CDC/NHSN surveillance definition of health care-associated infection and criteria for specific types of infections in the acute care setting

International Nosocomial Infection Control Consortium (INICC) report, data summary for 2003-2008, issued June 2009

We report the results of the International Infection Control Consortium (INICC) surveillance study from January 2003 through December 2008 in 173 intensive care units (ICUs) in Latin America, Asia, Africa, and Europe. During the 6-year study, using Centers for Disease Control and Prevention (CDC) US National Healthcare Safety Network (NHSN; formerly the National Nosocomial Infection Surveillance system [NNIS]) definitions for device-associated health care-associated infection, we collected prospective data from 155,358 patients hospitalized in the consortium's hospital ICUs for an aggregate of 923,624 days. Although device utilization in the developing countries' ICUs was remarkably similar to that reported from US ICUs in the CDC's NHSN, rates of device-associated nosocomial infection were markedly higher in the ICUs of the INICC hospitals: the pooled rate of central venous catheter (CVC)-associated bloodstream infections (BSI) in the INICC ICUs, 7.6 per 1000 CVC-days, is nearly 3-fold higher than the 2.0 per 1000 CVC-days reported from comparable US ICUs, and the overall rate of ventilator-associated pneumonia (VAP) was also far higher, 13.6 versus 3.3 per 1000 ventilator-days, respectively, as was the rate of catheter-associated urinary tract infection (CAUTI), 6.3 versus 3.3 per 1000 catheter-days, respectively. Most strikingly, the frequencies of resistance of Staphylococcus aureus isolates to methicillin (MRSA) (84.1% vs 56.8%, respectively), Klebsiella pneumoniae to ceftazidime or ceftriaxone (76.1% vs 27.1%, respectively), Acinetobacter baumannii to imipenem (46.3% vs 29.2%, respectively), and Pseudomonas aeruginosa to piperacillin (78.0% vs 20.2%, respectively) were also far higher in the consortium's ICUs, and the crude unadjusted excess mortalities of device-related infections ranged from 23.6% (CVC-associated bloodstream infections) to 29.3% (VAP).

Risk factors associated with methicillin resistance among Staphylococcus aureus infections in veterans

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is an emerging concern in infectious disease practice. Although MRSA infections occur in a wide variety of anatomic sites, the majority of studies considering the risk factors for methicillin resistance among S. aureus infections have focused on MRSA bacteremia.

OBJECTIVE

To describe risk factors associated with methicillin resistance among S. aureus infections at different anatomic sites.

METHODS

We collected information on the demographic and clinical characteristics of patients examined at the Atlanta Veterans Affairs Medical Center with S. aureus infections during the period from June 2007 through May 2008. We used multivariate logistic regression to describe factors significantly associated with methicillin resistance.

RESULTS

There were 568 cases of S. aureus infection among 528 patients. We identified 352 cases (62%) of MRSA infection and 216 cases (38%) of methicillin-sensitive S. aureus infection. The adjusted odds of methicillin resistance were higher among infections that occurred among patients who had a prior history of MRSA infection (odds ratio [OR], 3.9 [95% confidence interval {CI}, 2.3-6.4]) or resided in a long-term care facility during the past 12 months (OR, 2.0 [95% CI, 1.0-4.0]) but were lower for infections that occurred among patients who had undergone a biopsy procedure during the past 12 months (OR, 0.7 [95% CI, 0.6-0.9]). Most cases of infection were community-onset infections (523 [92%] of 568 cases), and about one-half (278 [49%]) were not healthcare associated.

CONCLUSIONS

Compared with previous studies of methicillin resistance among patients with S. aureus bacteremia, we found similar factors to be associated with methicillin resistance among S. aureus isolates recovered from more diverse anatomic sites of infection. Of note, nearly one-half of our cases of MRSA infection were not healthcare associated.

Risk factors for endometritis after low transverse cesarean delivery

OBJECTIVE

To determine independent risk factors for endometritis after low transverse cesarean delivery.

STUDY DESIGN

We performed a retrospective case-control study during the period from July 1999 through June 2001 in a large tertiary care academic hospital. Endometritis was defined as fever beginning more than 24 hours or continuing for at least 24 hours after delivery plus fundal tenderness in the absence of other causes for fever. Independent risk factors for endometritis were determined by means of multivariable logistic regression. A fractional polynomial method was used to examine risk of endometritis associated with the continuous variable, duration of rupture of membranes.

RESULTS

Endometritis was identified in 124 (7.7%) of 1,605 women within 30 days after low transverse cesarean delivery. Independent risk factors for endometritis included age (odds ratio [OR] for each additional year, 0.93 [corrected] [95% confidence interval {CI}, 0.90-0.97]) and anemia or perioperative blood transfusion (OR, 2.18 [CI, 1.30-3.68]). Risk of endometritis was marginally associated with a proxy for low socioeconomic status, lack of private health insurance (OR, 1.72 [CI, 0.99-3.00]); with amniotomy (OR, 1.69 [CI, 0.97-2.95]); and with longer duration of rupture of membranes.

CONCLUSION

Risk of endometritis was independently associated with younger age and anemia and was marginally associated with lack of private health insurance and amniotomy. The odds of endometritis increased approximately 1.7-fold within 1 hour after rupture of membranes, but increased duration of rupture was only marginally associated with increased risk. Knowledge of these risk factors can guide selective use of prophylactic antibiotics during labor and heighten awareness of the risk in subgroups at highest risk of infection.

Implementing a unit-level intervention to reduce the probability of ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is the second most common hospital-acquired infection and is associated with high morbidity and mortality rates for mechanically ventilated patients in the intensive care unit. Routine nursing interventions have been shown to reduce VAP rates.

OBJECTIVES

The purpose of this study was to evaluate the effectiveness of a unit-specific education intervention that emphasized hand hygiene, head-of-the-bed elevation, and oral care. The goals were to improve staff compliance with hand washing, head-of-the-bed elevation, and oral care; to decrease VAP rates, and to decrease number of ventilator days.

