Optimization of Antimicrobial Stewardship Programs Using Therapeutic Drug Monitoring and Pharmacokinetics-Pharmacodynamics Protocols: A Cost-Benefit Review.

PURPOSE: Antimicrobial stewardship programs are important for reducing antimicrobial resistance because they can readjust antibiotic prescriptions to local guidelines, switch intravenous to oral administration, and reduce hospitalization times. Pharmacokinetics-pharmacodynamics (PK-PD) empirically based prescriptions and therapeutic drug monitoring (TDM) programs are essential for antimicrobial stewardship, but there is a need to fit protocols according to cost benefits. The cost benefits can be demonstrated by reducing toxicity and hospital stay, decreasing the amount of drug used per day, and preventing relapses in infection. Our aim was to review the data available on whether PK-PD empirically based prescriptions and TDM could improve the cost benefits of an antimicrobial stewardship program to decrease global hospital expenditures. METHODS: A narrative review based on PubMed search with the relevant studies of vancomycin, aminoglycosides, beta-lactams, and voriconazole. RESULTS: TDM protocols demonstrated important cost benefit for patients treated with vancomycin, aminoglycosides, and voriconazole mainly due to reduce toxicities and decreasing the hospital length of stay. In addition, PK-PD strategies that used infusion modifications to meropenem, piperacillin-tazobactam, ceftazidime, and cefepime, such as extended or continuous infusion, demonstrated important cost benefits, mainly due to reducing daily drug needs and lengths of hospital stays. CONCLUSIONS: TDM protocols and PK-PD empirically based prescriptions improve the cost-benefits and decrease the global hospital expenditures.

COVID-19-associated aspergillosis in a Brazilian referral centre: Diagnosis, risk factors and outcomes.

BACKGROUND: COVID-19 patients on mechanical ventilation are at risk to develop invasive aspergillosis. To provide additional data regarding this intriguing entity, we conducted a retrospective study describing risk factors, radiology and prognosis of this emerging entity in a Brazilian referral centre. METHODS: This retrospective study included intubated (≥18 years) patients with COVID-19 admitted from April 2020 until July 2021 that had bronchoscopy to investigate pulmonary co-infections. COVID-19-associated aspergillosis (CAPA) was defined according to the 2020 European Confederation of Medical Mycology/International Society of Human and Animal Mycosis consensus criteria. The performance of tracheal aspirate (TA) cultures to diagnose CAPA were described, as well as the radiological findings, risk factors and outcomes. RESULTS: Fourteen patients (14/87, 16%) had probable CAPA (0.9 cases per 100 ICU admissions). The sensitivity, specificity, positive predictive value and negative predictive value of TA for the diagnosis of CAPA were 85.7%, 73.1%, 46.2% and 95% respectively. Most of the radiological findings of CAPA were classified as typical of invasive pulmonary aspergillosis (64.3%). The overall mortality rate of probable CAPA was 71.4%. Age was the only independent risk factor for CAPA [p = .03; odds ratio (OR) 1.072]. CAPA patients under renal replacement therapy (RRT) may have a higher risk for a fatal outcome (p = .053, hazard ratio 8.047). CONCLUSIONS: CAPA was a prevalent co-infection in our cohort of patients under mechanical ventilation. Older patients had a higher risk to develop CAPA, and a poor prognosis may be associated with RRT.

Entropy as a Measure of Attractiveness and Socioeconomic Complexity in Rio de Janeiro Metropolitan Area.

Defining and measuring spatial inequalities across the urban environment remains a complex and elusive task which has been facilitated by the increasing availability of large geolocated databases. In this study, we rely on a mobile phone dataset and an entropy-based metric to measure the attractiveness of a location in the Rio de Janeiro Metropolitan Area (Brazil) as the diversity of visitors' location of residence. The results show that the attractiveness of a given location measured by entropy is an important descriptor of the socioeconomic status of the location, and can thus be used as a proxy for complex socioeconomic indicators.

Ensuring successful introduction of Wolbachia in natural populations of Aedes aegypti by means of feedback control.

The control of the spread of dengue fever by introduction of the intracellular parasitic bacterium Wolbachia in populations of the vector Aedes aegypti, is presently one of the most promising tools for eliminating dengue, in the absence of an efficient vaccine. The success of this operation requires locally careful planning to determine the adequate number of individuals carrying the Wolbachia parasite that need to be introduced into the natural population. The introduced mosquitoes are expected to eventually replace the Wolbachia-free population and guarantee permanent protection against the transmission of dengue to human. In this study, we propose and analyze a model describing the fundamental aspects of the competition between mosquitoes carrying Wolbachia and mosquitoes free of the parasite. We then use feedback control techniques to devise an introduction protocol that is proved to guarantee that the population converges to a stable equilibrium where the totality of mosquitoes carry Wolbachia.

