Proportion Of Positive Blood Cultures Research Articles

Real-World Evaluation of the Impact of Implementation of the Virtuo Blood Culture System in a Tertiary Care Hospital.

The bioMérieux BacT/Alert Virtuo blood culture system used in combination with resin-containing media may enhance the growth of microorganisms. Our objective was to assess the impact of transitioning to the Virtuo system in comparison to the VersaTREK blood culture system at a tertiary care medical center. We retrospectively reviewed all blood cultures performed at a 1,250-bed academic medical center between January and December 2018 (VersaTREK) and January and December 2019 (Virtuo). Blood culture positivity rates and contamination rates were compared before and after Virtuo implementation. Of 101,438 blood cultures performed during the study period, 48,839 (48.1%) were processed preimplementation and 52,599 (51.9%) postimplementation. The blood culture positivity rate increased from 8.1% preimplementation to 11.7% postimplementation (P < 0.001). Staphylococcus aureus was the most frequently isolated species in both time periods and had a higher recovery rate postimplementation (1.5% of all blood cultures obtained preimplementation versus 3.4% postimplementation; P < 0.001). A higher recovery rate in the postimplementation period was also noted for coagulase-negative staphylococci (1.9% preimplementation versus 2.7% postimplementation; P < 0.001), as well as modest but statistically significant changes for Escherichia coli (0.8% versus 1.0%; P < 0.001), Klebsiella pneumoniae (0.4% versus 0.5%; P = 0.005), and Candida albicans. (0.1% versus 0.2%; P = 0.038). The inpatient blood culture contamination rate was higher postimplementation (1.5% preimplementation versus 1.9% postimplementation; P < 0.001). The Virtuo blood culture system was associated with a higher observed proportion of positive blood cultures than the VersaTREK system. Future studies are needed to assess whether an increased rate of positive blood cultures is associated with changes in clinical outcomes.

Experiencia de cinco años en el manejo de endocarditis infecciosa complicada en un centro de referencia nacional

Objetivo. Evaluar las características epidemiológicas, clínicas, ecocardiográficas, microbiológicas y complicaciones de pacientes con endocarditis infecciosa complicada, atendidos en un hospital de referencia peruano.&#x0D; Material y métodos. Se realizó un estudio retrospectivo, descriptivo, de pacientes con diagnóstico de endocarditis infecciosa atendidos en el Instituto Nacional Cardiovascular (INCOR) entre los años 2012 y 2016; se recolectaron sus variables clínicas, imagenológicas y de laboratorio.&#x0D; Resultados. Se incluyeron 59 casos, con predominio del sexo masculino (66,1%) y mediana de edad de 50 años (RIQ 37-62). Las comorbilidades más frecuentes fueron la cardiopatía congénita (42,3%) y la presencia de válvula protésica (23,7%). El signo más frecuente en el examen físico fue la fiebre (69,49%) y el síntoma más común fue la disnea (52,5%). La proporción de hemocultivos positivos fue del 55,9%, y en el 51,5% de estos el patógeno aislado fue Staphylococcus spp. La válvula más afectada fue la aórtica (72,8%) y el hallazgo más frecuente por ecocardiografía fue la presencia de vegetaciones (91,5%). Las complicaciones más comunes fueron el bloqueo auriculoventricular (28,8%) y la falla cardiaca (22%). La mortalidad global intrahospitalaria fue del 20,3%.&#x0D; Conclusión. La endocarditis infecciosa continúa siendo una patología desafiante, nuestros resultados clínico-epidemiológicos son comparables a los encontrados internacionalmente, los que reflejan el cambio que está sufriendo esta patología tanto en su microbiología como en su epidemiologia. Sin embargo, a pesar de los avances en diagnóstico y tratamiento, la mortalidad se mantiene sin cambio.

