Diagnostic stewardship of urine cultures from patients with indwelling urinary catheters may improve diagnostic specificity and clinical relevance of the test, but risk of patient harm is uncertain.

We retrospectively evaluated the impact of a computerized clinical decision support tool to promote institutional appropriateness criteria (neutropenia, kidney transplant, recent urologic surgery, or radiologic evidence of urinary tract obstruction) for urine cultures from patients with an indwelling urinary catheter. The primary outcome was a change in catheter-associated urinary tract infection (CAUTI) rate from baseline (34 mo) to intervention period (30 mo, including a 2-mo wash-in period). We analyzed patient-level outcomes and adverse events.

Adjusted CAUTI rate decreased from 1.203 to 0.75 per 1,000 catheter-days (P = 0.52). Of 598 patients triggering decision support, 284 (47.5%) urine cultures were collected in agreement with institutional criteria and 314 (52.5%) were averted. Of 314 patients whose urine cultures were averted, 2 had a subsequent urine culture within 7 days that resulted in a change in antimicrobial therapy and 2 had diagnosis of bacteremia with suspected urinary source, but there were no delays in effective treatment.

A diagnostic stewardship intervention was associated with an approximately 50% decrease in urine culture testing for inpatients with a urinary catheter. However, the overall CAUTI rate did not decrease significantly. Adverse outcomes were rare and minor among patients who had a urine culture averted. Diagnostic stewardship may be safe and effective as part of a multimodal program to reduce unnecessary urine cultures among patients with indwelling urinary catheters.

To characterize the relationship between chlorhexidine gluconate (CHG) skin concentration and skin microbial colonization.

Serial cross-sectional study.

Adult patients in medical intensive care units (ICUs) from 7 hospitals; from 1 hospital, additional patients colonized with carbapenemase-producing Enterobacterales (CPE) from both ICU and non-ICU settings. All hospitals performed routine CHG bathing in the ICU.

Skin swab samples were collected from adjacent areas of the neck, axilla, and inguinal region for microbial culture and CHG skin concentration measurement using a semiquantitative colorimetric assay. We used linear mixed effects multilevel models to analyze the relationship between CHG concentration and microbial detection. We explored threshold effects using additional models.

We collected samples from 736 of 759 (97%) eligible ICU patients and 68 patients colonized with CPE. On skin, gram-positive bacteria were cultured most frequently (93% of patients), followed by Candida species (26%) and gram-negative bacteria (20%). The adjusted odds of microbial recovery for every twofold increase in CHG skin concentration were 0.84 (95% CI, 0.80–0.87; P < .001) for gram-positive bacteria, 0.93 (95% CI, 0.89–0.98; P = .008) for Candida species, 0.96 (95% CI, 0.91–1.02; P = .17) for gram-negative bacteria, and 0.94 (95% CI, 0.84–1.06; P = .33) for CPE. A threshold CHG skin concentration for reduced microbial detection was not observed.

On a cross-sectional basis, higher CHG skin concentrations were associated with less detection of gram-positive bacteria and Candida species on the skin, but not gram-negative bacteria, including CPE. For infection prevention, targeting higher CHG skin concentrations may improve control of certain pathogens.

To assess whether measurement and feedback of chlorhexidine gluconate (CHG) skin concentrations can improve CHG bathing practice across multiple intensive care units (ICUs).

A before-and-after quality improvement study measuring patient CHG skin concentrations during 6 point-prevalence surveys (3 surveys each during baseline and intervention periods).

The study was conducted across 7 geographically diverse ICUs with routine CHG bathing.

Adult patients in the medical ICU.

CHG skin concentrations were measured at the neck, axilla, and inguinal region using a semiquantitative colorimetric assay. Aggregate unit-level CHG skin concentration measurements from the baseline period and each intervention period survey were reported back to ICU leadership, which then used routine education and quality improvement activities to improve CHG bathing practice. We used multilevel linear models to assess the impact of intervention on CHG skin concentrations.

We enrolled 681 (93%) of 736 eligible patients; 92% received a CHG bath prior to survey. At baseline, CHG skin concentrations were lowest on the neck, compared to axillary or inguinal regions (P < .001). CHG was not detected on 33% of necks, 19% of axillae, and 18% of inguinal regions (P < .001 for differences in body sites). During the intervention period, ICUs that used CHG-impregnated cloths had a 3-fold increase in patient CHG skin concentrations as compared to baseline (P < .001).

Routine CHG bathing performance in the ICU varied across multiple hospitals. Measurement and feedback of CHG skin concentrations can be an important tool to improve CHG bathing practice.

