Changes in the incidence and etiological patterns of bacteremia associated with acute leukemia over a 25-year period

During the 25-year period from 1972-1996, 360 episodes of bacteremia occurred in 248 (45%) of a total of 548 patients with acute leukemia on our hematology ward, with the rate of occurrence remaining almost unchanged. Patients with acute nonlymphocytic leukemia, however, had a significant decrease in the incidence of bacteremia during the last 5-year period. Gram-negative bacilli decreased in relative frequency from 64% for the first 15-year period to 40% for the last 5-year period, whereas gram-positive cocci increased from 24% to 51%. Escherichia coli and Enterobacter cloacae somewhat decreased in frequency, whereas coagulase-negative staphylococci and streptococci had considerable increases. In contrast, Pseudomonas aeruginosa was isolated at a relatively constant frequency, forming one of the top two pathogens throughout the study period. Despite the shift toward gram-positive cocci, therefore, P. aeruginosa remains a key organism in considering the initial empiric antibiotic regimen and infection prevention during neutropenia.     

Prevention of acute allograft rejection by antibody targeting of TIRC7, a novel T cell membrane protein

The in vitro activity of trovafloxacin, a new fluoroquinolone, was compared with that of ciprofloxacin, ofloxacin, fleroxacin, ceftazidime, piperacillin/tazobactam, and meropenem against 613 consecutively recovered blood isolates from recently hospitalized patients. Susceptibility testing was performed by agar dilution according to NCCLS guidelines. Test strains included Acinetobacter species (n = 26), Escherichia coli (n = 137), Enterobacter species (n = 27), Klebsiella species (n = 42), Proteus species (n = 16), Pseudomonas aeruginosa (n = 28), Serratia marcescens (n = 13), Stenotrophomonas maltophilia (n = 7), enterococci (n = 54), coagulase-negative staphylococci (n = 38), Staphylococcus aureus (n = 137), Streptococcus pneumoniae (n = 27), beta-haemolytic streptococci (n = 13), and viridans group streptococci (n = 48). The overall respective MICs at which 50% and 90% of isolates were inhibited (MIC50s and MIC90s) were as follows: trovafloxacin, 0.06 and 1 mg/l; ciprofloxacin, 0.25 and 4 mg/l; ofloxacin, 0.5 and 4 mg/l; fleroxacin, 0.5 and 16 mg/l; ceftazidime, 2 and 128 mg/l; piperacillin/tazobactam, 2 and 8 mg/l; meropenem, 0.06 and 4 mg/l. For the quinolones, the rank order of activity against gram-negative microorganisms was ciprofloxacin > trovafloxacin > ofloxacin = fleroxacin, against gram-positive organisms, trovafloxacin > ciprofloxacin = ofloxacin > fleroxacin. Data obtained showed the similar activity of trovafloxacin and ciprofloxacin against gram-negative pathogens and the superior activity of trovafloxacin against gram-positive bacteria thus making it a potential candidate for the empiric treatment of patients with suspected bacteremia and sepsis.     

In vitro activity of RU 64004, a new ketolide antibiotic, against gram-positive bacteria

The comparative in vitro activity of RU 64004 (also known as HMR 3004), a new ketolide antibiotic, was tested by agar dilution against approximately 500 gram-positive organisms, including multiply resistant enterococci, streptococci, and staphylococci. All streptococci were inhibited by < or = 1 microg of RU 64004 per ml. The ketolide was more potent than other macrolides against erythromycin A-susceptible staphylococci and was generally more potent than clindamycin against erythromycin A-resistant strains susceptible to this agent. Clindamycin-resistant staphylococci (MIC, > 128 microg/ml) proved resistant to the ketolide, but some erythromycin A- and clindamycin-resistant enterococci remained susceptible to RU 64004.     