Bioecological representations and social characteristics of students influence their attitudes toward wild vertebrates.

BACKGROUND: The origin of different human emotions directed towards animals (whether in the utilitarian, affective, conflictual, or cosmological context) is strongly influenced by sociocultural factors, although our genetic predispositions also play an important role in the origin of these emotions. Such emotions guide people's representations of different species, which in turn affect their attitudes toward them. For this reason, understanding the factors that guide such attitudes becomes a key element in making conservationist decisions. In this sense, the main objective of this study was to analyze how sociocultural characteristics and bioecological representations can influence students' attitudes of empathy or antipathy towards vertebrate species; as well as which classes and species are related to greater and lesser support in people for their conservation. METHODS: To do so, 667 interviews were conducted with students from urban (n = 1) and rural (n = 2) schools in the Brazilian semi-arid region. We used mixed generalized linear models (GLMM) to examine the effect of social factors and bioecological representations on empathy and antipathy attitudes and multiple factor analysis (MFA) to examine the relationship between the biological characteristics of the animals (positive or negative) and the attitudes toward them (antipathetic or empathetic). RESULTS: Through GLMM, we found that students from the urban area and from lower school levels are more extreme in their responses, more frequently expressing both empathy and antipathy towards wild animals. Regarding gender, women had a higher frequency of responses associated with aversion than men for species perceived as dangerous and poisonous (p < 0.001). Through the MFA, we found greater support (empathy) for the conservation of fish species (31.56%), birds (29.37%) and mammals (25.94%), with emphasis on the Red-cowled cardinal (Paroaria dominicana) and clownfish (Amphiprion ocellaris) species, and less support (antipathy) for reptile and amphibian species such as rattlesnakes (Crotalus durissus) and horned frogs (Ceratophrys joazeirensis). CONCLUSIONS: The attitudinal ambivalence reflected by varying empathy for certain species and antipathy to others has important implications for wildlife conservation. Understanding the socioeconomic factors and emotions that influence attitudes towards animals can enable integrating educational strategies for the conservation of species, especially those which are culturally important.

Human mobility and socioeconomic datasets of the Rio de Janeiro metropolitan area.

This data descriptor presents two main datasets and a set of auxiliary files. The mobility dataset presents a long-term study of human mobility in the Rio de Janeiro Metropolitan Area (RJMA) performed in the entire year of 2014 based on mobile phone data. The socioeconomic dataset presents selected socioeconomic variables of the Brazilian 2010 census. A set of auxiliary files is included to present georeferenced information and geographic features (shapefiles) and data used to validate the mobility estimates. The human mobility estimation was carried out using a methodology that allows direct integration with census data, based on an approximation of the geographic boundaries of census units by an aggregation of Voronoi polygons of the mobile phone antennas. The study area is the Brazilian local area 21, which includes the entire RJMA and four other municipalities. The mobility dataset is divided into two files: one is an estimation of the origin-destination (OD) matrix per day, and the other is a visitors' dataset where the number of visitors of each location is estimated in four shifts each day. The socioeconomic dataset presents information of 55 variables for each location, which have been used in different studies and present the longest human mobility dataset available for public use.

Characteristics, risk factors, and outcomes of bloodstream Candida infections in the intensive care unit: a retrospective cohort study.

OBJECTIVE: The main objective was to assess the clinical characteristics, associated factors, and outcomes of patients admitted to the ICU for candidemia. The secondary objective was to examine the relationship of candidemia with the length of stay and mortality. METHODS: The analysis was a retrospective single-center cohort study addressing the effect of invasive candidemia on outcomes. This study was performed in a medical-surgical ICU located in a tertiary private hospital in São Paulo, Brazil. Data was collected through the review of the hospital database. RESULTS: In total, 18,442 patients were included in our study, including 22 patients with candidemia. The median age was similar in patients with and without candidemia [67 (56-84) vs. 67 (51-80)]. Most patients were male, and the proportion of men was higher among patients with candidemia (77% vs. 55.3%). The rates of renal replacement therapy (40.9% vs. 3.3%), mechanical ventilation (63.6% vs. 29.6%), and parenteral nutrition (40.9% vs. 4.8%) were higher in patients with candidemia than in those without candidemia. The mortality rate (77.3% vs. 11.9%) and length of hospital stay [42 days (23.0-78.8) vs. 8 days (5.0-17.0)] were significantly higher in patients with candidemia. CONCLUSIONS: Patients with candidemia are prone to longer hospital stay and mortality. In addition, we found associations of candidemia with the use of invasive mechanical ventilation, renal replacement therapy, and parenteral nutrition.

