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Biomedical subjects

Trish M Perl

Publications and source records attributed to Trish M Perl.

16 recordsLinked to original sources

Epidemiological and microbiological characterization of infections caused by Staphylococcus aureus with reduced susceptibility to vancomycin, United States, 1997-2001.

Infections caused by Staphylococcus aureus with reduced vancomycin susceptibility (SA-RVS; minimum inhibitory concentration [MIC], >or=4 microg/mL), including vancomycin-intermediate S. aureus (VISA; MIC, 8 microg/mL), are a new clinical and public health dilemma. Prospective surveillance and a nested case-control study of patients in the United States infected with SA-RVS was conduced from March 1999 through December 2000. Control patients were persons infected with oxacillin-resistant S. aureus (MIC of vancomycin, <or=2 microg/mL). Among 19 case patients, 4 infections were due to VISA and 15 were due to non-VISA SA-RVS. Case patients with and those without VISA infection had similar clinical presentations and outcomes; the overall attributable mortality rate was 63%. Isolates recovered from case patients had heterogeneous pulsed-field gel electrophoresis banding patterns, regardless of the MIC of vancomycin. Neither dialysis nor chronic renal failure were predictive of case status compared with control status. Independent risk factors for being a case patient included antecedent vancomycin use and prior oxacillin-resistant S. aureus infection 2 or 3 months before the current infection.

Adult↗

An outbreak of Pseudomonas aeruginosa infections associated with flexible bronchoscopes.

BACKGROUND: Endoscopes, including bronchoscopes, are the medical devices most frequently associated with outbreaks of nosocomial infections. We investigated an outbreak of Pseudomonas aeruginosa infections after bronchoscopic procedures. METHODS: Microbiologic results were reviewed to determine the rates of recovery of P. aeruginosa from bronchoalveolar-lavage specimens. Environmental samples from endoscopes and the endoscopy suite were cultured. Medical records were reviewed to identify infections in the 14 days after a bronchoscopy. RESULTS: The rate of recovery of P. aeruginosa from bronchoalveolar-lavage specimens obtained with use of endoscopy-suite bronchoscopes increased from 10.4 percent at base line to 31.0 percent during the outbreak (relative risk, 2.97; 95 percent confidence interval, 2.28 to 3.90). Cultures of samples from three bronchoscopes grew P. aeruginosa, whereas cultures of samples from the environment, instrument-cleaning machines, and gastrointestinal endoscopes did not. The three bronchoscopes had been part of a nationwide recall. A total of 414 patients underwent bronchoscopy during the outbreak, and there were 48 respiratory tract and bloodstream infections among 39 of these patients (9.4 percent). In 32 infections (66.7 percent), P. aeruginosa was confirmed as a potentially causative organism. Exposure to a potentially contaminated bronchoscope may have had a role in the death of three patients. The rate of recovery of P. aeruginosa returned to base line after the instruments were removed from service. CONCLUSIONS: This large outbreak of P. aeruginosa infections related to bronchoscopy was apparently caused by a loose biopsy-port cap in the bronchoscopes. Instrument safety and surveillance methods for bronchoscopy must be improved, and better recall procedures are needed for medical devices.

Academic Medical Centers↗

Effect of nosocomial vancomycin-resistant enterococcal bacteremia on mortality, length of stay, and costs.

OBJECTIVE: To determine the impact of vancomycin-resistant enterococcal bacteremia on patient outcomes and costs by assessing mortality, excess length of stay, and charges attributable to it. DESIGN: A population-based, matched, historical cohort study. SETTING: A 1,025-bed, university-based teaching facility and referral hospital. PATIENTS: Two hundred seventy-seven vancomycin-resistant enterococcal bacteremia case-patients and 277 matched control-patients identified between 1993 and 2000. RESULTS: The crude mortality rate was 50.2% and 19.9% for case-patients and control-patients, respectively, yielding a mortality rate of 30.3% attributable to vancomycin-resistant enterococcal bacteremia. The excess length of hospital stay attributable to vancomycin-resistant enterococcal bacteremia was 17 days, of which 12 days were spent in intensive care units. On average, dollars 77,558 in extra charges was attributable to each vancomycin-resistant enterococcal bacteremia. To adjust for severity of illness, 159 pairs of case-patients and control-patients, who had the same severity of illness (All Patient Refined-Diagnosis Related Group complexity level), were further analyzed. When patients were stratified by severity of illness, the crude mortality rate was 50.3% among case-patients compared with 27.7% among control-patients, accounting for an attributable mortality rate of 22.6%. Attributable excess length of stay and charges were 17 days and dollars 81,208, respectively. CONCLUSION: Vancomycin-resistant enterococcal bacteremia contributes significantly to excess mortality and economic loss, once severity of illness is considered. Efforts to prevent these infections will likely be cost-effective.