METHODS

Two-hour observations were conducted on a convenience sample of 100 ventilated patients not diagnosed with VAP and the clinical staff that interacted with them. Instrumentation included a compliance checklist, a demographic patient survey, and the Acute Physiology and Chronic Health Evaluation AEIV tool. Unit-specific educational interventions were designed and implemented on each participating unit.

RESULTS

: The VAP and the ventilator day rates did not improve significantly. There were no significant changes in clinician adherence to hand hygiene, provision of oral care, or patient positioning.

DISCUSSION

Despite implementation of both structured and creative education, team-based approach, and frequent staff reminders, patient outcomes and staff compliance did not improve significantly. Unit-based education interventions may not be the best strategy to facilitate change. Organizations with frequent changes in personnel and leadership may not have the unit-level infrastructure necessary to attain and sustain change.

Nasopharyngeal colonization with methicillin-resistant staphylococcus aureus and mortality among patients in an intensive care unit

Nasopharyngeal colonization with Methicillin-resistant Staphylococcus aureus (MRSA) is common in critically ill patients, but its effect on patient prognosis is not fully elucidated. A retrospective cohort study was carried out enrolling 122 patients from an intensive care unit who were screened weekly for nasopharyngeal colonization with MRSA. The outcomes of interest were: general mortality and mortality by infection. Several exposure variables (severity of illness, procedures, intercurrences and MRSA nasopharyngeal colonization) were analyzed through univariate and multivariable models. Factors significantly associated with mortality in general or due to infection were: APACHE II and lung disease. The performance of surgery predicted favorable outcomes. MRSA colonization did not predict mortality in general (OR=1.02; 95%CI=0.35-3.00; p=0.97) or by infectious causes (OR=0.96; 95%CI=0.33-2.89; p=0.96). The results suggest that, in the absence of severity of illness factors, colonization with MRSA is not associated with unfavorable outcomes.

A surgical site infection cluster: the process and outcome of an investigation--the impact of an alcohol-based surgical antisepsis product and human behavior

BACKGROUND

The institution of a process used to successfully execute a perioperative antibiotic administration system is but 1 component of preventing postoperative infections. Continued surveillance of infections is an important part of the process of decreasing postoperative infections. We recently experienced an increase in the number of postoperative infections in our patients. Using standard infection control methods of outbreak investigation, we tracked multiple variables to search for a common cause. We describe herein the process by which Quality Improvement methodology was used to investigate and manage this surgical site infection (SSI) cluster.

METHODS

As part of routine surveillance for SSI, the infection control division seeks out evidence of postoperative infections. Patients were defined as having an SSI according to National Healthcare Safety Network SSI criteria. SSI data are reviewed monthly and aggregated on a quarterly basis. The SSI rate was above our usual level for 3 consecutive quarters of 2007. This increase in the infection rate led to an internal outbreak investigation, termed a "cluster investigation." This investigation comprised multiple concurrent methods including manual chart review of all cases; review of microbiological data; and inspection of operating rooms, instrument processing facilities, and storage areas.

RESULTS

During 3 quarters, a trend emerged in our general surgical population that demonstrated that 4 surgical types had a sustained increase in SSI. The institutional antibiotic protocol was appropriate for prevention of the majority of these SSIs. As part of the investigation, direct observation of hand hygiene and surgical hand antisepsis technique was undertaken. At this time, there were 2 types of surgical hand preparation being used, at the discretion of the clinician: either a "standard" scrub with an antimicrobial soap or the application of a chlorhexidine gluconate and alcohol-based surgical hand antisepsis product. Observers noted improper use of this alcohol-based surgical hand antiseptic. This product was withdrawn from our operating rooms, and the SSI rate markedly decreased in the following 2 quarters.

DISCUSSION

In conclusion, we report the results of a quality improvement process that investigated a 3-quarter increase in our SSI rate. An investigation was undertaken, and it was thought that the (mis)use of an alcohol-based hand antiseptic product was associated with the increased infection rate. Removing this product, along with reemphasizing the importance of infection control, was associated with a decrease in the infection rate to a level at or below our historical rate.

Nosocomial infections prevalence study in a Serbian university hospital

BACKGROUND/AIM

Nosocomial infections (NI) are a serious health problem resulting in an enromous burden of excess morbidity and mortaliti rates, and health care costs. The aim of this study was to assess the prevalence of NI and to identify groups of patients at special risk for NI in the University Clinical Center, Kragujevac, Serbia.

METHODS

A period prevalence study design was used in this study. A survey of NI included all patients hospitalized in all departments in the University Clinical Center, Kragujevac.

RESULTS

Among 764 patients surveyed, the global prevalence rate of patients with at least one NI was 6.2% (95% CI = 5.6-6.8), while the prevalence of NI was 7.1%. The most frequent infections were surgical site infections (14.1%; 95% CI = 12.9-15.3), followed by pneumonia (2.3%; 95% CI = 2.1-2.5) in surgical patients. In medical wards, the most common NI were skin and subcutaneous tissue infections (1.6%; 95% CI = 1.4-1.8), and urinary infections (1.4%; 95% CI = 1.3-1.5). Overall, 85.1% NI were culture-proven; the leading pathogens were Pseudomonas species (40.0%), followed by Staphylococcus species (25.0%), Escherichia coli (22.5%), Proteus mirabilis (17.5%) and Klebsiella-Enterobacter (12.5%). Multivariate logistic regression analysis identified 3 risk factors independently associated with NI appearance: hospital stay > or =8 days (p = 0.0015), urinary catheter (p = 0.0022) and antibiotic use (p < 0.001).

CONCLUSION

This study showed that NI are a serious health problem in our hospital. The most common infections were surgical site infections, followed by skin and subcutaneous tissue infection and urinary tract infections. Nosocomial infections were most common in patients in urological and orthopedic departments, and then in intensive care units. Prolonged hospital stay, urinary catheter and antibiotic exposure were risk factors independently associated with NI appearance.

