Colonization and molecular epidemiology of coagulase-negative Staphylococcal bacteremia in cancer patients: a pilot study

BACKGROUND: Controversy surrounds the source (skin vs mucosa) of coagulase-negative staphylococci (CoNS) bacteremia in cancer patients. Determining the source of this infection has clinical and epidemiologic implications. OBJECTIVE: To determine the source(s) of CoNS bacteremia in cancer patients. METHODS: Between November 1998 and October 2000, cultures of nasal and rectal mucosa and skin at central venous catheter (CVC) sites were obtained in 62 patients (66 episodes) with CoNS-positive blood culture(s). Bacteremia was classified as true, indeterminate, or unlikely on the basis of clinical and microbiologic findings. Molecular relatedness of strains isolated from the blood and from colonized sites of patients with true and those with unlikely bacteremia was examined using pulsed-field gel electrophoresis (PFGE). RESULTS: CoNS colonization was present in 55 episodes (83%). The nasal mucosa was the most frequently colonized site (86%), followed by rectal mucosa (40%) and skin at site of CVC insertion (38%) (P < .001). Colonization at > or =1 site was common. True and unlikely bacteremia accounted for 11 and 10 episodes, respectively, with the remaining 45 episodes considered undetermined or had negative surveillance cultures. Among patients with true bacteremia, 6 mucosal isolates and only 1 skin isolate were related by PFGE to the blood isolate recovered from the same patient. CONCLUSION: Mucosa is the most common site of CoNS colonization and is the likely source of CoNS bacteremia in cancer patients.     

Molecular typing of coagulase-negative staphylococci from blood cultures does not correlate with clinical criteria for true bacteremia

PURPOSE: Determining whether a blood culture that contains coagulase-negative staphylococci represents bacteremia or contamination is a clinical dilemma. We compared molecular-typing results of coagulase-negative staphylococcal blood culture isolates with clinical criteria for true bacteremia. SUBJECTS AND METHODS: Pulsed-field gel electrophoresis and arbitrary primed polymerase chain reaction (PCR) were used to determine whether patients with two or more blood cultures with coagulase-negative staphylococcal isolates had the same strain of organism in each culture (same strain bacteremia). We evaluated three different clinical criteria for bacteremia: whether the patient received more than 4 days of antibiotics, whether there was an explicit note in the medical chart in which the physician diagnosed a true bacteremia, and the Centers for Disease Control surveillance criteria for primary bloodstream infection. Agreement between same-strain bacteremia and each definition was examined, based on the assumption that most true infections should be the result of a single strain. RESULTS: The study sample consisted of 42 patients and 106 isolates. Nineteen of the 42 bacteremias (45%) were the same strain. Classification of bacteremias as same-strain correlated poorly with all three clinical assessments (range of percent agreement, 50% to 57%; range of kappa statistic, 0.01 to 0.15). There were both false-positive and false-negative errors. Patients with three or more positive blood cultures were more likely to have same-strain bacteremia than those with only two positive cultures [11 of 15 (73%) vs 8 of 27 (30%), P = 0.006]. Pulsed-field gel electrophoresis was more discriminating than arbitrary primed PCR (percent agreement, 83%; kappa, 0.67). CONCLUSION: Molecular typing correlated poorly with clinical criteria for true bacteremia, suggesting either that true bacteremias are frequently the result of multiple strains or that the commonly used clinical criteria are not accurate for distinguishing contamination from true bacteremia. Vancomycin treatment of clinically defined coagulase-negative staphylococcal bacteremia may frequently be unnecessary.     

