What is the impact of surgical site infection on graft function in kidney transplant recipients?

The impact of surgical site infections (SSIs) on graft function in kidney transplant recipients is controversial. We conducted a matched case-control study (1:1 ratio) between April 2001 and December 2004 in a Brazilian cohort of kidney transplant recipients. The epidemiological and clinical characteristics of SSIs were described based on chart review. The impact on graft function was assessed by comparing serum creatinine measurements and creatinine clearance up to 18 months after transplantation with analysis of variance model. Among 1939 kidney transplants, 120 patients with 145 SSIs were enrolled. Most wound infections were superficial (73.1%). The mortality rate was 0.8%. No impact on graft function was detected. In conclusion, accurate identification of SSIs may have resulted in shorter hospitalization periods, but they had no impact on graft function up to 18 months post transplantation.

Health and economic outcomes of the detection of Klebsiella pneumoniae-produced extended-spectrum beta-lactamase (ESBL) in a hospital with high prevalence of this infection.

INTRODUCTION: Klebsiella pneumoniae is of high prevalence in hospital infections, mainly in bloodstream infections (BSI), and some produce extended-spectrum beta-lactamase (ESBL). For hospitals with a high prevalence of strains producing this enzyme, there is no reference material to show whether the use of the E-test method for their detection, which can be quite expensive, is actually required. OBJECTIVE: To evaluate the cost-benefit of the disk diffusion and E-test methods for the detection of ESBL-producing K. pneumoniae strains in hospitals where a high prevalence of this resistance mechanism in BSI is found. METHODS: One hundred and eight patients with K. pneumoniae BSI were evaluated retrospectively. ESBL-producing strains were identified by the disk diffusion method and by the E-test method. We estimated the costs of both diagnostic methods based on antimicrobial therapy adequacy. RESULTS: Fifty-two percent of K. pneumoniae infections were due to ESBL-producing strains. The disk diffusion method yielded a positive predictive value (PPV) of 94.7% (95% CI: 88.9-100%) and a negative predictive value (NPV) of 96.1% (CI 95%: 90.8-101.4%) in relation to the E-test. We evaluated cost-effectiveness, i.e., we analyzed the cost of both E-test and disk diffusion methods with carbapenem and cephalosporins, and found that the use of the disk diffusion method accounts for approximately US$3300. CONCLUSIONS: In hospitals with a high prevalence of ESBL-producing strains, the disk diffusion method can be used to detect ESBL-producing K. pneumoniae without compromising the clinical progression of patients with BSI. The E-test showed higher accuracy but this method was more expensive than the disk diffusion method. However, the use of the E-test method was demonstrated to be more cost-effective, as we evaluated cost based on antimicrobial therapy adequacy.

Risk factors for hospital-acquired candidemia. A matched case-control study.

Nosocomial candidemia has become an important infection not only because of an apparently increasing incidence but also because of its high fatality rate. We studied 28 risk factors through a matched case-control study that included 88 pairs of patients hospitalized between July 1983 and December 1986. The strongest single risk factor found in the univariate analysis was the number of prior antibiotics administered: the exposure odds ratio (OR) was 12.50 when patients who received three to five antibiotics were compared with those who received none to two antibiotics. A multiple logistic regression analysis using a conditional likelihood method was performed to evaluate several risk factors simultaneously. The final model selected by a stepwise procedure included the following variables: number of antibiotics received prior to infection (OR, 1.73 per unit increase), isolation of Candida species from sites other than blood (OR, 10.37), prior hemodialysis (OR, 18.13), and prior use of a Hickman catheter (OR, 7.23). It remains to be shown in controlled clinical trials whether limiting the number of antibiotics or instituting prophylaxis and/or early treatment for high-risk patients will reduce the incidence of nosocomial candidemia.

Hospital-acquired candidemia. The attributable mortality and excess length of stay.

Between 1977 and 1984, estimates of hospital-acquired bloodstream infections caused by Candida species increased in the United States from 0.5 to 1.5 per 10,000 admissions (National Nosocomial Infection Study data). We examined crude and attributable mortality rates and excess length of stay in 88 closely matched pairs of cases and controls with illnesses occurring between July 1983 and December 1986. The crude mortality rates for cases and controls were 57% and 19%, respectively; thus the attributable mortality rate was 38% with a 95% confidence interval of 26% to 49%. The risk ratio was 2.94 with a 95% confidence interval of 1.95 to 4.43. The median length of stay was 48 days for all cases and 40 days for all controls. An analysis of the length of stay for the 34 matched pairs that survived showed a median of 70 days for cases and 40 days for controls. Candida bloodstream infections represented 10% of all nosocomial bloodstream infections in the period studied at our University Hospital; they are associated with a significant medical and economic burden well above that expected of the underlying diseases alone.