Independent risk factors for infection in tissue expander breast reconstruction

BACKGROUND

Postoperative infection in tissue expander breast reconstruction causes increased morbidity, cost, and suboptimal patient outcomes. To improve outcomes, it is important to preoperatively identify factors that might predispose to infection and minimize them when possible. It is hypothesized that certain patient characteristics are associated with an increased infection rate.

METHODS

A retrospective, 6-year, single-institution review of patient records was performed from 413 tissue expanders placed in 300 women for postmastectomy breast reconstruction. Infection was defined as any case where antibiotics were given in response to clinical signs of infection. Fourteen potential risk factors were analyzed. A generalized estimation equations approach was used to perform univariable and multivariable analyses.

RESULTS

Antibiotics were given to treat clinical infection in 68 of 413 expanders (16.5 percent), with a median time to diagnosis of 6.5 weeks (range, 1 to 52 weeks). Univariable analysis showed significant association with breast size larger than C cup (p < 0.001), previous irradiation (p = 0.007), repeated implant (p = 0.008), and delayed reconstruction (p = 0.04). All variables except delayed reconstruction remained significant (p < 0.002 for all) in a multivariable model. Additional significant covariates in this model included one surgical oncologist (p = 0.003) and contralateral surgery (p = 0.046). Given infection, one surgical oncologist was associated with an increased rate of mastectomy flap necrosis (p = 0.01).

CONCLUSIONS

Certain patient characteristics are associated with increased infection in tissue expansion breast reconstruction. Understanding how these predispose to infection requires additional study. Patients identified with these characteristics should be educated about these risks and other reconstructive options to optimize the success of their breast reconstruction.

Validation of statewide surveillance system data on central line-associated bloodstream infection in intensive care units in Australia

OBJECTIVE

To measure the interobserver agreement, sensitivity, specificity, positive predictive value, and negative predictive value of data submitted to a statewide surveillance system for identifying central line-associated bloodstream infection (BSI).

DESIGN

Retrospective review of hospital medical records comparing reported data with gold standard according to definitions of central line-associated BSI.

SETTING

Six Victorian public hospitals with more than 100 beds.

METHODS

Reporting of surveillance outcomes was undertaken by infection control practitioners at the hospital sites. Retrospective evaluation of the surveillance process was carried out by independent infection control practitioners from the Victorian Hospital Acquired Infection Surveillance System (VICNISS). A sample of records of patients reported to have a central line-associated BSI were assessed to determine whether they met the definition of central line-associated BSI. A sample of records of patients with bacteremia in the intensive care unit during the assessment period who were not reported as having central line-associated BSI were also assessed to see whether they met the definition of central line-associated BSI.

RESULTS

Records of 108 patients were reviewed; the agreement between surveillance reports and the VICNISS assessment was 67.6% (k = 0.31). Of the 46 reported central line-associated BSIs, 27 were confirmed to be central line-associated BSIs, for a positive predictive value of 59% (95% confidence interval [CI], 43%-73%). Of the 62 cases of bacteremia reviewed that were not reported as central line-associated BSIs, 45 were not associated with a central line, for a negative predictive value of 73% (95% CI, 60%-83%). Estimated sensitivity was 35%, and specificity was 87%. The positive likelihood ratio was 3.0, and the negative likelihood ratio was 0.72.

DISCUSSION

The agreement between the reporting of central line-associated BSI and the gold standard application of definitions was unacceptably low. False-negative results were problematic; more than half of central line-associated BSIs may be missed in Victorian public hospitals.

Economic and clinical contributions of an antimicrobial barrier dressing: a strategy for the reduction of surgical site infections

OBJECTIVE

In patients at risk of surgical site infection (SSI), there is evidence that an antimicrobial barrier dressing (Acticoat* ) applied immediately post-procedure is effective in reducing the incidence of infection. The objective of this study was to assess when it is appropriate to use an antimicrobial barrier dressing rather than a post-operative film dressing, by evaluating the net cost and budget impact of the two strategies.

METHODS

An economic model was developed, which estimates expected expenditure on dressings and the expected costs of surgical site infection during the initial inpatient episode, based on published literature on the pre-discharge costs of surgical infection and the efficacy of an antimicrobial barrier dressing in preventing SSI.

RESULTS

At an SSI risk of 10%, an antimicrobial barrier dressing strategy is cost neutral if the incidence of infection is reduced by at least 9% compared with a post-operative film dressing. At 35% efficacy, expenditure on dressings would be higher by £30,760 per 1000 patients, and the cost of treating infection would be lower by £111,650, resulting in a net cost saving of £80,890. The break-even infection risk for cost neutrality is 2.6%.

LIMITATIONS

Although this cost analysis is based on published data, there are limitations in methodology: the model is dependent on and subject to the limitations of the data used to populate it. Further studies would be useful to increase the robustness of the conclusions, particularly in a broader range of surgical specialties.

CONCLUSIONS

A strategy involving the use of an antimicrobial barrier dressing in patients at moderate (5-10%) or high (>10%) risk of infection appears reasonable and cost saving in light of the available clinical evidence.

Calculating the frequency of serious reportable adverse events and hospital-acquired conditions

The Centers for Medicare and Medicaid Services (CMS) mandated that Medicare Advantage Organizations (MAOs) begin reporting the number of serious reportable adverse events and hospital-acquired conditions received on Medicare claims. There are additional state mandates and health insurance plan requirements. The author provides an analysis of the reporting methodology and proposes an alternative approach using rate-based formulas that would yield information that is more useful.