Infective endocarditis at a large community teaching hospital, 1980-1990. A review of 210 episodes

We studied 210 episodes of infective endocarditis in 204 patients. The prevalence of this disease in our series ranged from 0.32 to 1.30 (mean, 0.75) episodes per 1000 admissions per year. There were 115 male and 89 female patients, whose ages ranged from newborn to 91 years (median, 60-70). One-hundred-and-forty-eight episodes involved host valves and another 33 episodes occurred in intravenous drug users. There were 2 episodes of early and 27 episodes of late prosthetic valve endocarditis. Staphylococcus aureus accounted for 99 episodes (47.1%), alpha-hemolytic streptococci for 29 episodes (13.8%), enterococci for 11 episodes (5.2%), culture-negative endocarditis for 11 episodes (5.2%), and other organisms for 60 episodes (28.6%). Severe back pain was the chief complaint in 15 patients. 2-D echocardiography was performed in 164 episodes, results in 67 (40.9%) of which were positive. Valve surgery was performed in 29 episodes (23 host valves and 6 prosthetic valves). The overall mortality was 21.4%. Autopsy was performed in 22 of the 45 patients who died (48.9%). The mortality rate increased with age, (10.1% and 31.5% for patients < 60 years old and 60 years or older, respectively (p < 0.001).     

Changing patterns of self-poisoning in a UK health district

Details of admissions to a dedicated district poisons treatment unit in South Glamorgan were analysed to assess changes in self-poisoning patterns between 1987-1988 and 1992-1993. Self-poisoning rates increased in both men and women, with male rates showing a relatively larger increase, resulting in a fall in female to male ratio for person-based rates from 1.33:1 to 1.13:1. The highest age-specific rates in both period were found in 15-19-year-old females. Paracetamol was the most commonly ingested poison in 1992-1993, with 43.4% of episodes involving its use, compared with 31.3% of episodes in 1987-88. Antidepressant involvement in self-poisoning also increased from 11.3% of episodes in 1987-1988 to 17.6% of episodes in 1992-1993. Repetition of self-poisoning was relatively common, with 18% of admissions per year in 1992-1993 representing repeats. Although hospital admission increased in this health district over the study periods, this was not reflected in an increase in in-patient all-cause mortality, which was only 0.5% in 1987-1988 and 0.1% in 1992-1993.     

Injury prevention strategies to promote helmet use decrease severe head injuries at a level I trauma center

Head injuries (HIs) remain a major contributor to trauma mortality, with many deaths occurring despite optimal use of available therapy. Injury prevention is vital to decrease the impact of HIs. Helmets can decrease the severity of HIs in both bicycle crashes (BCs) and motorcycle crashes (MCCs). A major challenge is to increase helmet use. A mandatory motorcycle helmet law in 1990 and information campaigns aimed at bicyclists have increased the percentage of riders wearing helmets in Washington State. We hypothesized that there would be an associated decrease in the proportion of severe HIs in BC and MCC admissions to the state's only level I trauma center. We analyzed injury region and outcomes for all 466 BC and 992 MCC instate admissions from 1986 to 1993. For BCs, the proportion of severe HIs (Abbreviated Injury Scale score of 4 or 5) declined from 29% in 1986 to 11% in 1993 (p = 0.02). BC trends paralleled helmet use in observations on 8,860 bicycle riders in the area, in which the percentage of helmeted riders rose from 5% in 1987 to 62% in 1993 (p < 0.001). For MCCs, severe HIs declined from 20% before passage of the helmet law to 9% afterward (p < 0.001). Mortality decreased for BCs and MCCs (p < 0.05), and length of hospital stay and ICU stay decreased for BCs (p < 0.05). The percentage of helmeted BC admissions rose from 0% to 32% (p = 0.009), and helmeted MCC admissions rose from 41% to 80% (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of sodium-hydrogen exchange inhibition on functional and metabolic impairment produced by oxidative stress in the isolated rat heart

