Interventional evaluation of environmental contamination by vancomycin-resistant enterococci: failure of personnel, product, or procedure?

It is not clear whether improvement in environmental decontamination is more efficiently achieved through changes in cleaning products, cleaning procedures, or performance of cleaning personnel. To assess the impact of cleaning performance on environmental contamination with vancomycin-resistant enterococci (VRE), we conducted a sequential trial in which a multifaceted environmental cleaning improvement intervention was introduced in a medical intensive care unit and respiratory step-down unit. The intervention included educational lectures for housekeepers and an observational programme of their activities without changes in cleaning products or written procedures. Following these interventions, the proportion of environmental sites cleaned improved from 49% to 85% (P<0.001); contamination of environmental sites declined from 21% to 8% (P<0.0001) before cleaning and from 13% to 8% (P<0.0001) after cleaning. The improved cleaning and contamination rates persisted in a washout period. In a multivariate model, cleaning thoroughness strongly influenced the degree of environmental contamination, with a 6% decline in VRE prevalence with every 10% increase in percentage of sites cleaned. These findings suggest that surface contamination with VRE is due to a failure to clean rather than to a faulty cleaning procedure or product.

Flocked nylon swabs versus RODAC plates for detection of multidrug-resistant organisms on environmental surfaces in intensive care units.

To compare two culture methods [nylon fiber flocked swabs with broth enrichment versus RODAC ('replicate organism detection and counting') plates] for recovery of multidrug-resistant organisms, 780 environmental surfaces in 63 rooms of patients on contact precautions in four intensive care units at one hospital were examined. Among sites that had at least one positive culture, swab culture with broth enrichment detected the target organisms more frequently than RODAC plates (37.5% vs 26.0%, P = 0.06). There was moderate agreement between the two methods (κ = 0.44) with agreement better for small or flat surfaces compared to large or irregular surfaces.

Are active microbiological surveillance and subsequent isolation needed to prevent the spread of methicillin-resistant Staphylococcus aureus?

BACKGROUND: Infection-control strategies usually combine several interventions. The relative value of individual interventions, however, is rarely determined. We assessed the effect of daily microbiological surveillance alone (e.g., without report of culture results or isolating colonized patients) as an infection-control measure on the spread of methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) in a medical intensive care unit (MICU). METHODS: Colonization of patients with MSSA and MRSA was assessed by cultures of nasal swabs obtained daily and, if a patient was intubated, by cultures of additional endotracheal aspirates. Pulsed-field gel electrophoresis was used to determine relatedness between MSSA or MRSA isolates in surveillance cultures (i.e., cultures of nasal swab specimens obtained daily) and those in clinical cultures (i.e., any other culture performed for clinical purposes). Adherence to infection-control measures by health care workers (HCWs) was determined by observations of HCW-patient interaction. RESULTS: During a 10-week period, surveillance cultures were performed for 158 patients. Fifty-five patients (34.8%) were colonized with MSSA, and 9 (5.7%) were colonized with MRSA. Sixty-two patients were colonized before admission to the hospital (53 had MSSA, and 9 had MRSA). Two patients appeared to have acquired MSSA in the MICU, but, on the basis of genotyping analysis, we determined that this was not the result of cross-acquisition. CONCLUSION: Surveillance cultures and genotyping of MRSA and MSSA isolates demonstrated the absence of cross-transmission among patients in the MICU, despite ongoing introduction of these pathogens. Reporting culture results and isolating colonized patients, as suggested by some guidelines, would have falsely suggested the success of such infection-control policies.

Sarcoidosis of the pancreas.

A case of painful granulomatous infiltration of the pancreas occurred in a patient with well-documented sarcoidosis. In the few previous reports of symptomatic granulomatous pancreatitis, none occurred in a clear setting of sarcoidosis. Granulomatous pancreatitis alone has not been reported to cause exocrine or endocrine dysfunction and appears to improve with steroid therapy. Although distinctly rare, granulomatous involvement of the pancreas should be considered in the examination of patients with sarcoidosis and abdominal pain of unclear cause.

Antibiotic-resistant flora in nursing home patients admitted to the hospital.