Clinical pharmacodynamics of cefepime in patients infected with Pseudomonas aeruginosa

We evaluated cefepime exposures in patients infected with Pseudomonas aeruginosa to identify the pharmacodynamic relationship predictive of microbiological response. Patients with non-urinary tract P. aeruginosa infections and treated with cefepime were included. Free cefepime exposures were estimated by using a validated population pharmacokinetic model. P. aeruginosa MICs were determined by Etest and pharmacodynamic indices (the percentage of the dosing interval that the free drug concentration remains above the MIC of the infecting organism [fT > MIC], the ratio of the minimum concentration of free drug to the MIC [fC(min)/MIC], and the ratio of the area under the concentration-time curve for free drug to the MIC [fAUC/MIC]) were calculated for each patient. Classification and regression tree analysis was used to partition the pharmacodynamic parameters for prediction of the microbiological response. Monte Carlo simulation was utilized to determine the optimal dosing regimens needed to achieve the pharmacodynamic target. Fifty-six patients with pneumonia (66.1%), skin and skin structure infections (SSSIs) (25%), and bacteremia (8.9%) were included. Twenty-four (42.9%) patients failed cefepime therapy. The MICs ranged from 0.75 to 96 microg/ml, resulting in median fT > MIC, fC(m)(in)/MIC, and fAUC/MIC exposures of 100% (range, 0.8 to 100%), 4.3 (range, 0.1 to 27.3), and 206.2 (range, 4.2 to 1,028.7), respectively. Microbiological failure was associated with an fT > MIC of < or =60% (77.8% failed cefepime therapy when fT > MIC was < or =60%, whereas 36.2% failed cefepime therapy when fT > MIC was >60%; P = 0.013). A similar fT > MIC target of < or =63.9% (P = 0.009) was identified when skin and skin structure infections were excluded. While controlling for the SSSI source (odds ratio [OR], 0.18 [95% confidence interval, 0.03 to 1.19]; P = 0.07) and combination therapy (OR, 2.15 [95% confidence interval, 0.59 to 7.88]; P = 0.25), patients with fT > MIC values of < or =60% were 8.1 times (95% confidence interval, 1.2 to 55.6 times) more likely to experience a poor microbiological response. Cefepime doses of at least 2 g every 8 h are required to achieve this target against CLSI-defined susceptible P. aeruginosa organisms in patients with normal renal function. In patients with non-urinary tract infections caused by P. aeruginosa, achievement of cefepime exposures of >60% fT > MIC will minimize the possibility of a poor microbiological response.

[Nosocomial infections. Evidence based infection control measures]

Nosocomial infections remain a major side effect of medical care and are at least in part preventable. Evidence-based, valid infection control recommendations are needed based on multidisciplinary development with local adjustment and incorporation into every-day practice. The article reviews the special aspects which have to be considered for producing evidence based guidelines in the field of infection control. However, guidelines designed to prevent nosocomial infections may be ignored even in the face of persuasive scientific evidence. Insufficient compliance to hand hygiene is the most prominent example. Factors which impede the process of translating research findings into infection control practice have to be identified and suggestions how these barriers may be overcome should be provided.

Effectiveness of oral rinse with chlorhexidine in preventing nosocomial respiratory tract infections among intensive care unit patients

OBJECTIVE

To evaluate the effectiveness of the oral application of a 0.12% solution of chlorhexidine for prevention of respiratory tract infections among intensive care unit (ICU) patients.

DESIGN

The study design was a double-blind, randomized, placebo-controlled trial.

SETTING

The study was performed in an ICU in a tertiary care hospital at a public university. PATIENTS. Study participants comprised 194 patients admitted to the ICU with a prospective length of stay greater than 48 hours, randomized into 2 groups: those who received chlorhexidine (n = 98) and those who received a placebo (n = 96).

INTERVENTION

Oral rinses with chlorhexidine or a placebo were performed 3 times a day throughout the duration of the patient's stay in the ICU. Clinical data were collected prospectively.

RESULTS

Both groups displayed similar baseline clinical features. The overall incidence of respiratory tract infections (RR, 1.0 [95% confidence interval [CI], 0.63-1.60]) and the rates of ventilator-associated pneumonia per 1,000 ventilator-days were similar in both experimental and control groups (22.6 vs 22.3; P = .95). Respiratory tract infection-free survival time (7.8 vs 6.9 days; P = .61), duration of mechanical ventilation (11.1 vs 11.0 days; P = .61), and length of stay (9.7 vs 10.4 days; P = .67) did not differ between the chlorhexidine and placebo groups. However, patients in the chlorhexidine group exhibited a larger interval between ICU admission and onset of the first respiratory tract infection (11.3 vs 7.6 days; P = .05). The chances of surviving the ICU stay were similar (RR, 1.08 [95% CI, 0.72-1.63]).

CONCLUSION

Oral application of a 0.12% solution of chlorhexidine does not prevent respiratory tract infections among ICU patients, although it may retard their onset.

The Spanish national health care-associated infection surveillance network (INCLIMECC): data summary January 1997 through December 2006 adapted to the new National Healthcare Safety Network Procedure-associated module codes

BACKGROUND

In 1997, a national standardized surveillance system (designated INCLIMECC [Indicadores Clínicos de Mejora Continua de la Calidad]) was established in Spain for health care-associated infection (HAI) in surgery patients, based on the National Nosocomial Infection Surveillance (NNIS) system. In 2005, in its procedure-associated module, the National Healthcare Safety Network (NHSN) inherited the NNIS program for surveillance of HAI in surgery patients and reorganized all surgical procedures.

METHODS

INCLIMECC actively monitors all patients referred to the surgical ward of each participating hospital. We present a summary of the data collected from January 1997 to December 2006 adapted to the new NHSN procedures.

RESULTS

Surgical site infection (SSI) rates are provided by operative procedure and NNIS risk index category. Further quality indicators reported are surgical complications, length of stay, antimicrobial prophylaxis, mortality, readmission because of infection or other complication, and revision surgery.

CONCLUSION

Because the ICD-9-CM surgery procedure code is included in each patient's record, we were able to reorganize our database avoiding the loss of extensive information, as has occurred with other systems.