PURPOSE: To determine the frequency, associate factors and clinical features of bacteremia in patients undergoing endoscopic retrograde cholangiopancreatography (ERCP), with or without therapeutic procedures. METHODS: Prospectively, 42 consecutives patients undergoing 46 endoscopic retrograde cholangiopancreatographies (ERCPs) from August to December 1994 were analyzed. The search for bacteremia was done by drawing 6 blood samples for cultures from peripheral blood. Two blood samples were collected before the ERCP and 4 of them after. The bottles used for cultures were Bactec bottles. The bottles were incubated in the Bactec 9240 system, and eventual bacteria detect were identificated by the manual routine of the laboratory and also with the autoScan/Microscan system. RESULTS: All blood cultures obtained before the ERCPs were negatives. Bacteremia were detected after 7 endoscopic procedures. In two episodes of bacteremia, the microorganism identified (Staphylococcus epidermidis) was considered to be a contaminant. The other 5 episodes of bacteremia were considered true bacteremia (frequency- 10.9%), and the microorganisms identified were: Streptococcus viridans, Corynebacterium sp., Enterobacter cloacae, Klebsiello oxytoca and Enterobacter aerogenes. This episodes were more frequent in the blood cultures obtained immediately after the ERCPs (p < 0.05), and occurred exclusively in the patients who were not receiving antibiotics (p = 0.0192). Clinical manifestation of the episodes of bacteremia were not detected. CONCLUSION: The episodes of bacteremia occurred exclusively in the patients who were not receiving antibiotics, were transient and completely no symptomatic.     

Bacteremic pneumonia in neutropenic patients with cancer: causes, empirical antibiotic therapy, and outcome

BACKGROUND: Bacteremic pneumonia is a major cause of death among neutropenic patients with cancer. METHODS: We analyzed the causes, empirical antibiotic therapy, and outcome of 40 consecutive cases of bacteremic pneumonia identified among 408 episodes of bacteremia in adult neutropenic patients with cancer, prospectively documented from 1986 to 1995. RESULTS: The most frequent causative organisms were Pseudomonas aeruginosa (17 cases), Streptococcus pneumoniae (12 cases), Escherichia coli (5 cases), and Streptococcus mitis (3 cases). Overall, P. aeruginosa and S. pneumoniae caused 72.5% of all episodes of bacteremic pneumonia, compared with 11.4% of bacteremic episodes from other sources (P< .001). Thirty patients received ceftazidime and 10 patients received imipenem as the beta-lactam component of the initial empirical treatment. All strains of P. aeruginosa were susceptible to both agents. Forty-seven percent of streptococcal strains were penicillin resistant and showed a decreased susceptibility to ceftazidime (minimum inhibitory concentration ranged from 1 to 64 microg/mL). Five patients (12.5%) were considered to have received inappropriate empirical antibiotic therapy. Attributable mortality in patients with bacteremic pneumonia was higher than in patients with bacteremia from other sources; 22 (55%) of the 40 patients with bacteremic pneumonia died, whereas 39 (10.6%) of the 368 patients with bacteremia from other sources died (P<.001). CONCLUSIONS: Our data suggest that bacteremic pneumonia in neutropenic cancer patients is associated with a poor outcome and that empirical antibiotic therapy for neutropenic patients with pneumonia should include agents active against both P. aeruginosa and cephalosporin-resistant streptococci.     

Predation of livestock ticks by chickens as a tick-control method in a resource-poor urban environment

