hospital-acquired infections, and 40% from outpatients. Among Enterococcus spp., 85% were either E. faecalis or E. faecium. They were 14% resistant to vancomycin. Among gram-negative bacteria, K. pneumoniae and Acinetobacter baumanii were hospital-acquired isolates that were most clearly more resistant than community acquired isolates. This difference was less apparent in the case of Enterobacter cloacae, Serratia marcescens, and P. aeruginosa. These bacteria were generally more resistant from all sources. Fifty-one percent of Salmonella were resistant to ampicillin; however, these were all sensitive to ciprofloxacin. Isolates from the East were least resistant. Plotting the disc zone diameters of antibiotics within the susceptible range, we identified subpopulations with smaller diameters in the case of vancomycin against S. aureus, ciprofloxacin against E. coli, and ciprofloxacin against Salmonella spp. These findings represent one of the purposes of this surveillance as they may portend developing resistances which bear careful watching in the future.

Ciprofloxacin↗
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↗