Bacteremia in a long term care facility

Episodes of bacteremia identified in a long term care facility over a seven and a half-year period from July 1984 to December 1991 were reviewed. Twenty-nine episodes of bacteremia were identified, a rate of 4.35/100,000 patient-days. The most common infecting organisms were Escherichia coli (11 episodes), Streptococcus pneumoniae (four), Proteus mirabilis (three), Staphylococcus aureus (three) and Bacteroides species (two). The source of bacteremia was urinary in 45% of patients, gastrointestinal in 17%, pneumonia in 14%, skin in 14% and unknown in 10%. The overall case fatality rate was 24%, but for the final six years of the review the case fatality rate was only 9.5%. These observations report a rate of bacteremia 10-fold lower than reported from other North American long term care facilities and, potentially, a lower case fatality rate. The primary site of bacteremia, however, in long term care facilities is the urinary tract.     

Antimicrobial resistance and clinical outcome of Bacteroides bacteremia: findings of a multicenter prospective observational trial.

There is debate regarding the correlation between in vitro susceptibility testing and clinical response to therapy for Bacteroides bacteremia. We conducted a prospective multicenter observational study of 128 patients with bacteroides bacteremia. Outcome was correlated with results of in vitro susceptibility testing of Bacteroides isolates recovered from blood and/or nonblood sites, determined with use of 3 end points: mortality at 30 days, clinical response (cure vs. failure), and microbiological response (eradication vs. persistence). The mortality rate among patients who received inactive therapy (45%) was higher than among patients who received active therapy (16%; P=.04). Clinical failure (82%) and microbiological persistence (42%) were higher for patients who received inactive therapy than for patients who received active therapy (22% and 12%, respectively; P=.0002 and.06, respectively). In vitro activity of agents directed at Bacteroides species reliably predicts outcome: the specificity was 97%, and positive predictive value was 82%. Antimicrobial susceptibility testing may be indicated for patients whose blood specimens yield Bacteroides species.     

Anaerobic bacterial bacteremia: 12-year experience in two military hospitals

Clinical and microbiologic data of 296 patients with anaerobic bacteremia were reviewed. Anaerobes were isolated with aerobic or facultative bacteremia in 23 instances. The Bacteroides fragilis group accounted for 148 (70%) of 212 isolates of Bacteroides species. B. fragilis accounted for 78% and B. thetaiotaomicron for 14%. Among other species, there were 20 (6%) Fusobacterium organisms, 63 (18%) Clostridium isolates, and 53 (15%) anaerobic cocci. Seventy-five patients died: 40 had B. fragilis group isolates - B. fragilis, 28, and B. thetaiotaomicron, 8 - and 21 had Clostridium organisms isolated. The primary portals of entry were the gastrointestinal tract (42%), decubiti and gangrene (10%), the female genital tract (8%), and the oropharynx (7%). The gastrointestinal tract, decubiti, and gangrene were the predominant sources for B. fragilis and Clostridium organisms, the female genital tract and oropharynx for anaerobic cocci and Fusobacterium species, and the oropharynx for pigmented Bacteroides. Foreign body was associated with Propionibacterium acnes and Clostridium species. Factors predisposing to bacteremia were abscesses, 53; malignancy, 51; surgery, 30; and intestinal obstruction or perforation, 27.     

Gram-negative bacillary bacteremia in the elderly: incidence, ecology, etiology, and mortality