The increasing prevalence of streptococci as causes of potentially fatal nosocomial bacteremia requires that antimicrobial agents used for empiric therapy in hospitalized patients include both pneumococci and viridans group streptococci as well as beta-hemolytic streptococci in their activity profile. In this study, the in vitro activity of cefepime, a new fourth-generation cephalosporin, was compared with other cephalosporins versus 197 nosocomial blood stream isolates of streptococci (20 Streptococcus pneumoniae, 104 viridans group, and 73 beta-hemolytic) isolated from patients at more than 30 medial centers from 1995 to 1997. Additional agents tested included penicillin, erythromycin, and vancomycin. Overall, cefepime inhibited 83% of the isolates at concentrations < or = 0.5 microgram/mL and 100% at < or = 8 micrograms/mL. By comparison, ceftazidime inhibited 35 and 88% of isolates at the same concentrations. Cefepime was approximately eightfold more potent than ceftazidime against S. pneumoniae, viridans group streptococci, and beta-hemolytic streptococci. Among the 42 isolates with penicillin MICs > 0.12 microgram/mL, 100% were inhibited by cefepime and only 48% by ceftazidime at < or = 8 micrograms/mL. The rank order of activity for all six agents against the 197 isolates was vancomycin > ceftriaxone > cefepime > penicillin > erythromycin > ceftazidime. Based on the results of the present study, cefepime and ceftriaxone were the superior cephalosporins in potency and spectrum for empiric coverage of patients at risk for streptococcal blood stream infections.     

Increased prevalence of penicillin-resistant viridans group streptococci in Japanese children with upper respiratory infection treated by beta-lactam agents and in those with oncohematologic diseases

BACKGROUND: Viridans group streptococci, especially penicillin-resistant strains, have been emerging as pathogens of bacteremia in neutropenic patients with hematologic malignancies. OBJECTIVES: To survey the penicillin susceptibilities of viridans group streptococci in Japanese children with and without oncohematologic diseases and to evaluate the effect of the short term administration of beta-lactam agents on the antibiotic susceptibility. METHODS: We tested 113 isolates of viridans group streptococci by the microdilution method for the minimal inhibitory concentrations (MICs) to 10 antibiotics. We isolated 40 isolates from the throats of children with an upper respiratory infection (URI) before beta-lactam antibiotic treatment, 32 isolates after the treatment, 33 isolates in hospitalized children with oncohematologic diseases and 8 isolates from blood. RESULTS: Twenty-five isolates (62.5%) from the children with URI before treatment were penicillin-intermediate or -high level resistant (MIC > or = 0.25 microg/ml). The prevalence of those isolates after antibiotic treatment (87.5%) was significantly increased compared with that before treatment (P = 0.03). The prevalences of the penicillin-high level resistant isolates (MIC > or = 4 microg/ml) in the children with oncohematologic diseases (39.4%) and in the isolates from blood (62.5%) were significantly higher than that in the children with URI before treatment (12.5%) (P < 0.01). Decreased susceptibilities to other beta-lactam agents were observed in the penicillin-high level resistant strains. CONCLUSIONS: The high prevalence of penicillin-intermediate or -high level resistant viridans group streptococci in healthy Japanese children was documented. The administration of beta-lactam agents decreased the prevalence of penicillin-susceptible isolates in the children with URI. High prevalences of penicillin-high level resistant isolates were observed in the oncohematologic patients and in the isolates from blood.     

The impact of mucositis on alpha-hemolytic streptococcal infection in patients undergoing autologous bone marrow transplantation for hematologic malignancies

