Screening Patients Undergoing Total Hip or Knee Arthroplasty with Perioperative Urinalysis and the Effect of a Practice Change on Antimicrobial Use.

OBJECTIVE To identify predictors of treatment for urinary tract infections (UTI) among patients undergoing total hip (THA) or knee (TKA) arthroplasties and to assess an intervention based on these predictors. DESIGN We conducted a retrospective cohort study of 200 consecutive patients undergoing THA/TKA between February 21, 2011, and June 30, 2011, to identify predictors of treatment for UTI and a prospective cohort study of 50 patients undergoing these procedures between May 21, 2012, and July 17, 2012, to assess the association of signs or symptoms and UTI treatment. We then conducted a before-and-after study to assess whether implementing an intervention affected the frequency of treatment for UTI before or after THA/TKA. SETTING The orthopedics department of a university health center. PATIENTS Patients undergoing THA or TKA. INTERVENTION Surgeons revised their UTI screening and treatment practices. RESULTS Positive leukocyte esterase (P5 (P=.01; P=.01) were associated with preoperative or postoperative UTI treatment. In the prospective study, 12 patients (24%) had signs and symptoms consistent with UTI. The number of patients treated for presumed UTI decreased 80.2% after the surgeons changed their practices, and surgical site infection (SSI) rates, including prosthetic joint infections (PJIs), did not increase. CONCLUSIONS Urine leukocyte esterase and white blood cell count were the strongest predictors of treatment for UTI before or after THA/TKA. The intervention was associated with a significant decrease in treatment for UTI, and SSI/PJI rates did not increase. Infect Control Hosp Epidemiol 2017;38:281-286.

Risk Factors for Surgical Site Infections Following Adult Spine Operations.

OBJECTIVE To identify risk factors for surgical site infections (SSIs) after spine operations. DESIGN Case-control study of SSIs among patients undergoing spine operations. SETTING An academic health center. PATIENTS We studied patients undergoing spinal fusions or laminectomies at the University of Iowa Hospitals and Clinics from January 1, 2007, through June 30, 2009. We included patients who acquired SSIs meeting the National Healthcare Safety Network definition. We randomly selected controls among patients who had spine operations during the study period and did not meet the SSI definition. RESULTS In total, 54 patients acquired SSIs after 2,309 spine operations (2.3 per 100 procedures). SSIs were identified a median of 20 days after spinal fusions and 17 days after laminectomies; 90.7% were identified after discharge and 72.2% were deep incisional or organ-space infections. Staphylococcus aureus caused 53.7% of SSIs. Of patients with SSIs, 64.9% (fusion) and 70.6% (laminectomy) were readmitted and 59.5% (fusion) and 64.7% (laminectomy) underwent reoperation. By multivariable analysis, increased body mass index, Surgical Department A, fusion of 4-8 vertebrae, and operation at a thoracic or lumbar/sacral level were significant risk factors for SSIs after spinal fusions. Lack of private insurance and hypertension were significant risk factors for SSIs after laminectomies. Surgeons from Department A were more likely to use nafcillin or vancomycin for perioperative prophylaxis and to do more multilevel fusions than surgeons from Department B. CONCLUSIONS SSIs after spine operations significantly increase utilization of healthcare resources. Possible remediable risk factors include obesity, hypertension, and perioperative antimicrobial prophylaxis. Infect Control Hosp Epidemiol 2016;1458-1467.

Risk factors for surgical site infections after pediatric spine operations.