807 Implementation of an Evidence-based Wound Care Process at a Regional Burn Center Reduces Hospital Acquired Infections

Abstract Introduction Central line associated blood stream infection (CLABSI) rates in burn patients exceeds the national average. The purpose of this study was to determine if implementation of an evidence-based process for wound care and central line management reduce infections. Methods A protocol for central line and wound care was developed in conjunction with another burn center with lower CLABSI rates and a care bundle, based on colorectal surgical literature. The new protocol required hand to elbow washing prior to wound care, separating the dirty and clean steps of the wound care process, changing protective gear when going from dirty to clean and performing the Hospital Acquired Infection (HAI) bundle elements separate from wound care. CLABSI and Ventilator Associated Pneumonia (VAP) rates were then compared with the previous year. Results Following implementation of the new wound care guidelines, the number of CLABSIs declined from 10 in 2017 to 2 in 2018 and 1 so far in 2019 (through August 2019). The median number of CLABSIs per 1000 days was 0 (range of 0 to 11) before the bundle and 0 (range of 0 to 4.2) after implementation of the bundle. Using the Wilcox rank sum test, there was no significant difference (p=0.09) between the CLABSI rate per 1000 device days between the time period before the bundle implementation and after the bundle implementation, however this may be due to the small sample size. Although the CLABSI rate did not show a statistically significant decrease, the proportion of positive blood cultures decreased by 50% after implementation of the bundle. The number of VAPs declined from 8 in 2017 to 6 in 2018 and so far in 2019 no VAPs have been reported (through August 2019). There was no difference in device days between groups. Conclusions Creating a wound care process that clearly defines and separates clean and dirty steps, similar to colorectal surgical bundles in the reduction of Surgical Site Infection, reduced CLABSI and HAI rates in a clinically significant, if not statistically significant way in the Burn Intensive Care Unit. Further study is needed to increase the power of this study to possibly detect statistically significant differences. Applicability of Research to Practice Implementation of an evidence-based, standardized practice for wound care improved infection rates at one regional burn center. It would be beneficial for this process to be replicated at other centers to further test correlation with infection reduction.

Blood Culture Results Before and After Antimicrobial Administration in Patients With Severe Manifestations of Sepsis: A Diagnostic Study.

Administering antimicrobial agents before obtaining blood cultures could potentially decrease time to treatment and improve outcomes, but it is unclear how this strategy affects diagnostic sensitivity. To determine the sensitivity of blood cultures obtained shortly after initiation of antimicrobial therapy in patients with severe manifestations of sepsis. Patient-level, single-group, diagnostic study. (ClinicalTrials.gov: NCT01867905). 7 emergency departments in North America. Adults with severe manifestations of sepsis, including systolic blood pressure less than 90 mm Hg or a serum lactate level of 4 mmol/L or more. Blood cultures were obtained before and within 120 minutes after initiation of antimicrobial treatment. Sensitivity of blood cultures obtained after initiation of antimicrobial therapy. Of 3164 participants screened, 325 were included in the study (mean age, 65.6 years; 62.8% men) and had repeated blood cultures drawn after initiation of antimicrobial therapy (median time, 70 minutes [interquartile range, 50 to 110 minutes]). Preantimicrobial blood cultures were positive for 1 or more microbial pathogens in 102 of 325 (31.4%) patients. Postantimicrobial blood cultures were positive for 1 or more microbial pathogens in 63 of 325 (19.4%) patients. The absolute difference in the proportion of positive blood cultures between pre- and postantimicrobial testing was 12.0% (95% CI, 5.4% to 18.6%; P < 0.001). Sensitivity of postantimicrobial culture was 52.9% (CI, 42.8% to 62.9%). When the results of other microbiological cultures were included, microbial pathogens were found in 69 of 102 (67.6% [CI, 57.7% to 76.6%]) patients. Only a proportion of screened patients were recruited. Among patients with severe manifestations of sepsis, initiation of empirical antimicrobial therapy significantly reduces the sensitivity of blood cultures drawn shortly after treatment initiation. Vancouver Coastal Health, St. Paul's Hospital Foundation Emergency Department Support Fund, the Fonds de recherche Santé-Québec, and the Maricopa Medical Foundation.