BACKGROUND: Antibacterial prophylaxis with quinolone antibiotics has resulted in an increase in streptococcal infections among bone marrow transplantation (BMT) recipients with myelosuppression. Oral ulceration (mucositis), which frequently occurs as a consequence of chemotherapy, has been implicated as a significant portal of entry for streptococci. The objectives of this study were to confirm the correlation between mucositis and streptococcal bacteremia, determine the risk associated with this correlation, and evaluate the impact of mucositis and streptococcal bacteremia on hospital course and costs associated with autologous BMT. METHODS: This was a retrospective, case-control study in which the charts of autologous BMT recipients treated for hematologic malignancies between 1990 and 1996 were reviewed. Twenty-four patients were identified who met the criteria of autologous BMT; their blood cultures confirmed (x2) alpha-hemolytic streptococcal sepsis. A control group of 45 without positive cultures was matched by gender, age, diagnosis, and treatment to the study group. RESULTS: The results confirm that ulcerative mucositis is a significant risk factor for alpha-hemolytic streptococcal bacteremia among autologous BMT patients. Of the 24 patients with bacteremia, 15 of 24 (62%) had ulcerative mucositis, compared with 16 of 45 (36%) of patients in the control population (P < 0.05). Patients with ulcerative mucositis were found to be three times as likely to develop alpha-hemolytic streptococcal bacteremia as those without ulcerative mucositis (odds ratio=3.02). Both independently and as a cofactor associated with bacteremia, mucositis adversely affected the length of hospital stay (LOS). Of all the patients studied, those with oral ulcerations had a LOS of 34 days, compared with 29 days for patients without oral ulcerations (P < 0.05). Of patients in the study group, those with oral ulcerations stayed in the hospital 6 days longer than patients without oral ulcerations (40 days vs. 34 days, P < 0.05). CONCLUSIONS: Oral ulcerative mucositis is a significant, common, and important risk factor for alpha-hemolytic streptococcal bacteremia in BMT recipients with myelosuppression; it results in longer hospital stay and increased costs.     

Characteristic difference in gastrointestinal excretion of clarithromycin and roxithromycin

BACKGROUND: This paper describes trends in hospital activity, hospital admissions, and treatments for colorectal cancer on residents of the South Thames regions (population 8 million) between 1989-1993 against the background of the Calman Report on the future of cancer services in England and Wales. METHODS: The analyses are derived from UK hospital data, which are collected as finished consultant episodes (FCEs). These are defined as episodes "where a patient has completed a period of care under a consultant and is either transferred to another consultant or is discharged." Probability matching was used to derive patient-based records, matching FCEs to admissions. A total of 18,542 South Thames residents aged 40-99 were admitted for colorectal cancer between 1 January 1989 and 31 December 1993. Time trends were analysed for procedures, FCEs, admissions, and patient numbers by admission type (ordinary admissions and day case admissions). RESULTS: Between 1989 and 1993 inclusive colorectal cancer admissions doubled (98% increase p (trend) < 0.0001). These admissions were a result of a 6.4-fold increase in day case admissions and a 41% increase in ordinary admissions. The proportion of patients having a day case admission rose from 9% in 1989 to 18% in 1993 (p < 0.0001). Overall, 2894 (16%) patients had a day case admission; 1894 of these (65%) were also admitted as ordinary admissions. The number of FCEs and admissions per patient rose from 1.37 and 1.28 respectively in 1989 to 2.09 and 1.99 respectively in 1993. FCEs were between 5% and 8% higher than admissions over the five years. The number of ordinary (that is, overnight) inpatient admissions per patient rose from 1.23 to 1.41 over the five year period and day case inpatient admissions from 1.25 to 3.45. Chemotherapy accounted for 50% of the rise in day case admissions; colonoscopy and sigmoidoscopy were associated with a further 18%. Fourteen per cent of the increase in ordinary admissions was also because of chemotherapy. CONCLUSION: The monitoring of site specific trends in admission, treatments, and procedures on a population basis should be a core requirement of health authorities to inform needs assessment, resource allocation, and service planning. The rise in admissions and chemotherapy treatments have implications for drug costs, laboratory and inpatient services, monitoring, and clinical audit.     

Hospital practices influence the pattern of infective endocarditis

OBJECTIVE: To identify factors contributing to infective endocarditis at a major teaching hospital. METHODS: Retrospective review of clinical records of patients diagnosed with endocarditis by standard case definitions with respect to causative organisms, clinical features and outcome. RESULTS: One hundred and ninety-three episodes of endocarditis seen between 1979 and 1992 at Westmead Hospital, Sydney, were reviewed. In the 174 cases where the causative organism was isolated, 75 (43%) were Staphylococcus aureus and 50 (29%) were viridans streptococci. Nosocomial acquisition and/or inter-hospital transfer accounted for 83 episodes; 48 (58%) S. aureus (P < 0.001) and nine (11%) viridans streptococci (P < 0.001). In cases from the local community, viridans streptococci were more common than S. aureus (37% versus 25%); these included 18 episodes (14 S. aureus) in intravenous drug users. CONCLUSION: We conclude that, compared with community-acquired infections, the aetiology of endocarditis in a large teaching hospital is influenced strongly by the prevalence of nosocomial endocarditis and the need for interhospital transfer of complicated cases.     