The impact of monitoring software on antimicrobial management in a pediatric intensive care unit.

INTRODUCTION: Antimicrobial stewardship programs are necessary practices to combat resistance in hospital infections. However, studies frequently cite the scarcity of technological resources as an obstacle to the comprehensive development of ASPs. OBJECTIVES: The aim of the study was to assess the impact of monitoring software on reducing antibiotic consumption and reducing resistance in a pediatric intensive care unit. METHODS: We conducted an analytical longitudinal study during the period January 1, 2007, to December 31, 2018, in the pediatric intensive care unit of a high-complexity tertiary general hospital in Brazil. RESULTS: In the period after the implementation of software, we observed decreases in total antimicrobial consumption (P = .037). Regarding Enterobacterales, we observed a decrease in the proportion of antimicrobial resistance of first and second-generation cephalosporin classes (P = .041) and third and fourth-generation cephalosporins (P = .028). There was a decrease in the proportion of resistance of nonfermenting gram-negative bacilli to aminoglycoside scans (P = .016). We also observed evidence of a decrease in the proportion of resistance of Staphylococcus aureus agents to oxacillin (P < .001). CONCLUSIONS: The monitoring software reduced the total consumption of antimicrobials and decreased the proportion of resistance, therefore demonstrating its importance in controlling the development of multidrug-resistant bacteria.

What are the factors influencing the aversion of students towards reptiles?

BACKGROUND: Reptiles form a paraphyletic group with significant roles for human society, including species that are considered important for food, medicinal and mystical use and as pets. Some species are considered to be aversive, whereas others are captivating among people. Aversion is an important factor which should be considered in the conservation policies of these animals. As such, here, we investigate the demographic, educational, perceptives and behavioural factors of students related to their aversion and non-conservationist attitudes directed towards different reptile species and evaluated the effect of educational exhibition of animals as a strategy of mitigating these attitudes. METHODS: The data were obtained through forms on the aversion and conservation of reptiles represented by three species, a chelonian, a snake and a lizard. The form was given in two instances, before and after a visit to a private zoo (Museu Vivo Répteis da Caatinga), where the students had contact with the aforementioned species. A total of 133 students participated in the study, among these, 43 from elementary school (21 females and 22 males), 29 from high school (16 females and 13 males), 37 from university biology students (22 females and 15 males) and 24 university mathematics students (6 females and 18 males). RESULTS: Among all evaluated species, snakes were considered to be the most aversive species. The aversion attitudes differed between the three evaluated species when correlated to age and type of university courses. However, this pattern did not differ between student sexes. Older students had a lower aversion to the chelonian compared to the younger ones, but for snakes and lizards, the aversion was high among students of all ages. The university biology students had a lower aversion compared to the university mathematics students for the three species. The recognition and handle of the tested species and previous visits to educational exhibitions of animals were negatively related to aversion. The comparative analysis of the forms applied before and after the visit to the Museu Vivo Répteis da Caatinga showed that this visit influenced the decrease of aversion, but not in non-conservationist attitudes, for which the attitude scores had always been low. CONCLUSIONS: We conclude that reptile aversion varies in accordance with the taxon, being snakes the most disliked by students. The visit to the educational exhibition of animals contributed to the reduction of the observed aversion. This is especially true when the acquisition of educational information about species is associated with practical activities which includes contact with the animals. Finally, the fact that non-conservationist attitudes had been low towards all species perhaps demonstrates a conservationist tendency even for the most aversive species.

Fauna and conservation in the context of formal education: a study of urban and rural students in the semi-arid region of Brazil.