STUDY DESIGN: Matched case-control study. OBJECTIVE: To identify modifiable risk factors for surgical site infections (SSIs) after pediatric spinal fusion. SUMMARY OF BACKGROUND DATA: The number of SSIs after pediatric spinal fusions increased. METHODS: Between July 2001 and July 2010, 22 of 598 pediatric patients who underwent spinal fusion at a university hospital acquired SSIs. Each patient with an SSI was matched with 2 controls by procedure date. Bivariable and multivariable analyses were used to identify risk factors for SSIs and outcomes of SSIs. RESULTS: Gram-negative organisms caused more than 50% of the SSIs. By multivariable analysis, neuromuscular scoliosis (odds ratio [OR] = 20.8; 95% confidence interval [CI], 3.1-889.5; P < 0.0001) and weight-for-age at the 95th percentile or higher (OR = 8.6; 95% CI, 1.2-124.9; P = 0.02) were preoperative factors associated with SSIs. Blood loss (OR = 1.0; 95% CI, 1.0-1.0; P = 0.039) and allografts and allografts in combination with other grafts were operative risk factors for SSIs. The final overall risk model for SSIs was weight-for-age at the 95th percentile or higher (OR = 4.0; 95% CI, 1.4-∞; P = 0.037), American Society of Anesthesiologists score 3 or more (OR = 3.8; 95% CI, 1.6-∞; P = 0.01), and prolonged operation duration (OR = 1.0/min increase; 95% CI, 1.0-1.0; P = 0.004). SSIs were associated with 2.8 days of additional postoperative length of stay (P = 0.02). Neuromuscular scoliosis was the only factor significantly associated with hospital readmission (OR = 23.6; 95% CI, 3.8-147.3; P = 0.0007). CONCLUSION: Our results suggest that pediatric patients undergoing spinal fusion might benefit from antimicrobial prophylaxis that covers gram-negative organisms. Surgical duration, graft implantation, and blood loss are potentially modifiable operative risk factors. Neuromuscular scoliosis, high weight-for-age, and American Society of Anesthesiologists scores 3 or more may help surgical teams identify patients at high risk for SSI.

Risk factors and outcomes associated with surgical site infections after craniotomy or craniectomy.

OBJECT: Many studies that have evaluated surgical site infections (SSIs) after craniotomy or craniectomy (CRANI) did not use robust methods to assess risk factors for SSIs or outcomes associated with SSIs. The authors conducted the current study to identify risk factors for SSIs after CRANI procedures and to evaluate outcomes attributed to SSIs. METHODS: The authors performed a nested case-control study of patients undergoing CRANI procedures between 2006 and 2010 at the University of Iowa Hospitals and Clinics. They identified 104 patients with SSIs and selected 312 controls. They collected data from medical records and used multivariate analyses to identify risk factors and outcomes associated with SSIs. RESULTS: Thirty-two percent of SSIs were caused by Staphylococcus aureus, 88% were deep incisional or organ space infections, and 70% were identified after discharge. Preoperative length of stay (LOS) ≥ 1 day was the only significant patient-related factor in the preoperative model (OR 2.1 [95% CI 1.2-3.4]) and in the overall model (OR 1.9 [95% CI 1.1-3.3]). Procedure-related risk factors that were significant in the overall model included Gliadel wafer use (OR 6.7 [95% CI 2.5-18.2]) and postoperative CSF leak (OR 3.5 [95% CI 1.4-8.5]). The preoperative SSI risk index, including body mass index, previous brain operation, chemotherapy on admission, preoperative LOS, procedure reason, and preoperative glucose level, had better predictive efficacy (c-statistic = 0.664) than the National Healthcare Safety Network risk index (c-statistic = 0.547; p = 0.004). Surgical site infections were associated with increased LOS during the initial hospitalizations (average increase of 50%) or readmissions (average increase of 100%) and with an increased risk of readmissions (OR 7.7 [95% CI 4.0-14.9]), reoperations (OR 36 [95% CI 14.9-87]), and death (OR 3.4 [95% CI 1.5-7.4]). CONCLUSIONS: Surgeons were able to prospectively assess a patient's risk of SSI based on preoperative risk factors and they could modify some processes of care to lower the risk of SSI. Surgical site infections substantially worsened patients' outcomes. Preventing SSIs after CRANI could improve patient outcomes and decrease health care utilization.

Surgical site infections and cellulitis after abdominal hysterectomy.

