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D Pittet

Publications and source records attributed to D Pittet.

At least 73 records · Page 4Linked to original sources
PubMed1998

Increasing bacteremia due to coagulase-negative staphylococci: fiction or reality?

BACKGROUND: The role of coagulase-negative staphylococci (CNS) in bacteremias continues to be controversial. Until the 1970s, CNS were mostly recognized as contaminants, being part of the cutaneous flora. Since then, several studies have reported increasing incidence and severity of infections due to CNS. PURPOSE: To review the literature concerning the epidemiology of CNS bacteremia in the United States and Europe with reference to the multiple definitions of infection versus contamination, considering the effect of potential biases influencing the validity of the reported results. METHODS: Literature search of the MEDLINE database from January 1980 to February 1998. Studies with fewer than 500 episodes of bloodstream infections or fewer than 100 episodes of CNS bacteremia were not included in the pooled analysis. RESULTS: (1) CNS remain the most frequent contaminants (58%-83% of positive blood cultures); (2) the proportion of all bloodstream infections caused by CNS is increasing (R=.51); (3) the overall incidence of true CNS bacteremia is increasing (R=.54, P=.0014); (4) comparing the United States to Europe, there is an increasing trend in the incidence of nosocomial bacteremia due to CNS in the United States (R=.82, P=.0006), but no trend is seen in European studies; (5) the mortality associated with true CNS bacteremia varies between 4.9% and 28%. DISCUSSION: This review confirms the increasing importance of CNS bacteremias, measured both as a proportion and as an incidence of bloodstream infections. The contributions of several possible explanations for the incidence increase and the difference between the United States and Europe need further evaluation: (1) increased recognition and awareness of CNS infections among clinicians; (2) a gradual change in the definition of true bacteremia from an obligatory two positive blood cultures to one positive blood culture associated with a clinical picture compatible with infection; (3) a change in blood culture practices and techniques; (4) an increase in the numbers of blood cultures performed, which is reported both in the United States and in Europe; (5) a shift toward more elderly patients with increasingly severe underlying illnesses; and (6) increasing use of intravascular devices. CONCLUSIONS: The apparent trend of increasing CNS bacteremia seems to be valid. Whether there is a real difference between the United States and Europe concerning the increase of CNS bacteremia is difficult to establish due to the large number of confounding factors. Few studies take into account the number of blood cultures performed or the use of intravascular devices to adjust for the observed trends. Further on-site surveillance studies are needed to investigate the phenomenon more extensively.

Bacteremia↗
PubMed1998

Invasive aspergillosis. Clinical features of 35 proven cases at a single institution.

Thirty-five patients with clinical features and histologically or microbiologically proven infection met predetermined stringent criteria for invasive aspergillosis over a 5-year period at our institution. Underlying conditions included hematologic malignancy, solid tumor, bone marrow and solid organ transplantation, and immunosuppressive therapy. The majority of patients (94%) presented with respiratory symptoms and abnormal pulmonary chest radiography; only 40% had neutropenia at time of infection. Invasive aspergillosis was suspected in only 21 cases (60%). Concomitant infections were present in 83% of patients. Half of patients had pathogenic or potentially pathogenic microorganisms other than Aspergillus spp. isolated from pulmonary specimens at time of aspergillosis. Aspergillus spp. were recovered from sputum in 75% of patients and from bronchoalveolar lavage in only 52%. Invasive aspergillosis is an unexpectedly unrecognized disease with poor outcome; overall mortality was 94% in our series. The lack of sensitivity of diagnostic procedures, together with the high frequency of concomitant infections, delays the time of diagnosis. Early diagnostic tests are needed, and presumptive antifungal therapy among high-risk patients is mandatory.

Adult↗
PubMed1998

Cefepime--assessment of its need at a tertiary care center.

