Estimating the risk of a complicated course of Clostridium difficile infection (CDI) might help doctors guide treatment. We aimed to validate 3 published prediction models: Hensgens (2014), Na (2015), and Welfare (2011).

The validation cohort comprised 148 patients diagnosed with CDI between May 2013 and March 2014. During this period, 70 endemic cases of CDI occurred as well as 78 cases of CDI related to an outbreak of C. difficile ribotype 027. Model calibration and discrimination were assessed for the 3 prediction rules.

A complicated course (ie, death, colectomy, or ICU admission due to CDI) was observed in 31 patients (21%), and 23 patients (16%) died within 30 days of CDI diagnosis. The performance of all 3 prediction models was poor when applied to the total validation cohort with an estimated area under the curve (AUC) of 0.68 for the Hensgens model, 0.54 for the Na model, and 0.61 for the Welfare model. For those patients diagnosed with CDI due to non-outbreak strains, the prediction model developed by Hensgens performed the best, with an AUC of 0.78.

All 3 prediction models performed poorly when using our total cohort, which included CDI cases from an outbreak as well as endemic cases. The prediction model of Hensgens performed relatively well for patients diagnosed with CDI due to non-outbreak strains, and this model may be useful in endemic settings.

Infect Control Hosp Epidemiol 2017;38:897–905

To investigate whether the safety culture of a hospital unit is associated with the ability to improve.

Qualitative investigation of safety culture on hospital units following a before-and-after trial on hand hygiene.

VU University Medical Center, a tertiary-care hospital in the Netherlands.

With support from hospital management, we implemented a hospital-wide program to improve compliance. Over 2 years, compliance was measured through direct observation, twice before, and 4 times after interventions. We analyzed changes in compliance from baseline, and selected units to evaluate safety culture using a positive deviance approach: the hospital unit with the highest hand hygiene compliance and 2 units that showed significant improvement (21% and 16%, respectively) were selected as high performing. Another 2 units showed no improvement and were selected as low performing. A blinded, independent observer conducted interviews with unit management, physicians, and nurses, based on the Hospital Survey on Patient Safety Culture. Safety culture was categorized as pathological (lowest level), reactive, bureaucratic, proactive, or generative (highest level).

Overall, 3 units showed a proactive or generative safety culture and 2 units had bureaucratic or pathological safety cultures. When comparing compliance and interview results, high-performing units showed high levels of safety culture, while low-performing units showed low levels of safety culture.

Safety culture is associated with the ability to improve hand hygiene. Interventions may not be effective when applied in units with low levels of safety culture. Although additional research is needed to corroborate our findings, the safety culture on a unit can benefit from enhancement strategies such as team-building exercises. Strengthening the safety culture before implementing interventions could aid improvement and prevent nonproductive interventions.

Infect Control Hosp Epidemiol 2017;38:1277–1283

Syndromic surveillance for influenza-like illness (ILI) is predominantly performed in the outpatient setting. The objective of this study was to compare patterns of ILI activity in outpatient, emergency department (ED), and inpatient settings using an electronic syndromic surveillance algorithm.

Retrospective cohort study over 7.5 years.

A large community health system comprised of 5 hospitals and >50 clinics.

We applied an electronic syndromic surveillance algorithm for ILI to all primary-care outpatient visits, inpatient encounters, and ED encounters at our health system. Comparisons of ILI activity over time were performed using Spearman’s rank correlation coefficient. Cross correlation was used to compare the timing of ILI activity among treatment settings.

Overall, 4,447,769 patient encounters occurred during the study period; 152,607 of these (3.4%) were consistent with ILI. The correlation coefficient for ILI activity in the outpatient versus ED setting was 0.877, and for the outpatient versus inpatient setting, the correlation coefficient was 0.699. ILI activity among outpatients preceded ILI activity among inpatients by 1 week. ILI activity among children in the outpatient setting preceded ILI activity among adults in all 3 settings by 1 week.

Syndromic surveillance for ILI in the outpatient setting yields similar results to surveillance in the ED setting, but it produces less similar results than ILI surveillance in the inpatient setting. ILI activity in the pediatric outpatient population is a potential predictor of future ILI activity in the general population.

