Pranavi Sreeramoju

Prior Antimicrobial Therapy and Risk for Hospital-Acquired Candida glabrata and Candida krusei Fungemia: a Case-Case-Control Study

ABSTRACT The incidence of infections caused by Candida glabrata and Candida krusei, which are generally more resistant to fluconazole than Candida albicans, is increasing in hospitalized patients. However, the extent to which prior exposure to specific antimicrobial agents increases the risk of subsequent C. glabrata or C. krusei candidemia has not been closely studied. A retrospective case-case-control study was performed at a university hospital. From 1998 to 2003, 60 patients were identified with hospital-acquired non-C. albicans candidemia (C. glabrata or C. krusei; case group 1). For comparison, 68 patients with C. albicans candidemia (case group 2) and a common control group of 121 patients without candidemia were studied. Models were adjusted for demographic and clinical risk factors, and the risk for candidemia associated with exposure to specific antimicrobial agents was assessed. After adjusting for both nonantimicrobial risk factors and receipt of other antimicrobial agents, piperacillin-tazobactam (odds ratio [OR], 4.15; 95% confidence interval [CI], 1.04 to 16.50) and vancomycin (OR, 6.48; CI, 2.20 to 19.13) were significant risk factors for C. glabrata or C. krusei candidemia. For C. albicans candidemia, no specific antibiotics remained a significant risk after adjusted analysis. Prior fluconazole use was not significantly associated with either C. albicans or non-C. albicans (C. glabrata or C. krusei) candidemia. In this single-center study, exposure to antibacterial agents, specifically vancomycin or piperacillin-tazobactam, but not fluconazole, was associated with subsequent hospital-acquired C. glabrata or C. krusei candidemia. Further studies are needed to prospectively analyze specific antimicrobial risks for nosocomial candidemia across multiple hospital centers.

Predictive factors for the development of central line-associated bloodstream infection due to gram-negative bacteria in intensive care unit patients after surgery.

OBJECTIVES To examine the relative proportions of central line-associated bloodstream infection (BSI) due to gram-negative bacteria and due to gram-positive bacteria among patients who had undergone surgery and patients who had not. The study also evaluated clinical predictive factors and unadjusted outcomes associated with central line-associated BSI caused by gram-negative bacteria in the postoperative period. DESIGN Observational, case-control study based on a retrospective review of medical records. SETTING University of Chicago Medical Center, a 500-bed tertiary care center located on Chicagos south side. PATIENTS Adult intensive care unit (ICU) patients who developed central line-associated BSI. RESULTS There were a total of 142 adult patients who met the Centers for Disease Control and Prevention National Nosocomial Infection Surveillance System definition for central line-associated BSI. Of those, 66 patients (46.5%) had infections due to gram-positive bacteria, 49 patients (34.5%) had infections due to gram-negative bacteria, 23 patients (16.2%) had infections due to yeast, and 4 patients (2.8%) had mixed infections. Patients who underwent surgery were more likely to develop central line-associated BSI due to gram-negative bacteria within 28 days of the surgery, compared with patients who had not had surgery recently (57.6% vs 27.3%; P= .002). On multivariable logistic regression analysis, diabetes mellitus (adjusted odds ratio [OR], 4.6 [95% CI, 1.2-18.1]; P= .03) and the presence of hypotension at the time of the first blood culture positive for a pathogen (adjusted OR, 9.8 [95% CI, 2.5-39.1]; P= .001) were found to be independently predictive of central line-associated BSI caused by gram-negative bacteria. Unadjusted outcomes were not different in the group with BSI due to gram-negative pathogens, compared to the group with BSI due to gram-positive pathogens. CONCLUSIONS Clinicians caring for critically ill patients after surgery should be especially concerned about the possibility of central line-associated BSI caused by gram-negative pathogens. The presence of diabetes and hypotension appear to be significant associated factors.

Recurrent skin and soft tissue infections due to methicillin-resistant Staphylococcus aureus requiring operative debridement

BACKGROUND The aim of this study was to examine clinical factors associated with the recurrence of community-onset skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus. METHODS An observational case-comparison study based on a retrospective review of medical records was conducted in a public health system. All patients with community-onset skin and soft tissue infections caused by methicillin-resistant S aureus who underwent operative debridement from January 1999 to December 2003 were included. The outcome of interest was recurrence within 1 year. RESULTS Two hundred fifty-three patients met the criteria for inclusion. Fifty-three (21%) patients returned with recurrent episodes. These patients were compared with 200 patients (79%) who did not develop recurrence. On multivariate analysis, factors independently predictive of recurrence were medical history of abscess requiring surgical debridement within the previous year (adjusted odds ratio, 2.6; 95% confidence interval, 1.4-5.0; P = .002) and obesity (adjusted odds ratio, 3.4; 95% confidence interval, 1.4-8.8; P = .008). CONCLUSIONS Patients with obesity or histories of methicillin-resistant S aureus infection are at significantly increased risk for recurrent soft tissue infection.