BACKGROUND: In addition to playing a key role in the dynamics of ecosystems, animal diversity, especially that of wild vertebrates, is intimately linked with human evolutionary history, which has resulted in diverse interactions that must be emphasized in formal education processes. We analyzed several methods of approaches used for biological education in order to teach about wild vertebrates and their conservation in urban and rural schools in the semi-arid region of Brazil. METHODS: Data were obtained via questionnaires applied to 990 students, of which 528 were urban and 462 rural, distributed among the seven grades/years that comprise the last two cycles of basic education in Brazil. The richness and diversity of the animals cited by the students were calculated, being the diversity using an adaptation of the equation for the Shannon-Weaver Index (H'). Data were analyzed using non-parametric descriptive statistics. RESULTS: Mammals and birds had the greatest richness and diversity of animals cited as most-studied in science/biology classes, and also the most indicated as occurring in the studied region. Among mammals, large carnivores with a showy appearance and utilitarian value had the highest citation frequencies, while there was a tendency for limited recognition of faunistic diversity in the other groups mentioned. Almost 70% of the students stated that their schooling processes dealt with the conservation of wild animals; however, about 50% of the students in both urban and rural contexts did not express conceptual understanding about the conservation of nature. CONCLUSIONS: The recognition of animal diversity, especially vertebrates, beyond just mammals and birds, as well as conceptual clarity about the conservation of nature, are fundamental factors for the development of critical awareness of fauna and its conservation, and where the processes of schooling have a preponderant role. Finally, the study contributes to the legitimization of Ethnobiology as an interdisciplinary field of knowledge, especially in its interface with education, in addition to pointing out the importance of optimizing efforts in approaches to biodiversity conservation in formal educational processes.

Purple urine bag syndrome: case report for Streptoccocus agalactiae and literature review.

We report a case of purple urine bag syndrome, associated to Streptococcus agalactiae urinary tract infection, progressing to septic shock and death. We present a review of the literature on the subject and take the opportunity to attend readers about increasing incidence with population aging and its potential bad outcome.

HER2 amplification ratios by fluorescence in situ hybridization and correlation with immunohistochemistry in a cohort of 6556 breast cancer tissues.

To analyze HER2 amplification in a large cohort of diagnostic breast cancer specimens, fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) were performed on the same specimens with use of Food and Drug Administration&approved products. Procedures were standardized following the manufacturers' recommendations. Of 116,736 IHC specimens, 20% were positive for HER2. In 16,092 FISH specimens, 22.7% showed HER2 amplification. In the subset of 6556 tissues analyzed with IHC and FISH, however, 59% were positive on IHC and 23.6% were amplified on FISH. The increased frequency of positive test results is skewed by more frequent reflex FISH testing. In general, expression and amplification trended together, with the least amplification (4.1%) seen in IHC-negative cases, 7.4% amplification seen in IHC 1+ cases, 23.3% amplification seen in IHC 2+ cases, and 91.7% amplification seen in IHC 3+ cases. When FISH amplification ratios were stratified, the low FISH ratios (2.0-2.2) were most frequently seen in specimens with negative IHC results, high ratios (>5.0) were seen in IHC 3+ specimens, and intermediate levels of amplification were similar for all levels of IHC. The effect of changing the cutoff point was analyzed: removing cases with a ratio of exactly 2.0 decreased the FISH positivity rate to 22.2% in the combined IHC and FISH cohort. Sequentially moving the cutoff point to 2.2 and 2.5 affected cases at all IHC expression levels. Each change removed approximately 2% from the apparent positivity. This large database provides the distribution frequency of HER2 protein expression and gene amplification in invasive ductal and lobular breast cancer. The relationship between level of HER2 amplification and clinical outcome will require reanalysis of pivotal trial data.

Culling dogs in scenarios of imperfect control: realistic impact on the prevalence of canine visceral leishmaniasis.

BACKGROUND: Visceral leishmaniasis belongs to the list of neglected tropical diseases and is considered a public health problem worldwide. Spatial correlation between the occurrence of the disease in humans and high rates of canine infection suggests that in the presence of the vector, canine visceral leishmaniasis is the key factor for triggering transmission to humans. Despite the control strategies implemented, such as the sacrifice of infected dogs being put down, the incidence of American visceral leishmaniasis remains high in many Latin American countries. METHODOLOGY/PRINCIPAL FINDINGS: Mathematical models were developed to describe the transmission dynamics of canine leishmaniasis and its control by culling. Using these models, imperfect control scenarios were implemented to verify the possible factors which alter the effectiveness of controlling this disease in practice. CONCLUSIONS/SIGNIFICANCE: A long-term continuous program targeting both asymptomatic and symptomatic dogs should be effective in controlling canine leishmaniasis in areas of low to moderate transmission (R0 up to 1.4). However, the indiscriminate sacrifice of asymptomatic dogs with positive diagnosis may jeopardize the effectiveness of the control program, if tests with low specificity are used, increasing the chance of generating outrage in the population, and leading to lower adherence to the program. Therefore, culling must be planned accurately and implemented responsibly and never as a mechanical measure in large scale. In areas with higher transmission, culling alone is not an effective control strategy.