We quantified hospital-acquired coronavirus disease 2019 (COVID-19) during the early phases of the pandemic, and we evaluated solely temporal determinations of hospital acquisition.

Retrospective observational study during early phases of the COVID-19 pandemic, March 1–November 30, 2020. We identified laboratory-detected severe acute respiratory coronavirus virus 2 (SARS-CoV-2) from 30 days before admission through discharge. All cases detected after hospital day 5 were categorized by chart review as community or unlikely hospital-acquired cases, or possible or probable hospital-acquired cases.

The study was conducted in 2 acute-care hospitals in Chicago, Illinois.

The study included all hospitalized patients including an inpatient rehabilitation unit.

Each hospital implemented infection-control precautions soon after identifying COVID-19 cases, including patient and staff cohort protocols, universal masking, and restricted visitation policies.

Among 2,667 patients with SARS-CoV-2, detection before hospital day 6 was most common (n = 2,612; 98%); detection during hospital days 6–14 was uncommon (n = 43; 1.6%); and detection after hospital day 14 was rare (n = 16; 0.6%). By chart review, most cases after day 5 were categorized as community acquired, usually because SARS-CoV-2 had been detected at a prior healthcare facility (68% of cases on days 6–14 and 53% of cases after day 14). The incidence rates of possible and probable hospital-acquired cases per 10,000 patient days were similar for ICU- and non-ICU patients at hospital A (1.2 vs 1.3 difference, 0.1; 95% CI, −2.8 to 3.0) and hospital B (2.8 vs 1.2 difference, 1.6; 95% CI, −0.1 to 4.0).

Most patients were protected by early and sustained application of infection-control precautions modified to reduce SARS-CoV-2 transmission. Using solely temporal criteria to discriminate hospital versus community acquisition would have misclassified many “late onset” SARS-CoV-2–positive cases.

Ventilator-capable skilled nursing facilities (vSNFs) are critical to the epidemiology and control of antibiotic-resistant organisms. During an infection prevention intervention to control carbapenem-resistant Enterobacterales (CRE), we conducted a qualitative study to characterize vSNF healthcare personnel beliefs and experiences regarding infection control measures.

A qualitative study involving semistructured interviews.

One vSNF in the Chicago, Illinois, metropolitan region.

The study included 17 healthcare personnel representing management, nursing, and nursing assistants.

We used face-to-face, semistructured interviews to measure healthcare personnel experiences with infection control measures at the midpoint of a 2-year quality improvement project.

Healthcare personnel characterized their facility as a home-like environment, yet they recognized that it is a setting where germs were ‘invisible’ and potentially ‘threatening.’ Healthcare personnel described elaborate self-protection measures to avoid acquisition or transfer of germs to their own household. Healthcare personnel were motivated to implement infection control measures to protect residents, but many identified structural barriers such as understaffing and time constraints, and some reported persistent preference for soap and water.

Healthcare personnel in vSNFs, from management to frontline staff, understood germ theory and the significance of multidrug-resistant organism transmission. However, their ability to implement infection control measures was hampered by resource limitations and mixed beliefs regarding the effectiveness of infection control measures. Self-protection from acquiring multidrug-resistant organisms was a strong motivator for healthcare personnel both outside and inside the workplace, and it could explain variation in adherence to infection control measures such as a higher hand hygiene adherence after resident care than before resident care.

Due to shortages of N95 respirators during the coronavirus disease 2019 (COVID-19) pandemic, it is necessary to estimate the number of N95s required for healthcare workers (HCWs) to inform manufacturing targets and resource allocation.

We developed a model to determine the number of N95 respirators needed for HCWs both in a single acute-care hospital and the United States.

For an acute-care hospital with 400 all-cause monthly admissions, the number of N95 respirators needed to manage COVID-19 patients admitted during a month ranges from 113 (95% interpercentile range [IPR], 50–229) if 0.5% of admissions are COVID-19 patients to 22,101 (95% IPR, 5,904–25,881) if 100% of admissions are COVID-19 patients (assuming single use per respirator, and 10 encounters between HCWs and each COVID-19 patient per day). The number of N95s needed decreases to a range of 22 (95% IPR, 10–43) to 4,445 (95% IPR, 1,975–8,684) if each N95 is used for 5 patient encounters. Varying monthly all-cause admissions to 2,000 requires 6,645–13,404 respirators with a 60% COVID-19 admission prevalence, 10 HCW–patient encounters, and reusing N95s 5–10 times. Nationally, the number of N95 respirators needed over the course of the pandemic ranges from 86 million (95% IPR, 37.1–200.6 million) to 1.6 billion (95% IPR, 0.7–3.6 billion) as 5%–90% of the population is exposed (single-use). This number ranges from 17.4 million (95% IPR, 7.3–41 million) to 312.3 million (95% IPR, 131.5–737.3 million) using each respirator for 5 encounters.