Adolescent↗

Risk factors for development of vancomycin-resistant enterococcal bloodstream infection in patients with cancer who are colonized with vancomycin-resistant enterococci.

Vancomycin-resistant Enterococcus faecium (VRE) is a common nosocomial isolate, especially among patients with cancer. VRE infections have substantial attributable mortality among patients with cancer. The purpose of this study was to identify risk factors for developing bloodstream infection with VRE in patients with cancer who are colonized with VRE. VRE colonization was prospectively identified in 197 patients with cancer during 4-year period, of whom 179 (91%) had complete records for evaluation. Of these 179 patients, 24 (13.4%) developed hospital-acquired VRE bloodstream infections. Risk factors for VRE bloodstream infection included vancomycin use (relative risk [RR], 1.98; 95% confidence interval [CI], 1.25-3.14), diabetes mellitus (RR, 3.91; 95% CI, 1.20-12.77), gastrointestinal procedures (RR, 4.56; 95% CI, 1.05-19.7), and acute renal failure (RR, 3.10; 95% CI, 1.07-8.93). Strategies for preventing VRE bloodstream infection in VRE-colonized patients with cancer should include limiting vancomycin use and, perhaps, gastrointestinal procedures.

Bacteremia↗

Intranasal mupirocin to prevent postoperative Staphylococcus aureus infections.

BACKGROUND: Patients with nasal carriage of Staphylococcus aureus have an increased risk of surgical-site infections caused by that organism. Treatment with mupirocin ointment can reduce the rate of nasal carriage and may prevent postoperative S. aureus infections. METHODS: We conducted a randomized, double-blind, placebo-controlled trial to determine whether intranasal treatment with mupirocin reduces the rate of S. aureus infections at surgical sites and prevents other nosocomial infections. RESULTS: Of 4030 enrolled patients who underwent general, gynecologic, neurologic, or cardiothoracic surgery, 3864 were included in the intention-to-treat analysis. Overall, 2.3 percent of mupirocin recipients and 2.4 percent of placebo recipients had S. aureus infections at surgical sites. Of the 891 patients (23.1 percent of the 3864 who completed the study) who had S. aureus in their anterior nares, 444 received mupirocin and 447 received placebo. Among the patients with nasal carriage of S. aureus, 4.0 percent of those who received mupirocin had nosocomial S. aureus infections, as compared with 7.7 percent of those who received placebo (odds ratio for infection, 0.49; 95 percent confidence interval, 0.25 to 0.92; P=0.02). CONCLUSIONS: Prophylactic intranasal application of mupirocin did not significantly reduce the rate of S. aureus surgical-site infections overall, but it did significantly decrease the rate of all nosocomial S. aureus infections among the patients who were S. aureus carriers.

Administration, Intranasal↗

Pseudo-outbreak of Mycobacterium fortuitum on a Human Immunodeficiency Virus Ward: transient respiratory tract colonization from a contaminated ice machine.

Infection Control surveillance revealed an abnormally high number of sputum samples growing Mycobacterium fortuitum from a single ward that houses the human immunodeficiency virus service. We investigated the outbreak using a retrospective case-control study and molecular epidemiology. A total of 47 patients were identified with >/=1 sputum sample that grew M. fortuitum. No significant demographic or clinical variables were found to be associated with colonization. Environmental investigation demonstrated that the M. fortuitum isolated from patients was identical to the ice machine isolates by pulsed-field gel electrophoresis. Fortunately, there has been no evidence of progressive pulmonary disease developing in our patients after >/=6 months of follow-up. All cases were thought to represent transient colonization and not infection. The ice machine was disconnected and cleaned successfully with vinegar and then bleach. Only when a 0.5-micrometer filter was installed were no further patients colonized or water cultures found to be positive.

Adult↗

Hemorrhagic fever viruses as biological weapons: medical and public health management.