Infect Control Hosp Epidemiol 2017;38:393–398

To describe current practice around urine testing and identify factors leading to overtreatment of asymptomatic bacteriuria in community nursing homes (NHs)

Observational study of a stratified random sample of NH patients who had urine cultures ordered in NHs within a 1-month study period

31 NHs in North Carolina

254 NH residents who had a urine culture ordered within the 1-month study period

We conducted an NH record audit of clinical and laboratory information during the 2 days before and 7 days after a urine culture was ordered. We compared these results with the urine antibiogram from the 31 NHs.

Empirical treatment was started in 30% of cases. When cultures were reported, previously untreated cases received antibiotics 89% of the time for colony counts of ≥100,000 CFU/mL and in 35% of cases with colony counts of 10,000–99,000 CFU/mL. Due to the high rate of prescribing when culture results returned, 74% of these patients ultimately received a full course of antibiotics. Treated and untreated patients did not significantly differ in temperature, frequency of urinary signs and symptoms, or presence of Loeb criteria for antibiotic initiation. Factors most commonly associated with urine culture ordering were acute mental status changes (32%); change in the urine color, odor, or sediment (17%); and dysuria (15%).

Urine cultures play a significant role in antibiotic overprescribing. Antibiotic stewardship efforts in NHs should include reduction in culture ordering for factors not associated with infection-related morbidity as well as more scrutiny of patient condition when results become available.

Infect Control Hosp Epidemiol 2017;38:524–531

To determine whether antimicrobial-impregnated textiles decrease the acquisition of pathogens by healthcare provider (HCP) clothing.

We completed a 3-arm randomized controlled trial to test the efficacy of 2 types of antimicrobial-impregnated clothing compared to standard HCP clothing. Cultures were obtained from each nurse participant, the healthcare environment, and patients during each shift. The primary outcome was the change in total contamination on nurse scrubs, measured as the sum of colony-forming units (CFU) of bacteria.

Nurses working in medical and surgical ICUs in a 936-bed tertiary-care hospital.

Nurse subjects wore standard cotton-polyester surgical scrubs (control), scrubs that contained a complex element compound with a silver-alloy embedded in its fibers (Scrub 1), or scrubs impregnated with an organosilane-based quaternary ammonium and a hydrophobic fluoroacrylate copolymer emulsion (Scrub 2). Nurse participants were blinded to scrub type and randomly participated in all 3 arms during 3 consecutive 12-hour shifts in the intensive care unit.

In total, 40 nurses were enrolled and completed 3 shifts. Analyses of 2,919 cultures from the environment and 2,185 from HCP clothing showed that scrub type was not associated with a change in HCP clothing contamination (P=.70). Mean difference estimates were 0.118 for the Scrub 1 arm (95% confidence interval [CI], −0.206 to 0.441; P=.48) and 0.009 for the Scrub 2 rm (95% CI, −0.323 to 0.342; P=.96) compared to the control. HCP became newly contaminated with important pathogens during 19 of the 120 shifts (16%).

Antimicrobial-impregnated scrubs were not effective at reducing HCP contamination. However, the environment is an important source of HCP clothing contamination.

Clinicaltrials.gov Identifier: NCT 02645214

Infect Control Hosp Epidemiol 2017;38:1147–1154

To evaluate the use of a perianal swab to detect CDI.

A perianal swab was collected from each inpatient with a positive stool sample for C. difficile (by polymerase chain reaction [PCR] test) and was tested for C. difficile by PCR and by culture. The variables evaluated included demographics, CDI severity, bathing before perianal swab collection, hours between stool sample and perianal swab, cycle threshold (Ct) to PCR positivity, and doses of CDI treatment before stool sample and before perianal swab.

Of 83 perianal swabs, 59 (71.1%) tested positive for C. difficile by PCR when perianal swabs were collected an average of 21 hours after the stool sample. Compared with the respective stool sample, the perianal sample was less likely to grow C. difficile (P=.005) and had a higher PCR Ct (P<.001). A direct, significant but weak correlation was detected between the Ct for a positive perianal sample and the respective stool sample (r=0.36; P=.006). An inverse dose relationship was detected between PCR positivity and CDI treatment doses before perianal swab collection (P=.27).