The incidence, ecology, and mortality of gram-negative bacillary bacteremia in elderly patients were studied in an analysis of 334 episodes over a four-year-period in a 489-bed North Carolina community teaching hospital, 135 (40.4%) of which occurred in patients 70 years of age or older. The bacteremia rate per 1000 hospital admissions increased sharply with increasing age. The ecology and in vitro antimicrobial susceptibilities of the bacterial isolates were strongly influenced by community v hospital acquisition, but not by age. Urosepsis was significantly more likely to be the underlying source of hospital-acquired bacteremia in patients 70 years or older (P less than 0.01). Total bacteremia-related mortality did not increase with increasing age; in the group of patients aged 70 years or older with nonfatal/ultimately fatal underlying diseases (NF/UFUD), however, mortality was 9.1% compared to 2.9% in the younger age group (P less than 0.001). Significantly increased bacteremia-related mortality was also noted in the older patients with NF/UFUD admitted from nursing homes (P less than 0.05) and those not treated with an appropriate antimicrobial agent within 24 hours (P less than 0.01). Overall, the older patients with hospital-acquired bacteremia, neutropenia-associated infection, those bacteremic from a nonurinary source of infection, and those treated with multiple-drug regimens had higher mortality (P less than 0.05). Gram-negative bacteremia is much more common in patients 70 years of age or older and compared with younger patients mortality appears to be significantly increased for the important subgroup of older patients with nonfatal or ultimately fatal underlying diseases.     

Pneumococcal bacteremia. Update from an adult hospital with a high rate of nosocomial cases

Eighty-nine episodes of pneumococcal bacteremia were reviewed over a 66-month period at a Veterans Administration Medical Center. Forty-one percent of these episodes were nosocomial in origin, and 59% of the patients were elderly (60 years of age or older). Nosocomial infection occurred more often in the elderly (55%) compared to those less than 60 years of age (32%; P less than 0.05). Within the elderly group, those older than 75 years of age had a higher rate of nosocomial bacteremia than those 60 to 75 years of age (76 versus 44%; P less than 0.05). The clinical presentation of the elderly and younger groups was not significantly different. All but one patient had serious underlying diseases. Eighty-three percent of the episodes were due to pneumonia, and penicillin alone was prescribed for only 21% of all cases. The mortality rate directly due to the bacteremia was 22%, while the overall mortality during the hospitalization was 47%. In the elderly, the percentage of deaths due to infection was similar to the younger group, but overall mortality during the hospitalization was significantly higher in the elderly (74 versus 26%; P less than 0.01). Physicians showed poor recognition of the significance of pneumococcal disease, as demonstrated by inclusion of the diagnosis of pneumococcal infection or bacteremia in only 27% of the discharge summaries and by predischarge vaccination of only 7% (6 of 82) of those without previous pneumococcal vaccination. In conclusion, the rate of nosocomial pneumococcal bacteremia was high in a predominantly elderly male population; it may be appropriate to consider a hospital-based vaccine program in similar populations.     

Bacteremia associated with decubitus ulcers

We studied 104 episodes of bacteremia in 102 patients with decubitus ulcers observed over five years in the hospitals of one metropolitan area. The ulcers were considered to be the "probable" source of bacteremia in 49% of episodes. Another site of infection was documented in 86% of patients. Proteus mirabilis, Staphylococcus aureus, and Escherichia coli were the most frequent blood isolates in these patients, but only Bacteroides species correlated with "probable" origin of bacteremia from the ulcers. The overall mortality was 55%, with 51% of deaths being attributed to infection. These findings emphasize the importance of decubitus ulcers as potential sources of bacteremia in hospitalized patients.     

Occult bacterial infection in adults with unexplained fever. Validation of a diagnostic index

We tested the performance of a previously developed index to diagnose occult bacterial infection and bacteremia in febrile patients. A total of 113 patients consecutively hospitalized because of an acute febrile disease, without a recognizable source of fever, were divided into four groups, with increasing probability of bacterial infection and bacteremia. None of the patients in the first group had bacterial infection or bacteremia. The incidence of bacterial infection and bacteremia was 27% and 11% in the second group, 32% and 17% in the third group, and 53% and 35% in the fourth group. No patient in the first group died, as opposed to 29% of patients in the fourth group. The use of the index at admission would have probably changed the treatment of 11% of patients. Thus, the index could be used to identify patients to be discharged from the emergency department (first group) or hospitalized and treated empirically (fourth group).     