Ultrastructural assessment of the myocardium receiving intermittent antegrade warm blood cardioplegia

PURPOSE: We compared the in vitro susceptibility of gram-positive bacteria to ciprofloxacin and ofloxacin using human corneal susceptibility levels. METHODS: The concentrations of ciprofloxacin and ofloxacin that can be attained in 99% of human corneas (Cornea99) after topical administration were calculated statistically from reported data. The minimal inhibitory concentrations (MICs) were determined for 95 corneal isolates of gram-positive bacteria (51 Staphylococcus aureus, 16 Streptococcus pneumoniae, 16 Streptococcus viridans group, and 12 coagulase-negative staphylococci). Susceptibility was interpreted by comparing the MICs with the respective Cornea99 for each antibiotic. Time-kill studies of representative gram-positive bacteria were tested using the Cornea99 and the maximal corneal concentrations reported for ciprofloxacin and ofloxacin. RESULTS: The Cornea99 of ciprofloxacin and ofloxacin were calculated to be 3.57 microg/ml (n = 22) and 2.22 microg/ml (n = 20), respectively. The reported mean corneal concentrations of ciprofloxacin (6.90 +/- 6.20 microg/ml) and ofloxacin (5.71 +/- 6.15 microg/ml) were comparable (p = 0.54). All gram-positive bacteria were equally susceptible to ciprofloxacin and ofloxacin (p = 0.54) based on the Cornea99. The time-kill studies determined that 8-24 h were required for both ciprofloxacin and ofloxacin to reach bactericidal levels. CONCLUSION: Ciprofloxacin and ofloxacin demonstrated comparable penetration into the cornea and provided equivalent in vitro efficacy against representative gram-positive bacteria. Time-kill studies indicated that 8-24 h of continual corneal concentrations of ciprofloxacin and ofloxacin were necessary in this study to reduce susceptible gram-positive bacteria by 99.9%.     

Viridans streptococcal bacteremia after esophageal stricture dilation

BACKGROUND: The incidence of bacteremia with organisms that may cause infective endocarditis after esophageal stricture dilation is unknown. There is disagreement among physicians regarding the need for antibiotic prophylaxis for patients with valvular heart disease undergoing dilation. Our aim was to determine the frequency and duration of bacteremia associated with esophageal stricture dilation. METHODS: Blood cultures were obtained before and after stricture dilation in patients without valvular heart disease and in a control group of patients undergoing upper endoscopy without dilation. RESULTS: A total of 103 patients undergoing dilation and 50 control patients were studied; 22 of 103 patients (21%) undergoing dilation had at least one post-procedure blood culture positive for viridans streptococcus, compared with 1 of 50 (2%) of control patients (p = 0. 001). Blood cultures obtained 1 minute after stricture dilation were positive for viridans streptococcus in 19 of 81 (23%), in 16 of 96 (17%) 5 minutes post-dilation, and in 3 of 63 (5%) 20 to 30 minutes post-dilation. Of the 19 patients with viridans streptococcus bacteremia 1 minute after dilation, cultures were still positive in 14 of 19 (74%) at 5 minutes and in 2 of 19 (10%) 20 to 30 minutes post-dilation. CONCLUSIONS: These data support the use of antibiotic prophylaxis before esophageal stricture dilation for patients with valvular heart disease at risk for the development of infective endocarditis.     