Perianal swabs are a simple method to detect C. difficile tcdB gene by PCR, with a sensitivity of 71%. These data were limited because stool samples and perianal swabs were not collected simultaneously. Compared with stool samples, the perianal Ct values and culture results were consistent with a lower bacterial load on the perianal sample due to the receipt of more CDI treatment before collection or unknown factors affecting perianal skin colonization.

Infect Control Hosp Epidemiol 2017;38:658–662

We report an outbreak of respiratory syncytial virus (RSV) and human metapneumovirus (HMPV) infections in a dementia care ward containing 2 separately locked units (A and B) to heighten awareness of these pathogens in the older adult population and highlight some of the infection prevention challenges faced during a noninfluenza respiratory viral outbreak in a congregate setting.

Cases were defined by the presence of new signs or symptoms that included (1) a single oral temperature ≥ 37.8°C (100.0°F) and (2) the presence of at least 2 of the following symptoms: cough, dyspnea, rhinorrhea, hoarseness, congestion, fatigue, and malaise. Attempted infection-control measures included cohorting patients and staff, empiric isolation precautions, and cessation of group activities. Available nasopharyngeal swab specimens were sent to the Tennessee Department of Health for identification by rT-PCR testing.

We identified 30 of the 41 (73%) residents as cases over this 16-day outbreak. Due to high numbers of sick personnel, we were unable to cohort staff to 1 unit. Unit B developed its first case 8 days after infection control measures were implemented. Of the 14 cases with available specimens, 6 patients tested positive for RSV-B, 7 for HMPV and 1 patient test positive for influenza A. Overall, 15 cases (50%) required transfer to acute care facilities; 10 of these patients (34%) had chest x-ray confirmed pulmonary infiltrates; and 5 residents (17%) died.

This case report highlights the importance of RSV and HMPV in causing substantial disease in the older adult population and highlights the challenges in preventing transmission of these viruses.

Infect Control Hosp Epidemiol 2017;38:399–404

To describe the hospital stays of patients with Clostridium difficile infection (CDI) and to measure the hospitalization costs of CDI (as primary and secondary diagnoses) from the French national health insurance perspective

Burden of illness study

All acute-care hospitals in France

Data were extracted from the French national hospitalization database (PMSI) for patients covered by the national health insurance scheme in 2014. Hospitalizations were selected using the International Classification of Diseases, 10threvision (ICD-10) code for CDI. Hospital stays with CDI as the primary diagnosis or the secondary diagnosis (comorbidity) were studied for the following parameters: patient sociodemographic characteristics, mortality, length of stay (LOS), and related costs. A retrospective case-control analysis was performed on stays with CDI as the secondary diagnosis to assess the impact of CDI on the LOS and costs.

Overall, 5,834 hospital stays with CDI as the primary diagnosis were included in this study. The total national insurance costs were €30.7 million (US $33,677,439), and the mean cost per hospital stay was €5,267±€3,645 (US $5,777±$3,998). In total, 10,265 stays were reported with CDI as the secondary diagnosis. The total national insurance additional costs attributable to CDI were estimated to be €85 million (US $93,243,725), and the mean additional cost attributable to CDI per hospital stay was €8,295±€17,163, median, €4,797 (US $9,099±$8,827; median, $5,262).

CDI has a high clinical and economic burden in the hospital, and it represents a major cost for national health insurance. When detected as a comorbidity, CDI was significantly associated with increased LOS and economic burden. Preventive approaches should be implemented to avoid CDIs.

Infect Control Hosp Epidemiol 2017;38:906–911

To evaluate invasiveness index as a potential predictor of spine surgical site infection (SSI) after spinal fusion, revision fusion, or laminectomy.

Retrospective cohort study.

Single, large, academic medical center.

Adults undergoing spinal fusion, revision fusion, or laminectomy.

Data were obtained from electronic hospital databases; cases of SSI were extracted from the infection control database using National Healthcare Safety Network (NHSN) definitions. For each case, an invasiveness index, determined by surgical approach, procedure, and number of spine levels treated, was calculated using current procedural terminology (CPT) billing codes. Statistical analyses were performed using univariate and multivariate logistic regression models.