Genetic polymorphisms in CX3CR1 predict HIV-1 disease progression in children independently of CD4+ lymphocyte count and HIV-1 RNA load

BACKGROUND: The impact of CX3CR1 polymorphisms on human immunodeficiency virus type 1 (HIV-1) pathogenesis is controversial, with conflicting reports of their role in disease progression in HIV-1-infected adults. METHODS: A cohort of 1055 HIV-1-infected children were genotyped for 2 CX3CR1 polymorphisms, V/I249 and T/M280, and their impact on HIV-1-related disease progression, including central nervous system (CNS) impairment, was evaluated. RESULTS: Children with the CX3CR1 I/I249 genotype experienced more-rapid disease progression (I/I249 vs. V/V249: relative hazard [RH], 2.19 [95% confidence interval {CI}, 1.30-3.68], P=.003; I/I249 vs. V/I249: RH, 1.77 [95% CI, 1.00-3.14], P=.05) and a trend toward more CNS impairment (I/I249 vs. V/V249: RH, 2.19 [95% CI, 1.00-4.78], P=.049; I/I249 vs. V/I249: RH, 2.02 [95% CI, 0.85-4.83], P=.11). Children with the V249-T280 haplotype experienced significantly less disease progression (RH, 0.42 [95% CI, 0.24-0.73]; P=.002) and CNS impairment (RH, 0.39 [95% CI, 0.39-0.22]; P=.001). Of note, these effects remained significant after CD4+ lymphocyte count and plasma HIV-1 RNA load at baseline were adjusted for and in a longitudinal, multivariate analysis. CONCLUSIONS: CX3CR1 genotypes and haplotypes impact HIV-1 disease progression independently of CD4+ lymphocyte count and plasma HIV-1 RNA load, suggesting that the fundamental role of CX3CR1 in the alteration of disease progression might be the recruitment of immunomodulatory cells responsible for the control of HIV-1.     

Serious complications of bacteremia caused by Viridans streptococci in neutropenic patients with cancer.

We prospectively studied 485 episodes of bacteremia in neutropenic patients with cancer. Viridans streptococci caused a total of 88 episodes (18%). Ten (11%) of these 88 cases were associated with serious complications: acute respiratory distress syndrome (ARDS) plus septic shock (5 cases), ARDS (3), and septic shock (2). Streptococcus mitis was the species most frequently isolated (7 of 10 episodes). Four viridans streptococci showed a diminished susceptibility to penicillin (MICs ranged from 0.25 to 4 microg/mL), and 5 strains were resistant to ceftazidime (MICs ranged from 2 to >32 microg/mL). Patients with viridans streptococcal bacteremia (VSB) who developed serious complications were compared with patients with VSB without complications. Severe oral mucositis (70% vs. 32.5%, respectively; P=.036), high-dose chemotherapy with cyclophosphamide (60% vs. 25%, respectively; P=.043), and allogeneic bone marrow transplantation (40% vs. 10%, respectively; P=.040) were the only variables found to be significantly associated with the development of complications. Neither a specific species of viridans streptococci nor resistance to penicillin was associated with the occurrence of complications. The mortality rate was higher in case patients than in control patients (80% vs. 17.5%, respectively; P<.001). Serious complications associated with VSB occur mainly in patients receiving high-dose chemotherapy with cyclophosphamide before allogeneic bone marrow transplantation who develop severe oral mucositis; these complications are associated with a high mortality rate.     

Epidemiologic changes in bacteremic pneumococcal disease in patients with human immunodeficiency virus in the era of highly active antiretroviral therapy