Bacteremia in the old hemodialysis patient

Bacteremia accounts for about 10% of the deaths of European hemodialysis (HD) patients. The aim of this retrospective study was to compare old HD patients (65 or more years of age; group I) to younger patients (less than 65 years; group II), with respect to bacteremia. Of interest were several aspects: the prevalence of bacteremia, the spectrum of pathogens, the oxacillin (methicillin)-resistance of the pathogens, the antibiotics used, and the clinical outcome. Group I included 43 HD patients, 25 women and 18 men with a median age of 70 years; group II included 52 patients, 24 women and 28 men with a median age of 55 years. In both groups more than 90% of the bacteremias were infections related to the use of plastic material. They originated from central venous catheters and were caused by staphylococci in about 75% of the cases. The prevalence of oxacillin-resistance was 10% in group I during the years 1982–1988 and rose to 24% during the years 1989–1992. With the younger patients the prevalence of oxacillin-resistance rose from 16% to 32% in the same periods. For this reason, the antibiotic regimen was changed. Before 1990 oxacillin was the antibiotic of first choice if a HD access infection was suspected. After 1989 teicoplanin, a relatively new glycopeptide antibiotic was given. Imipenem was used if it was not clear if Gram-positive or Gram-negative pathogens were involved or imipenem was used in the second line of therapy. Most bacteremias were cured in both groups. The mortality was 19% in group I and 17% in group II.     

Metronidazole therapy of anaerobic bacteremia, meningitis, and brain abscess.

Four patients with Bacteroides fragilis bacteremia, one patient with a brain abscess due to Bacteroides species, Fusobacterium naviforme, and Peptostreptococcus species, and an infant with Bacteroides species ventriculitis and meningitis were treated with metronidazole. In all cases the anaerobic pathogens were eradicated. Five of the six patients recovered. One patient with leukemia in whom B fragilis bacteremia was eradicated by metronidazole treatment subsequently died of Pseudomonas aeruginosa bacteremia. Ventricular fluid and serum concentrations of metronidazole were determined in the case of meningitis and are reported.     

Vancomycin treatment of bacteremia caused by oxacillin-resistant Staphylococcus aureus: comparison with beta-lactam antibiotic treatment of bacteremia caused by oxacillin-sensitive Staphylococcus aureus

The epidemiology and therapy of 29 episodes of bacteremia caused by oxacillin- and aminoglycoside-resistant Staphylococcus aureus (OARSA) were compared with 29 episodes of bacteremia due to oxacillin-sensitive S. aureus (OSSA) that occurred during a 36-month period. Patients with bacteremia due to OSSA were younger (P less than 0.05) and were admitted more frequently with acute traumatic injury (P less than 0.01). The overall survival rate one month after persistent bacteremia was 74% for patients with OARSA bacteremia treated with vancomycin compared with 70% for patients with OSSA bacteremia treated with a beta-lactam antibiotic. The results indicate that vancomycin is an effective antibiotic for the treatment of bacteremia caused by OARSA and suggest that its effectiveness is comparable to that of beta-lactam antibiotic treatment of bacteremia due to OSSA.     

Characteristics of non-typhi Salmonella gastroenteritis associated with bacteremia in infants and young children

Purpose

To characterize the clinical and laboratory manifestations of non-typhi Salmonella gastroenteritis associated with bacteremia in children less than 36?months old.

Methods

The study group included 17 patients, aged 2?C34?months, with non-typhi Salmonella gastroenteritis and bacteremia, hospitalized in a tertiary pediatric medical center during the period 1995?C2010. Clinical data were collected by medical chart review. Culture-related data were taken from the microbiology laboratory files. The results were compared with an assigned, age-matched, control group of 17 infants hospitalized with non-typhi Salmonella gastroenteritis without bacteremia.