Contribution and evolution of blood culture quality indicators

The monitoring of quality indicators, combined with a detailed risk analysis, validates the process of automated blood culture. Here we report the methodology of 5 years monitoring for 5 indicators at the Biology Department of Foch Hospital: volume sampled, proportion of contaminants, proportion of positive blood cultures in each instrument and drawer, epidemiological indicator and proportion of false-positive instrument signals. The results obtained were outside the expected target for the volume sampled and were acceptable for the other indicators. The analysis of these results leads us to discuss the evolution of quality indicators and more particularly the implementation of corrective measures, their periodicity, their relevance as well as the need to refine their results to carry out targeted actions.

Invasive pneumococcal disease in children aged younger than 5 years in India: a surveillance study

Invasive pneumococcal disease continues to be a major cause of morbidity and mortality among children younger than 5 years of age in India. We aimed to provide nationally representative data for the pattern of disease due to Streptococcus pneumoniae, trends in the serotype of invasive pneumococci, and invasive pneumococci antimicrobial resistance patterns, in India. In this prospective hospital-based and retrospective laboratory-based surveillance study, we prospectively enrolled children aged younger than 5 years with suspected or proven invasive pneumococcal disease from 18 hospitals or institutional centres and retrospectively included laboratory-confirmed pneumococcal isolates from ten sentinel laboratories, together representing 11 states in India. Eligibility criteria were fever higher than 38°C without localising symptoms, clinical presentation of suspected meningitis or pneumonia, and evidence of radiographic pneumonia. We cultured blood and other normally sterile body fluids, reconfirmed and serotyped pneumococcal isolates, and established antimicrobial susceptibility using standard study protocols. Between Jan 1, 2011, and June 30, 2015, we enrolled 4377 patients. Among 361 (8%) patients with culture-proven pneumococcal disease, all clinical data were known for 226 (63%); among these patients, 132 (58%) presented with pneumonia, 78 (35%) presented with meningitis, and 16 (7%) had other clinical conditions. 131 (3%) died overall and 29 (8%) patients with invasive pneumococcal disease died. Serotypes 14 (52 [14%] of 361), 1 (49 [14%]), 5 (37 [10%]), and 19F (33 [9%]) were the most common. Penicillin non-susceptibility occurred in isolates from 29 (8%) patients, co-trimoxazole resistance occurred in 239 (66%), erythromycin resistance occurred in 132 (37%), and chloramphenicol resistance occurred in 33 (9%). We found multidrug resistance in 33 (9%) of 361 patients. The proportion of positive blood cultures, number of isolates, geographical representation, and data generated over the 4·5 years of the study are representative of data for most of India. Continued surveillance is warranted as the decision to introduce protein conjugated vaccine in India is made. GlaxoSmithKline India.

Value of routine blood cultures in febrile children presenting to the Emergency Department

Background: A minority of children attend an Emergency may have a serious underlying, systemic infection as a cause of fever. Blood culture remains the gold standard approach to establish the diagnosis and presence of pathogens in a child with suspected, serious bacterial infection. This study describes the proportion of positive blood cultures and correlation with a basic investigation (C-reactive protein, absolute neutrophil count) and clinical presentation in children visiting an emergency. Methods: A retrospective study at Qatar- Al Wakra Hospital- pediatric emergency over one year. Patients younger than or equal to 3 months of age, patients with any form of immune deficiency and patient with no fever were excluded. Results: A total 828 patients (mean age 3.83 years), presenting with fever or a history of fever, 121 (14.6%) admitted to the pediatric ward, 10 (1.2%) admitted to the pediatric intensive care unit, 1 (0.12%) admitted to the pediatric surgery. In total, 20 (2.4%) had positive blood culture, of these 20, 4 (20%) were admitted to the pediatric ward, and 9 (45%) were observed in the hospital less than 24 hrs, 7 (35%) were sent to their home after the investigations. We find no differences in the mean value of ANC (p = 0.934) or CRP (p = 0.572) in patient with positive or negative blood culture. Conclusion: The yield of positive Blood Culture in routine care in an emergency department setting is low, 2.4%. There were no significant differences in associated clinical and laboratory investigations (ANC and CRP) between the groups with positive and negative blood cultures.