Infection control in a country with annual inflation of 3,600%.

The economic crisis that has been seen worldwide affects developing countries such as Brazil even more severely. Worsening budget shortfalls for the healthcare system progressively threaten patients care. Infection control programs also are affected, and basic preventive policies are not implemented. Infection control practitioners face lack of equipment and poor microbiological support. In contrast, the motivation of the infection control people can be maintained through training courses, conferences, and meetings. Administrative support may be the most important single factor determining success in decreasing the infection control rate and should be (but is not always) provided, given that several infection control measures are cost effective.

Risk factors for mortality in Staphylococcus aureus bacteremia.

OBJECTIVE: To analyze risk factors for, and the role of methicillin resistance in, mortality in Staphylococcus aureus bacteremia. DESIGN: Nested case-control study. SETTING: General teaching hospital with a high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) strains, in São Paulo, Brazil. PATIENTS: 136 patients over 14 years old with documented S aureus bacteremia. Those who died were compared with those who survived at least 14 days. RESULTS: Mortality within 14 days of bacteremia was 39% (53/136). Mean age was 47 years. Hospital-acquired bacteremia represented 86% (117/136) of episodes. In 26% (35/136), infection was related to an intravascular catheter and in 13% (17/136) to the respiratory tract. Septic shock occurred in 22% (30/136) of cases. MRSA was isolated in 66% (90/136). Multivariate analysis identified three variables that were significantly and independently associated with mortality: site of entry (lung, odds ratio [OR], 17.0; unknown, OR, 12.3; others, OR, 6.6); occurrence of shock (OR, 8.9), and resistance of S aureus to methicillin (OR, 4.2). CONCLUSION: Our study shows that S aureus bacteremia has a high mortality, especially when the lung is the source of infection and when shock develops; resistance to methicillin may be another risk factor for poor outcome.

High rate of non-albicans candidemia in Brazilian tertiary care hospitals.

In order to evaluate the epidemiology of candidemia in Brazil, we performed a prospective multicenter study conducted in six general hospitals from São Paulo and Rio de Janeiro, We enrolled a total of 145 candidemic patients (85 males) with a median age of 32 years. Non-albicans species accounted for 63% of all episodes and the species most frequently causing candidemia were C. albicans (37%), C. parapsilosis (25%), C. tropicalis (24%), C. rugosa (5%), and C. glabrata (4%). Systemic azoles were used before the onset of candidemia in only six patients. There were no differences in the coexisting exposures or underlying diseases associated with the species most frequently causing candidemia. The overall crude mortality rate was 50%. Nosocomial candidemias in our tertiary hospitals are caused predominantly by non-albicans species, which are rarely fluconazole resistant. This predominance of non-albicans species could not be related to the previous use of azoles.

Lactic acidosis and antiretroviral therapy: a case report and literature review.

Antiretrovirals, particularly nucleoside analogue reverse transcriptase inhibitors (RTIs) - DDI, 3TC and D4T, are widely used to effectively control human immunodeficiency virus (HIV) infection. These drugs have several adverse effects including anemia, peripheral neuropathy, pancreatitis and, on rare occasions, lactic acidosis. We describe the case of a 39 year old patient who had severe lactic acidosis after receiving stavudine (D4T) and didanosine (DDI) for an 8 month period. She had never manifested an opportunistic infection and presented a CD4 count of 378 cells/mm3 and an undetectable viral load (< 400 copies/ml). The purpose of the following report is to alert clinicians and infectious diseases specialists to the occurrence of lactic acidosis in asymptomatic HIV patients receiving antiretrovirals for long periods of time.

[Analysis of the program of control of the use of antimicrobials at the Hospital São Paulo--Escola Paulista de Medicina]. / Análise do programa de controle do uso de antimicrobianos no Hospital São Paulo--Escola Paulista de Medicina.