BACKGROUND: The use of highly active antiretroviral therapy (HAART) may change the incidence of, and the risk and prognostic factors for, invasive pneumococcal disease in patients with human immunodeficiency virus (HIV). METHODS: We prospectively studied 142 episodes of pneumococcal bacteremia in 122 HIV-infected adults. Eighty-five episodes occurred in the pre-HAART era (1986-1996) and 57 in the HAART era (1997-2002). A case-control study was conducted to identify risk factors for pneumococcal bacteremia in the HAART era. RESULTS: The incidence of pneumococcal bacteremia dropped from 24.1 episodes per 1000 patient-years in the pre-HAART era to 8.2 episodes per 1000 patient-years in the HAART era (P = .01). Compared with patients in the pre-HAART era, patients in the HAART era had more associated comorbidity (42% vs 26%; P = .04), fewer recurrences of bacteremia (4% vs 15%; P = .04), and a higher 30-day mortality rate (26% vs 8%; P=.004). High antibiotic resistance rates were observed in both periods. By multivariate analysis, the major risk factors for pneumococcal bacteremia in the HAART era were associated comorbidity (adjusted odds ratio [OR], 3.36), alcohol abuse (adjusted OR, 5.28), prior hospitalization (adjusted OR, 3.38), current smoking (adjusted OR, 5.19), and CD4 cell count lower than 100 cells/muL (adjusted OR, 2.38); while use of HAART (adjusted OR, 0.37) and pneumococcal vaccine (adjusted OR, 0.39) were protective factors. CONCLUSIONS: The widespread use of HAART and pneumococcal vaccine may decrease the incidence of invasive pneumococcal disease in HIV-infected patients. Risk factors and prognosis of pneumococcal bacteremia in the HAART era are more similar to those reported in non-HIV-infected individuals.     

Viral polymorphism in human papillomavirus types 33 and 35 and persistent and transient infection in the genital tract of women

BACKGROUND: Genetic polymorphism in human papillomavirus (HPV)-33 and -35 was investigated in 1055 sexually active women (732 human immunodeficiency virus [HIV] seropositive and 323 HIV seronegative). METHODS: Consecutive genital specimens obtained at 6-month intervals were screened for HPV-33 and -35 by use of MY09-MY11. HPV-33 and -35 isolates from 95 women were analyzed by polymerase chain reaction sequencing of the long control region (LCR), E6, and E7. RESULTS: For HPV-33, 101 (20%) of 506 nucleotides in the LCR were variable, compared with 10 (2.1%) of 483 nucleotides in E6 (P<.001) and 6 (1.9%) of 324 nucleotides in E7 (P<.001). For HPV-35, the proportion of variable nucleotide sites was similar between the LCR and both E6 (P=.54) and E7 (P=.33). The presence of a 78-base pair deletion in HPV-33 (relative risk [RR], 1.8 [95% confidence interval [CI], 1.2-2.7]) and the presence of nonsynonymous E7 variations in HPV-35 (RR, 2.6 [95% CI, 1.4-4.6]) were associated with persistence. When the data for HPV-33 and -35 were combined, infection by HPV isolates with nonsynonymous E7 variations (RR, 2.3 [95% CI, 1.6-3.4]; P=.001) and ethnicity (P=.04) were associated with persistence, whereas age (P = .14) and HIV infection/CD4 cell count status (P=.12) were not significantly associated with persistence, by logistic regression analysis. CONCLUSION: HPV-33 and -35 polymorphism was different between types and was associated with persistence of HPV infection.     

Persistent bacteremia due to methicillin-resistant Staphylococcus aureus infection is associated with agr dysfunction and low-level in vitro resistance to thrombin-induced platelet microbicidal protein

BACKGROUND: The causes of persistent bacteremia (PB) due to methicillin-resistant Staphylococcus aureus (MRSA) are poorly understood. This investigation examined potential associations between PB with key clinical features and several in vitro bacterial genotypic and phenotypic characteristics, in isolates from 1 institution. METHODS: Pulsed-field gel electrophoresis (PFGE) relatedness, thrombin-induced platelet microbicidal protein (tPMP)-susceptibility phenotype, accessory gene regulator (agr) genotype and functionality (via delta-lysin production), and autolysis phenotypes were assessed in MRSA isolates from the bloodstream of 21 prospectively identified patients with PB (blood cultures positive after > or =7 days of therapy) and of 18 patients with resolving bacteremia (RB) (sterile blood cultures within the first 2-4 days of therapy) due to MRSA. RESULTS: The 2 groups had comparable baseline characteristics but differed in their clinical courses (e.g., endocarditis was more frequent in patients with PB than in those with RB [43% vs. 0%, respectively; P=.0016]); isolates from patients with PB exhibited higher rates of (1) survival in vitro after exposure to tPMP (22.4+/-14.8% vs. 11.6+/-6.5%, respectively; P=.005); (2) defective delta-lysin production (71.4% vs. 38.9%, respectively; P=.057); (3) non-agr genotype II profile (100% vs. 77.8%, respectively; P=.037); and (4) overrepresentation of a specific PFGE genotype (85.7% vs. 44.4%, respectively; P=.015). CONCLUSIONS: Isolates from patients with PB differed from those in patients with RB, in several in vitro characteristics. Further studies will be necessary to define how these factors might affect clinical outcome.     