We quantified the number of N95 respirators needed for a given acute-care hospital and nationally during the COVID-19 pandemic under varying conditions.

Cohorting patients who are colonized or infected with multidrug-resistant organisms (MDROs) protects uncolonized patients from acquiring MDROs in healthcare settings. The potential for cross transmission within the cohort and the possibility of colonized patients acquiring secondary isolates with additional antibiotic resistance traits is often neglected. We searched for evidence of cross transmission of KPC+ Klebsiella pneumoniae (KPC-Kp) colonization among cohorted patients in a long-term acute-care hospital (LTACH), and we evaluated the impact of secondary acquisitions on resistance potential.

Genomic epidemiological investigation.

A high-prevalence LTACH during a bundled intervention that included cohorting KPC-Kp–positive patients.

Whole-genome sequencing (WGS) and location data were analyzed to identify potential cases of cross transmission between cohorted patients.

Secondary KPC-Kp isolates from 19 of 28 admission-positive patients were more closely related to another patient’s isolate than to their own admission isolate. Of these 19 cases, 14 showed strong genomic evidence for cross transmission (<10 single nucleotide variants or SNVs), and most of these patients occupied shared cohort floors (12 patients) or rooms (4 patients) at the same time. Of the 14 patients with strong genomic evidence of acquisition, 12 acquired antibiotic resistance genes not found in their primary isolates.

Acquisition of secondary KPC-Kp isolates carrying distinct antibiotic resistance genes was detected in nearly half of cohorted patients. These results highlight the importance of healthcare provider adherence to infection prevention protocols within cohort locations, and they indicate the need for future studies to assess whether multiple-strain acquisition increases risk of adverse patient outcomes.

Hospitals may implement admission screening cultures and may review transfer documentation to identify patients colonized with carbapenem-resistant Enterobacteriaceae (CRE) to implement isolation precautions; however, outcomes and logistical considerations have not been well described.

At an academic hospital in Chicago, we retrospectively studied the implementation and outcomes of CRE admission screening from 2013 to 2016 during 2 periods. During period 1, we implemented active CRE rectal culture screening for all adults patients admitted to intensive care units (ICUs) and for those transferred from outside facilities to general wards. During period 2, screening was restricted only to adults transferred from outside facilities. For a subset of transferred patients who were previously reported to the health department as CRE positive, we reviewed transfer paperwork for appropriate documentation of CRE.

Overall, 11,757 patients qualified for screening; rectal cultures were performed for 8,569 patients (73%). Rates of CRE screen positivity differed by period, previous facility type (if transferred), and current inpatient location. A higher combined CRE positivity rate was detected in the medical and surgical ICUs among period 2 patients (3.3%) versus all other ward-period comparisons (P<.001). Among 13 transferred patients previously known to be CRE colonized, appropriate CRE transfer documentation was available for only 4 patients (31%).

Active screening for CRE is feasible, and screening patients transferred from outside facilities to the medical or surgical ICU resulted in the highest screen positivity rate. Furthermore, CRE carriage was inconsistently documented in transfer paperwork, suggesting that admission screening or enhanced inter-facility communication are needed to improve the identification of CRE-colonized patients.

Bathing intensive care unit (ICU) patients with 2% chlorhexidine gluconate (CHG)–impregnated cloths decreases the risk of healthcare-associated bacteremia and multidrug-resistant organism transmission. Hospitals employ different methods of CHG bathing, and few studies have evaluated whether those methods yield comparable results.

To determine whether 3 different CHG skin cleansing methods yield similar residual CHG concentrations and bacterial densities on skin.

Prospective, randomized 2-center study with blinded assessment.

Healthcare personnel in surgical ICUs at 2 tertiary-care teaching hospitals in Chicago, Illinois, and Boston, Massachusetts, from July 2015 to January 2016.

Cleansing skin of one forearm with no-rinse 2% CHG-impregnated polyester cloth (method A) versus 4% CHG liquid cleansing with rinsing on the contralateral arm, applied with either non–antiseptic-impregnated cellulose/polyester cloth (method B) or cotton washcloth dampened with sterile water (method C).