BACKGROUND AND OBJECTIVE: Antimicrobial agents represent a group of drugs that are frequently used in hospitals. Approximately, 50% of hospitalized patients receive at least one antimicrobial drug during the hospitalization period. However, half of these drugs are prescribed incorrectly. The objective of this paper was to analyse the antimicrobial control program that has been used at Escola Paulista de Medicina since 1989. CASUISTIC & METHODS: The prescription of eleven controlled antibiotics should be done in a special form. Any requisition of a controlled antibiotic was evaluated, within 24 hours, by an infection diseases specialist who was hired exclusively for this function. RESULTS: During 1989, 5,573 controlled antimicrobials were requested by the hospital staff, and 17.6% of them were considered inadequate and were refused. Such a percentage was high considering that our institution is a university hospital where the antibiotic usage should be more precise and adequate. We also should take into account that the indication of only 11 antimicrobial drugs were evaluated. CONCLUSION: The results allow us to conclude that each hospital should have not only a policy on antimicrobial usage but also an effective program of control of these drugs.

[Epidemiology of bacteremias at a university hospital]. / Epidemiologia das bacteremias em hospital universitário.

The epidemiological aspects of bacteremias were determined in a university hospital, according to service, age, sex and place of acquisition (nosocomial or community-acquired). From August 1985 through July 1986 the incidence rate of bacteremias at the Sao Paulo Hospital was 21.7/1000 admissions. Such a high rate is probably related to the characteristics of the patients admitted to the hospital. The incidence was higher in the extremes of age and was similar in either sex. Approximately 60% of the bacteremias were nosocomial including 9.1% that were present at admission in patients transferred from other hospitals. The most frequent isolated pathogen was S. aureus. The most important source of bacteremia was the respiratory tract followed by the gastrointestinal and urinary tracts.

[Effect of nosocomial bacteremia caused by oxacillin-resistant Staphylococcus aureus on mortality and length of hospitalization]. / Efeito da infecção hospitalar da corrente sanguínea por Staphylococcus aureus resistente à oxacilina sobre a letalidade e o tempo de hospitalização.

OBJECTIVES: To identify the attributed mortality rate of bloodstream hospital infection by Staphylococcus aureus resistant to methicillin (MRSA) and its effect on length of hospital stay. DESIGN: Case-control study. SETTING: Hospital São Paulo da Universidade Federal de São Paulo, a 660-bed, tertiary-care teaching hospital in São Paulo, Brazil. PATIENTS: Seventy one adults patients with hospital-acquired MRSA bacteremia diagnosed between January 1, 1991, and September 30, 1992, and 71 MRSA-free controls were matched by the following criteria: age, sex, underlying disease, surgical procedure, same risk time and admission date. RESULTS: The incidence of patients with hospital sepsis by MRSA accounted for 73.22% of the patients with hospital bloodstream infection by Staphylococcus aureus. The mortality rate of the cases was 56.33 (40/71) and 11.26 (8/71) of the controls. The attributable mortality rate was 45.07% (OR = 17.0; IC 95% = 3.58-202.26; p = 0.000001). The length of hospital stay median time was of 32.55 days for the cases and 29.75 for the controls (p = 0.32). CONCLUSION: A high level of sepsis by MRSA was observed in all the Staphylococcus aureus bacteremia. The bloodstream hospital infection by MRSA itself does provide a high level of mortality independently from the patients base disease, without however, increasing their hospital length of stay.

[Complications of central venous catheters: prospective study]. / Complicações de cateteres venosos centrais: estudo prospectivo.

The insertion of central venous catheters (CVC) represent a very common procedure in intensive care units. The purpose of this study was to determine the via that provide the best chance for a good location of the tip of a CVC. The 563 CVCs that were inserted percutaneously and that had a radiology control were analyzed. The infraclavicular via was used for 303 (25%) CVCs; the jugular via had 142 (25%) CVCs and the supraclavicular via was used in 118 (21%) CVCs. The rate of bad location of the tip of the CVC were 17%, 6% and 9%, respectively. There was a significant difference when the insertion through infraclavicular via and jugular via were compared. There were 9 pneumothorax (1.4%). 127 CVCs were sent to microbiology laboratory, 26 (20%) had positive culture (> 15 colony forming units). The most frequent agents isolates were: Candida spp (7), S. aureus (5), S. epidermidis (4) and P. aeruginosa (3).