The Outcome of Blood Cultures in Febrile Children Presenting at theEmergency Department

Background: An unknown number of children who attend an Emergency Department may have a serious underlying, systemic infection as a cause of their fever. Blood culture (BC) remains the gold standard approach to establish the diagnosis and presence of pathogens in a child with a suspected, serious bacterial infection. This study investigated the proportion of positive blood cultures and the correlation with basic laboratory investigations (Creactive protein, white blood cell count, and absolute neutrophil count), prescription of antibiotics in patients visiting a pediatric emergency department in a primary hospital Methods: A retrospective study in Qatar- Al Wakra Hospital- Pediatric Emergency Department, over one year. Patients younger than 3 months of age and patients with any form of immune deficiency were excluded. Results: A total of 828 patients (median age 3.55 years) with fever (>38°C) or a history of fever (>38°C). 121 (14.6%) were later admitted to the pediatric ward; 10 (1.2%) to the pediatric intensive care unit and 4 (0.4%) to pediatric surgery. In total, positive blood culture was present in 20 (2.42%) children. Of these 20,4 (20%) were admitted to the pediatric ward, and 9 (45%) were observed in the hospital for less than 24 hrs and 7 (35.0%) were sent back home after a clinical assessment and the results of the initial laboratory tests. The referrals of patients with negative blood culture were similar. There were no differences in the mean value of absolute neutrophil counts or CRP measurement between patients exhibiting positive or negative BC. Conclusion: The incidence of a positive BC in routine care of febrile patients in an emergency department setting is low, 2.42%. There were no significant differences in associated clinical laboratory results (WBC, CRP or ANC) or admission to hospital wards between the groups with positive or negative BC.

Characteristics of vertebral osteomyelitis after liver transplantation

We performed a retrospective single-centre 1:3 case–control study to investigate the characteristics of vertebral osteomyelitis (VO) occurring in orthotopic liver transplant (OLT) recipients between 2000 and 2012. Nine cases were identified in 752 OLT recipients (1.2%), with a median time from OLT to VO of 12 weeks. In comparison with 27 VO not occurring in OLT patients (controls), VO occurring in OLT recipients was characterized by decreased levels of inflammation biomarkers (average C-reactive protein 65.1 mg·L−1 vs. 167 mg·L−1, p 0.02; average white blood cell count 4.8 × 109·L−1 vs. 12.9 × 109·L−1, p < 0.001), higher rate of fungal infections (3/9 vs. 0/27, p 0.01), lower rate of bacterial infections (3/9 vs. 25/27, p 0.001) and decreased proportion of positive blood cultures (1/9 vs. 16/27, p 0.02) despite a trend towards higher rate of multifocal infection. Microbiologic outcomes were similar between the two groups. Overall, VO in OLT patients was more difficult to diagnose as a result of altered inflammation response and specific microbial epidemiology of causal microorganisms.

Salmonella blood stream infections in a tertiary care setting in Ghana.