Results

Eleven cases (65%) occurred during the summer season. All patients presented with diarrhea, usually mixed with blood or mucus (clinical dysentery 65%). All but one had a high-grade fever (average 39.5°C). Three patients (19%) experienced convulsions during the acute episode of gastroenteritis. None of the patients had been previously treated with antibiotics. The most prevalent Salmonella serotype identified in the stool and blood was group C. Toxic appearance and convulsions on admission were more common among children with non-typhi Salmonella bacteremia, as opposed to those with non-typhi Salmonella gastroenteritis alone. No other epidemiological or laboratory differences were found.

Conclusions

Non-typhi Salmonella gastroenteritis poses a risk of bacteremia not only in infants younger than 3?months of age, but also in children younger than 36?months of age.     

Serratia bacteremia: a review of 44 episodes

This report reviews 44 episodes of serratia bacteremia over a 9-year period (1980-1988) in a community-teaching hospital in the USA. The median age of patients was 64 years and 34% of the patients were older than 70 years. Nosocomial acquisition of bacteremia occurred in 70% of episodes, and 11% of patients were admitted from nursing homes. Nine episodes (20%) were polymicrobial bacteremia. The major portals of entry were the lower respiratory tract (11 episodes) and the urinary tract (6 episodes). The overall mortality was 52%. Factors that adversely influenced the mortality rate were rapidly fatal and ultimately fatal underlying conditions (p less than 0.001), platelet counts less than or equal to 100 x 10(0)/l at the onset of bacteremia (p less than 0.01), and total serum bilirubin greater than 18 mumol/l at the onset of bacteremia (p less than 0.01). All serratia strains tested were susceptible to gentamicin, kanamycin, amikacin and ceftizoxime.     

Bacteremia caused by non-sporulating anaerobes in cancer patients. A 12-year experience

The clinical, epidemiological and laboratory characteristics of bacteremia caused by anaerobic organisms other than Clostridium spp. in cancer patients are described and compared to other previously reported series. Of the 315 episodes, 246 (78%) were caused by a single organism and 69 (22%) were polymicrobial. The most common underlying malignancies were genitourinary and gynecological tumors, acute leukemia, and gastrointestinal malignancies. Most patients (94%) were febrile, and septic shock was documented in 24% of monomicrobial episodes and in 58% of those with polymicrobial infection. Soft-tissue infection was present in 44% of the cases, and it presented as tissue necrosis in 11%. The most common sites identified as the portal of entry were intra-abdominal abscesses, soft tissue, and the oropharynx. The most common organisms were Bacteroides fragilis (57%) and other Bacteroides spp. (22%). Most polymicrobial infections were caused by 2 organisms, the second most commonly another anaerobe or an aerobic gram-negative bacillus. The most active antibiotic in vitro was chloramphenicol. High rates of resistance to penicillin were observed not only among B. fragilis, but also among Bacteroides spp. The frequency of penicillin resistance increased throughout the study years. The overall survival was 70%. The cure rate for monomicrobial bacteremias was 76% vs. 51% for polymicrobial episodes. Infection was the cause of death in 20 and 16 episodes, respectively. The response rate for patients in septic shock was 47% in contrast to an 85% recovery rate for those without it. Ninety-five patients had documented abscesses accompanying the bacteremic episode. The most effective antibiotics were clindamycin and chloramphenicol. Overall response to penicillin was only 13%. Suboptimal responses were also observed for the antipseudomonal penicillins. High response rates (82%) were also obtained with cefoxitin, metronidazole, and moxalactam.     