OBJECTIVE: To develop consensus-based recommendations for measures to be taken by medical and public health professionals if hemorrhagic fever viruses (HFVs) are used as biological weapons against a civilian population. PARTICIPANTS: The Working Group on Civilian Biodefense included 26 representatives from academic medical centers, public health, military services, governmental agencies, and other emergency management institutions. EVIDENCE: MEDLINE was searched from January 1966 to January 2002. Retrieved references, relevant material published prior to 1966, and additional sources identified by participants were reviewed. CONSENSUS PROCESS: Three formal drafts of the statement that synthesized information obtained in the evidence-gathering process were reviewed by the working group. Each draft incorporated comments and judgments of the members. All members approved the final draft. CONCLUSIONS: Weapons disseminating a number of HFVs could cause an outbreak of an undifferentiated febrile illness 2 to 21 days later, associated with clinical manifestations that could include rash, hemorrhagic diathesis, and shock. The mode of transmission and clinical course would vary depending on the specific pathogen. Diagnosis may be delayed given clinicians' unfamiliarity with these diseases, heterogeneous clinical presentation within an infected cohort, and lack of widely available diagnostic tests. Initiation of ribavirin therapy in the early phases of illness may be useful in treatment of some of these viruses, although extensive experience is lacking. There are no licensed vaccines to treat the diseases caused by HFVs.

Aerosols↗

Anthrax as a biological weapon, 2002: updated recommendations for management.

OBJECTIVE: To review and update consensus-based recommendations for medical and public health professionals following a Bacillus anthracis attack against a civilian population. PARTICIPANTS: The working group included 23 experts from academic medical centers, research organizations, and governmental, military, public health, and emergency management institutions and agencies. EVIDENCE: MEDLINE databases were searched from January 1966 to January 2002, using the Medical Subject Headings anthrax, Bacillus anthracis, biological weapon, biological terrorism, biological warfare, and biowarfare. Reference review identified work published before 1966. Participants identified unpublished sources. CONSENSUS PROCESS: The first draft synthesized the gathered information. Written comments were incorporated into subsequent drafts. The final statement incorporated all relevant evidence from the search along with consensus recommendations. CONCLUSIONS: Specific recommendations include diagnosis of anthrax infection, indications for vaccination, therapy, postexposure prophylaxis, decontamination of the environment, and suggested research. This revised consensus statement presents new information based on the analysis of the anthrax attacks of 2001, including developments in the investigation of the anthrax attacks of 2001; important symptoms, signs, and laboratory studies; new diagnostic clues that may help future recognition of this disease; current anthrax vaccine information; updated antibiotic therapeutic considerations; and judgments about environmental surveillance and decontamination.

Adolescent↗

Vancomycin-sensitive and vancomycin-resistant enterococcal infections in the ICU: attributable costs and outcomes.

OBJECTIVES: To determine the economic and clinical outcomes associated with infection with vancomycin-resistant Enterococcus (VRE) and to compare these outcomes to those associated with infection with vancomycin-sensitive Enterococcus (VSE). METHODS: During a 3-month, prospective, cohort study of 117 high-risk, critically ill patients we collected complete clinical and demographic and ICU cost data from all patients during their ICU stays. RESULTS: After adjusting for variables in a stepwise multiple regression model VRE infections were associated with a median attributable increased ICU cost per patient of $33,251 (38,088 euros) and an increased length of hospital stay (LOS) of 22 days, while VSE infections were associated with an increased cost of $21,914 (25,102 euros) and an increased LOS of 27 days. The effect of VRE and VSE infections were not significantly different. Over the entire cohort the attributable cost per ICU patient day associated with VRE infection was $304 (348 euros). CONCLUSIONS: The attributable cost of ICU care associated with VRE infection is $33,251 (38,088 euros) and per ICU patient day was $304 (348 euros). VRE and VSE infections do not differ in associated cost of ICU care, LOS, or mortality. Any VRE control strategy is be cost-effective if the overall cost per ICU patient-day is less than $304 (348 euros).

APACHE↗

An outbreak of Staphylococcus aureus in a pediatric cardiothoracic surgery unit.