Natural T, gammadelta, and NK cells in mycobacterial, Salmonella, and human immunodeficiency virus infections

NK cells, gammadelta T cell antigen receptor chain-positive cells, and CD3(+)CD16/56(+) (natural T [NT]) cells are involved in innate immunity and immunoregulation; however, their role in clinical infection is not well defined. Cytofluorometric analysis was used to examine peripheral blood from bacteremic, nonbacteremic, and healthy human immunodeficiency virus (HIV)-positive and -negative persons in Malawi, Africa. Mycobacteremia was associated with a higher proportion of CD3(+)CD8(-) gammadelta cells (median, 16.6% vs. 0.7% for all other cells; P<.001), and Salmonella bacteremia was associated with a higher proportion of NT cells (4.3% vs. 2.2%; P=. 002). HIV plasma RNA levels were weakly positively correlated with NT cells (rs=.39; P=.002), NK cells (rs=.38; P=.003), and gammadelta cells (rs=.43; P<.001). Compared with patients who survived, patients who died had a higher percentage of NT cells (3.7% vs. 1. 9%; P=.017) and a higher percentage of NT cells that spontaneously produced interferon-gamma (2.4% vs. 1.2%; P=.035). The data support the clinical relevance of gammadelta and NT cells in mycobacterial, Salmonella, and HIV infections and of NT cells in mortality.     

Health and economic outcomes of antibiotic resistance in Pseudomonas aeruginosa.

BACKGROUND: Antimicrobial resistance is an increasing problem. OBJECTIVE: To examine the clinical and economic impact of antibiotic resistance in Pseudomonas aeruginosa. METHODS: In-hospital mortality, secondary bacteremia, length of stay, and hospital charges were examined in a cohort of 489 inpatients with positive clinical cultures for P aeruginosa. One hundred forty-four had a resistant baseline P aeruginosa isolate and 30 had resistance emerge during follow-up. Multivariable and survival analytic methods were used to adjust for confounding and effects of time. RESULTS: The overall in-hospital mortality rate was 7.6%, 7.7% in patients with a resistant isolate at baseline (relative risk [RR], 1.3; 95% confidence interval [CI], 0.6-2.8) and 27% in patients in whom resistance emerged (RR, 3.0; 95% CI, 1.2-7.8). Secondary bacteremia developed in 1.4% of patients in whom resistance did not emerge and in 14% of those in whom resistance emerged (RR, 9.0; 95% CI, 2.7-30). The median duration of hospital stay following the initial P aeruginosa isolate was 7 days. Emergence of resistance, but not baseline resistance, was significantly associated with a longer hospital stay (P<.001 and P=.71, respectively). The average daily hospital charge was $2059. Neither baseline resistance nor emergence of resistance had a significant effect on the daily hospital charge. In a matched cohort analysis, a trend was seen toward increased total charges in patients demonstrating emergence of resistance (difference, $7340; P=.14). CONCLUSIONS: Emergence of antibiotic resistance in P aeruginosa results in severe adverse outcomes. Efforts should be directed toward early detection and prevention of emergence of antibiotic resistance.     