To study carriage of multiply resistant gram-negative bacilli, 50 patients admitted to the hospital from nursing homes (NHs) and 50 control admissions not from NHs were matched for age and recent antibiotic use. Their antibiotic resistance patterns were similar: 20 NH patients and 14 controls had resistant strains. However, significantly more patients (64%) from NHs with large numbers of "skilled beds" had resistant bacteria than did patients from small NHs (21%) or controls (28%). Also, more patients from NHs had members of the Proteus-Providencia-Morganella group in their urine than did controls. Discriminant analysis showed that residence in NHs with large numbers of skilled beds, recent antibiotic use, and bladder dysfunction (indwelling catheter or incontinence) were independently important in predicting carriage of resistant strains in NH and control patients. Over 75% of resistant isolates were from rectal specimens, emphasizing the occult way that such strains are brought into the hospital.

Prevention of peripheral venous catheter complications with an intravenous therapy team: a randomized controlled trial.

BACKGROUND: More than 25 million patients have peripheral intravenous (IV) catheters placed each year in US hospitals. Infusion therapy is believed to account for one third of all nosocomial bacteremias. METHODS: We performed a randomized, prospective, controlled study in a university-affiliated hospital to determine whether the use of an IV therapy team decreases peripheral venous catheter-related complications in adult medical patients. Patients were randomized to undergo peripheral catheter insertion and/or maintenance either by the IV team or by medical house staff. A dedicated observer reviewed catheter sites daily; findings were applied to a scoring system to define the severity of complications. Bacteremic complications were reviewed by a physician. RESULTS: Patients with catheters started by the house staff and maintained by ward nursing staff more often had signs or symptoms of inflammation (21.7%) than did patients with catheters maintained by the IV team (7.9%) (P<.001). Patients monitored by the IV team had a greater mean number of catheters placed per patient than did patients monitored by house staff (2.1 and 1.6, respectively) (P<.01). Three episodes of catheter-related sepsis occurred in house staff patients and none in IV team patients (P=.004). CONCLUSIONS: An IV therapy team significantly reduced both local and bacteremic complications of peripheral IV catheters. Timely replacement of the catheter appeared to be the most important factor in reducing the occurrence of complications.

The role of "colonization pressure" in the spread of vancomycin-resistant enterococci: an important infection control variable.

OBJECTIVE: The spread of nosocomial multiresistant microorganisms is affected by compliance with infection control measures and antibiotic use. We hypothesized that "colonization pressure" (ie, the proportion of other patients colonized) also is an important variable. We studied the effect of colonization pressure, compliance with infection control measures, antibiotic use, and other previously identified risk factors on acquisition of colonization with vancomycin-resistant enterococci (VRE). METHODS: Rectal colonization was studied daily for 19 weeks in 181 consecutive patients who were admitted to a single medical intensive care unit. A statistical model was created using a Cox proportional hazards regression model including length of stay in the medical intensive care unit until acquisition of VRE, colonization pressure, personnel compliance with infection control measures (hand washing and glove use), APACHE (Acute Physiology and Chronic Health Evaluation) 11 scores, and the proportion of days that a patient received vancomycin or third-generation cephalosporins, sucralfate, and enteral feeding. RESULTS: With survival until colonization with VRE as the end point, colonization pressure was the most important variable affecting acquisition of VRE (hazard ratio [HR], 1.032; 95% confidence interval [C1], 1.012-1.052; P=.002). In addition, enteral feeding was associated with acquisition of VRE (HR, 1.009; 95% CI, 1.000-1.017; P=.05), and there was a trend toward association of third-generation cephalosporin use with acquisition (HR, 1.007; 95% CI, 0.999-1.015; P=.11). The effects of enteral feeding and third-generation cephalosporin use were more important when colonization pressure was less than 50%. Once colonization pressure was 50% or higher, these other variables hardly affected acquisition of VRE. CONCLUSIONS: Acquisition of VRE was affected by colonization pressure, the use of antibiotics, and the use of enteral feeding. However, once colonization pressure was high, it became the major variable affecting acquisition of VRE.

Racial differences in care among hospitalized patients with Pneumocystis carinii pneumonia in Chicago, New York, Los Angeles, Miami, and Raleigh-Durham.

BACKGROUND: While strategies for medical care for human immunodeficiency virus-related Pneumocystis carinii pneumonia (PCP) are well established, racial variations in care have not been evaluated. OBJECTIVE: To determine whether sociodemographic characteristics influence patterns of care and patient outcomes, by analyzing the use of diagnostic tests and anti-PCP medications and in-hospital mortality rates for persons who were hospitalized with human immunodeficiency virus-related PCP. METHODS: Retrospective chart review of a cohort of 627 Veterans Administration (VA) patients and 1547 non-VA patients with empirically treated or cytologically confirmed PCP who were hospitalized from 1987 to 1990. Outcomes included representative aspects of the process of care for PCP and short-term mortality rates. RESULTS: Among VA patients, black and Hispanic patients were not significantly different from white patients with regard to in-hospital mortality rates, use and timing of a bronchoscopy, or receipt of timely anti-PCP medications. Among non-VA patients, black and Hispanic patients were more likely to die in the hospital and less likely to undergo a diagnostic bronchoscopy in the first 2 days of hospitalization. These racial and ethnic group differences in the use of a bronchoscopy and in-hospital mortality among non-VA patients were almost fully accounted for by differences in health insurance status and hospital characteristics. CONCLUSIONS: Racial factors do not appear to be an important determinant of the intensity of diagnostic or therapeutic care among patients who are hospitalized with PCP. Variations in care are largely attributable to differences in health insurance and admitting hospital characteristics.