OBJECTIVES: To identify risk factors for and outcomes of surgical site infections and cellulitis after abdominal hysterectomies. STUDY DESIGN: We used logistic regression analysis to analyze data from a case-control study of 1104 patients undergoing abdominal hysterectomies at a university hospital between Jan. 1, 2007 and Dec. 30, 2010. RESULTS: Factors significantly associated with surgical site infections and with cellulitis were: pulmonary disease, operations done in Main Operating Room East, and seroma. Body mass index >35, no private insurance, and fluid and electrolyte disorders were risk factors for surgical site infections. The mean prophylactic dose of cefazolin was significantly higher for controls than for patients with surgical site infections. Preoperative showers with Hibiclens (Molnlycke Health Care US, LLC, Norcross, GA) and cefazolin prophylaxis were associated with a significantly decreased cellulitis risk. Surgical site infections and cellulitis were significantly associated with readmissions and return visits and surgical site infections were associated with reoperations. CONCLUSION: Preoperative showers, antimicrobial prophylaxis, surgical techniques preventing seromas, and the operating room environment may affect the risk of surgical site infections and cellulitis after abdominal hysterectomies.

Benefits of universal gloving on hospital-acquired infections in acute care pediatric units.

BACKGROUND: To prevent transmission, some pediatric units require clinicians to wear gloves for all patient contacts during RSV season. We sought to assess whether a mandatory gloving policy reduced the risk of other health care-acquired infections (HAIs). METHODS: This retrospective cohort study included all patients admitted to pediatric units of a tertiary care center between 2002 and 2010. Poisson regression models were used to measure the association between mandatory gloving and HAI incidence. Autoregressive models were used to adjust for time correlation. RESULTS: During the study period, 686 HAIs occurred during 363 782 patient-days. The risk of any HAI was 25% lower during mandatory gloving periods compared with during nongloving periods (relative risk [RR]: 0.75; 95% confidence interval [CI]: 0.69-0.93; P = .01), after adjusting for long-term trends and seasonal effect. Mandatory gloving was associated with lower risks of bloodstream infections (RR: 0.63; 95% CI: 0.49-0.81; P < .001), central line-associated bloodstream infections (RR: 0.61; 95% CI: 0.44-0.84; P = 0.003), and hospital-acquired pneumonia (RR: 0.20; 95% CI: 0.03-1.25; P= 0.09). The reduction was significant in the PICU (RR: 0.63; 95% CI: 0.42-0.93; P = .02), the NICU (RR: 0.62; 95% CI: 0.39-0.98; P = .04), and the Pediatric Bone Marrow Transplant Unit (RR: 0.52; 95% CI: 0.29-0.91, P = .02). CONCLUSIONS: Universal gloving during RSV season was associated with significantly lower rates of bacteremia and central line-associated bloodstream infections, particularly in the ICUs and the Pediatric Bone Marrow Transplant Unit.

Clinical significance of positive cranial bone flap cultures and associated risk of surgical site infection after craniotomies or craniectomies.

OBJECT: The risk of surgical site infection (SSI) after craniotomies or craniectomies in patients in whom contaminated bone flaps have been reimplanted has not been determined. The objectives of this study were to identify the prevalence of bone flaps with positive cultures--especially those contaminated with Propionibacterium acnes--to assess the risk of SSI after reimplanting (either during the initial operation or subsequently) bone flaps with positive cultures, and to identify risk factors for SSI following the initial craniotomies or craniectomies. METHODS: The authors conducted a retrospective review of cases in which patients underwent craniotomy/craniectomy procedures between January and October 2007 in the neurosurgery department at the University of Iowa Hospitals and Clinics. They also reviewed processes and procedures and did pulsed field gel electrophoresis of P. acnes isolates to look for a common source of contamination. They then conducted a prospective cohort study that included all patients who underwent craniotomy/craniectomy procedures between November 2007 and November 2008 and met the study criteria. For the cohort study, the authors obtained cultures from each patient's bone flap during the craniotomy/craniectomy procedures. Data about potential risk factors were collected by circulating nurses during the procedures or by a research assistant who reviewed medical records after the procedures. An infection preventionist independently identified SSIs through routine surveillance using the Centers for Disease Control and Prevention's definitions. Univariate and bivariate analyses were performed to determine the association between SSI and potential risk factors. RESULTS: The retrospective review did not identify specific breaks in aseptic technique or a common source of P. acnes. Three hundred seventy-three patients underwent 393 craniotomy/craniectomy procedures during the cohort study period, of which 377 procedures met the study criteria. Fifty percent of the bone flaps were contaminated by microorganisms, primarily skin flora such as P. acnes, coagulase-negative staphylococci, and Staphylococcus aureus. Reimplanting bone flaps that had positive culture results did not increase the risk of infection after the initial craniotomy/craniectomy procedures and the subsequent cranioplasty procedures (p = 0.80). Allowing the skin antiseptic to dry before the procedures (p = 0.04, OR 0.26) was associated with lower risk of SSIs. Female sex (p = 0.02, OR = 3.49) was associated with an increased risk of SSIs; Gliadel wafer implants (p = 0.001, OR = 8.38) were associated with an increased risk of SSIs after procedures to treat tumors. CONCLUSIONS: Operative factors such as the way the skin is prepared before the incision rather than the skin flora contaminants on the bone flaps may play an important role in the pathogenesis of SSIs after craniotomy/craniectomy. Gliadel wafers significantly increased the risk of SSI after procedures to treat tumors.