[Polyalveolosis: pathogenesis of congenital lobar emphysema?]. / Polialveolose: patogênese do enfisema lobar congênito?

BACKGROUND: Congenital lobar emphysema is an unusual condition and its pathogenesis remains unknown. The variety of findings in pathology studies of the resected specimens led to increasing academic interest. About 50 per cent of the cases have no definitive diagnosis in pathology. The most recent theory proposes an increased number of alveoli within each acinus (polyalveolar lobe). PURPOSE: The aim of this paper is to report the morphometric measures of surgical specimens of 12 patients with congenital lobar emphysema, using the Emery and Mithal technique (radial alveolar count). METHODS: We made a case-control study, classifying the cases by age. Mann-Whitney's U test and linear regression techniques were used in data analysis: Mann-Whitney's U in comparing the cases and respective controls and linear regression to evaluate the influence of age in the measures found. RESULTS: The results revealed a significantly higher radial alveolar count than expected for the age group under 3 years; no difference was observed in the age group between 3 and 7 years and in children older than 7, the radial alveolar count was lower than expected. The normal development of the lung consists in an increasing number of alveoli increase from birth until adulthood, but this number remains constant, independent of age in congenital lobar emphysema. CONCLUSIONS: Such findings allow us to conclude that polyalveolar lobe can and must be diagnosed by a simple and practical method, such as the radial alveolar count, which decreases the incidence of the unknown etiology. The findings of an increased number of alveoli on patients younger than 3 is related to congenital lobar emphysema, since the number of alveoli does not increase in congenital lobar emphysema, just the opposite to what one would expect in the normal development of the lung.

Risk factors for hospital-acquired pneumonia caused by imipenem-resistant Pseudomonas aeruginosa in an intensive care unit.

Imipenem-resistant Pseudomonas aeruginosa is a leading cause of hospital-acquired pneumonia. Aiming to determine the risk factors associated for hospital-acquired pneumonia due to imipenem-resistant Pseudomonas aeruginosa, we undertook a retrospective case-case-control study. Patients admitted to a 14-bed medical-surgical intensive care unit from a university-affiliated hospital with hospital-acquired pneumonia caused by imipenem-resistant Pseudomonas aeruginosa strains and by imipenem-susceptible Pseudomonas aeruginosa strains were matched to control patients by time under risk and comorbidities. A total of 58 resistant cases, 47 susceptible cases and 237 controls were evaluated. The risk factors independently associated to hospital-acquired pneumonia caused by imipenem-resistant Pseudomonas aeruginosa were: duration of hospitalisation, Acute Physiological and Chronic Health Evaluation II score, male gender receipt of haemodialysis, receipt of piperacillin-tazobactam and receipt of third-generation cephalosporins.

[Is the epidemiological surveillance system of nosocomial infections recommended by the American CDC applicable in a Chilean hospital?]. / Es aplicable el sistema de vigilancia epidemiológica de las infecciones intrahospitalarias que recomienda el CDC-americano (sistema NNIS) en un hospital chileno?

BACKGROUND: The National Nosocomial Infections Surveillance System (NNIS system) is the method for surveying nosocomial infections used by the Centers for Disease Control (CDC). This strategy allows the comparison of different hospitals, using rate adjustments. In Chile, this system is not used. AIM: To report the application of this system in a tertiary reference hospital in Chile. MATERIALS AND METHODS: We performed a six months prospective cohort study. The active surveillance was carried out by using the intensive care unit and surgery components of the NNIS system. Tabulation and analysis of the data were done according to the NNIS system. In a parallel prevalence study, we determined the NNIS system sensitivity to detect nosocomial infections. RESULTS: A total of 492 patients were followed with a global nosocomial infection rate of 14%, for discharged patients. The calculated sensitivity and specificity of the system was 84.2 and 97% respectively. In the intensive care unit, 45 of 169 patients had nosocomial infections, with an adjusted rate of 2.8% for mean hospitalization time and severity of illness. In the cardiovascular and thoracic surgical units, 216 and 107 procedures were surveyed, respectively. The global rates of nosocomial infections were 7.4 and 7.5%, respectively. The adjusted rates according to risk factors were 0.9 and 2.3%, respectively. CONCLUSIONS: These data indicate that the surgical units had surgical site infections rates similar to those reported by the CDC. Nosocomial infections rates in Chile can be compared with rates observed in other countries. The epidemiological data collected can be useful to focus intervention or preventive strategies.