Anal intraepithelial neoplasia in heterosexual and homosexual HIV-positive men with access to antiretroviral therapy

BACKGROUND: Studies of human immunodeficiency virus (HIV)-positive men have demonstrated high rates of anal intraepithelial neoplasia (AIN), a precursor to anal carcinoma, mostly in white homosexual men and men not receiving effective antiretroviral therapy (ART). METHODS: Ninety-two participants--53% Latino, 36% African American, and 40% without a history of receptive anal intercourse (RAI)--were evaluated with a behavioral questionnaire, liquid-based anal cytological testing, Hybrid Capture 2 human papillomavirus (HPV) DNA assay and polymerase chain reaction, and anal colposcopy with biopsy of lesions. RESULTS: High-risk HPV DNA was identified in 61%, and this was associated with a history of RAI (78% vs. 33%; P<.001); 47% had abnormal cytological results, and 40% had AIN on biopsy. In multivariate analysis, both were associated with a history of RAI (odds ratio [OR], 10 [P<.001] and OR, 3.6 [P=.02], respectively) and lower nadir CD4(+) cell counts (P=.06 and P=.01). Current ART use was protective (OR, 0.09; P<.01 and OR, 0.18; P=.02). CONCLUSIONS: Although anal infections with high-risk HPV and AIN in HIV-positive men are associated with a history of RAI, both conditions are commonly identified in HIV-positive men without this history. Both lower nadir CD4(+) cell counts and lack of current ART were associated with AIN but not with the detection of anal HPV.     

Predicting bacteremia in hospitalized patients. A prospectively validated model

OBJECTIVE: To develop and validate a model for the prediction of bacteremia in hospitalized patients, and to identify subgroups of patients with a very low likelihood of bacteremia in whom a positive blood culture has a low positive predictive value. DESIGN: Prospective cohort study with clinical data on 1516 episodes collected from a random sample of all patients who had blood cultures done at one institution. SETTING: Urban, tertiary care hospital. PATIENTS: Derivation set: 1007 blood culture episodes sampled from all blood cultures done on patients at Brigham and Women's Hospital between October 1988 and February 1989. Validation set: 509 episodes, May 1989 to June 1989. The unit of evaluation was the episode, defined as a 48-hour period beginning after a blood culture was drawn. MEASUREMENTS AND MAIN RESULTS: True- and false-positive rates of blood cultures in the derivation set as assessed by independent reviewers were 7% (74 of 1007) and 8% (81 of 1007), respectively. Independent multivariate predictors of true bacteremia were temperature of 38.3 degrees C or higher, presence of a rapidly (less than 1 month) or ultimately (less than 5 years) fatal disease; shaking chills; intravenous drug abuse; acute abdomen on examination; and major comorbidity. In the low-risk group, defined by absence of these predictors, the misclassification rate of the model in the derivation set was 1% (4 of 303), and a positive blood culture had a positive predictive value of only 14% for true bacteremia. The model also identified a high-risk subset in which 16% (41 of 264) of episodes represented true bacteremia. The model was prospectively validated in 509 additional episodes, and the misclassification rate in the low-risk group was 2% (3 of 155). INTERVENTIONS: None. CONCLUSION: These findings provide a means of stratifying hospitalized patients according to their risk for bacteremia. If prospectively validated in other settings, this model may be helpful when deciding whether or not to do blood cultures or start antibiotic therapy and, when evaluating a positive blood culture, to determine whether or not it is a true-positive.     