Complications of infection in pediatric spine surgery

Pediatric spinal surgery postoperative infections are highly variable, ranging from acute postoperative infections necessitating urgent, and probably repeated, irrigation and debridement with retention of spinal implants to delayed, insidious-appearing infections that smolder. Appreciation of the pathophysiology, bacterial organisms, risk factors and preventative measures are paramount in minimizing not only potentially devastating individual patient outcomes but also in recognizing the tremendous economic burden placed on our healthcare system. The history, physical examination, laboratory values and radiographic imaging of these delayed infections can be underwhelming. Awareness and heightened clinical suspicion must be maintained in order to accurately diagnose these surgical site infections. Experience and keen clinical intuition effectively preserve the ultimate goals of pediatric spinal surgery, mainly halting the progression of deformity and safely correcting existing deformity, allowing physiologic musculoskeletal and other visceral functions to occur. With timely diagnosis, surgical debridement, hardware removal with or without reinstrumentation and fusion, and guided antimicrobial therapy can affect good outcomes.

Clinical Performance and Nursing Satisfaction of a Transparent Chlorhexidine Gluconate IV Securement Dressing with Peripherally Inserted Central Catheters

Background: Bloodstream Infections (BSI) caused by central venous catheters, including peripherally inserted central catheters, can result in longer patient stays and increased complications. Using methods of best practice is needed to reduce the occurrence of these infections.

Objective: To evaluate both the clinical performance and nursing satisfaction is using the 3M Tegaderm CHG IV Securement Dressing®.

Methods: Prospective, controlled, convenience sampling and in a single center, comparing using the 3M Tegaderm CHG IV Securement Dressing® to a regular transparent semi-permeable dressing There were a total of 107 patients in the study sample, and 110 patients in the control sample.

Results: The results of the satisfaction survey for the investigational dressing group compared with the control dressing group reflected significant p-values of the following primary efficacy variable (1–5 Likert scale), “Overall performance of dressing” (p=0.019951).

Conclusions: The 3M Tegaderm CHG IV Securement Dressing® was easy to apply, able to absorb fluid and mold and conform around the PICC catheters, and rated highly by staff nurses for overall performance of the dressing compared to control dressing.

Detection and characterization of heterogeneous vancomycin-intermediate Staphylococcus aureus isolates in Canada: results from the Canadian Nosocomial Infection Surveillance Program, 1995-2006

We describe the epidemiology of heterogeneously resistant Staphylococcus aureus (hVISA) identified in Canadian hospitals between 1995 and 2006. hVISA isolates were confirmed by the population analysis profiling-area under the curve method. Only 25 hVISA isolates (1.3% of all isolates) were detected. hVISA isolates were more likely to have been health care associated (odds ratio [OR], 5.1; 95% confidence interval [CI], 1.9 to 14.2) and to have been recovered from patients hospitalized in central Canada (OR, 3.0; 95% CI, 1.2 to 7.4). There has been no evidence of vancomycin "MIC creep" in Canadian strains of methicillin (meticillin)-resistant S. aureus, and hVISA strains are currently uncommon.

Reducing use of indwelling urinary catheters and associated urinary tract infections

BACKGROUND

Use of indwelling urinary catheters can lead to complications, most commonly catheter-associated urinary tract infections. Duration of catheterization is the major risk factor. These infections can result in sepsis, prolonged hospitalization, additional hospital costs, and mortality.

OBJECTIVES

To implement and evaluate the efficacy of an intervention to reduce catheter-associated urinary tract infections in a medical intensive care unit by decreasing use of urinary catheters.

METHODS

Indications for continuing urinary catheterization with indwelling devices were developed by unit clinicians. For a 6-month intervention period, patients in a medical intensive care unit who had indwelling urinary catheters were evaluated daily by using criteria for appropriate catheter continuance. Recommendations were made to discontinue indwelling urinary catheters in patients who did not meet the criteria. Days of use of a urinary catheter and rates of catheter-associated urinary tract infections during the intervention were compared with those of the preceding 11 months.

RESULTS

During the study period, 337 patients had a total of 1432 days of urinary catheterization. With use of guidelines, duration of use was significantly reduced to a mean of 238.6 d/mo from the previous rate of 311.7 d/mo. The number of catheter-associated urinary tract infections per 1000 days of use was a mean of 4.7/mo before the intervention and zero during the 6-month intervention period.

CONCLUSIONS

Implementation of an intervention to judge appropriateness of indwelling urinary catheters may result in significant reductions in duration of catheterization and occurrences of catheter-associated urinary tract infections.

Nosocomial Infections among Pediatric Patients with Neoplastic Diseases

Background. Pediatric patients with neoplastic diseases are more likely to develop nosocomial infections (NIs). NIs may prolong their hospital stay, and increase morbidity and mortality. Objectives. The objectives of this study were to determine: (1) the incidence of NIs, (2) sites of NIs, (3) causal organisms, and (4) outcomes of NIs among pediatric patients with neoplastic diseases. Methods. This study was a prospective cohort study of pediatric patients with neoplastic diseases who were admitted to the Chiang Mai University Hospital, Thailand. Results. A total of 707 pediatric patients with neoplastic diseases were admitted. Forty-six episodes of NIs in 30 patients were reported (6.5 NIs/100 admission episodes and 7 NIs/1000 days of hospitalization). Patients with acute lymphoblastic leukemia had the highest number of NIs (41.3%). The most common causal organisms were gram-negative bacteria (47.1%). Patients who had undergone invasive procedures were more likely to develop NIs than those who had not (P < .05). The mortality rate of patients with NIs was 19.6%. Conclusion. Pediatric patients with neoplastic diseases are more likely to develop NIs after having undergone invasive procedures. Pediatricians should be aware of this and strictly follow infection control guidelines in order to reduce morbidity and mortality rates related to NIs.

Mortality for intra-abdominal infection is associated with intrinsic risk factors rather than the source of infection

BACKGROUND

Intra-abdominal infections (IAIs) are an important cause of mortality and morbidity. Nosocomial IAIs (NIAIs) have been associated with higher mortality than community-acquired IAIs (CIAIs). We hypothesized that intrinsic risk factors were a better predictor of mortality than the type of infection.