The effect of renal dysfunction on antimicrobial use measurements.

The defined daily dose, a popular measurement of antimicrobial use, may underestimate the use of antimicrobials that are dose-adjusted in patients with renal insufficiency. To evaluate the effect of renal dysfunction on these measures, we performed a retrospective cohort study that involved patients receiving ceftriaxone, levofloxacin, or vancomycin, with use of defined daily doses and 2 methods based on therapy duration--stop-start days (i.e., entire therapy duration) and transaction days (i.e., unique therapeutic days). The vancomycin use rate for patients with renal insufficiency was 36% lower than that of patients with normal renal function for defined daily doses, and it was 23% lower for transaction days; for levofloxacin, there was a 27% rate reduction for the defined daily dose. No significant reduction was noted when the stop-start day method was used. Compared with the defined daily dose method, measures of therapy duration are less affected by renal function and may improve comparisons between populations.

Risk factors for antibiotic-resistant infection and treatment outcomes among hospitalized patients transferred from long-term care facilities: does antimicrobial choice make a difference?

A prospective observational study of 153 patients transferred from long-term care facilities and admitted to acute-care hospitals who had microbiologically confirmed infections was undertaken to determine the risk factors, outcomes, and resource use associated with isolation of antibiotic-resistant bacteria (ARB). Eighty patients (52%) were infected with ARB. In multivariable logistic analysis, the presence of a feeding tube (odds ratio, 3.0) or polymicrobial infection (odds ratio, 4.6) was associated with isolation of ARB. Forty-nine percent of patients infected with ARB received an initial antibiotic regimen to which their isolate was not susceptible. Fifty-one percent of all patients had a change in their antibiotic regimen during their hospital course. For these patients, length of stay, number of days of antibiotic therapy, and cost of hospitalization were significantly higher. However, neither infection with ARB nor appropriateness of initial treatment regimen was significantly related to outcome or resource use.

Radiation-induced thyroid and other head and neck tumors: occurrence of multiple tumors and analysis of risk factors.

In 2561 patients who received conventional external radiation treatment before age 15 yr for benign conditions of the head, neck, and upper thoracic area, we found an increase in the number of salivary gland tumors and benign neural tumors of the head and neck area. To determine whether patients who developed these relatively uncommon tumors were more susceptible to the long term effects of radiation, we analyzed how frequently these patients also developed benign and malignant thyroid neoplasms. Compared to the remainder of the irradiated population, the patients with salivary and neural tumors had an increased frequency of thyroid disease (19.4% vs. 11.2% for thyroid cancer and 52.4% vs. 39.9% for all thyroid nodules). Various risk factors were studied to determine whether they were related to the eventual occurrence of thyroid disease. Higher doses, being female, and lower ages at time of treatment were associated with increased risk. However, these factors did not fully explain the differences in the frequency of coexisting tumors, suggesting that additional factors, such as radiation sensitivity, may account for the increased risk.

Vancomycin-resistant enterococci: why are they here, and where do they come from?

Vancomcyin-resistant enterococci (VRE) have emerged as nosocomial pathogens in the past 10 years, causing epidemiological controversy. In the USA, colonisation with VRE is endemic in many hospitals and increasingly causes infection, but colonisation is absent in healthy people. In Europe, outbreaks still happen sporadically, usually with few serious infections, but colonisation seems to be endemic in healthy people and farm animals. Vancomycin use has been much higher in the USA, where emergence of ampicillin-resistant enterococci preceded emergence of VRE, making them very susceptible to the selective effects of antibiotics. In Europe, avoparcin, a vancomycin-like glycopeptide, has been widely used in the agricultural industry, explaining the community reservoir in European animals. Avoparcin has not been used in the USA, which is consistent with the absence of colonisation in healthy people. From the European animal reservoir, VRE and resistance genes have spread to healthy human beings and hospitalised patients. However, certain genogroups of enterococci in both continents seem to be more capable of causing hospital outbreaks, perhaps because of the presence of a specific virulence factor, the variant esp gene. By contrast with the evidence of a direct link between European animal and human reservoirs, the origin of American resistance genes remains to be established. Considering the spread of antibiotic-resistant bacteria and resistance genes, the emergence of VRE has emphasised the non-existence of boundaries between hospitals, between people and animals, between countries, and probably between continents.