The use of a diversion tube to reduce blood culture contamination: A “real-life” quality improvement intervention study

BackgroundBlood culture contamination is associated with health care costs and potential patient harm. Diversion of the initial blood specimen reduces blood culture contamination. We report results of the "real-life" clinical implementation of this technique.MethodsFollowing an educational campaign, use of a dedicated diversion tube was recommended prior to all blood cultures. Blood culture sets taken from adults using a diversion tube were defined as "diversion sets," those without, "non-diversion" sets. Blood culture contamination and true positive rates were compared for diversion and nondiversion sets and to nondiversion historical controls. A secondary analysis investigated efficacy of diversion by patient age.ResultsOut of 20,107 blood culture sets drawn, the diversion group included 12,774 (60.5%) and the nondiversion group 8,333 (39.5%) sets. The historical control group included 32,472 sets. Comparing nondiversion to diversion, contamination decreased by 31% (5.5% [461/8333] to 3.8% [489/12744], P < .0001]. Contamination was also 12% lower in diversion than historical controls [3.8% (489/12744) vs 4.3% (1,396/33,174) P = .02)]. The rate of true bacteremia was similar. In older patients, contamination rate was higher, and the relative reduction associated with diversion decreased (54.3% amongst 20-40-year-olds vs 14.5% amongst >80-year-olds).ConclusionsUse of a diversion tube in the ED reduced blood culture contamination in this large real life observational study. Efficacy decreased with increasing age, which requires further investigation.     

An invasive strategy in non-ST-segment elevation acute coronary syndromes. From large trials to the real world

INTRODUCTION AND OBJECTIVES: We report the impact on prognosis of an invasive strategy used at our center for non-ST-segment elevation acute coronary syndrome. PATIENTS AND METHOD: We analyzed 504 consecutive patients with typical chest pain, electrocardiographic changes or increased troponin I serum values, who were divided into 2 cohorts: a) conservative group, 272 patients admitted between October 2001 and September 2002 and managed with a conservative strategy, and b) invasive group, 232 patients admitted between October 2002 and September 2003 for whom an invasive strategy was recommended. We recorded major events (death or reinfarction) and minor events (readmission or need for postdischarge revascularization) within a 12-week follow-up period. RESULTS: In the invasive group in-hospital angioplasty (21% vs 35%, P<.0001) and in-hospital revascularization (33% vs 48%, P=.001) increased. There were no significant differences between the conservative and the invasive group regarding major events (17% vs 15%). The invasive group was associated with a reduction in minor events (17% vs 9%, P=.01). The incidence of any event was reduced (28% vs 20%, P=.04). In the multivariate analysis for the whole group (n=504) the invasive strategy significantly reduced minor events (hazard ratio 0.5 [0.3-0.8], P=.008) and any event (hazard ratio 0.5 [0.3-0.8], P=.005), but not major events (hazard ratio 0.6 [0.4-1.1], P=.09). CONCLUSIONS: The results observed in recent randomized clinical trials regarding the use of an invasive strategy were confirmed in the real world. In the short term, the benefits seem to be confined to a reduction in minor events, i.e., fewer readmissions and less need for postdischarge revascularization.     

Impact of vancomycin resistance on mortality among patients with neutropenia and enterococcal bloodstream infection

We performed a retrospective cohort study to measure the impact of vancomycin resistance on clinical outcome for 83 episodes of enterococcal bloodstream infection (BSI; 22 with vancomycin-resistant enterococci [VRE] and 61 with vancomycin-susceptible enterococci [VSE]) in 77 patients with neutropenia. Cox proportional hazards models showed that vancomycin resistance was an independent predictor of mortality, after controlling for severity of illness, enterococcal species, gram-negative copathogens, sex, race, duration of neutropenia before bacteremia, and early administration of active antibiotics. This effect was evident only > or =10 days after the onset of bacteremia (P=.0263; hazard ratio [HR], 4.969) but not after adjustment for duration of bacteremia. The median duration of bacteremia was 4.5 days for VRE BSI and <1 day for VSE BSI (P=.0001). The only independent predictor of bacteremia duration was vancomycin resistance (P=.0284; HR, 3.863). Vancomycin resistance is associated with increased mortality in patients with neutropenia, possibly because of prolonged duration of bacteremia.     