METHODS

Patients with IAI treated at a single urban academic hospital over 8 years (June 1999-June 2007) were retrospectively reviewed. Data collected included demographics, comorbidities, source of infection, type of infection (community vs nosocomial), type of intervention (operation versus percutaneous drainage), and postoperative complications. Charlson Comorbidity Index and multiple organ dysfunction (MOD) scores were evaluated at admission and on postoperative day 7 (POD-7).

RESULTS

There were 452 patients; 234 (51.8%) had CIAI and 218 (48.2%) had NIAI. The mean age was 51.3 +/- 0.8. The most common source of CIAI was the appendix (n = 129, 28.5%); 137 patients with NIAI had postoperative infections (30.3%). When patients with appendicitis were excluded, there was no difference in mortality or complications between patients with CIAI and NIAI. Logistic regression analysis demonstrated catheter-related bloodstream infection (P < .001; OR 7.3, 95% CI, 2.5-22.2), cardiac event (P < .001; OR 6.0, 95% CI, 2.3-16.1), and age > or = 65 (P = .009; OR 3.8, 95% CI, 1.4-8.8) to be independent risk factors for mortality. Among patients who failed initial therapy, a non-appendiceal source of infection (P < .001; OR 4.7, 95% CI, 2.3-9.8) and a Charlson score > or =2 (P = .033; OR 1.6, 95% CI, 1.0-2.6) were determined to be independent risk factors. Non-appendiceal source of infection (P = .001, OR 3.3, 95% CI, 1.6-7.0) and POD-7 MOD score > or =4 (P < .001; OR 3.4, 95% CI, 1.9-6.0) were found to be independent predictors for re-intervention.

CONCLUSION

These results suggest mortality from IAI is strongly related to age and organ dysfunction; however, catheter-related bloodstream infection and postoperative cardiac events have a greater effect on outcome.

The Problems Diagnosing Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) is the most common healthcare-associated infection in the intensive care unit. Clinical, radiological and microbiological criteria are used to make the diagnosis, but there is no consensus definition, as no individual criterion or combination of criteria offer sufficient diagnostic accuracy to support their sole use in defining VAP. Neither invasive bronchoscopic sampling nor less invasive quantitative tracheal aspirate, conveys an advantage when making the microbiological diagnosis of VAP. Of the scoring systems and definitions presently in use, the Clinical Pulmonary Infection Score (CPIS) has been shown to be prone to inter-observer variability; the US Centers for Disease Control (CDC) National Healthcare Safety Network (NHSN) definition relies heavily on subjective clinical criteria, and the Hospitals in Europe Link for Infection Control through Surveillance (HELICS) criteria employ similarly subjective clinical criteria with five different possibilities for microbiological diagnosis. The use of these different diagnostic methods leads to marked variation in the reported incidence of VAP. Clinical practice requires an objective and transferable definition for VAP so that we can improve the reporting, monitoring and treatment of VAP.

Large dissemination of VIM-2-metallo-{beta}-lactamase-producing pseudomonas aeruginosa strains causing health care-associated community-onset infections

During a 3-year period (May 2005 to April 2008), a series of 45 outpatients presented with community-onset urinary tract infections due to carbapenem-resistant Pseudomonas aeruginosa isolates. Forty of them had a history of previous hospitalization or exposure to healthcare facilities, while the remaining five had not been previously admitted to our healthcare facilities or elsewhere within the preceding 12 months. In 18 outpatients, the carbapenem-resistant organisms caused recurrent community-onset urinary tract infections, while in three outpatients the organisms were also implicated in bacteremic episodes. All 45 single-patient P. aeruginosa isolates harbored the bla(VIM-2) metallo-beta-lactamase (MBL) gene in a common class 1 integron structure. They belonged to one predominant pulsed-field gel electrophoresis type and three sporadically detected types; two of the sporadic clonal types were identified among outpatients without previous exposure to healthcare facilities, while the predominant clonal type was also identified to cause infections in hospitalized patients. This is the first study documenting that MBL-producing P. aeruginosa isolates cause community-onset infections that are related or not with exposure to healthcare facilities. Community-onset infections in our patients most likely resulted from the nosocomial acquisition of MBL producers, followed by a prolonged digestive carriage. The high rate of recurrent infections in the community underlies the difficulty of constraining infections caused by such microorganisms in the extrahospital setting.

Alcohol consumption and development of acute respiratory distress syndrome: a population-based study

This retrospective population-based study evaluated the effects of alcohol consumption on the development of acute respiratory distress syndrome (ARDS). Alcohol consumption was quantified based on patient and/or family provided information at the time of hospital admission. ARDS was defined according to American-European consensus conference (AECC). From 1,422 critically ill Olmsted county residents, 1,357 had information about alcohol use in their medical records, 77 (6%) of whom developed ARDS. A history of significant alcohol consumption (more than two drinks per day) was reported in 97 (7%) of patients. When adjusted for underlying ARDS risk factors (aspiration, chemotherapy, high-risk surgery, pancreatitis, sepsis, shock), smoking, cirrhosis and gender, history of significant alcohol consumption was associated with increased risk of ARDS development (odds ratio 2.9, 95% CI 1.3–6.2). This population-based study confirmed that excessive alcohol consumption is associated with higher risk of ARDS.