Epidemiology and prognosis of bacteremia: a 10-y study in a community hospital

In order to determine the epidemiology and factors influencing the outcome of adult bacteremia in a community hospital, episodes of significant bacteremia were recorded prospectively over a 10-y period (1989-98). The following variables were included: age, sex, etiology, acquisition and source of the bacteremia, risk factors, clinical manifestations, empirical antibiotic treatment and outcome. A total of 798 episodes of bacteremia were recorded (436 in males) and 185 (24%) were hospital-acquired. The most frequent source was the urinary tract, followed by the respiratory tract and primary bacteremia. The crude mortality was 14.4% (n = 111) and related mortality was 8.5% (n = 66). The most frequent etiology was Escherichia coli, followed by Streptococcus pneumoniae and Staphylococcus aureus. Multivariate analysis revealed age > 70 y, nosocomial acquisition, respiratory source, primary bacteremia, septic shock, McCabe groups I and II, leukopenia, inappropriate antibiotic treatment and etiology due to S. aureus as factors associated with crude mortality. Pseudomonas aeruginosa, Proteus spp. and Bacteroides spp. were associated with related mortality. In conclusion, it is possible to modify or eliminate factors influencing the outcome of adult bacteremia. The prevention of nosocomial infection, the use of support therapies in critical patients and appropriate antibiotic treatment are measures that can improve the prognosis of patients with bacteremia.     

Dental health and viridans streptococcal bacteremia in allogeneic hematopoietic stem cell transplant recipients

Viridans streptococci were the most common cause of bacteremia in 61 consecutive myeloablative allogeneic hematopoietic stem cell transplant (HSCT) recipients, occurring in 19 of 31 bacteremic patients (61%) during the period of post-transplant neutropenia. Seven of the 19 had more than one viridans streptococcus in the same blood culture. Twenty isolates from 15 patients were Streptococcus mitis. Most viridans streptococci were resistant to norfloxacin, used routinely for prophylaxis. Comparison of the 19 patients with viridans streptococcal bacteremia with a contemporaneous group of 23 allogeneic HSCT recipients with fever and neutropenia but no identified focus of infection found that patients with viridans streptococcal bacteremia were more likely to have severe intraoral pathology while neutropenic (26% vs 0%) and slightly shorter interval between the last dental procedure and the onset of neutropenia (11 vs 14 days). Poor underlying dental health and the use of norfloxacin thus appear to predispose to viridans streptococcal bacteremia.     

Bacteremia due to Stenotrophomonas maltophilia in patients with hematologic malignancies.

Predisposing factors, clinical characteristics, and antimicrobial treatment of 37 hematology patients with Stenotrophomonas maltophilia bacteremia who were seen at the department of hematology of the University La Sapienza (Rome) from 1987 to 1996 were evaluated. The results were compared with a control group of patients with Pseudomonas aeruginosa bacteremia. Profound neutropenia was more prolonged in the S. maltophilia group (P=.025), severe cellulitis occurred only in S. maltophilia-infected patients (11 [30%]; P=.0002), and the bacteremia presented as breakthrough infection in 56% of the cases due to S. maltophilia (vs. only 24% of those due to P. aeruginosa; P=.002). Acute mortality rates associated with S. maltophilia and P. aeruginosa bacteremia were 24% and 21%, respectively. In both groups, profound neutropenia and hypotension at the onset of bacteremia, duration of profound neutropenia during bacteremia, severity-of-illness score > or =4, and inappropriate antibacterial treatment were factors significantly associated with death. Most S. maltophilia isolates were resistant to aminoglycosides, beta-lactams, and ciprofloxacin. Cotrimoxazole and ticarcillin-clavulanic acid showed borderline activity. Prompt administration of in vitro-active antibiotics may improve the prognosis of S. maltophilia bacteremia, especially for immunocompromised patients, and novel drug combinations are needed for the treatment of severe infections.     

Detection of specific IgG antibody in sera from patients infected with Bacteroides fragilis by enzyme-linked immunosorbent assay.

During a period of 13 months, 28 serious infections caused by Bacteroides were seen in 27 patients. Sixteen patients yielded Bacteroides fragilis; sera from 13 (81%) of these 16 had increased levels of IgG specific for B. fragilis lipopolysaccharide (LPS) antigens by enzyme-linked immunosorbent assay (ELISA). Sera from 20 normal controls did not have increased specific IgG. Sera from 22 of 23 patients with bacteremia caused by other gram-negative rods also failed to yield increased levels of specific antibody (P less than 0.0012). Analysis of sera from patients with B. fragilis infections disclosed a significant correlation between the levels of specific IgG to B. fragilis LPS measured by ELISA and the IgG antibody to the infecting B. fragilis by indirect immunofluorescence (r = 0.84, P less than 0.012). Two of the remaining 12 infections caused by Bacteroides not apparently due to B. fragilis organisms were also associated with increased levels of specific IgG to B. fragilis LPS antigens. Specific IgG antibody response may be an important adjunct in diagnosis of common B. fragilis infections and may allow better management of antimicrobial agents.     