Nosocomial and community acquired bacteremia: variables associated with outcomes.

Bacteremia is related to high morbidity and lethality. The present investigation was conducted to evaluate the variables associated with outcomes of bacteremia at a University Hospital in São Paulo, Brazil. Patients with bacteremia were identified through positive blood cultures performed at the microbiology laboratory between August 1985 and July 1986. Their charts were reviewed and the following variables were considered: age, sex, presence of underlying disease, where was the bacteremia acquired, source of infection, presence of shock and appropriateness of antimicrobial therapy. In the period of the study, there were 362 cases of bacteremia out of 16,636 admissions to the hospital. The lethality rate was 33.4%, six times higher than the mortality rate for non-bacteremic patients. Age greater than 40 years, presence of severe underlying disease, nosocomial acquisition, respiratory tract as the source of bacteremia, presence of shock and, being infected with Pseudomonas sp were significantly associated with fatal outcome. Appropriate antimicrobial therapy reduced the incidence of shock and improved survival of patients with bacteremia. This study provides information on outcome of patients with bacteremia at a University Hospital in Brazil and, settles the variables associated with poor outcome in these patients.

Microbiological characteristics of yeasts isolated from urinary tracts of intensive care unit patients undergoing urinary catheterization.

We studied 70 intensive care unit patients to determine the incidence of nosocomial candiduria associated with indwelling urinary catheters and to assess microbiological characteristics of the yeasts. The yeasts were isolated, 13 of 17 in urine cultures and 4 of 17 in blood cultures, and colonization had occurred 3 days after the insertion of indwelling urinary catheters. For four strains the MICs of the antifungal drugs were high.

Risk factors for nosocomial urinary tract and postoperative wound infections in renal transplant patients: a matched-pair case-control study.

A matched-pair case-control study was done on 4 groups of renal transplant patients who acquired nosocomial infections: 1) urinary tract infection, 2) postoperative wound infection, 3) urinary tract plus postoperative wound infection and 4) the entire group of patients. For urinary tract infection patients a prolonged period of hemodialysis before hospitalization was considered a risk factor. Renal transplantation with an HLA-1 (identical) donor graft was a characteristic related to the control group. High levels of plasma creatinine and prolonged vesical catheterization were risk factors for acquiring postoperative wound infection. The latter was also considered to be a risk factor for both infections, as well as the inadequate use of antibiotic prophylaxis and the number of antibiotics used. For the entire group of patients surgical wall hematoma was a risk factor. In this group the independent risk factors analyzed by multivariate logistic regression were renal transplantation with a cadaver donor graft, prolonged vesical catheterization and prolonged use of antibiotics. Careful management of the cadaver donor allograft, decreasing the changes of contamination, decreasing the interval of urinary catheter maintenance and use of antibiotics in the postoperative period are measures that can contribute to lessen the incidence of these nosocomial infections in renal transplant recipients.

Neonatal late-onset bloodstream infection: attributable mortality, excess of length of stay and risk factors.

BACKGROUND: Bloodstream infection represents a major threat among neonates under intensive care with considerable impact on morbidity and mortality. This study evaluated extra stay, attributable mortality and the risk factors associated with late-onset bloodstream infection (LO-BSI) among neonates admitted to a neonatal intensive care unit during a 4-year period. METHODS: A retrospective matched cohort study was conducted. For each case, there was one control patient without LO-BSI matched for sex, birth weight, gestational age, duration of hospitalization prior to the date of LO-BSI in the respective cases, underlying illness and birth date. A novel test, sequential plan, was employed for attributable mortality analysis in addition to standard tests. Multiple logistic regression was employed for risk factor analysis. RESULTS: Fifty pairs of cases and controls were compared. LO-BSI prolonged hospital stay of 25.1 days in pairs where both subjects survived. Overall attributable mortality was 24% (95% CI: 9-39% p < 0.01) and specific attributable mortality due to Staphylococcus epidermidis was 26.7% (95% CI: 23-30.4%; p = 0.01). Blood and/or blood components transfusion was independently associated with neonatal LO-BSI (OR: 21.2; 95% CI: 1.1-423). CONCLUSIONS: LO-BSI infection prolongs hospital stay and is associated with increased mortality among neonates. In the present series, blood transfusion was a significant risk factor for LO-BSI.