BackgroundDespite the clinical significance of Salmonella infections, surveillance data worldwide remains limited and is more so exemplified by the lack of reports from Africa especially in eastern, central and western Africa. This study reports on Salmonella serotypes as significant causes of blood stream infections (BSI) and multidrug antibiotic resistance at Korle-Bu Teaching Hospital in Accra, Ghana.MethodsAntibiogram patterns, seasonal variations in disease incidence and predisposing factors for infection with Salmonella serotypes were analyzed retrospectively over a 4-year period from January 2010 to December 2013. Blood cultures were processed with BACTEC 9240 blood culture system. Speciation was done with BBL Crystal Enteric/Nonfermenter identification system®, and with slide agglutination using specific antisera. Antimicrobial susceptibility testing was carried out by the Kirby-Bauer disc diffusion method according to Clinical and Laboratory Standard Institute guidelines.ResultsWe report a 6.5% (n = 181/2768) prevalence of Salmonella bacteraemia at the Korle-Bu Teaching Hospital; with a preponderance of non-typhoidal salmonellae (NTS) over typhoidal salmonella (TS) (n = 115/181, 63.5% versus n = 66/181, 36.5%; P-value <0.002). Children under 5 years bore the brunt of the disease (n = 93/174, 53.4%). Resistance to ciprofloxacin (n = 1/127, 0.7%), amikacin (n = 3/81, 3.7%), and cefotaxime (n = 6/99, 6.1%) remained low, despite high levels of multidrug resistant Salmonella phenotypes (n = 81/181, 44.2%). In multivariate analysis, and among patients with Salmonella BSI, those < 1 year old had reduced risk of non-typhoidal infections [Odds ratio, 0.51; 95% confidence interval (95% CI), 0.16-0.92, P-value 0.021]. Similarly, patients with cefuroxime resistant strans were at increased risk of having multidrug resistant Salmonella BSI (OR, 8.97; 95% CI, 3.62-24.15; P-value, 0.001).ConclusionsSalmonellae, predominantly NTS, account for a reasonable low proportion of positive blood cultures in our tertiary care setting; but with significant multidrug resistant phenotypes and low ciprofloxacin and cefotaxime resistance.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-014-0697-7) contains supplementary material, which is available to authorized users.

Epidemiology and microbiology of sepsis in mainland China in the first decade of the 21st century

This study describes the epidemiological and microbiological profile of sepsis during the first decade of the 21(st) century in mainland China. The sepsis-related mortality data from 2003 and 2007 were retrieved from the China Health Statistical Yearbook. The microbiology data were retrieved and selected from a literature search of the China Academic Journal Database between 2001 and 2009. A meta-analysis was performed to synthesize the available data on the proportion of positive blood cultures in septic patients and the microorganism distribution. The sepsis mortality in small and medium-sized cities and rural areas declined obviously over time. The mortality of the subpopulations aged 1-54 years tended to be lower than the national averages. In contrast, the sepsis mortality among neonates and the elderly (≥75 years) was obviously higher than national averages. While the mortality in the elderly declined between 2003 and 2007, the neonate sepsis mortality increased dramatically, especially among male neonates. The overall positivity of blood culture were 17.0%, 13.3% and 10.6% among neonatal, pediatric and adult patients with suspected sepsis, respectively; this proportion tended to decrease over time. Among identified microorganisms, the proportions of Gram (+) and (-) bacteria were similar (47.2% vs. 44.5%) among adult patients, while Gram (+) bacteria was predominant among neonatal (77.4%) and pediatric (73.2%) patients and increased in prevalence over time. The positivity of blood cultures and proportions of microorganisms varied by geographical region across mainland China. Sepsis with fungus was rare but was more prevalent in adult sepsis patients (6.4%) than in neonatal patients (0.8%). The difference in sepsis mortality between urban and rural areas decreased over time. Males, the elderly, and neonates were found to be high-risk subpopulations. Gram (+) bacteria were predominant among neonates with sepsis, but the proportion of patients with Gram (+) or Gram (-) bacteria was similar among adults with sepsis.

Bacteremia in Children With Sickle Hemoglobinopathies

Bacteremia is one of the most feared infectious complications of sickle cell disease, and it is associated with a high mortality rate in children. The objective of our study was to investigate the proportion of bacteremia among febrile children with sickle hemoglobinopathies and the clinical factors associated with bacteremia. Clinical and microbiological data from children with sickle hemoglobinopathies being followed up at the Pediatric Hematology Clinic at the University of Rochester Medical Center in Rochester, New York, were retrospectively analyzed. The data were collected from medical records covering the time period of June 1997 to December 2006, which included the periods before and after the introduction of routine heptavalent pneumococcal conjugate vaccine usage. Proportions of positive blood cultures among febrile children, the types of organisms causing bacteremia, and clinical and sociodemographic factors were analyzed by χ and t tests as appropriate. The overall proportion of positive blood cultures was 3.8%; 1% was considered to yield true pathogens. Pneumococcal bacteremia decreased from 0.7% in the pre-pneumococcal conjugate vaccine-7 era to 0.2% in the post-pneumococcal conjugate vaccine-7 era; however, the difference was not statistically significant. Pathogens other than pneumococcus were responsible for most bacteremic episodes. No clinical or social factors were found to have statistically significant associations with positive blood cultures. Approximately 1% of children with sickle hemoglobinopathies with fever have bacteremia despite current penicillin prophylaxis and pneumococcal immunization, although most episodes are due to nonpneumococcal pathogens. Prompt evaluation of such febrile children with sickle hemoglobinopathies remains warranted.