Infections with VIM-1 metallo-{beta}-lactamase-producing enterobacter cloacae and their correlation with clinical outcome

The aim of this study was to ascertain the incidence and clinical significance of metallo-beta-lactamases among Enterobacter strains isolated from patients with nosocomial infections. We prospectively collected data on patients with Enterobacter infection during a 13-month period. All of the strains were investigated for antibiotic susceptibility, the presence and expression of metallo-beta-lactamases, and clonality. Of 29 infections (11 involving the urinary tract, 7 pneumonias, 3 skin/soft tissue infections, 3 intra-abdominal infections, 3 bacteremias, and 2 other infections), 7 (24%) were caused by Enterobacter cloacae strains harboring a bla(VIM-1) gene associated or not with a bla(SHV12) gene. Infections caused by VIM-1-producing strains were more frequently associated with a recent prior hospitalization (P = 0.006), cirrhosis (P = 0.03), relapse of infection (P < 0.001), and more prolonged duration of antibiotic therapy (P = 0.01) than were other infections. All of the isolates were susceptible to imipenem and meropenem and had bla(VIM-1) preceded by a weak P1 promoter and inactivated P2 promoters. Most VIM-1-producing Enterobacter isolates belonged to a main clone, but four different clones were found. Multiclonal VIM-1-producing E. cloacae infections are difficult to diagnose due to an apparent susceptibility to various beta-lactams, including carbapenems, and are associated with a high relapse rate and a more prolonged duration of antibiotic therapy.

Improved hospital-level risk adjustment for surveillance of healthcare-associated bloodstream infections: a retrospective cohort study

BACKGROUND

To allow direct comparison of bloodstream infection (BSI) rates between hospitals for performance measurement, observed rates need to be risk adjusted according to the types of patients cared for by the hospital. However, attribute data on all individual patients are often unavailable and hospital-level risk adjustment needs to be done using indirect indicator variables of patient case mix, such as hospital level. We aimed to identify medical services associated with high or low BSI rates, and to evaluate the services provided by the hospital as indicators that can be used for more objective hospital-level risk adjustment.

METHODS

From February 2001-December 2007, 1719 monthly BSI counts were available from 18 hospitals in Queensland, Australia. BSI outcomes were stratified into four groups: overall BSI (OBSI), Staphylococcus aureus BSI (STAPH), intravascular device-related S. aureus BSI (IVD-STAPH) and methicillin-resistant S. aureus BSI (MRSA). Twelve services were considered as candidate risk-adjustment variables. For OBSI, STAPH and IVD-STAPH, we developed generalized estimating equation Poisson regression models that accounted for autocorrelation in longitudinal counts. Due to a lack of autocorrelation, a standard logistic regression model was specified for MRSA.

RESULTS

Four risk services were identified for OBSI: AIDS (IRR 2.14, 95% CI 1.20 to 3.82), infectious diseases (IRR 2.72, 95% CI 1.97 to 3.76), oncology (IRR 1.60, 95% CI 1.29 to 1.98) and bone marrow transplants (IRR 1.52, 95% CI 1.14 to 2.03). Four protective services were also found. A similar but smaller group of risk and protective services were found for the other outcomes. Acceptable agreement between observed and fitted values was found for the OBSI and STAPH models but not for the IVD-STAPH and MRSA models. However, the IVD-STAPH and MRSA models successfully discriminated between hospitals with higher and lower BSI rates.

CONCLUSION

The high model goodness-of-fit and the higher frequency of OBSI and STAPH outcomes indicated that hospital-specific risk adjustment based on medical services provided would be useful for these outcomes in Queensland. The low frequency of IVD-STAPH and MRSA outcomes indicated that development of a hospital-level risk score was a more valid method of risk adjustment for these outcomes.

Improving surveillance system and surgical site infection rates through a network: A pilot study from Thailand

Background:

Surveillance of surgical site infections (SSI) provides data upon which interventions to improve patient safety can be based. In Thailand, however, SSI surveillance has not yet been standardized.

Objectives:

To develop a standardized SSI surveillance system and to monitor SSI rates after introduction of such a system.

Methods:

We conducted a prospective study among 17,752 patients who underwent surgery in ten hospitals in Thailand from April 2004 to May 2005. The SSI rates were computed and benchmarked with the US rates, reported in terms of standardized infection ratio (SIR). We estimated the incidence rate ratio of surgical site infections by comparing the incidence in the last study period with the incidence in the first study period.

Results:

The study included 17,869 operations and identified 248 SSIs, yielding an SSI rate of 1.4 infections/100 operations and a corresponding SIR of 0.6 (95% confidence interval [CI] = 0.5–0.7). During the study period the overall SSI rate decreased from 1.8 infections/100 operations to 1.2 infections/100 operations, yielding an incidence rate ratio of 0.65 (95% CI = 0.47–0.89).

Conclusion:

Our study highlighted that a standardized SSI surveillance in a developing country can be initiated through a network and may be followed by a decrease in SSI rates.

Risk factors and outcome of Acinetobacter baumanii infection in severe trauma patients

OBJECTIVE

To investigate incidence, risk factors and outcome of Acinetobacter baumanii infection in trauma patients.

DESIGN AND SETTING

A retrospective analysis of prospectively collected data of all trauma patients admitted to a general intensive care unit (ICU) of a 1,500-bed university hospital over 3 years.

PATIENTS

Three hundred thirty trauma patients were included in the study.

RESULTS

Thirty-six (10.9%) cases of A. baumanii infection were observed; 29 of them were late onset pneumonia. Patients with A. baumanii infection had a significantly higher Injury Severity Score (ISS) (p = 0.02), a lower Glasgow Coma Scale (GCS) on ICU admission (p = 0.03), stayed longer in the ICU (p = 0.00001), were mechanically ventilated for a longer period of time (p = 0.00001), were more frequently admitted to the emergency department with hypotension (p = 0.02), and had trans-skeletal traction for more than 3 days (p = 0.003) in comparison to the 294 patients who did not develop A. baumanii infection. At multivariate analysis the time spent on mechanical ventilation (p = 0.02) and the presence of long-term trans-skeletal traction (p = 0.04) were the only independent risk factors for A. baumanii infection. Patients with A. baumanii infection had a high mortality rate (9 out of 36; 25.0%). ISS (p = 0.003), GCS (p = 0.001) and older age (p = 0.00001), but not A. baumanii infection (p = 0.15), were independently correlated with mortality.