Isolation of herpes simplex virus from the cerebrospinal fluid in viral meningitis.

Two cases of meningitis are reported in which the etiologic diagnosis was established by isolation of herpes simplex virus from the cerebrospinal fluid. Both patients were afebrile and had bradycardia when the cultures were obtained, and one patient had been thought to have leukemic meningitis. This experience added to that of others in the literature indicates the value of culture for herpes simplex virus in the cerebrospinal fluid.

Eosinophilic meningitis and ibuprofen therapy.

We describe eosinophilic meningitis associated with ibuprofen therapy in a young woman who had no evidence of underlying illness. Discontinuation of ibuprofen was followed by prompt resolution of symptoms and disappearance of eosinophils from the CSF. Ibuprofen has been implicated previously in only five cases of aseptic meningitis--all in patients with an underlying autoimmune disease. No drug has been implicated previously as a cause of eosinophilic meningitis to our knowledge.

Failure of infection control in intensive care units: can sucralfate improve the situation?

Conventional infection control measures in intensive care units (ICUs) are aimed primarily at stemming cross-infections. The role of patients' endogenous flora in the pathogenesis of nosocomial infection and occasional lapses in aseptic technique in ICUs help to explain the frequent failure of the conventional approaches. Newer control strategies include avoiding gastric and oropharyngeal overgrowth of gram-negative bacilli by using sucralfate to avoid gastric alkalinization and/or suppressing nosocomial flora by use of topical antimicrobials.

Epidemiology and control of nosocomial infections in adult intensive care units.

Traditional infection control measures in intensive care units (ICUs) have been directed at limiting person to person spread of infection and improving care of invasive devices. These measures often fail because they have little effect on patients' endogenous flora, which is an important source of infection in ICUs. Improvements in the design and aseptic care of invasive devices have helped to decrease the risk of progression from colonization to infection in individual patients. Interest is growing also in use of selective decontamination to decrease ICU infection rates. Despite these advances, basic hygiene and appropriate, prospectively monitored use of antibiotics remain essential components of ICU care.

Strategies for prevention and control of multiple drug-resistant nosocomial infection.

Multiple drug-resistant bacteria are common in the hospital and are often isolated from patients on admission. Spread in hospital and occasional epidemics result from transient contamination of the personnel's hands, environmental contamination and excessive use of antibiotics. Traditional control measures have relied on improved asepsis and handwashing, isolation (or cohorting) of infected and colonized patients, antibiotic control and elimination of any significant environmental sources. Newer approaches have focused on ways of preventing (or eliminating) patient carriage of multiple drug-resistant strains. We have tailored selected barrier-type "antibiotic resistance precautions" for everyday use to control endemic aminoglycoside resistant gram-negative bacilli. We detail our multifaceted approach and suggest its ongoing use for key multiple drug-resistant strains, in "epi-centers," such as intensive care units, for potential heavy shedders of multiple drug-resistant strains, and when certain epidemic thresholds are reached.

Comparison of endemic and epidemic nosocomial infections.

Epidemics account for a small proportion of preventable infections acquired in hospitals, but they have been important in defining sources, modes of spread, and methods for prevention and control of nosocomial infections. To characterize hospital-based epidemics, 265 consecutive outbreaks investigated by the Center for Disease Control between 1956 and 1979 were reviewed. Pseudoepidemics were found in 11 percent of the investigations, most often resulting from errors in processing microbiologic specimens or from surveillance artifacts. In 223 actual epidemics, the pathogens most commonly involved were Staphylococcus aureus (19 percent), tribe Klebsielleae (14 percent), Salmonella (13 percent), hepatitis B virus (8 percent), enteropathogenic Escherichia coli (5 percent), Pseudomonas (4 percent) and group A streptococci (4 percent). Sites of epidemic infection were closely linked to the responsible pathogens. Gastroenteritis (21 percent), skin infection (18 percent), bacteremia (12 percent), meningitis (11 percent) and hepatitis (10 percent), infrequent causes of endemic nosocomial infections, were frequently involved in epidemics. Over the 25-year period reviewed, staphylococcal epidemics and outbreaks of gastroenteritis due to Salmonella and Esch. coli declined in frequency and those due to gram-negative bacilli and hepatitis B virus increased. Since 1970, clusters of primary bacteremia were the most frequently investigated type of epidemic. Many epidemic strains of staphylococci obtained since 1975 or Enterobacteriaceae obtained since 1970 exhibited unusual drug resistance. Specific site-pathogen combinations were closely associated with characteristic reservoirs and modes of spread.