Typhoid Fever among Children, Ghana

Typhoid Fever among Children, Ghana

Outcomes in patients with an emergency department diagnosis of fever of unknown origin

To describe the outcomes in patients given an ED diagnosis of fever of unknown origin (FUO). A retrospective analysis of ED records linked to hospital morbidity, mortality and microbiology records of patients presenting to Western Australia's teaching hospitals from July 2000 to July 2003. There were 3218 presentations diagnosed with FUO, 2049 (63.7%) children (median age 1.8 years) and 1169 (36.3%) adults (median age 56.0 years). FUO accounted for 0.3% of adult and 1.5% of paediatric ED presentations. Overall, 1997 (62.1%, 95% confidence interval 60.4-63.8%) were admitted (82% adults vs 50.7% children; P < 0.001). Adults had a longer median length of stay than children (4 days vs 2 days; P < 0.001) and a higher proportion of positive blood cultures (admissions 15.1%vs 4.9%; P < 0.001) commonly with Escherichia coli. Streptococcus pneumoniae was the most common organism isolated from children. Of 3053 FUO index presentations, 338 (11.1%, 95% confidence interval 10.0-12.2%) re-presented. Children were more likely to re-present than adults (13.5% of 1959 vs 6.8% of 1094; P < 0.001). Fever of unknown origin is diagnosed less frequently in adults than in children. Adult patients are more likely to be admitted, have longer lengths of stay and have positive blood cultures. Although FUO is diagnosed infrequently in the ED, blood cultures remain useful in the evaluation of unexplained fever, particularly in adults as age increases.

Bacteraemia following debanding and gold chain adjustment

The purpose of this research was to estimate the prevalence, intensity, and nature of bacteraemia following deband and gold chain adjustment. Forty-nine children, 25 males and 24 females, mean age 15.4 years, attending the Orthodontic Department at the Eastman Dental Hospital were recruited. A cannula was inserted into either the left or the right antecubital fossa using an aseptic technique. A 6 ml sample of blood was taken before treatment and another 6 ml, 30 seconds after either upper deband (n = 42) or gold chain adjustment (n = 7). McNewmar's test was used to determine differences in the proportion of positive blood cultures and Wilcoxon matched pairs test to compare continuous variables. There was no significant difference (P > 0.05) in the prevalence of bacteraemia between baseline (eight, 19 per cent) and following upper deband (11, 26 per cent) or between baseline (four, 57 per cent) and gold chain adjustment (four, 57 per cent). There was also no significant difference (P > 0.05) in the intensity of the anaerobic bacteraemia between baseline and following deband or gold chain adjustment. Although the number of subjects undergoing gold chain adjustment was small, the findings demonstrate that neither upper debanding nor gold chain adjustment is associated with a significant bacteraemia.

A 62-month retrospective epidemiological survey of anaerobic bacteraemia in a university hospital