Anaerobic wound infection: Bacteroides mediastinitis after cardiovascular surgery

A case of postoperative anaerobic mediastinitis after coronary artery bypass grafting is reviewed. One of the causative organisms, Bacteroides oralis, has never previously been described as a pathogen causing mediastinitis after median sternotomy incision. There was associated Bacteroides fragilis bacteremia. Only three cases of Bacteroides species mediastinitis after open heart surgery have been reported. This anaerobic bacterium remains a rare pathogen in median sternotomy infections despite the increasing number of cases of mediastinitis seen in association with the burgeoning number of patients undergoing cardiac surgery. Multiple risk factors may contribute to mediastinal infections, which occur in about 2% of patients undergoing coronary artery surgery. When infection occurs, aerobic and anaerobic wound cultures should be made and appropriate antimicrobial and surgical therapy instituted.     

Bacteremia due to beta-hemolytic Streptococcus group G: increasing incidence and clinical characteristics of patients

PURPOSE: To describe the epidemiology and clinical characteristics of patients diagnosed with Streptococcus group G bacteremia from 1990 to 1999 at a community teaching hospital in Israel. SUBJECTS AND METHODS: We calculated the annual rate of bacteremia with Streptococcus group G, expressed as a percentage of positive blood cultures (after excluding contaminants) and per 1000 admissions. Medical records of patients with Streptococcus group G were reviewed. RESULTS: During the 10-year study period, there was a total of 7415 positive blood cultures, 327 (4.4%) of which were beta-hemolytic Streptococcus species, of which 49 (15%) were group G. The rate of Streptococcus group G bacteremia per 1000 admissions increased from zero (0/18,783) in 1990 to 0.41 (13/31,440) in 1999 (P = 0.001), surpassing Streptococcus group A in frequency. Of the 47 patients with Streptococcus group G, 40 medical records were available for review: 25 patients (63%) were older than 75 years and 32 (80%) were men. The probable source of Streptococcus group G bacteremia was a skin or soft tissue infection in 37 patients (93%). Six of the 40 patients died. CONCLUSION: Community-acquired group G streptococcal bacteremia occurred with increasing frequency from 1990 to 1999 at our hospital. Most patients were elderly men, and the portal of entry was usually the skin or soft tissue. Our findings suggest a change in the epidemiology of bacteremia due to beta-hemolytic streptococci.     

Causes of community-acquired bacteremia and patterns of antimicrobial resistance in Vientiane, Laos

There is no published information on the causes of bacteremia in the Lao PDR (Laos). Between 2000 and 2004, 4512 blood culture pairs were taken from patients admitted to Mahosot Hospital, Vientiane, Laos, with suspected community-acquired bacteremia; 483 (10.7%) cultures grew a clinically significant community-acquired organism, most commonly Salmonella enterica serovar typhi (50.9%), Staphylococcus aureus (19.0%), and Escherichia coli (12.4%). S. aureus bacteremia was common among infants (69.2%), while children 1-5 years had a high frequency of typhoid (44%). Multi-drug-resistant S. Typhi was rare (6%). On multiple logistic regression analysis, typhoid was associated with younger age, longer illness, diarrhea, higher admission temperature, and lower peripheral white blood cell count than non-typhoidal bacteremia. Empirical parenteral ampicillin and gentamicin would have some activity against approximately 88% of clinically significant isolates at a cost of US $1.4/day, an important exception being B. pseudomallei. Bacteremic infants in this setting require an anti-staphylococcal antibiotic.