In total, 3,143 patients met inclusion criteria, and 43 of these developed SSI. Multivariate regression showed that advanced age (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.005–1.05, for each year of life) and invasiveness index (medium invasiveness index OR, 5.36; 95% CI, 1.92–14.96; high invasiveness index OR, 14.1; 95% CI, 4.38–45.43) were significant predictors of infection. In subgroup analyses of spinal fusion patients, morbid obesity (OR, 2.542; 95% CI, 1.08–5.99), trauma (OR, 2.41; 95% CI, 1.05–5.55), and invasiveness index (medium invasiveness index OR, 5.39; 95% CI, 1.56–18.61; high invasiveness index OR, 13.44; 95% CI, 3.28–55.01) were significant predictors of SSI. Models containing invasiveness index were compared to NHSN models and demonstrated similar performance.

Invasiveness index is a predictor of SSI after spinal fusion and performs similarly to NHSN models. Invasiveness index shows promise as a potential risk stratification tool that is easily calculated and is available preoperatively.

Infect Control Hosp Epidemiol 2016:1–7

To determine the impact of an environmental disinfection intervention on the incidence of healthcare-associated Clostridium difficile infection (CDI).

A multicenter randomized trial.

In total,16 acute-care hospitals in northeastern Ohio participated in the study.

We conducted a 12-month randomized trial to compare standard cleaning to enhanced cleaning that included monitoring of environmental services (EVS) personnel performance with feedback to EVS and infection control staff. We assessed the thoroughness of cleaning based on fluorescent marker removal from high-touch surfaces and the effectiveness of disinfection based on environmental cultures for C. difficile. A linear mixed model was used to compare CDI rates in the intervention and postintervention periods for control and intervention hospitals. The primary outcome was the incidence of healthcare-associated CDI.

Overall, 7 intervention hospitals and 8 control hospitals completed the study. The intervention resulted in significantly increased fluorescent marker removal in CDI and non-CDI rooms and decreased recovery of C. difficile from high-touch surfaces in CDI rooms. However, no reduction was observed in the incidence of healthcare-associated CDI in the intervention hospitals during the intervention and postintervention periods. Moreover, there was no correlation between the percentage of positive cultures after cleaning of CDI or non-CDI rooms and the incidence of healthcare-associated CDI.

An environmental disinfection intervention improved the thoroughness and effectiveness of cleaning but did not reduce the incidence of healthcare-associated CDI. Thus, interventions that focus only on improving cleaning may not be sufficient to control healthcare-associated CDI.

Infect Control Hosp Epidemiol 2017;38:777–783

To investigate the scale of antimicrobial prescribing without a corresponding visit, and to compare the attributes of patients who received antimicrobials with a corresponding visit with those who did not have a visit.

Retrospective cohort.

We followed up 185,010 Medicare patients for 1 year after an acute myocardial infarction. For each antimicrobial prescribed, we determined whether the patient had an inpatient, outpatient, or provider claim in the 7 days prior to the antimicrobial prescription being filled. We compared the proportions of patient characteristics for those prescriptions associated with a visit and without a visit (ie, phantom prescriptions). We also compared the rates at which different antimicrobials were prescribed without a visit.

We found that of 356,545 antimicrobial prescriptions, 14.75% had no evidence of a visit in the week prior to the prescription being filled. A higher percentage of patients without a visit were identified as white (P<.001) and female (P<.001). Patients without a visit had a higher likelihood of survival and fewer additional cardiac events (acute myocardial infarction, cardiac arrest, stroke, all P<.001). Among the antimicrobials considered, amoxicillin, penicillin, and agents containing trimethoprim and methenamine were much more likely to be prescribed without a visit. In contrast, levofloxacin, metronidazole, moxifloxacin, vancomycin, and cefdinir were much less likely to be prescribed without a visit.

Among this cohort of patients with chronic conditions, phantom prescriptions of antimicrobials are relatively common and occurred more frequently among those patients who were relatively healthy.

Infect Control Hosp Epidemiol 2017;38:273–280

Recently, robotic surgery has been introduced in many hospitals. The structure of robotic instruments is so complex that updating their cleaning methods is a challenge for healthcare professionals. However, there is limited information on the effectiveness of cleaning for instruments for robotic surgery.

To determine the level of residual contamination of instruments for robotic surgery and to develop a method to evaluate the cleaning efficacy for complex surgical devices.