OBJECTIVE: To investigate an outbreak of Staphylococcus aureus surgical-site infections. DESIGN: Case-control study. SETTING: Pediatric cardiothoracic surgery service of a tertiary-care university medical center. METHOD: Molecular typing was used to identify healthcare workers who carried the epidemic strain. RESULTS: Three children acquired surgical-site infections caused by a single strain of S. aureus. Fourteen (25%) of the staff members in the operating room and 17 (11%) on nursing units carried the epidemic strain (P = .01). A case-control study identified 4 healthcare workers who were associated statistically with the outbreak, 2 of whom (a cardiothoracic surgeon and a perfusionist) carried the epidemic strain in their nares. The surgeon also carried the epidemic strain on his hands. Each staff member who carried the epidemic strain was treated with mupirocin; those carrying the strain on their hands were required to wash their hands with chlorhexidine. The surgeon was not allowed to perform surgery until 2 of his hand cultures did not grow S. aureus. CONCLUSIONS: Only three children were infected with the epidemic strain, but it was disseminated widely among staff who cared for children who underwent cardiothoracic surgery. No additional cases were identified after staff members who carried the epidemic strain were decolonized. Both classic epidemiologic methods and molecular typing techniques were necessary to identify the source and extent of this outbreak.

Carrier State↗

Preventing nosocomial transmission of pulmonary tuberculosis: when may isolation be discontinued for patients with suspected tuberculosis?

OBJECTIVE: The Centers for Disease Control and Prevention and the American Thoracic Society recommend obtaining cultures of at least three sputum specimens for acid-fast bacilli (AFB) from patients in whom tuberculosis (TB) is suspected. On the basis of this, most hospitals isolate patients with suspected TB for 3 days or more until three smear (not culture) results are negative. Our objective was to evaluate the predictive value and sensitivity of these smears. DESIGN: Observational study. SETTING: Four urban medical centers. METHODS: The posttest probability of TB given sequential negative AFB smears from 274 patients isolated for suspected TB and the sensitivity of sequential AFB smears from 209 patients with positive results on culture for pulmonary TB were measured. RESULTS: The posttest probabilities of having TB given one, two, and three negative AFB smears were low: 1.1% (3 of 265; 95% confidence interval [CI95], 0.23% to 3.27%), 0.4% (1 of 262; CI95 0% to 2.1%), and 0% (0 of 260; CI95, 0% to 1.4%), respectively. Among the 209 patients with positive results on culture for pulmonary TB, 169 (81%) had an expectorated sputum specimen sent, of which 91 (54%) were positive for AFB. Forty (24%) of the 169 patients had a second expectorated sputum specimen sent after the results of the first specimen were negative; only 6 (15%) of these had positive AFB smears. None of the 10 patients in whom the first two expectorated sputum samples yielded an AFB smear without an organism had a third AFB smear that was positive. CONCLUSION: Unless there is high clinical suspicion of pulmonary TB in a specific patient, the use of three AFB smears on expectorated sputa is a rational approach to discontinuing isolation for patients with suspected TB.

Baltimore↗

A prospective study to determine whether cover gowns in addition to gloves decrease nosocomial transmission of vancomycin-resistant enterococci in an intensive care unit.

BACKGROUND: Vancomycin-resistant enterococci (VRE) remain a significant nosocomial pathogen. Current guidelines of the Hospital Infection Control Practices Advisory Committee (HICPAC) of the Centers for Disease Control and Prevention (CDC) recommend the use of gowns and gloves for some interactions with VRE-infected or -colonized patients to prevent nosocomial transmission of VRE. OBJECTIVE: To assess the effect of disposable cover gowns on preventing nosocomial transmission of VRE. DESIGN AND SETTING: Prospective study in a 16-bed medical intensive care unit of a university teaching hospital. PATIENTS: All patients who were at risk to acquire VRE, were admitted to the intensive care unit from August 1998 to January 1999, and had at least two perirectal cultures were included in the analysis of VRE acquisition. INTERVENTION: VRE isolation precautions were changed from gowns and gloves to gloves alone. MAIN OUTCOME risk factors for VRE acquisition. RESULTS: The VRE acquisition rate was 1.80 cases per 100 days at risk in the gown and gloves period compared with 3.78 in the gloves only period (P = .04). In a proportional hazards model adjusted for length of stay, gloves only precautions with a hazard ratio of 2.5 (P = .02; 95% confidence interval, 1.2 to 5.3) were the only independent risk factor for VRE acquisition. CONCLUSION: Our data lend support to current HICPAC recommendations for the use of cover gowns to decrease nosocomial transmission of VRE.