Infection control resources in Iowa.

BACKGROUND: The duties of infection control professionals (ICPs) have increased over time, but resources have not increased substantially. Numerous states have passed or have considered mandatory reporting laws for health care-associated infections. Such laws would increase ICPs' work further. METHODS: We conducted two surveys of ICPs in Iowa to determine their current responsibilities and resources and to estimate the resources they would need if they were required to report all nosocomial infections to the state. RESULTS: Most hospitals had less than 1 full time equivalent performing infection control (mean = 0.64). Many respondents had several roles within the hospital. Surveillance methods and scope varied by hospital size. Most ICPs did not use catheter days as the denominator for rates of bloodstream infections. Over 50% of Iowa's hospitals are critical access hospitals, most of which did not have intensive care units, and most had very few patients with central venous catheters. CONCLUSIONS: Hospitals in Iowa have limited resources for infection control. "One size fits all" public reporting systems are not appropriate for states like Iowa that have a few large hospitals and many small hospitals.

Improving methicillin-resistant Staphylococcus aureus surveillance and reporting in intensive care units.

BACKGROUND: Routine culturing of patients in intensive care units (ICUs) for methicillin-resistant Staphylococcus aureus (MRSA) identifies unrecognized carriers and facilitates timely isolation. However, the benefit of surveillance in detecting prevalent and incident carriers likely varies among ICUs. In addition, many assessments underestimate the incidence of acquisition by including prevalent carriers in the at-risk population. METHODS: We performed a retrospective cohort study using accurate at-risk populations to evaluate the range of benefit of admission and weekly surveillance cultures in detecting otherwise unrecognized MRSA in 12 ICUs in 5 states. RESULTS: We assessed 142 ICU-months. Among the 12 ICUs, the admission prevalence of imported MRSA was 5%-21%, with admission surveillance providing 30%-135% increases in rates of detection. The monthly hospital-associated incidence was 2%-6%, with weekly surveillance providing 7%-157% increases in detection. The common practice of reporting incidence using the total number of patients or total patient-days underestimated incidence by one-third. Surgical ICUs had lower MRSA importation but higher MRSA incidence. Overall, routine surveillance prevented the misclassification of 17% (unit range, 11%-29%) of "incident" carriers, compared with clinical cultures, and increased precaution days by 18% (unit range, 11%-91%). CONCLUSIONS: Routine surveillance significantly increases the detection of MRSA, but this benefit is not uniform across ICUs, even with high compliance and the use of correct denominators.

Improving the assessment of vancomycin-resistant enterococci by routine screening.