Dose of Trimethoprim-Sulfamethoxazole To Treat Skin and Skin Structure Infections Caused by Methicillin-Resistant Staphylococcus aureus

ABSTRACT We undertook this study to investigate whether treatment with a higher dose of trimethoprim-sulfamethoxazole (TMP/SMX) led to greater clinical resolution in patients with skin and soft tissue infections (SSTIs) caused by methicillin-resistant Staphylococcus aureus (MRSA). A prospective, observational cohort with nested case-control study was performed at a public tertiary health system. Among patients with MRSA SSTIs during the period from May 2008 to September 2008 who received oral monotherapy with TMP/SMX and whose clinical outcome was known, the clinical characteristics and outcomes were compared between patients treated with a high dose of TMP/SMX (320 mg/1,600 mg twice daily) for 7 to 15 days and patients treated with the standard dose of TMP/SMX (160 mg/800 mg twice daily) for 7 to 15 days. In patients with MRSA SSTIs, those treated with the high dose of TMP/SMX (n = 121) had clinical characteristics similar to those of patients treated with the standard dose of TMP/SMX (n = 170). The only exception was a higher proportion of patients with a history of trauma upon admission among the patients treated with the higher dose. The proportion of patients with clinical resolution of infection was not different in the two groups (88/121 [73%] versus 127/170 [75%]; P = 0.79). The lack of significance remained in patients with abscess upon stratified analysis by whether surgical drainage was performed. The study found that patients with MRSA SSTIs treated with the higher dose of TMP/SMX (320/1,600 mg twice daily) for 7 to 15 days had a similar rate of clinical resolution as patients treated with the standard dose of TMP/SMX (160/800 mg twice daily) for 7 to 15 days.

Risk factors for development of methicillin-resistant Staphylococcus aureus infection among colonized patients

BACKGROUND This study was conducted to identify clinical factors associated with development of infection caused by methicillin-resistant Staphylococcus aureus (MRSA) among hospitalized patients with nasal MRSA colonization. METHODS We conducted a prospective cohort with nested case-control study at a 672-bed, public, academic hospital in Dallas, Texas. The study duration was from January 1, 2008, to July 28, 2009. From the cohort of patients who had presence of nasal colonization with MRSA at admission, we identified patients who developed subsequent infection with MRSA during a 3-month period. We compared these patients (cases) with colonized patients who remained uninfected (controls; 2 controls per case). We collected demographic and clinical data and performed statistical analyses. RESULTS During the 19-month study period, 426 patients were found to have nasal colonization with MRSA. Of these, 36 (8.5%) developed a subsequent infection with MRSA within 3 months. When these 36 cases were compared with 72 controls, the factors independently associated with the development of subsequent infection were development of pressure ulcer during hospital stay (adjusted odds ratio, 5.82; 95% confidence interval: 2.21-15.31; P value=.000) and preadmission steroid therapy (adjusted odds ratio, 13.2; 95% confidence interval: 2.44-70.97; P value=.003). CONCLUSION History of steroid therapy prior to admission and development of pressure ulcer are associated with increased risk of subsequent MRSA infection in patients nasally colonized with MRSA.

Antimicrobial prophylaxis may not be the answer: Surgical site infections among patients receiving care per recommended guidelines

BACKGROUND It is believed that compliance with all 3 components of perioperative antimicrobial prophylaxis, ie, timing, choice, and duration, yields greater reduction in surgical site infections (SSI). METHODS An observational study was performed among patients in the surgical care improvement project at a tertiary public academic hospital in the United States. The rates of SSI among patients who received appropriate antimicrobial agent(s) per current guidelines were compared with patients who did not. Medical record review was performed to compare the clinical characteristics of patients with SSI (cases) and an equal number of patients without SSI (matched controls). RESULTS From January 2008 to June 2009, 762 patients underwent 763 eligible surgical procedures. Forty-seven (6.2%) developed SSI. The rate of SSI in patients who received appropriate antimicrobial prophylaxis per guidelines was not different from those who did not (42/611, 6.9% vs 5/152, 3.3%, respectively; P value = .13). Patients with SSI were more likely to have an elevated body mass index (median and interquartile range in cases: 28.7 [27.0-34.9] vs 25.0 [22.4-30.4] in controls; P value = .02) and more likely to have diabetes (36% vs 9%, respectively; odds ratio, 5.71; 95% confidence interval: 1.43-22.8; P value = .02). CONCLUSION Compliance with timing, choice, and duration of antimicrobial prophylaxis as a whole did not lead to lower SSI. Elevated body mass index and diabetes were associated with a higher rate of SSI.