CONCLUSIONS

In trauma patients prolonged mechanical ventilation and delayed fracture fixation with the persistence of trans-skeletal traction were major risk factors for A. baumanii infection. The presence of this infection was not correlated with mortality.

Use of anti-infective serial prevalence studies to identify and monitor hospital-acquired infection

We developed the 'Pragmatic Proxy Protocol' (PPP) to estimate the prevalence of hospital-acquired infection (HAI) by integrating our existing pharmacy serial point prevalence studies of anti-infective prescribing practices with electronic data on microbiological and radiographic markers of infection. Our method was evaluated against the standard Hospital Infection Society/Infection Control Nurses Association Protocol (HIP). In the non-surgical patients, PPP has a sensitivity of 1.00 [confidence interval (CI): 0.70-1.00] and specificity of 0.97 (CI: 0.93-0.99). PPP suggests that for non-surgical patients, the prevalence of HAI using HIP could be underestimated by 42%. PPP takes about two-thirds of the time of HIP (75 vs 106 h) and is at least one-third cheaper. It could easily be adapted to advances in electronic reporting and, with the development of Anti-infective Care Bundles, would increase its sensitivity for the detection of HAI in surgical patients. PPP could be used to increase the frequency of routine HAI surveillance to determine the overall burden of infection and assess the efficacy of intervention strategies in a timely manner allowing rapid, direct feedback and engagement with clinicians.

Extended-spectrum beta-lactamase-producing pathogens in a children's hospital: a 5-year experience

BACKGROUND

Pediatric infection with bacteria producing extended-spectrum beta-lactamases (ESBLs) has not been well described. We sought to determine the proportion of isolates producing ESBLs and the incidence of infection or colonization with these organisms in our tertiary care pediatric facility over 5 years. In addition, we sought to evaluate the characteristics of children affected.

METHODS

We identified all Escherichia coli or Klebsiella spp cultured from children younger than 18 years of age at our facility between January 2003 and December 2007. Medical records were reviewed for affected children.

RESULTS

Of 2697 E coli, K pneumoniae, and K oxytoca cultured, 26 ESBL producers were isolated from 16 children. Rates of ESBL production among cultured isolates significantly increased, from 0.53% in the first half of the study period to 1.4% in the second. Incidence of a primary ESBL infection also increased significantly, from 0.14/10,000 patient encounters to 0.31/10,000. The majority of children infected or colonized with ESBL-producing organisms were those with chronic medical conditions, frequent hospitalizations, or a history of recurrent infection. However, 4 affected children were less than 5 months old and evaluated in an outpatient setting.

CONCLUSION

Rates and incidence of ESBL infection increased over the study period. Whereas most patients belonged to traditional risk groups for antibiotic-resistant infection, infants in the ambulatory setting were also affected, an at-risk population not previously described.

Hospital-acquired device-associated infections at a deployed military hospital in Iraq

BACKGROUND

To date, there have been no published studies describing rates of device-associated infections over extended periods at deployed military hospitals. We describe the rates of utilization and device-associated infections at the Air Force Theater Hospital (AFTH) in Iraq.

METHODS

This is a retrospective review of infection control (IC) records at the AFTH intensive care unit (ICU) from November 2006 through December 2007. Monthly device utilization and infection rates (per 1000 device days) were analyzed for trend and compared with pooled means for US trauma ICUs.

RESULTS

Central line utilization rates were constant (mean, 64%) with central line- associated bloodstream infection (CLAB) rates of 0 to 7.7 (US rate 4.6) except from September to December 2007, when the rate ranged from 7.4 to 29.3. An IC program reduced ventilator-associated pneumonia (VAP) rates to a baseline of 9.7 to 11.6. However, VAP rates rose to 13.3 to 56.3 in the 4-month period of January through April 2007 and 14.3 to 28.2 during September through December 2007. Neither CLAB nor VAP rates correlated with ICU admissions. The urinary catheter-associated urinary tract infection rate was 0 to 6.7 (US rate 5.5). Overall, Staphylococcus aureus was the predominant organism during May through October 2007 and Acinetobacter in November and December 2007.

CONCLUSIONS

Substantial variability exists in the rates of CLAB and VAP in the AFTH. Potential explanations are staff turnover and prolonged stays among non-US personnel who may serve as a reservoir for ongoing infections. Identification of barriers to IC may help inform the process of creating and implementing effective IC strategies in deployed military hospitals.

Effectiveness and safety of colistin for the treatment of multidrug-resistant Pseudomonas aeruginosa infections

PURPOSE

To describe the clinical and microbiological outcomes of patients infected with multidrug-resistant Pseudomonas aeruginosa (MDRP) treated with colistin (colistimethate sodium) and the adverse events observed with this treatment.

METHODS

Retrospective study of MDRP infections treated with colistin from 1997 to 2006.

RESULTS

121 episodes were identified. The median daily intravenous dose was 240 mg/day; 28.9% of patients received intravenous and nebulized colistin. Clinical outcome was favorable in ten cases of bacteremia (62.5%, n = 16), 43 cases of bronchial infection (72.9%, n = 59), 13 cases of pneumonia (65%, n = 20), 11 cases of urinary infection (84.6%, n = 13), eight cases of skin and soft tissues (72.7%, n = 11), and in the one case of arthritis and one case of otitis. Eradication was achieved in 31 (34.8%) of the 89 patients with available bacteriologic data. Factors associated with bacteriological failure were smoking, chronic obstructive pulmonary disease (COPD), and previous infection with P. aeruginosa. Nephrotoxicity occurred in ten cases (8.3%), with the associated factors being previous chronic renal insufficiency, diabetes mellitus, and aminoglycoside use. Crude mortality was 16.5%, and related MDRP was 12.4%, and was higher in patients with pneumonia or bacteremia (36.1%) than in other types of infections (8.2%).

CONCLUSIONS

Colistin is a safe option for the treatment of MDRP infections, with acceptable clinical outcomes. However, bacteriological eradication is difficult to achieve, especially in COPD patients.