In total, 63 participants (126 forearms) received method A on 1 forearm (n=63). On the contralateral forearm, 33 participants received method B and 30 participants received method C. Immediately and 6 hours after cleansing, method A yielded the highest residual CHG concentrations (2500 µg/mL and 1250 µg/mL, respectively) and lowest bacterial densities compared to methods B or C (P<.001).

In healthy volunteers, cleansing with 2% CHG-impregnated cloths yielded higher residual CHG concentrations and lower bacterial densities than cleansing with 4% CHG liquid applied with either of 2 different cloth types and followed by rinsing. The relevance of these differences to clinical outcomes remains to be determined.

Infect Control Hosp Epidemiol 2018;39:405–411

Because antibacterial history is difficult to obtain, especially when the exposure occurred at an outside hospital, we assessed whether infection-related diagnostic billing codes, which are more readily available through hospital discharge databases, could infer prior antibacterial receipt.

Retrospective cohort study.

This study included 121,916 hospitalizations representing 78,094 patients across the 3 hospitals.

We obtained hospital inpatient data from 3 Chicago-area hospitals. Encounters were categorized as “infection” if at least 1 International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) code indicated a bacterial infection. From medication administration records, we categorized antibacterial agents and calculated total therapy days using Centers for Disease Control and Prevention (CDC) definitions. We evaluated bivariate associations between infection encounters and 3 categories of antibacterial exposure: any, broad spectrum, or surgical prophylaxis. We constructed multivariable models to evaluate adjusted risk ratios for antibacterial receipt.

Of the 121,916 inpatient encounters (78,094 patients) across the 3 hospitals, 24% had an associated infection code, 47% received an antibacterial, and 13% received a broad-spectrum antibacterial. Infection-related ICD-9-CM codes were associated with a 2-fold increase in antibacterial administration compared to those lacking such codes (RR, 2.29; 95% confidence interval [CI], 2.27–2.31) and a 5-fold increased risk for broad-spectrum antibacterial administration (RR, 5.52; 95% CI, 5.37–5.67). Encounters with infection codes had 3 times the number of antibacterial days.

Infection diagnostic billing codes are strong surrogate markers for prior antibacterial exposure, especially to broad-spectrum antibacterial agents; such an association can be used to enhance early identification of patients at risk of multidrug-resistant organism (MDRO) carriage at the time of admission.

Infect Control Hosp Epidemiol 2018;39:377–382

To determine the impact of recurrent Clostridium difficile infection (RCDI) on patient behaviors following illness.

Using a computer algorithm, we searched the electronic medical records of 7 Chicago-area hospitals to identify patients with RCDI (2 episodes of CDI within 15 to 56 days of each other). RCDI was validated by medical record review. Patients were asked to complete a telephone survey. The survey included questions regarding general health, social isolation, symptom severity, emotional distress, and prevention behaviors.

In total, 119 patients completed the survey (32%). On average, respondents were 57.4 years old (standard deviation, 16.8); 57% were white, and ~50% reported hospitalization for CDI. At the time of their most recent illness, patients rated their diarrhea as high severity (58.5%) and their exhaustion as extreme (30.7%). Respondents indicated that they were very worried about getting sick again (41.5%) and about infecting others (31%). Almost 50% said that they have washed their hands more frequently (47%) and have increased their use of soap and water (45%) since their illness. Some of these patients (22%–32%) reported eating out less, avoiding certain medications and public areas, and increasing probiotic use. Most behavioral changes were unrelated to disease severity.

Having had RCDI appears to increase prevention-related behaviors in some patients. While some behaviors are appropriate (eg, handwashing), others are not supported by evidence of decreased risk and may negatively impact patient quality of life. Providers should discuss appropriate prevention behaviors with their patients and should clarify that other behaviors (eg, eating out less) will not affect their risk of future illness.

Infect Control Hosp Epidemiol. 2017;38:1351–1357

To identify modifiable risk factors for acquisition of Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae (KPC) colonization among long-term acute-care hospital (LTACH) patients.

Multicenter, matched case-control study.

Four LTACHs in Chicago, Illinois.

Each case patient included in this study had a KPC-negative rectal surveillance culture on admission followed by a KPC-positive surveillance culture later in the hospital stay. Each matched control patient had a KPC-negative rectal surveillance culture on admission and no KPC isolated during the hospital stay.