BACKGROUND: As infection with vancomycin-resistant enterococci (VRE) increases in hospitals, knowledge about VRE reservoirs and improved accuracy of epidemiologic measures are needed. Many assessments underestimate incidence by including prevalent carriers in at-risk populations. Routine surveillance cultures can substantially improve prevalence and incidence estimates, and assessing the range of improvement across diverse units is important. METHODS: We performed a retrospective cohort study using accurate at-risk populations to evaluate the range of benefit of admission and weekly surveillance cultures in detecting unrecognized VRE in 14 patient-care units. RESULTS: We assessed 165 unit-months. The admission prevalence of VRE was 2.2%-27.2%, with admission surveillance providing 2.2-17-fold increased detection. Medical units were significantly more likely to admit VRE carriers than were surgical units. Monthly incidence was 0.8%-9.7%, with weekly surveillance providing 3.3-15.4-fold increased detection. The common practice of reporting incidence using the total number of patients, rather than patients at risk, underestimated incidence by one-third. Overall, routine surveillance prevented the misclassification of 43.0% (unit range, 0%-85.7%) of "incident" carriers on the basis of clinical cultures alone and increased VRE precaution days by 2.4-fold (unit range, 2.0-2.6-fold). CONCLUSIONS: Routine surveillance markedly increases the detection of VRE, despite variability across patient-care units. Correct denominators prevent the substantial underestimation of incidence.

Predominance of a single restriction endonuclease analysis group with intrahospital subgroup diversity among Clostridium difficile isolates at two Chicago hospitals.

OBJECTIVE: To determine the epidemiology and relatedness of Clostridium difficile isolates in two geographically separated hospitals in a large metropolitan area, each with unique patients and personneL DESIGN: Observational descriptive molecular epidemiology of clinical C. difficile isolates. SETTING: Two tertiary-care hospitals in Chicago. METHODS: Consecutive C. difficile isolates from the clinical laboratory of a Veterans Affairs hospital during a 13-month period were typed by restriction endonuclease analysis (REA). During an overlapping 3-month period, stool specimens that tested positive for C. difficile toxin from patients at a nearby county hospital were cultured and the recovered isolates typed by the same method. RESULTS: Nineteen (68%) of 28 nosocomial isolates at the smaller, Veterans Affairs hospital belonged to REA group K. Within this group of closely related strains, 9 distinct REA types were recognized. Twenty-one (72%) of 29 nosocomial isolates at the larger, county hospital also belonged to group K. However, the predominant REA types within group K differed markedly at each institution. CONCLUSIONS: These findings demonstrate a high degree of similarity among nosocomial C. difficile strains from different hospitals in the same city and suggest the possibility of an extended outbreak of a prototype group K strain with subsequent genetic drift at the two different institutions.

Molecular epidemiology of methicillin-resistant Staphylococcus aureus in a Veterans Administration Medical Center.

OBJECTIVES: To determine whether patients who were colonized or infected with methicillin-resistant Staphylococcus aureus (MRSA) persistently carried the same strain and to identify the extent of strain variation within a population of patients. DESIGN: Molecular typing by pulsed-field gel electrophoresis (PFGE) of stored MRSA isolates. SETTING: A Veterans Administration Medical Center with 288 hospital, 45 intermediate-care, and 75 extended-care beds. ISOILATES: Between January 1991 and March 1993, 91 patients had MRSA identified in routine cultures. One hundred isolates from 57 patients (63%) were available for typing. RESULTS: Before 1988, only occasional MRSA isolates were identified. By 1993, 50% of S. aureus isolates from unique patients were resistant to methicillin. PFGE identified 7 MRSA strains, 3 of which were identified in specimens from 1 patient each. The most common strains were SD4 (20 patients), SD1 (12 patients), SD2 (12 patients), and SD5a (5 patients). Twenty patients had 2 or more isolates obtained at least 1 week apart (mean, 30.7 weeks; range, 1 to 102 weeks). Of these patients, 12 were colonized or infected with only one strain (mean time observed, 25.1 weeks; range, 1 to 82 weeks). Eight patients had at least 2 different strains (mean time observed, 39 weeks; range, 2 to 102 weeks). CONCLUSION: Numerous MRSA strains circulated in this endemic setting, 40% of patients observed over time were colonized or infected with more than one strain. Molecular typing was an essential tool for evaluating the epidemiology of MRSA in this setting.