Bacteremia with esophageal dilation

(GUMMI BEARS)Background: Antibiotic prophylaxis has been recommended for selected patients undergoing esophageal stricture dilation because of a reported high rate of bacteremia. The aim of this study was to determine the rate of bacteremia after esophageal dilatation in a large series and the source of the organisms recovered. Methods: Blood cultures and oral temperatures were obtained before esophageal dilation and at 5 and 30 minutes after dilation. Dilators were cultured immediately before dilation. Procedural data collected included type of dilation, number of passes, and presence of malignancy. Results: Of 100 procedures in 86 patients undergoing esophageal dilation, 22 (22%) were associated with a positive post-dilation blood culture. Bacteremia was more frequent with dilation of malignant strictures compared with benign strictures (9 of 17 [52.9%] vs. 13 of 83 [15.7%], respectively, p = 0.002) and with passage of multiple dilators compared with passage of a single dilator (16 of 46 [34.8%] versus 6 of 54 [11.1%], respectively, p = 0.007). Bacterial isolates from 22 positive blood cultures matched those from a dilator in only one episode (4.5%). Conclusion: The rate of bacteremia after esophageal dilation is 22% and is associated with dilation of malignant strictures or passage of multiple dilators. Organisms cultured from the blood are not transmitted from the dilator. (Gastrointest Endosc 1998;48:563-7.)     

Recurrent Staphylococcus aureus bacteremia: pulsed-field gel electrophoresis findings in 29 patients

To identify risk factors for relapse among 309 prospectively identified cases of Staphylococcus aureus bacteremia, patients with recurrent S. aureus bacteremia were identified, and pulsed-field gel electrophoresis (PFGE) was performed on isolates from both episodes. PFGE banding patterns from both isolates were identical in 23 patients, consistent with relapsed infection. Patients with PFGE-confirmed relapse were more likely by both univariate and multivariate analyses to have an indwelling foreign body (odds ratio [OR]=18.2, 95% confidence interval [CI]=7. 6-43.6; P<.001), to have received vancomycin therapy (OR=4.1, 95% CI=1.5-11.6; P=.008), or be hemodialysis-dependent (OR=4.1, 95% CI=1. 8-9.3; P=.002) than patients who did not develop recurrent bacteremia. These results suggest that recurrent episodes of S. aureus bacteremia are primarily relapses and are associated with an indwelling foreign body, receiving vancomycin therapy, and hemodialysis dependence.     

Recurrent pneumococcal bacteremia: risk factors and outcomes

BACKGROUND: Recurrent pneumococcal bacteremia receives infrequent mention in the literature, usually in association with patients who are immunocompromised. OBJECTIVE: To examine recurrent cases of pneumococcal bacteremia to determine risk factors and outcomes (mortality rates and emergence of resistance) associated with recurrences. METHODS: We retrospectively reviewed all cases of pneumococcal bacteremia identified by our microbiology laboratory from January 1, 1992, through December 31, 1996. Demographic, clinical, and laboratory data were abstracted. RESULTS: There were 462 bacteremic episodes in 432 patients; 23 of these patients had 30 recurrent episodes. The 5.3% recurrence rate (23/432) is greater than that previously described. The median time to recurrence was 200 days. The mean age of patients with recurrences was 34 years, 70% were women, all were black or Hispanic (in near equal numbers), and 87% were infected with the human immunodeficiency virus (HIV). Human immunodeficiency virus infection, coexistent cancer, and female sex were independent predictors of recurrence. Only patients who were HIV-infected had multiple recurrences. Isolates from recurrent bacteremias were more likely to be penicillin-resistant than were initial bacteremic isolates (relative risk, 2.0; P =.16). Patients with recurrences had a higher (although not statistically significant) mortality rate than those without recurrences (22% vs 16%; P =.33). There was an inverse relationship between severity of illness and likelihood of recurrence. CONCLUSIONS: Rates of recurrent pneumococcal bacteremia may be higher than previously reported. In patients with recurrent pneumococcal bacteremia, the presence of an underlying immunodeficiency should be investigated.     