OBJECTIVE: To assess the need and possible indications for a fourth-generation cephalosporin (cefepime). METHOD: A cohort study was carried out over a 17-month period in a 1500-bed Swiss university hospital. RESULTS: In 256 (22.6%) of the 1135 patients followed consecutively by our Infectious Diseases Division, cefepime could have been chosen as an alternative to other broad-spectrum antibiotics, including imipenem/cilastatin (n=94), ciprofloxacine (n=52) and ceftazidime (n=49). Considering the low price-strategy of the pharmaceutical company promoting this drug in Switzerland, there would have been considerable cost savings for the hospital pharmacy if cefepime had been used as first-line treatment in these occasions. Nevertheless, we could not observe any potential advantage of cefepime compared to already introduced broad-spectrum antibiotics, except that cefepime was effective against infections caused by Enterobacter spp. resistant to ceftazidime. CONCLUSION: We conclude that fourth-generation cephalosporins such as cefepime may be introduced into large hospitals only after careful assessment of their potential benefits and that consultation by an Infectious Diseases Division is useful when evaluating the need for new broad-spectrum antibiotics in the hospital setting.

Adult↗
PubMed1997

[Inter- and intrahospital transmission of methicillin-resistant Staphylococcus aureus].

Occurrence and spread of methicillin-resistant Staphylococcus aureus (MRSA) has become a major problem worldwide. The majority of hospitals in Switzerland have not so far been affected by this epidemic. We report two out-breaks of MRSA transmission in the surgical intensive care unit at the University Hospital of Geneva and show the possible inter- and intrahospital dissemination of MRSA. Evidence for cross-infection is confirmed by epidemiological investigation and molecular typing. Infection control measures and general precautions are necessary to halt further spread of MRSA.

Adult↗
PubMed1997

Microbiological factors influencing the outcome of nosocomial bloodstream infections: a 6-year validated, population-based model.

All patients (n = 1,745) with nosocomial bloodstream infection identified between 1986 and 1991 at a single 900-bed tertiary care hospital were studied to identify microbiological factors independently associated with mortality due to the infection. Patients were identified by prospective, case-based surveillance and positive blood cultures. Mortality rates were examined for secular trends. Prognostic factors were determined with use of univariate and multivariate analyses, and both derivation and validation sets were used. A total of 1,745 patients developed nosocomial bloodstream infection. The 28-day crude mortality was 22%, and crude in-hospital mortality was 35%. Factors independently (all P < .05) associated with increased 28-day mortality rates were older age, longer length of hospital stay before bloodstream infection, and a diagnosis of cancer or disease of the digestive system. After adjustment for major confounders, Candida species were the only organisms independently influencing the outcome of nosocomial bloodstream infection (odds ratio [OR] for mortality = 1.84; 95% confidence interval [CI], 1.22-2.76; P = .0035). The two additional microbiological factors independently associated with increased mortality were pneumonia as a source of secondary infection (OR = 2.74; 95% CI, 1.87-4.00; P < .0001) and polymicrobial infection (OR = 1.68; 95% CI, 1.22-2.32; P = .0014). Our data suggest that microbiological factors independently affect the outcome of nosocomial bloodstream infection.

Adult↗
PubMed1997

Etiological agents of infectious diarrhea: implications for requests for microbial culture.

