Moshe Drucker

Nontyphoid Salmonella Bacteremia: Age-Related Differences in Clinical Presentation, Bacteriology, and Outcome

In a retrospective study, 80 episodes of nontyphoid salmonella (NTS) bacteremia in children were compared with 55 episodes in adults over a 10-year period. The study disclosed major differences in the predisposition, clinical presentation, and outcome as well as the microbiology of NTS bacteremia in relation to age. Adults were more likely than children to have predisposing diseases (95% vs. 15%, respectively; P < .0001) and to receive prior medications (95% vs. 23%, respectively; P < .0001), particularly immunosuppressive agents (58% vs. 5%, respectively; P < .0001). In most adults (67%), NTS infection presented as a primary bacteremia and was associated with a high incidence of extraintestinal organ involvement (34%) and a high mortality rate (33%). In children, NTS bacteremia was usually secondary to gastroenteritis (75%) and caused no fatalities. Although group D Salmonella (78%) and the serovar Salmonella enteritidis were the predominant isolates from adults, the emergence of infections due to group C Salmonella (46%) and the serovar Salmonella virchow in children was noted.

Septic Shock in Bacteremic Patients: Risk Factors, Features and Prognosis

Of 4,289 episodes of bacteremia detected in 3,631 patients, septic shock was diagnosed in 453 episodes (10.5%). In 56% of shock episodes, septic shock developed more than 24 h after the first positive blood culture was taken. In a logistic regression analysis, variables predictive of septic shock were: advanced age [odds ratio (OR) of 1.015 for an increment of 1 year]; renal failure as an underlying disorder (OR = 1.47); neutropenia (OR of 2.26); curtailed functional capacity (OR of 1.54 for an increment of 1 category); unknown source of infection (OR = 1.66); anaerobic (OR = 2.86), polymicrobial bacteremia (OR = 1.54), or pathogens other than Streptococcus viridans (OR = 0.08 for Streptococcus viridans). The in-hospital mortality associated with septic shock was 80% vs 21% in episodes of bacteremia without shock, and shock episodes accounted for 31% of all deaths. The fatality rate in shock patients given appropriate empiric antibiotic treatment was 74.9% vs 84.7% in patients given inappropriate treatment (p = 0.01). Judging by the present results, host factors are more important determinants for development of septic shock in bacteremic patients than the type of pathogen. Even in patients with shock, appropriate empiric antibiotic treatment was associated with an improved chance of survival.

Bacteremia in Adult Diabetic Patients

objective To compare the microbiology, sources, complications, and outcome of bacteremia in diabetic and nondiabetic patients. Research Design and Methods A prospective study was conducted of all episodes of bacteremia in hospitalized diabetic and nondiabetic patients. The study consisted of patients ≥ 18 yr of age with bacteremia detected within a 19-mo interval. Results We compared 124 episodes of bacteremia in 119 diabetic patients to 508 episodes in 480 nondiabetic patients. Diabetic patients were older than nondiabetic patients (median age 74 vs. 68 yr, P = 0.0001). In patients with an indwelling urinary catheter and bacteremic urinary tract infection, the percentage of Klebsiella in diabetic patients was 60% (6 of 10) and in nondiabetic patients was 17% (4 of 23, P = 0.04). In patients without an obvious source of bacteremia, the percentage of staphylococcal isolates in diabetic patients was 29% (10 of 35) and in nondiabetic patients was 14% (24 of 176, P = 0.04). Staphylococci were a common cause of bacteremic infections of the extremities in diabetic patients (12 of 19, 63%) and nondiabetic patients (20 of 50, 40%). Septic shock was the only complication that was more common in diabetic patients. The mortality in diabetic and nondiabetic patients was 28 and 29%, respectively. Conclusions Our results represent elderly patients with non-insulin-dependent diabetes mellitus. In this group, empirical treatment for suspected bacteremic urinary tract infection in patients with a urinary catheter should include coverage for Klebsiella. Empiric treatment for suspected bacteremia of unknown origin or caused by infection of the extremities should include an antistaphylococcal drug. The prognosis of bacteremia in diabetic and nondiabetic patients was similar.