Contact precautions in the intensive care unit setting: 12 years of surveillance.

The utilization of isolation precautions has increased in tertiary care hospitals due to the increase in colonization with multidrug-resistant organisms over time. We assessed the frequency of multidrug-resistant microorganisms responsible for implementation of contact precautions in the ICU of a tertiary care hospital over a 12-year period.

Humoral immune response following seasonal influenza vaccine in islet transplant recipients.

Annual influenza vaccine is recommended for organ transplant recipients, but immunogenicity is known to be suboptimal. Islet transplant recipients receive immunosuppressive therapy, but there are no data on the immunogenicity of influenza vaccine in this population. In this prospective cohort study, adult islet transplant recipients at least 3 months posttransplant were enrolled. All patients received the 2010-2011 seasonal influenza vaccine. Serum was obtained pre- and postvaccination to determine humoral response to each of the three influenza strains included in the vaccine. Adverse effects of vaccine were also noted. A total of 61 islet transplant recipients were enrolled and completed the study protocol. The median time from last transplant was 1.9 years (range 0.26-11.4 years), and most patients had undergone multiple prior islet transplant procedures (90.2%). Overall immunogenicity of the vaccine was poor. Seroconversion rates to H1N1, H3N2, and B antigens were 34.4%, 29.5%, and 9.8%, respectively. In the subset not seroprotected at baseline, a protective antibody titer postvaccination was achieved in 58.6%, 41.9%, and 34.5% of patients, respectively. Patients within the first year of transplant were significantly less likely to seroconvert to at least one antigen (23.5% vs. 54.5%; p = 0.029). Alemtuzumab recipients trended toward lower seroconversion rates (25% vs. 51%; p = 0.11). No vaccine-related safety concerns were identified. Seasonal influenza vaccine had suboptimal immunogenicity in islet transplant recipients especially those who were less than 1 year posttransplant or had received alemtuzumab induction. Novel strategies for protection in this group of patients need further study.

Secular trends in the epidemiology of Clostridium difficile infection (CDI): relationship with alcohol gel and antimicrobial usage in a hospital.

BACKGROUND: Clostridium difficile-associated diarrhea (CDAD) has shown increasing incidence, morbidity, and mortality in recent years. We assessed the number of CDAD tests requested, CDAD positivity rates, the use of alcohol-based hand rubs, and antimicrobial utilization. METHODS: We collected information on every adult patient (>18 years) who developed diarrhea and had a positive stool test for C. difficile toxin from June 2005 to December 2009 at a tertiary care hospital. A time-series analysis was performed using monthly data on the incidence of C. difficile infection (CDI) (i.e., cases of infection per 1000 patient-days), as well as the consumption of alcohol-based hand rubs (in liters/1000-patient days) and antibiotics (in defined daily doses per 1000 patient-days). RESULTS: The mean number of annual requests for C. difficile tests was 1031, and the rates per 1000 patient-days for each year from 2005 to 2009 were 0.30, 0.46, 0.39, 0.31, and 0.40 overall in the hospital, and 0.18, 0.10, 0.53, 0.38, and 0.37 in the intensive care unit (ICU). The use of alcohol-based hand rubs per 1000 patient-days increased from 37.4 to 73.0, and from 41.5 to 129.4 in the hospital and in the ICU, respectively. CONCLUSIONS: The incidence of CDI in the hospital and ICU remained low, despite the increased use of alcohol-based hand rubs and antimicrobials.

An analysis of regulatory T-cell and Th-17 cell dynamics during cytomegalovirus replication in solid organ transplant recipients.