Association of human herpesvirus 6 reactivation with severe cytomegalovirus-associated disease in orthotopic liver transplant recipients.

To explore the possible interaction between human herpesvirus 6 (HHV-6) and cytomegalovirus (CMV) in patients who have undergone organ transplantation, stored serum samples from 139 orthotopic liver transplant recipients were tested for HHV-6 immunoglobulin (Ig) G and IgM antibodies. HHV-6 reactivation occurred in 87 patients (62.6%) and was associated with CMV disease (P=.01), severe CMV-associated disease (P=.01), older age (P=.005), and use of muromonab-CD3 (Orthoclone; Orthobiotech) as treatment for rejection (P=.02). Trends for an association between HHV-6 reactivation and invasive fungal disease (P=.12), bacteremia (P=.10), and graft loss (P=.12) were seen. In a multivariate analysis of risk factors for severe CMV-associated disease, HHV-6 reactivation (relative risk [RR], 3.5; 95% confidence interval [CI], 1.2-10.2; P=.02), CMV donor-positive-recipient-negative match (RR, 5.7; 95% CI, 2.5-13.2; P<.001), and elevated serum creatinine level (P<.0001) were independent predictors. HHV-6 reactivation is associated with severe CMV-associated disease in liver transplant recipients.     

Molecular analysis of coagulase-negative Staphylococcus isolates from blood cultures: prevalence of genotypic variation and polyclonal bacteremia.

Fifty-seven coagulase-negative Staphylococcus isolates from 22 inpatients who had > or =2 blood cultures that were positive for Staphylococcus within 24 hours were analyzed to determine the frequency of polyclonal bacteremia. Patients were considered to have bacteremia (14 patients) or contamination of sample (8 patients) on the basis of clinical criteria. Nine colonies were randomly selected from each blood culture and genotyped by means of SmaI digestion/pulsed-field gel electrophoresis. Relatedness was determined by calculation of the Dice coefficient of banding-pattern similarity (S(AB)). Analysis of bacteremic isolates demonstrated the presence of a single species in 35 of 41 blood cultures, 1 related variant in 5 blood cultures (87%-92% S(AB)), and an unrelated strain in 1 blood culture (79% S(AB)). Analysis of contaminated samples demonstrated the presence of a single strain in 10 of 16 blood cultures and 1-3 variants (28%-97% S(AB)) in the remainder. Genotype diversity was significantly more common in the contaminated samples (P=.036). Almost all coagulase-negative Staphylococcus bacteremias were monoclonal.     

Recurrent urinary tract infections in postmenopausal women.

To evaluate factors associated with recurrent urinary tract infection (UTI) in postmenopausal women, we conducted a case-control study comparing 149 postmenopausal women referred to an infectious diseases outpatient clinic who had a history of recurrent UTI (case patients) with 53 age-matched women without a history of UTI (control patients). Each woman completed a questionnaire providing demographic data, history and clinical characteristics of prior infections, and information regarding risk factors for UTI. In addition, each patient underwent a gynecologic evaluation, renal ultrasound and urine flow studies, and blood group and secretor status testing. Three urologic factors-namely, incontinence (41% of case patients vs. 9.0% of control patients; P<.001), presence of a cystocele (19% vs. 0%; P<.001), and postvoiding residual urine (28% vs. 2.0%; P=.00008)-were all strongly associated with recurrent UTI. Multivariate analysis showed that urinary incontinence (odds ratio [OR], 5.79; 95% confidence interval [CI], 2.05-16.42; P=.0009), a history of UTI before menopause (OR, 4.85; 95% CI, 1.7-13.84; P=. 003), and nonsecretor status (OR, 2.9; 95% CI, 1.28-6.25; P=.005) were most strongly associated with recurrent UTI in postmenopausal women. Prospective studies are needed to confirm these observations and to develop approaches for prevention.