A prospective study of Gram-negative bacteremia in children.

BACKGROUND Hospital- and community-acquired Gram-negative bacteremia is a significant cause of mortality and morbidity in pediatric medical centers. Gram-negative organisms are isolated in > 50% of pediatric patients with bacteremia. OBJECTIVES To analyze clinical and epidemiologic variables associated with Gram-negative bacteremia in a tertiary childrens medical center. METHODS A 6-year prospective study of children with Gram-negative bacteremia in a tertiary care childrens medical center in Israel. RESULTS Three hundred seventy-four episodes of Gram-negative bacteremia were studied during 6 years. The predominant isolates were Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli, which accounted for 109, 81 and 79 episodes (26, 20 and 19%), respectively. Of all episodes 43% occurred in neonates and infants younger than 2 years and 47% were hospital-acquired. Underlying conditions mainly acute leukemia and lymphoma, were present in 55% of the patients. Urinary tract infection followed by lower respiratory tract infection were the most common identified sources of bacteremia. Central intravenous catheters were associated with 53% of the episodes. The crude mortality was 11.4%. Increased mortality was significantly associated with acute leukemia, neutropenia, hospital-acquired infections and previous corticosteroid therapy (P = 0.03, 0.003, 0.006 and 0.01, respectively). Increased antibiotic resistance of hospital-acquired vs community-acquired isolates was noted; 44 to 77% resistance of nosocomial Klebsiella and Enterobacter sp. to second and third generation cephalosporins and 18% were resistant to amikacin. CONCLUSIONS Klebsiella pneumoniae is currently the most common organism causing Gram-negative bacteremia in children. Because of the relatively high resistance of Gram-negative organisms to second and third generation cephalosporins, we suggest that empiric antibiotic therapy for Gram-negative bacteremia include a combination of an aminoglycoside and an anti-Pseudomonas beta-lactam.

Five-year prospective study of bacteraemic urinary tract infection in a single institution

In order to determine the epidemiology, microbiology, and outcome of bacteraemia originating in the urinary tract in hospitalised patients, a prospective study was conducted in a large general hospital in Israel. Data from all patients with bacteraemia were collected prospectively, and a subgroup of patients with bacteraemia secondary to urinary tract infection was analysed. There were 702 episodes of bacteraemia secondary to urinary tract infection during a five-year period (33.9% of all episodes of bacteraemia). The mean age of the patients was 76 years, and the male: female ratio was 0.9∶1.0. The most common pathogens wereEscherichia coli (52%),Klebsiella spp. (14%), andProteus spp. (9%).Pseudomonas spp. were isolated from 8% of all patients, from 19% of those who had received antibiotics, and from 15% of males.Enterococcus spp. were isolated from 4% of males but from no females. Five percent of the episodes were polymicrobial, and 16% of the infections were hospital acquired. On logistic multivariate regression analysis, predictors of mortality were: hospitalisation in a medical department, hospital-acquired infection, inappropriate empiric antibiotic treatment, presence of decubitus ulcer(s), respiratory or renal failure, and elevated urea and decreased albumin levels.

Clinical index to predict bacteraemia caused by staphylococci

Abstract. Objectives. To define risk factors associated with bacteraemia caused by Staphylococcus aureus or coagulase‐negative staphylococci; and to use them to define patients in need of empiric anti‐staphylococcal antibiotic treatment.