EPIBACDIAL: a multicenter prospective study of risk factors for bacteremia in chronic hemodialysis patients

Bacteremic infections are a major cause of mortality and morbidity in chronic hemodialysis patients. New developments in managing these patients (erythropoietin therapy, nasal mupirocin, long-term implanted catheters, and synthetic membranes) may have altered the epidemiologic patterns of bacteremia in dialysis patients. This multicenter prospective cross-sectional study was carried out to determine the current incidence of and risk factors for bacteremia in chronic hemodialysis patients in France. A total of 988 adults on chronic hemodialysis for 1 mo or longer was followed up prospectively for 6 mo in 19 French dialysis units. The factors associated with the development of at least one bacteremic episode over 6 mo were determined using the multivariate Cox proportional hazards model. Staphylococcus aureus (n=20) and coagulase-negative staphylococci (n=15) were responsible for most of the 51 bacteremic episodes recorded. The incidence of bacteremia was 0.93 episode per 100 patient-months. Four risk factors for bacteremia were identified: (1) vascular access (catheter versus fistula: RR=7.6; 95% CI, 3.7 to 15.6); (2) history of bacteremia (> or =2 versus no previous episode: RR=7.3; 95% CI, 3.2 to 16.4); (3) immunosuppressive therapy (current versus no: RR=3.0; 95% CI, 1.0 to 6.1); and (4) corpuscular hemoglobin (per 1 g/dl increment: RR=0.7; 95% CI, 0.6 to 0.9). Catheters, especially long-term implanted catheters, were found to be the leading risk factor of bacteremia in chronic hemodialysis patients. There was a trend toward recurrence of bacteremia that was not associated with chronic staphylococcal nasal carriage. Synthetic membranes were not associated with a lower risk of bacteremia in this population of well dialyzed patients, but anemia linked to resistance to erythropoietin appeared to be a possible risk factor for bacteremia.     

The feasibility of creating a checklist for the assessment of the methodological quality both of randomised and non-randomised studies of health care interventions

Bacteraemia is an important cause of morbidity and mortality in the intensive care unit. In this study the distribution of organisms causing bacteraemic episodes in patients in the adult intensive care unit of a large teaching hospital was determined. Particular emphasis was placed on the type of organisms isolated from community- and hospital-acquired bacteraemia, the suspected source of infection, the possible risk factors associated with bacteraemia, and outcome. The incidence of bacteraemia and fungaemia increased from 17.7 per 1000 admissions in 1985 to 80.3 in 1996. A total of 315 episodes of bacteraemia and fungaemia were documented over a 12-year period, of which 18% were considered community-acquired and 82% hospital-acquired. Gram-positive and gram-negative bacteria accounted for 46.9% and 31.5% of the episodes, respectively. Polymicrobial infection accounted for 17.8% and fungi for 3.8% of the episodes. Staphylococcus aureus (22.5%), Staphylococcus epidermidis (7.6%), and Streptococcus pneumoniae (7.9%) were the predominant gram-positive bacteria implicated, whereas Escherichia coli (6%), Enterobacter cloacae (7%), Klebsiella aerogenes (3.8%), Pseudomonas aeruginosa (5.1%), and Acinetobacter spp. (3.8%) were the predominant gram-negative bacteria isolated. The two most common sources of infection were the respiratory tract (39.7%) and an intravascular line (24.5%), but in 8.9% of episodes the focus of infection remained unknown. Bacteraemic patients stayed in the unit for a longer period (12 days) than did non-bacteraemic patients (3 days). The overall mortality related to bacteraemia and candidaemia was 44.4%. Surveillance of bacteraemia in the intensive care unit is important in detecting major changes in aetiology, e.g., the increasing incidence of gram-positive bacteraemia, the emergence of methicillin-resistant Staphylococcus aureus in 1995, and the emergence of Enterobacter cloacae. It is of value in determining empirical antimicrobial therapy to treat presumed infection pending a microbiological diagnosis and in directing the development of guidelines for infection prevention, e.g., guidelines for central venous catheter care.     