Baltimore↗

The ability of hospital ventilation systems to filter Aspergillus and other fungi following a building implosion.

OBJECTIVES: To assess the ability of hospital air handling systems to filter Aspergillus, other fungi, and particles following the implosion of an adjacent building; to measure the quantity and persistence of airborne fungi and particles at varying distances during a building implosion; and to determine whether manipulating air systems based on the movement of the dust cloud would be an effective strategy for managing the impact of the implosion. DESIGN: Air sampling study. SETTING: A 976-bed teaching hospital in Baltimore, Maryland. METHODS: Single-stage impactors and particle counters were placed at outdoor sites 100, 200, and 400 m from the implosion and in five locations in the hospital: two oncology floors, the human immunodeficiency virus unit, the cardiac surgical intensive care unit, and the ophthalmology unit. Air handling systems would operate normally unless the cloud approached the hospital. RESULTS: Wind carried the bulk of the cloud away from the hospital. Aspergillus counts rose more than tenfold at outdoor locations up to 200 m from the implosion, but did not increase at 400 m. Total fungal counts rose more than sixfold at 100 and 200 m and twofold at 400 m. Similar to Aspergillus, particle counts rose several-fold following the implosion at 100 and 200 m, but did not rise at 400 m. No increases in any fungi or particles were measured at indoor locations. CONCLUSION: Reacting to the movement of the cloud was effective, because normal operation of the hospital air handling systems was able to accommodate the modest increase in Aspergillus, other fungi, and particles generated by the implosion. Aspergillus measurements were paralleled by particle counts.

Air Conditioning↗

Pilot study of antibiotic cycling in a pediatric intensive care unit.

OBJECTIVE: This pilot study was performed to determine the safety and size of effect of antibiotic cycling to reduce colonization and infection with antibiotic-resistant bacteria. DESIGN: Open, observational study. SETTING: The study was performed in a 16-bed pediatric medical-surgical intensive care unit. PATIENTS: Critically ill children requiring antibiotic therapy. INTERVENTIONS: Three antibiotic classes were systematically cycled for 3-month intervals over 18 months. Antibiotic regimens were used for all empirical therapy and continued if the bacterial isolate was susceptible. MEASUREMENTS: The primary outcome was colonization with antibiotic-resistant bacteria, determined by surveillance cultures obtained twice monthly from all patients in the unit. Rates of antibiotic-resistant, nosocomial blood stream infections, and risks of colonization over calendar time in the intensive care unit were also evaluated. MAIN RESULTS: The cycling of broad-spectrum, empirical antibiotics was safe and did not generate increased antibiotic resistance nor select for new organisms. Over the study period, the trend in prevalence of children colonized with antibiotic-resistant bacteria was from 29% to 24% (p =.41). The effect on prevalence of resistant blood stream infections was similar (p =.29). Changes in individual risks of colonization with resistant bacteria over calendar time were consistent with the ecologic effect in size and direction. CONCLUSIONS: Results of this pilot intervention suggest that cycling antibiotics may be a safe and viable strategy to minimize the emergence of antibiotic resistance in intensive care units. A definitive study will require a randomized and controlled trial of only four pediatric intensive care units over an 18-month period.

Anti-Bacterial Agents↗

Vancomycin resistance in staphylococci.

Vancomycin resistance has been reported in clinical isolates of both coagulase-negative staphylococci and Staphylococcus aureus. The emerging threat of widespread vancomycin resistance poses a serious public health concern given the fact that vancomycin has long been the preferred treatment of antibiotic-resistant gram-positive organisms. Though major efforts are now being focused on improving our understanding of vancomycin resistance, there is much that remains unknown at this time. This article reviews the major epidemiologic, microbiologic, and clinical characteristics of vancomycin resistance in both coagulase-negative staphylococci and S. aureus. The review begins with a discussion of issues common to both coagulase-negative staphylococci and S. aureus, such as definitions, laboratory detection of vancomycin resistance, and infection control issues related to vancomycin-resistant staphylococci. The rest of the article is then devoted to a discussion of issues unique to each organism, including epidemiology, risk factors for infection, mechanisms of resistance, and management options.

Anti-Bacterial Agents↗