Patients at risk for inappropriate antibiotic treatment of bacteraemia

Abstract. In order to define patients at high risk for inappropriate antibiotic treatment of bacteraemia, we compared 682 bacteraemic patients, treated with an antibiotic drug to which the infecting micro‐organism was susceptible, with 419 patients who were inappropriately treated. On a multivariate logistic regression analysis including only clinical variables, four factors were found to be both significantly and independently associated with inappropriate antibiotic treatment: hospital‐acquired bacteraemia (oddsratio (OR) of 1.9), antibiotic treatment in the month prior to the bacteraemia (OR 1.9), residence in a nursing home (OR 1.8), and the presence of a central line (OR 1.7). A second model, including bacteriological data, showed four micro‐organisms to be independently associated with inappropriate antibiotic treatment: Candida sp. (OR 14.2), Acinetobacter sp. (OR 5.0), Enterococcus sp. (OR 3.6) and Pseudomonas sp. (OR 2.2). In this model, only two clinical features were included: hospital‐acquired infection and previous antibiotic treatment. Special efforts should be made to improve empirical antibiotic treatment in the groups defined above, and to facilitate early laboratory diagnosis of the micro‐organisms associated with inappropriate treatment.

Excess mortality in women with hospital-acquired bloodstream infection

PURPOSE We examined the outcomes of bloodstream infection in men and in women and whether any sex-related differences were explained by underlying disorders, severity of disease, or clinical management. SUBJECTS AND METHODS Using a prospectively collected database, we compared in-hospital mortality in men and women. We used multivariable logistic regression analysis to test whether sex-related differences could be due to potential confounders. RESULTS Of 4250 patients with bloodstream infections, 1750 (41%) had hospital-acquired infections. The overall case fatality was 31% (625 of 2032) in women and 29% (631 of 2218, P = 0.1) in men. However, 43% (325/758) of the women with hospital-acquired infections died, compared with 33% (327/992) of the men (P = 0.0001). In a multivariate analysis, female sex was associated with greater mortality in patients with hospital-acquired infections (odds ratio = 1.7; 95% confidence interval: 1.1 to 2.6). The excess mortality in women was mainly seen in patients with major underlying disorders (fatality rate of 45% [234 of 525] in women vs. 32% in men [234 of 743, P = 0.0001). CONCLUSIONS Mortality in women with hospital-acquired bloodstream infections is substantially greater than in men. The excess mortality was concentrated in women with severe underlying disorders, suggesting that sepsis might have accentuated differences in the outcome of underlying disorders in women.

Bacteremia in Patients Without Known Underlying Disorders

Of 2030 consecutive patients with bacteremia, only 102 were free from underlying disorders. 43 were males, and the median age was 66 years. The sources of infection were the urinary tract (in 48%), lower respiratory tract (13%), endocarditis (7%), biliary tract (6%) and the meninges (5%). The most common pathogens were Escherichia coli (in 45% of patients), Streptococcus pneumoniae (21%), Staphylococcus aureus (9%) and hemolytic streptococci (9%). Overall mortality rate was 13%, 4% in patients with urinary tract infection and 19% in patients with other sources. Half of the deaths occurred within 2 days of hospitalization, and 75% of them within 4 days. All patients with septic shock and all patients with meningitis died. Other factors related to mortality were residence in a nursing home, low functional capacity, advanced age, high blood urea nitrogen and creatinine and low albumin, and infections caused by Staphylococcus aureus, Neisseria meningitidis and polymicrobial infections. A protective effect of appropriate antimicrobial antibiotic therapy could not be demonstrated. In conclusion, bacteremic patients with no known underlying disorder and source of their infection other than the urinary tract should be given maximum supportive treatment and should be closely watched.

Postcircumcision Urinary Tract Infection

The possible association of urinary tract infection (UTI) with ritual circumcision on the eighth day of life was studied by analyzing the epidemiology of urinary tract infections during the first year of life in 169 children with UTI (56 males and 113 females) born in Israel from 1979 to 1984. Forty-eight percent of the episodes of UTI occurring in males appeared during the 12 days following circumcision, and the increased incidence during that period was highly significant. The median age of the males at the time of the UTI was 16 days, compared with seven months in females. Ritual Jewish circumcision as practiced in Israel may be a predisposing factor for UTI during the 12-day period following that procedure.