Multicenter, randomized trial of ciprofloxacin plus azlocillin versus ceftazidime plus amikacin for empiric treatment of febrile neutropenic patients.

In a multicenter, randomized clinical trial, the efficacy of ciprofloxacin plus azlocillin was compared with that of a standard regimen of ceftazidime plus amikacin for the initial empiric treatment of fever in neutropenic cancer patients. In addition, the efficacy of early conversion from intravenous therapy to orally administered ciprofloxacin was compared with that of continued ceftazidime plus amikacin. Seventy-one oncology patients with 79 episodes of fever and neutropenia were randomly assigned to receive initial empiric antibiotic therapy with either intravenously administered ciprofloxacin and azlocillin followed by orally administered ciprofloxacin (regimen 1, 25 episodes); ceftazidime and amikacin (regimen 2, 30 episodes); or ceftazidime and amikacin followed by oral ciprofloxacin (regimen 3, 24 episodes). Microbiologically documented infections were the cause of fever in 10 (40 percent), seven (23 percent), and nine (38 percent) episodes in regimens 1, 2, and 3, respectively, including six, five, and four episodes of bacteremia. Patient survival was 90 to 92 percent in each regimen; however, some modification of antimicrobial therapy occurred in 65, 44, and 41 percent of surviving patients in regimens 1, 2, and 3, respectively. The rate of clearance of initial bacteremia was 67 percent (four of six) in regimen 1, 100 percent (five of five) in regimen 2 and 50 percent (two of four) in regimen 3. Patients in regimens 1 and 3 were able to convert to orally administered ciprofloxacin in 32 (65 percent) of 49 episodes after a mean of six days of intravenous therapy. Superinfections occurred in 24, 10, and 12 percent of patients receiving regimens 1, 2, and 3, respectively, and occurred similarly for patients receiving orally administered ciprofloxacin, 12 percent (four of 32), and intravenous therapy, 17 percent (eight of 47). Parenteral ciprofloxacin was generally well tolerated. One (4 percent) of 25 patients receiving regimen 1 experienced oto- or nephrotoxicity, compared with eight (15 percent) of 54 patients receiving regimens 1, 2, and 3 (p = 0.15), including three patients who required premature termination of aminoglycoside therapy. Our data suggest that the combination of ciprofloxacin and azlocillin is an effective alternative to ceftazidime and amikacin for the initial empiric therapy of febrile neutropenic patients, is generally well tolerated, and avoids the oto- and nephrotoxicity associated with aminoglycoside use. In addition, a majority of patients could change to orally administered ciprofloxacin alone after six days of parenteral therapy.

Preventing mismanagement of community-acquired pneumonia at an urban public hospital: implications for institution-specific practice guidelines.

STUDY OBJECTIVES: To assess institutional performance of key diagnostic and therapeutic interventions and to identify areas amenable to improvement in the management of community-acquired pneumonia (CAP). DESIGN: A chart-based retrospective study. SETTING: Cook County Hospital, a large, urban, public teaching hospital. PATIENTS: Adult inpatients with a hospital discharge diagnosis of CAP. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Fifty hospital admissions were reviewed. Only 25 patients (50%) had two specimens obtained for blood culture, and sputum was sent for Gram's stain and culture for only 11 patients (22%). Approximately one third of the patients had portable anterior-posterior instead of standard posterior-anterior and lateral chest radiographs performed. Physicians in the emergency department (ED) tended to be less likely to note the presence of multilobar infiltrates or pleural effusions than the attending radiologists. The antibiotic regimens employed in the ED and on the inpatient wards were widely variable. The mean time from hospital entry until administration of the first dose of antibiotics was 5.5 h for the 18 patients for whom treatment was initiated in the ED vs 16.1 h for the 27 patients admitted through the ED for whom therapy was deferred until ward admission (p < 0.001, Student's t test). CONCLUSIONS: Institutional variations in the performance of basic diagnostic and therapeutic interventions for patients with CAP may be substantial. The local performance of these key processes of care should be assessed to help direct the formulation of institutional practice guidelines for the management of CAP.