Gastrointestinal infections remain a frequent disease worldwide. In order to increase our knowledge of the epidemiology for our patient population, we retrospectively analyzed the results obtained for stool samples received at the clinical microbiology laboratory of the University Hospital of Geneva during a 4-year period. A total of 13,965 specimens from 7,124 patients (1.96 specimens per patient) were cultured, yielding 369 (2.6%) Salmonella spp., 408 (2.9%) Campylobacter spp., and 79 (0.6%) Shigella spp. The cumulative positivity rate of 6.1% decreased to 2.7% when patients received antimicrobial agents (P < 0.001). The positivity rate for 5,912 specimens obtained from patients hospitalized for < or = 3 days was 12.6%, whereas it dropped to 1.4% for patients hospitalized for > 3 days (P < 0.001). Of 3,837 stool samples originating from pediatric patients, 8.8% were positive, and 5.1% of 10,128 samples from adults were positive (P < 0.001). The cytotoxin of Clostridium difficile was detected in 379 of 3,723 samples analyzed (10.2%), and rotaviruses were detected in 190 of 1,601 samples (11.9%). We recommend that the use of cultures for enteric bacterial pathogens be restricted to patients hospitalized for < or = 3 days, with the exceptions of follow-up samples, specimens from immunocompromised patients, and patients whose first sample was culture negative or in the rare event of nosocomial food-borne outbreaks. For patients under antimicrobial therapy, testing for cytotoxin of C. difficile should primarily be requested; this analysis should also be accepted for samples from patients not receiving antimicrobial agents at the time of specimen collection. By applying these restrictions, we could have saved at least $5,000 annually.

Adult↗
PubMed1997

Identifying the hospitalized patient at risk for nosocomial bloodstream infection: a population-based study.

Included in a 3-year population-based study were all patients (n = 64,281) admitted to a single tertiary care hospital (902 beds) using prospective hospital-wide surveillance for nosocomial infections. The objective of the study was to identify patients at risk for nosocomial bloodstream infection by using readily available hospital admission variables. After identifying potential risk factors for infection by univariate analyses, we derived multivariate models for predicting bloodstream infection by using logistical regression procedures. A total of 931 patients (1.45 per 100 admissions) developed a nosocomial bloodstream infection (2.2 episodes per 1000 patient-days) between 1 July 1987, and 30 June 1990. The crude mortality among infected patients was 34%, and the 319 deaths represented 22% of the total in-hospital mortality. Independent predictors of bloodstream infection were age, gender, primary diagnosis, and admission to a critical care unit. The sensitivity and specificity of the models for classifying patients as infected or noninfected were 81% and 81% for infants (1-11 months old) and 72% and 72% for adults, respectively. The negative predictive value of both models exceeded 99%. Applied to all patients on admission, the models we developed allowed us to survey only 28% of patients to identify more than 70% of those who will develop a nosocomial bloodstream infection.

Adolescent↗
PubMed1996

Bedside prediction of mortality from bacteremic sepsis. A dynamic analysis of ICU patients.

The prognosis in patients with sepsis depends on severity of acute illness, underlying chronic diseases, and complications associated with infection. Adjusting for these factors is essential for evaluation of new therapies. The purpose of the present study was to determine variables readily identifiable at the bedside that predict mortality in intensive care unit (ICU) patients with sepsis and positive blood cultures. For a 5-yr period, all patients of a surgical ICU presenting with positive blood cultures and sepsis were systematically analyzed for clinical variables and organ dysfunctions at the day of onset of sepsis and bacteremia and during the subsequent clinical course. The prognostic value of these variables was determined using logistic regression procedures. Of the 5,457 admissions to the ICU, 176 patients developed sepsis with positive blood cultures (3.2 per 100 admissions). The fatality rate was 35% at 28 days after the onset of sepsis; in-hospital mortality was 43%. Independent predictors of mortality at onset of sepsis were previous antibiotic therapy (odds ratio [OR], 2.40; 95% confidence interval [CI95], 1.59 to 3.62; p = 0.034), hypothermia (OR, 1.43; CI95, 1.04 to 2.44; p = 0.030), requirement for mechanical ventilation (OR, 2.97; CI95, 1.96 to 4.51; p = 0.009), and onset-of-sepsis APACHE II score (OR, 1.21; CI95, 1.13 to 1.29; p < 0.001). Vital organ dysfunctions developing after the onset of sepsis influenced outcome markedly. The best two independent prognostic factors were the APACHE II score at the onset of sepsis (OR, 1.13 per unit; CI95, 1.08 to 1.17; p = 0.0016) and the number of organ dysfunctions developing thereafter (OR, 2.39; CI95, 2.02 to 2.82; p < 0.001). In ICU patients with sepsis and positive blood cultures, outcome can be predicted by the severity of illness at onset of sepsis and the number of vital organ dysfunctions developing subsequently. These variables are easily assessed at the bedside and should be included in the evaluation of new therapeutic strategies.