The incidence of anaerobic bacteraemia was studied retrospectively over 62 months at Mont-Godinne University Hospital, Yvoir, Belgium. The distribution of organisms, clinical presentations, choice of antimicrobial therapy and clinical outcome were analysed. The proportion of positive blood cultures yielding obligate anaerobes was 3.3%. The overall incidence of clinically significant anaerobic bacteraemia was 0.51 cases/1,000 patient admissions (0.61 cases/10,000 hospital-days), but was significantly higher in patients with active haematological malignancies than in other groups (5.97/10,000 vs. 0.33/10,000 hospital-days; p < 0.05). The Bacteroides fragilis group accounted for 61% of isolates, followed by Clostridium spp. (12.2%), Peptostreptococcus spp. and Leptotrichia spp. (7.3% each) and Fusobacterium spp. (4.8%). The most common risk-factors were gastrointestinal surgery (49%) and active haematological malignancies with chemotherapy and/or bone marrow graft (47%). One or more co-morbidities were present in 30 (77%) of 39 patients. The lower gastrointestinal tract (41%) and the oropharynx (23%) were the two most frequent presumed or proven sources for bacteraemia, with the origin remaining unknown in eight (20.5%) cases. The overall mortality rate (evaluated 7 days after the occurrence of bacteraemia) was 13%. Fatal outcome correlated with the severity of underlying diseases and the immunosuppressed status of the patients rather than with the causative pathogen or the effectiveness of antimicrobial therapy. Likewise, there was no difference in the mortality rate between patients with monomicrobial and polymicrobial bacteraemia. Overall, the data re-emphasise the importance of anaerobic bacteraemia, especially in patients with haematological malignancies.

225 Prognostic value of KIT mutation in localized gastrointestinal stromal tumors (GIST)

The incidence of anaerobic bacteraemia was studied retrospectively over 62 months at Mont-Godinne University Hospital, Yvoir, Belgium. The distribution of organisms, clinical presentations, choice of antimicrobial therapy and clinical outcome were analysed. The proportion of positive blood cultures yielding obligate anaerobes was 3.3%. The overall incidence of clinically significant anaerobic bacteraemia was 0.51 cases/1000 patient admissions (0.61 cases/10 000 hospital-days), but was significantly higher in patients with active haematological malignancies than in other groups (5.97/10 000 vs. 0.33/10 000 hospital-days; p < 0.05). The Bacteroides fragilis group accounted for 61% of isolates, followed by Clostridium spp. (12.2%), Peptostreptococcus spp. and Leptotrichia spp. (7.3% each) and Fusobacterium spp. (4.8%). The most common risk-factors were gastrointestinal surgery (49%) and activehaematological malignancies with chemotherapy and/or bone marrow graft (47%). One or more co-morbidities were present in 30 (77%) of 39 patients. The lower gastrointestinal tract (41%) and the oropharynx (23%) were the two most frequent presumed or proven sources for bacteraemia, with the origin remaining unknown in eight (20.5%) cases. The overall mortality rate (evaluated 7 days after the occurrence of bacteraemia) was 13%. Fatal outcome correlated with the severity of underlying diseases and the immunosuppressed status of the patients rather than with the causative pathogen or the effectiveness of antimicrobial therapy. Likewise, there was no difference in the mortality rate between patients with monomicrobial and polymicrobial bacteraemia. Overall, the data re-emphasise the importance of anaerobic bacteraemia, especially in patients with haematological malignancies.

Utility of blood cultures in community-acquired pneumonia requiring hospitalization: influence of antibiotic treatment before admission

It has been previously shown that antibiotics given before hospitalization significantly reduce the proportion of positive blood cultures in community-acquired pneumonia (CAP). The aim of this prospective study was to compare the utility and cost-benefits of blood cultures in patients, hospitalized for moderate CAP, who had or had not received antibiotic therapy prior to admission. During 1 year, 53 patients were included and separated into two groups: group 1 patients had not received antibiotic treatment prior to admission ( n=30), whereas group 2 patients had been treated with antibiotics ( n=23). Within the first 48 hours, a set of blood cultures was collected if the body temperature was higher than 38·5°C or in the case of shaking chills. A total of 136 blood cultures was collected; 74 in group 1 and 62 in group 2. Bacteraemia was significantly more frequent in group 1 than in group 2, 5 30 patients vs. 0 23 , respectively ( P<0·05). The cost of negative blood cultures was valued at 13,939.2 FF in group 1 and 13,164.8 FF in group 2, respectively 464.6 ± 244.3 FF and 569.3 ± 233.4 FF per patient (n.s.). Moreover, blood cultures were the method of diagnosis in only one of the five patients with bacteraemia and in no case did a positive blood-culture result influence the initial therapeutic regime. Thus, our results suggest a reduced clinical utility and cost-benefit of blood cultures in patients hospitalized for moderate CAP who have received an antibiotic treatment prior to admission.