Clindamycin-resistant methicillin-resistant Staphylococcus aureus: epidemiologic and molecular characteristics and associated clinical factors.

In this prospective, observational study of 618 consecutive adult patients with skin and soft tissue infections (SSTI) caused by methicillin-resistant Staphylococcus aureus (MRSA), the clinical characteristics, molecular epidemiology, and outcome of patients with clindamycin-resistant MRSA (n = 64) and clindamycin-susceptible MRSA (n = 554) were compared (including factors predictive of clindamycin-resistant MRSA SSTI). Patients with clindamycin-resistant MRSA were more likely to have had antibiotic exposure within 3 months (37.5% versus 17%, P < 0.01), surgery (25% versus 8%, P < 0.01), MRSA infection/colonization within 12 months (23% versus 7%, P < 0.01), or intravascular catheters (5% versus 0.5%, P = 0.02). On multivariate analysis, previous surgery (adjusted odds ratio [AOR] 2.97; 95% confidence interval [CI] 1.5-6.0), history of MRSA (AOR 3.4; 95% CI 1.7-7.1), and exposure to clindamycin (AOR 8.5; 95% CI 2.3-32) and to macrolides (AOR 7.2, 95% CI 1.6-31.8) were independently associated with presence of clindamycin-resistant MRSA. Clinical resolution was similar between groups (77% versus 68%; P = 0.26). Clindamycin-resistant MRSA was less often USA-300 (82% versus 98%, P = 0.004). Clindamycin resistance did not affect MRSA-SSTI clinical outcomes.

Correlation Between Respiratory Colonization With Gram-Negative Bacteria and Development of Gram-Negative Bacterial Infection After Cardiac Surgery

This pilot, observational study involving 286 patients who underwent cardiac surgery found that patients who had endotracheal colonization with gram-negative bacteria at 1 week after surgery were more likely to develop subsequent infection compared to those without colonization (8 of 23 vs. 4 of 40; relative risk 2.3 [95% confidence interval, 1.3-4.1; P value <.05]).

Preventing Healthcare-Associated Infections: Beyond Best Practice

The goal of this review is to evaluate best practices for preventing healthcare-associated infections (HAI) and to identify opportunities beyond best practice. Achieving an infection-free hospital stay for patients will require integration of infection prevention into routine bedside clinical care. The objectives are (1) to summarize the best practices for prevention of HAI; (2) to discuss the limitations of known best practices; and (3) to discuss potential approaches beyond best practice to prevent HAI. Rationale for comprehensive horizontal approaches with active caregiver participation is discussed.

Quality Improvement of Staphylococcus aureus Bacteremia Management and Predictors of Relapse-free Survival

PURPOSE The purpose of this study is to improve the quality of care and patient outcomes for Staphylococcus aureus bacteremia. METHODS A quasi-experimental pre- and postintervention study design was used to compare process and clinical endpoints before and after a quality-improvement initiative. All inpatients >18 years of age with a positive blood culture for S. aureus during the specified pre- and postintervention period with clinical information available in the electronic medical record were included. An institutional protocol for the care of patients with S. aureus bacteremia was developed, formalized, and distributed to providers using a pocket card, an electronic order set, and targeted lectures over a 9-month period. RESULTS There were 167 episodes of S. aureus bacteremia (160 patients) identified in the preintervention period, and 127 episodes (123 patients) in the postintervention period. Guideline adherence improved in the postintervention period for usage of transesophageal echocardiogram (43.9% vs 20.2%, P <.01) and adequate duration of intravenous therapy (71% vs 60%, P = .05). In a multivariate Cox proportional hazard model, the variables associated with increased relapse-free survival were postintervention period (hazard ratio [HR] 0.48; confidence interval [CI], 0.24-0.95; P .035) and appropriate source control (HR 0.53; CI, 0.24-0.92; P .027). Regardless of intervention, presence of cancer was associated with an increased risk of relapse or mortality at 90 days (HR 2.88; P <.0001; CI, 1.35-5.01). CONCLUSION A bundled educational intervention to promote adherence to published guidelines for the treatment of S. aureus bacteremia resulted in a significant improvement in provider adherence to guidelines as well as increased 90-day relapse-free survival.