APACHE↗
PubMed1996

Unusual cause of lethal pulmonary aspergillosis in patients with chronic obstructive pulmonary disease.

Two patients admitted to two different medical wards of our institution following respiratory decompensation of chronic obstructive pulmonary disease (COPD) were subsequently transferred to the same room of the medical intensive care unit (ICU) and intubated. Both patients developed invasive pulmonary aspergillosis and died soon after. Because COPD itself is rarely associated with lethal pulmonary aspergillosis, both cases were reviewed, and a retrospective investigation was conducted. Both patients had repeated sputum cultures while on the medical ward before their admission to the ICU; none of the sample grew Aspergillus spp. A. fumigatus was found in tracheal aspirates of both patients from the first day of their intubation while in the ICU. The pulmonary condition of both patients worsened, and invasive aspergillosis was diagnosed by bronchoalveolar lavage. Despite therapy with amphotericin B, the patients died 16 and 22 d after intubation, respectively. Both deaths were attributed to pulmonary aspergillosis; autopsy confirmed a massive pneumonia of the five lobes due to A. fumigatus in one patient. Investigation revealed that an air filter had been replaced 30 h before the first patient was admitted to the room. Experimental air filter replacement performed 12 d after the second patient died revealed the presence of A. fumigatus on the surface of the filters as well as a 10-fold increase in room air fungal counts during the procedure. This study shows that exposure to high concentrations of airborne Aspergillus spp. related to air filter change was associated with fatal invasive aspergillosis in two mechanically ventilated patients. Such infection can be prevented by the establishment and application of guidelines for air filter replacement.

Aged↗
PubMed1996

Automatic alerts for methicillin-resistant Staphylococcus aureus surveillance and control: role of a hospital information system.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is an escalating problem in hospitals worldwide. The hospital reservoir for MRSA includes recognized and unrecognized colonized or infected patients, as well as previously colonized or infected patients readmitted to the hospital. Early and appropriate infection control measures (ICM) are key elements to reduce MRSA transmission and to control the hospital reservoir. OBJECTIVE: To describe the role of an expert system applied to the control of MRSA at a large medical center (1,600 beds) with high endemic rates. METHODS: The University Hospital of Geneva has an extended hospital information system (HIS), DIOGENE, structured with an open distributed architecture. It includes administrative, medical, nursing, and laboratory applications with their relational databases. Among available patient databases, clinical microbiology laboratory and admission-discharge-transfer (ADT) databases are used to generate computer alerts. A laboratory alert (lab alert) is printed daily in the Infection Control Program (ICP) offices, listing all patients with cultures positive for MRSA detected within the preceding 24 hours. Patients might be either newly detected patients colonized or infected with MRSA, or previously recognized MRSA patients having surveillance cultures. The ICP nurses subsequently go to the ward or call the ward personnel to implement ICM. A second alert, the "readmission alert," detects readmission to the hospital of any patient previously colonized or infected with MRSA by periodic queries (q 1 min) to the ADT database. The readmission alert is printed in the ICP offices, but also forwarded with added guidelines to the emergency room. RESULTS: During the first 12 months of application (July 1994 to June 1995), the lab alert detected an average of 4.6 isolates per day, corresponding to 314 hospital admissions (248 patients); the use of this alert saved time for the ICP nurses by improving work organization. There were 438 readmission alerts (1.2 alerts per day) over the study period; of 347 patients screened immediately upon readmission, 114 (33%) were positive for MRSA carriage. Delayed recognition of readmitted MRSA carriers decreased significantly after the implantation of this alert; the proportion of MRSA patients recognized at the time of admission to the hospital increased from 13% in 1993 to 40% in 1995 (P < .001). CONCLUSIONS: Hospital information system-based alerts can play an important role in the surveillance and early prevention of MRSA transmission, and it can help to recognize patterns of colonization and transmission.