BACKGROUND: CMV-specific T-cells are crucial to control CMV-replication post-transplant. Regulatory T-cells (T-regs) are associated with a tolerant immune state and may contribute to CMV-replication. However, T-cell subsets such as T-regs and IL-17 producing T-cells (Th-17) are not well studied in this context. We explored T-regs and Th-17 frequencies during CMV-replication after transplantation. METHODS: We prospectively evaluated 30 transplant patients with CMV-viremia. We quantified CMV-specific CD4(+) and CD8(+) T-cells, T-regs (CD4(+)CD25(+)FoxP3(+)) and Th-17 frequencies using flow-cytometry and followed patients requiring anti-viral treatment. Two subsets were compared: anti-viral treatment requirement (n = 20) vs. spontaneous clearance of viremia (n = 10). RESULTS: Higher initial CMV-specific CD4(+) T-cells and lower T-regs were observed in patients with spontaneous clearance (p = 0.043; p = 0.021 respectively). Using a ratio of CMV-specific CD4(+) T-cells to T-regs allowed prediction of viral clearance with 80% sensitivity and 90% specificity (p = 0.001). One month after stop of treatment, the same correlation was observed in patients protected from CMV-relapse. The ratio of CMV-specific CD4(+) T-cells to T-regs allowed prediction of relapse with 85% sensitivity and 86% specificity (p = 0.004). Th-17 responses were not correlated with virologic outcomes. CONCLUSIONS: This study provides novel insights into T-regs and Th-17 subpopulations during CMV-replication after transplantation. These preliminary data suggest that measurement of CMV-specific CD4(+) T-cells together with T-regs has value in predicting spontaneous clearance of viremia and relapse.

Morbimortality of pandemic influenza A H1N1 infection in kidney transplant recipients requiring hospitalization: a comparative analysis with nonimmunocompromised patients.

BACKGROUND: Clinical and epidemiological data of pandemic influenza A H1N1 infection in solid-organ transplant recipients have been described, but scarce data compare these outcomes with nonimmunocompromised patients. METHODS: We retrospectively reviewed and compared the clinical presentation, morbidity, and mortality of all kidney transplant (KT) and nonimmunocompromised (non-KT) patients admitted for at least 12 hr with a diagnosis of pandemic influenza A H1N1 infection in a single hospital complex during the 2009 pandemic. RESULTS: There were 22 patients in the KT group (29.3%) and 53 in the non-KT group (70.7%). The prevalence of diabetes was higher in KT group (27.3% vs. 5.7%) while chronic pulmonary disease was more frequent in non-KT group (34% vs. 9.1%). Clinical and radiological presentations and duration of disease were similar between the two groups. The incidence of acute renal failure was higher among KT patients (40.9% vs. 17%). No differences in the rate of intensive care unit admission (22.7% vs. 22.6%) or hospital mortality (9.1% vs. 7.5%) were observed. For the overall population, poor outcome, defined as intensive care unit admission or death, was associated with in-hospital acquisition (relative risk [RR]=42.6 [95% confidence interval {95% CI } 2.2-831.9], P=0.003), symptom onset more than 48 hr (RR=12.17 [95% CI 1.3-117.2], P=0.007), and acute renal failure (RR=11.8 [95% CI 2.9-48.8], P<0.001). Among KT recipients, in-hospital acquisition was the only covariate associate with poor outcome (RR=30.0 [95% CI 2.1-421.1], P=0.004). CONCLUSIONS: No significant differences in morbidity and mortality were observed comparing KT and non-KT patients infected with pandemic H1N1 influenza A virus.

Bloodstream infection after kidney transplantation: epidemiology, microbiology, associated risk factors, and outcome.

BACKGROUND: Bloodstream infection (BSI) is associated with both relevant morbidity and mortality rates after kidney transplantation. METHODS: From January 1, 2000 to January 31, 2006, all episodes of BSI were retrospectively assessed through the review of medical records in two tertiary teaching Hospitals in Sao Paulo, Brazil, where 3308 transplant procedures were performed during this period. Contaminants and polymicrobial infections were excluded. The main objectives of the study were to describe clinical and microbiologic aspects of BSI, as well as risk factors for both BSI and mortality from these infections in kidney transplant patients. RESULTS: BSI was detected in 185 patients, with onset after a median of 235 days after transplantation; 62% occurred after 6 months. The primary source of infection was the urinary tract in 37.8%. The most prevalent pathogen overall was Escherichia coli (30.3%). Risk factors for early acquired BSI (first 6 months after transplantation) were acute rejection, ureteric stent placement, and receiving an organ from a deceased donor. For late BSI (after 6 months), associated risk factors were acute rejection, Charlson Comorbidity Score more than or equal to 3, and receiving an organ from a deceased donor. Risk factors related to 30-day mortality were Acute Physiology and Chronic Health Evaluation II Score more than or equal to 20, shock, and respiratory failure. CONCLUSIONS: BSI is most frequently a consequence of urinary tract infection, with a high prevalence of gram-negative bacilli. Severity of disease was the main determinant of 30-day mortality after BSI, and based on the knowledge of risk factors, some interventions are suggested for reducing the rate of BSI after transplantation.