Septicaemia in an Austrian neonatal intensive care unit: a 7-year analysis

The results of blood cultures and clinical data of 101 neonates with 110 episodes of septicaemia during a 7-y study period were reviewed. The overall incidence of culture-proven sepsis within the study period was 6.0 per 100 neonatal intensive care unit admissions and the mortality rate was 14%. Three groups of pathogens accounted for 70% of all isolates: coagulase-negative staphylococci (27%), aerobic Gram-negative rods (24%) and Enterococcus faecalis (19%). Group B streptococcus was the major pathogen of very early-onset septicaemia (within 24 h of birth), whereas late-onset infections were most commonly caused by coagulase-negative staphylococci. Birthweight <1500 g, gestational age <30 weeks of gestation and early onset of symptoms within the first week of life were associated with poor prognosis. In addition, the case fatality rate of episodes caused by Gram-negative organisms was significantly higher than that of Gram-positive bacteraemia.     

Epidemiological and clinical aspects of invasive group A streptococcal infections and the streptococcal toxic shock syndrome

In a retrospective study of invasive infections due to group A Streptococcus (GAS) in Stockholm during 1987 to 1995, the average incidence per 100,000 residents per year was 2.3, varying between 3.7 per 100,000 (in 1988) and 1.3 per 100,000 (in 1993). Incidence was 1.8 in the age group of 0-4 years but otherwise increased by age, from 0.48 in the age group of 5-14 years to 6.1 among those over 65 years of age. A review of 151 invasive episodes occurring in 1983-1995 showed cyclic increases of infections due to T1M1-serotype strains during 1986-1990 and 1993-1995. The T1M1 serotype accounted for 27 (20%) of 135 available GAS strains. Streptococcal toxic shock syndrome (STSS) developed in 19 (13%) of the 151 episodes. The case fatality rate was 11% overall but 47% among patients with STSS. In a multivariate logistic regression model, STSS was associated with a history of alcohol abuse (odds ratio [OR], 6.3; P = .004) and infection with a T1M1 strain (OR, 6.7; P = .007). Case fatality was associated with age (OR, 14.5; P = .08), immunosuppression (OR, 4.7; P = .02), and STSS (OR, 21.5; P < .0001) but not with T1M1 infection. Hypotension was significantly associated with a fatal outcome, regardless of whether STSS developed (P < .0001).     

Antibiotic susceptibility to microorganisms isolated in blood cultures of patients an the Ignacio Chavez National Institute of Cardiology

A microdilution method was utilized for determining susceptibility to several antimicrobial agents in 142 bacterial blood culture isolates obtained during a one year period. Associated clinical features were also identified. Three cases of polymicrobial bacteriemia were found. Endocarditis was the most frequent source of bacteriemia (28.5%) and the viridans streptococci were the most frequently isolated microorganism (53%). Surprisingly, half of the bacteriemic episodes corresponded to a nosocomial infection most of which were due to staphylococci (25%) and Enterobacter sp (22%). Viridans streptococci group were 61.5% resistant to penicillin (MIC > 0.12 micrograms/mL). These strains also showed a 31% resistance to ceftriaxone (MIC > 8 micrograms/mL). The staphylococcal strains showed a 19% resistance to oxacillin; this resistance occurred for coagulase negative staphylococcis in 32% (6/19) and for S. aureus in 9% (2/22). All Gram-positive microorganisms were susceptible to vancomycin. The enterobacteria group were susceptible to most antimicrobial agents; nevertheless this group showed a 45% resistance to amikacin. In contrast, the non enterobacteria group were resistant to most of the antimicrobial agents tested except to imipenem, ceftazidime and ciprofloxacin. When comparing susceptibility longitudinally, no significative changes were identified, but a significant increase was found in MIC50-90 to amikacin and cephalothin when testing S. aureus, and cefoperazone in the non enterobacteria group.