Cross Infection↗
PubMed1995

Nosocomial bloodstream infections. Secular trends in rates, mortality, and contribution to total hospital deaths.

BACKGROUND: Nosocomial bloodstream infections occur at a rate of 1.3 to 14.5 per 1000 hospital admissions and are believed to lead directly to 62,500 deaths per year in the United States. Measures of the incidence and the proportion of all hospital deaths related to deaths from these infections provide estimates of their impact. The objectives of the study were to characterize the secular trends in nosocomial bloodstream infection at a single institution and to estimate the population-attributable risk for death among patients experiencing the infection. METHODS: A 12-year retrospective study using prospectively collected data from a hospital-wide surveillance system for nosocomial infections in a 900-bed tertiary care institution. All patients (N = 260,834) admitted to the institution between 1980 and 1992 were included in the study. Bloodstream infection rates were calculated for the 10 leading groups of pathogens, and trends were analyzed using simple linear regression. In-hospital mortality rates from patients who did or did not develop nosocomial blood stream infections were compared. RESULTS: Between 1980 and 1992, a total of 3077 patients developed 3464 episodes of nosocomial bloodstream infection. The crude infection rates increased linearly from 6.7 to 18.4 per 1000 discharges (0.83 to 1.72 episodes per 1000 patient-days) during the 12-year study period (r = .87). Increases in the infection rates were due to gram-positive cocci (r = .96) and yeasts (r = .95) and essentially explained by infections caused by coagulase-negative staphylococci, Staphylococcus aureus, enterococci, and Candida species, respectively. Although the crude mortality in patients with nosocomial bloodstream infections decreased from 51% in 1981 to 29% in 1992, the in-hospital population-attributable mortality among infected patients increased from 3.55 deaths per 1000 discharges in 1981 to 6.22 per 1000 discharges in 1992 (r = .67). The etiologic fraction or the proportion of deaths in patients with bloodstream infection to all deaths occurring in the hospital increased from 11.4% in 1981 to 20.4% in 1992 (r = .59). CONCLUSIONS: The incidence, the etiologic fraction, and the population-attributable risk for death among patients experiencing nosocomial bloodstream infections increased progressively during the last decade.

Bacteremia↗
PubMed1995

[Candida infections in intensive care].

The incidence of Candida spp is increasing in critically ill patients. The impact of the infection is briefly reviewed. Infections mainly evolve from endogenous colonization facilitated by the use of broad spectrum antibiotics; nosocomial exogenous transmission occasionally occurs, however. A complete understanding of the process of infection requires careful epidemiological investigation as well as the use of powerful laboratory tools that allow intraspecies delineation of Candida strains. The value of contour-clamped homogeneous field gel electrophoresis is discussed. Preventive treatments with antifungal agents will help to improve the outcome of severe infection, but still need to be evaluated in appropriately controlled clinical trials.

Aged↗
PubMed1995

The natural history of the systemic inflammatory response syndrome (SIRS). A prospective study.