Surgical instruments were collected immediately after operations and/or after in-house cleaning, and the level of residual protein was measured. Three serial measurements were performed on instruments after cleaning to determine the changes in the level of contamination and the total amount of residual protein. The study took place from September 1, 2013, through June 30, 2015, in Japan.

The amount of protein released from robotic instruments declined exponentially. The amount after in-house cleaning was 650, 550, and 530 µg/instrument in the 3 serial measurements. The overall level of residual protein in each measurement was much higher for robotic instruments than for ordinary instruments (P<.0001).

Our data demonstrated that complete removal of residual protein from surgical instruments is virtually impossible. The pattern of decline differed depending on the instrument type, which reflected the complex structure of the instruments. It might be necessary to establish a new standard for cleaning using a novel classification according to the structural complexity of instruments, especially for those for robotic surgery.

Infect Control Hosp Epidemiol 2017;38:143–146

Biofilm has been implicated in bacterial persistence and survival after endoscope reprocessing. In this study, we assessed the impact of different methods of reprocessing on organic residues and viable bacteria after repeated rounds of biofilm formation when each was followed by full reprocessing.

ATS-2015, an artificial test soil containing 5–8 Log10 colony-forming units (CFU) of Enterococcus faecalis and Pseudomonas aeruginosa, was used to form biofilm in polytetrafluroethylene channels overnight on 5 successive days. Each successive day, full pump-assisted cleaning using bristle brushes or pull-through devices in combination with enzymatic or nonenzymatic detergents followed by fully automated endoscope reprocessor disinfection using peracetic acid was performed. Residuals were visualized by scanning electron microscopy (SEM). Destructive testing was used to assess expected cutoffs for adenosine triphosphate (ATP; <200 relative light units), protein (<2 µg/cm2), and viable bacteria count (0 CFU).

Protein residuals were above 2 µg/cm2, but ATP residuals were <200 relative light units for all methods tested. Only when enzymatic cleaner was used for cleaning were there no viable bacteria detected after disinfection irrespective of whether bristle brushes or pull-through devices were used. SEM revealed that some residual debris remained after all reprocessing methods, but more residuals were detected when a nonenzymatic detergent was used.

Surviving E. faecalis and P. aeruginosa were only detected when the non-enzymatic detergent was used, emphasizing the importance of the detergent used for endoscope channel reprocessing. Preventing biofilm formation is critical because not all current reprocessing methods can reliably eliminate viable bacteria within the biofilm matrix.

Infect Control Hosp Epidemiol 2017;38:1284–1290

To assess hand hygiene improvement and sustainability associated with a Breakthrough Collaborative.

Multicenter analysis of hand hygiene compliance through direct observation by trained observers.

A total of 5 publicly funded hospitals in 14 locations, with a total of 1,152 beds, in the County of Vaud, Switzerland.

Clinical staff.

In total, 59,272 opportunities for hand hygiene were monitored for the duration of the study, for an average of 5,921 per audit (range, 5,449–6,852). An 18-month Hand Hygiene Breakthrough Collaborative was conducted to implement the WHO multimodal promotional strategy including improved access to alcohol-based hand rub, education, performance measurement and feedback, reminders and communication, leadership engagement, and safety culture.

Overall hand hygiene compliance improved from 61.9% to 88.3% (P<.001) over 18 months and was sustained at 88.9% (P=.248) 12 months after the intervention. Hand hygiene compliance among physicians increased from 62% to 85% (P<.001) and finally 86% at follow-up (P=.492); for nursing staff, compliance improved from 64% to 90% (P<.001) and finally 90% at follow-up (P=.464); for physiotherapists compliance improved from 50% to 90% (P<.001) and finally 91% at follow-up (P=.619); for X-ray technicians compliance improved from 45% to 80% (P<.001) and finally 81% at follow-up (P=.686). Hand hygiene compliance also significantly increased with sustained improvement across all hand hygiene indications and all hospitals.

A rigorously conducted multicenter project combining the Breakthrough Collaborative method for its structure and the WHO multimodal strategy for content and measurement was associated with significant and substantial improvement in compliance across all professions, all hand hygiene indications, and all participating hospitals.