Anaerobic bacteremia: Incidence, patient characteristics, and clinical significance

purpose: In the 1970s, blood culture for obligate anaerobic bacteria became routine in most United States hospitals. Since then, various authorities have reported isolation of obligate anaerobes in 5% to 25% of blood cultures. Our experience suggests a much lower frequency, therefore, we retrospectively assessed the occurrence and significance of these cultures at our institutions. patients and methods: Sixty-six patients at the University of Michigan Hospitals (UMH) and nine patients at the Ann Arbor Veteran's Administration Medical Center (AAVAMC) had one or more blood cultures positive for an obligate anaerobe between July 1, 1987, and December 31, 1988. Their medical records were reviewed retrospectively. results: The proportion of positive blood cultures yielding obligate anaerobes was 3.2% at the UMH and 1.8% at the AAVAMC. The incidences of clinically significant anaerobic bacteremia at the two hospitals were 0.68 and 0.54 cases per 1,000 patient admissions. Among the 40 patients from whom significant isolates were obtained, 15 (38%) had a fatal outcome. Bacteroides and Clostridium species accounted for 90% of the isolates and all of the fatal cases. The source for anaerobic bacteremia was usually obvious; 30 of the 40 patients were given empiric antibiotic therapy for anaerobes. The gastrointestinal tract was the source in two thirds of the cases and was clearly implicated as the source of 80% of the fatal bacteremias. conclusions: The frequency of anaerobic bacteremia in our hospitals is much lower than was suggested in several large studies during the 1970s, probably reflecting a real decline in the incidence. The clinical features of our cases are similar to those of previous studies, and the mortality is still high despite the use of antibiotics effective against anaerobes. Since most patients were thought to have anaerobic infections at the time that cultures were obtained, they were usually treated empirically. Subsequent blood cultures positive for anaerobes infrequently influenced clinical management.

Enteric fever in Birmingham: Clinical features, laboratory investigation and comparison of treatment with pivmecillinam and co-trimoxazole

Summary The features of enteric fever have been assessed in 29 patients, predominantly from the Indian sub-continent. The disease presented as a non-specific febrile illness with an insidious, onset. Fever was almost invariable (96 per cent), but relative bradycardia was uncommon (14 per cent) and gastro-intestinal features were absent in over half of the patients. Splenomegaly (34 per cent) and rose spots (10 per cent) were also infrequent. Fever in Asian immigrants, associated with cough in 48 per cent, and with sweating (69 per cent) and rigors (30 per cent) in others may have accounted for the empirical prescription of antibiotics (40 per cent) and antimalarials (30 per cent) by the family practitioner prior to hospital admission. This variable presentation demands a high index of suspicion in febrile recent immigrants and stresses the need for laboratory investigation. The criteria for inclusion have resulted in a high proportion of positive blood cultures in the present series, but stool cultures were also positive in 96 per cent, even in patients in the first week of illness. The Widal reaction was rarely diagnostic but the relevant somatic (0) antibody titres were 1/100 or greater in 83 per cent on admission. Mild anaemia was common but leucopenia was found in only 17 per cent of patients. Twenty-six of the 29 patients were treated with pivmecillinam, 13 receiving parenteral mecillinam initially. The results have been compared with a re-analysis of a previous series of 21 patients treated with co-trimoxazole. Both agents were well tolerated and unwanted effects were few. Eighty-eight per cent of patients responded satisfactorily to pivmecillinam compared with 86 per cent of those receiving co-trimoxazole. Overall relapse rates were also similar (pivmecillinam 12 per cent; co-trimoxazole 14 per cent) but unlike co-trimoxazole, relapses on pivmecillinam occurred during treatment. Stool clearance immediately following pivmecillinam (13 per cent) was markedly lower than with co-trimoxazole (72 per cent) but clearance rates at the time of discharge were similar (co-trimoxazole 83 per cent; pivmecillinam 69 per cent) and only one patient in each group became a long term carrier.