OBJECTIVE: Define the epidemiology of the four recently classified syndromes describing the biologic response to infection: systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis, and septic shock. DESIGN: Prospective cohort study with a follow-up of 28 days or until discharge if earlier. SETTING: Three intensive care units and three general wards in a tertiary health care institution. METHODS: Patients were included if they met at least two of the criteria for SIRS: fever or hypothermia, tachycardia, tachypnea, or abnormal white blood cell count. MAIN OUTCOMES MEASURES: Development of any stage of the biologic response to infection: sepsis, severe sepsis, septic shock, end-organ dysfunction, and death. RESULTS: During the study period 3708 patients were admitted to the survey units, and 2527 (68%) met the criteria for SIRS. The incidence density rates for SIRS in the surgical, medical, and cardiovascular intensive care units were 857, 804, and 542 episodes per 1000 patient-days, respectively, and 671, 495, and 320 per 1000 patient-days for the medical, cardiothoracic, and general surgery wards, respectively. Among patients with SIRS, 649 (26%) developed sepsis, 467 (18%) developed severe sepsis, and 110 (4%) developed septic shock. The median interval from SIRS to sepsis was inversely correlated with the number of SIRS criteria (two, three, or all four) that the patients met. As the population of patients progressed from SIRS to septic shock, increasing proportions had adult respiratory distress syndrome, disseminated intravascular coagulation, acute renal failure, and shock. Positive blood cultures were found in 17% of patients with sepsis, in 25% with severe sepsis, and in 69% with septic shock. There were also stepwise increases in mortality rates in the hierarchy from SIRS, sepsis, severe sepsis, and septic shock: 7%, 16%, 20%, and 46%, respectively. Of interest, we also observed equal numbers of patients who appeared to have sepsis, severe sepsis, and septic shock but who had negative cultures. They had been prescribed empirical antibiotics for a median of 3 days. The cause of the systemic inflammatory response in these culture-negative populations is unknown, but they had similar morbidity and mortality rates as the respective culture-positive populations. CONCLUSIONS: This prospective epidemiologic study of SIRS and related conditions provides, to our knowledge, the first evidence of a clinical progression from SIRS to sepsis to severe sepsis and septic shock.

Diagnosis-Related Groups↗
PubMed1995

Systemic inflammatory response syndrome, sepsis, severe sepsis and septic shock: incidence, morbidities and outcomes in surgical ICU patients.

OBJECTIVES: To determine the incidence of systemic inflammatory response syndrome (SIRS), sepsis and severe sepsis in surgical ICU patients and define patient characteristics associated with their acquisition and outcome. DESIGN: One-month prospective study of critically ill patients with a 28 day in-hospital follow up. SETTING: Surgical intensive care unit (SICU) at a tertiary care institution. METHODS: All patients (n = 170) admitted to the SICU between April 1 and April 30, 1992 were prospectively followed for 28 days. Daily surveillance was performed by two dedicated, specifically-trained research nurses. Medical and nursing chart reviews were performed, and follow up information at six and twelve months was obtained. RESULTS: The in-hospital surveillance represented 2246 patient-days, including 658 ICU patient-days. Overall, 158 patients (93%) had SIRS for an incidence of 542 episodes/1000 patients-days. The incidence of SIRS in the ICU was even higher (840 episodes/1000 patients-days). A total of 83 patients (49%) had sepsis; among them 28 developed severe sepsis. Importantly, 13 patients had severe sepsis after discharge from the ICU. Patient groups were comparable with respect to age, sex ratio, and type of surgery performed. Apache II score on admission to the ICU and ASA score at time of surgery were significantly higher (p < 0.05) only for patients who subsequently developed severe sepsis. The crude mortality at 28 days was 8.2% (14/170); it markedly differed among patient groups: 6% for those with SIRS vs. 35% for patients with severe sepsis. Patients with sepsis and severe sepsis had a longer mean length of ICU stay (2.1 +/- 0.2 and 7.5 +/- 1.5, respectively) than those with SIRS (1.45 +/- 0.1) or control patients (1.16 +/- 0.1). Total length of hospital stay also markedly differed among groups (35 +/- 9 (severe sepsis), 24 +/- 2 (sepsis), 11 +/- 0.8 (SIRS), and 9 +/- 0.1 (controls, respectively). CONCLUSIONS: Almost everyone in the SICU had SIRS. Therefore, because of its poor specificity, SIRS was not helpful predicting severe sepsis and septic shock. Patients who developed sepsis or severe sepsis had higher crude mortality and length of stay than those who did not. Studies designed to identify those who develop complications of SIRS would be very useful.

Critical Care↗