Infect Control Hosp Epidemiol 2017;38:1420–1427

Activated alkaline glutaraldehyde (GTA) remains one of the most widely used high-level disinfectants worldwide. However, several reports have highlighted the potential for nontuberculous mycobacteria to develop high-level resistance to this product. Because aldehyde resistance may lead to cross-resistance to other biocides, we investigated the susceptibility profile of GTA-resistant Mycobacterium chelonae and M. abscessus isolates to various disinfectant chemistries.

High-level disinfectants commonly used in the reprocessing of endoscopes and other heat-sensitive, semicritical medical equipment, including different formulations of aldehyde-based products and oxidizing agents, were tested against 10 slow- and fast-growing, GTA-susceptible and GTA-resistant, Mycobacterium isolates in suspension tests and carrier tests at different temperatures.

While peracetic acid– and hydrogen peroxide–based disinfectants (S40, Resert XL, Reliance DG) efficiently killed all of the Mycobacterium isolates, GTA- and ortho-phthalaldehyde-based products (ie, Cidex, Aldahol, Cidex OPA) showed variable efficacy against GTA-resistant strains despite the ability of some formulations (Aldahol) to overcome the resistance of some of these isolates, especially when the temperature was increased from 20°C to 25°C.

Application permitting, oxidizing chemistries may provide a safe alternative to aldehyde-based products, particularly in GTA-resistant mycobacterial outbreaks.

Infect Control Hosp Epidemiol 2017;38:784–791

Infections and colonization with multidrug-resistant organisms (MDROs) identified >48 hours after hospital admission are considered healthcare-acquired according to the definition of the Centers for Disease Control and Prevention (CDC). Some may originate from delayed diagnosis rather than true acquisition in the hospital, potentially diluting the impact of infection control programs. In addition, such infections are not necessarily reimbursed in a healthcare system based on the diagnosis-related groups (DRGs).

The goal of the study was to estimate the preventable proportion of healthcare-acquired infections in a tertiary care hospital in Switzerland by analyzing patients colonized or infected with MDROs.

All hospitalized patients with healthcare-acquired MDRO infection or colonization (HAMIC) or according to the CDC definition (CDC-HAMIC) were prospectively assessed from 2002 to 2011 to determine whether there was evidence for nosocomial transmission. We utilized an additional work-up with epidemiological, microbiological, and molecular typing data to determine the true preventable proportion of HAMICs.

Overall, 1,190 cases with infection or colonization with MDROs were analyzed; 274 (23.0%) were classified as CDC-HAMICs. Only 51.8% of CDC-HAMICs had confirmed evidence of hospital-acquisition and were considered preventable. Specifically, 57% of MRSA infections, 83.3% of VRE infections, 43.9% of ESBL infections, and 74.1% of non-ESBL MDRO infections were preventable HAMICs.

The CDC definition overestimates the preventable proportion of HAMICs with MDROs by more than 50%. Relying only on the CDC definition of HAMICs may lead to inaccurate measurement of the impact of infection control interventions and to inadequate reimbursement under the DRG system.

Infect. Control Hosp. Epidemiol. 2016;1–6

Antibiotic resistance is a major threat to public health. Resistance is largely driven by antibiotic usage, which in many cases is unnecessary and can be improved. The impact of decreasing overall antibiotic usage on resistance is unknown and difficult to assess using standard study designs. The objective of this study was to explore the potential impact of reducing antibiotic usage on the transmission of multidrug-resistant organisms (MDROs).

We used agent-based modeling to simulate interactions between patients and healthcare workers (HCWs) using model inputs informed by the literature. We modeled the effect of antibiotic usage as (1) a microbiome effect, for which antibiotic usage decreases competing bacteria and increases the MDRO transmission probability between patients and HCWs and (2) a mutation effect that designates a proportion of patients who receive antibiotics to subsequently develop a MDRO via genetic mutation.

Intensive care unit

Absolute reduction in overall antibiotic usage by experimental values of 10% and 25%

Reducing antibiotic usage absolutely by 10% (from 75% to 65%) and 25% (from 75% to 50%) reduced acquisition rates of high-prevalence MDROs by 11.2% (P<.001) and 28.3% (P<.001), respectively. We observed similar effect sizes for low-prevalence MDROs.

In a critical care setting, where up to 50% of antibiotic courses may be inappropriate, even a moderate reduction in antibiotic usage can reduce MDRO transmission.

Infect Control Hosp Epidemiol 2017;38:663–669