From June 2012 to June 2013, 2,575 patients were admitted to 4 LTACHs; 217 of 2,144 KPC-negative patients (10.1%) acquired KPC. In total, 100 of these patients were selected at random and matched to 100 controls by LTACH facility, admission date, and censored length of stay. Acquisitions occurred a median of 16.5 days after admission. On multivariate analysis, we found that exposure to higher colonization pressure (OR, 1.02; 95% CI, 1.01–1.04; P=.002), exposure to a carbapenem (OR, 2.25; 95% CI, 1.06–4.77; P=.04), and higher Charlson comorbidity index (OR, 1.14; 95% CI, 1.01–1.29; P=.04) were independent risk factors for KPC acquisition; the odds of KPC acquisition increased by 2% for each 1% increase in colonization pressure.

Higher colonization pressure, exposure to carbapenems, and a higher Charlson comorbidity index independently increased the odds of KPC acquisition among LTACH patients. Reducing colonization pressure (through separation of KPC-positive patients from KPC-negative patients using strict cohorts or private rooms) and reducing carbapenem exposure may prevent KPC cross transmission in this high-risk patient population.

Infect Control Hosp Epidemiol 2017;38:670–677

Prevalence of blaKPC-encoding Enterobacteriaceae (KPC) in Chicago long-term acute care hospitals (LTACHs) rose rapidly after the first recognition in 2007. We studied the epidemiology and transmission capacity of KPC in LTACHs and the effect of patient cohorting.

Data were available from 4 Chicago LTACHs from June 2012 to June 2013 during a period of bundled interventions. These consisted of screening for KPC rectal carriage, daily chlorhexidine bathing, medical staff education, and 3 cohort strategies: a pure cohort (all KPC-positive patients on 1 floor), single rooms for KPC-positive patients, and a mixed cohort (all KPC-positive patients on 1 floor, supplemented with KPC-negative patients). A data-augmented Markov chain Monte Carlo (MCMC) method was used to model the transmission process.

Average prevalence of KPC colonization was 29.3%. On admission, 18% of patients were colonized; the sensitivity of the screening process was 81%. The per admission reproduction number was 0.40. The number of acquisitions per 1,000 patient days was lowest in LTACHs with a pure cohort ward or single rooms for colonized patients compared with mixed-cohort wards, but 95% credible intervals overlapped.

Prevalence of KPC in LTACHs is high, primarily due to high admission prevalence and the resultant impact of high colonization pressure on cross transmission. In this setting, with an intervention in place, patient-to-patient transmission is insufficient to maintain endemicity. Inclusion of a pure cohort or single rooms for KPC-positive patients in an intervention bundle seemed to limit transmission compared to use of a mixed cohort.

Infect Control Hosp Epidemiol 2015;36(10):1148–1154

Multidrug-resistant organisms (MDROs) are an increasing burden among healthcare facilities. We assessed facility-level perceived importance of and responses to various MDROs.

A pilot survey to assess staffing, knowledge, and the perceived importance of and response to various multidrug resistant organisms (MDROs)

Acute care and long-term healthcare facilities

In 2012, a survey was distributed to infection preventionists at ~300 healthcare facilities. Pathogens assessed were Clostridium difficile, carbapenem-resistant Enterobacteriaceae (CRE), carbapenem-resistant Acinetobacter, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus, multidrug-resistant (defined as bacterial resistance to ≥3 antibiotic classes) Pseudomonas, and extended-spectrum β-lactamase-producing Escherichia coli.

A total of 74 unique facilities responded, including 44 skilled nursing facilities (SNFs) and 30 acute care facilities (ACFs). While ACFs consistently isolated patients with active infections or colonization due to these MDROs, SNFs had more variable responses. SNFs had more multi-occupancy rooms and reported less specialized training in infection control and prevention than did ACFs. Of all facilities with multi-occupancy rooms, 86% employed a cohorting practice for patients, compared with 50% of those without multi-occupancy rooms; 20% of ACFs and 7% of SNFs cohorted staff while caring for patients with the same MDRO. MRSA and C. difficile were identified as important pathogens in ACFs and SNFs, while CRE importance was unknown or was considered important in <50% of SNFs.

We identified stark differences in human resources, knowledge, policy, and practice between ACFs and SNFs. For regional control of emerging MDROs like CRE, there is an opportunity for public health officials to provide targeted education and interventions. Education campaigns must account for differences in audience resources and baseline knowledge.

Infect Control Hosp Epidemiol 2015;00(0): 1–6

Central line–associated bloodstream infection (BSI) rates are a key quality metric for comparing hospital quality and safety. Traditional BSI surveillance may be limited by interrater variability. We assessed whether a computer-automated method of central line–associated BSI detection can improve the validity of surveillance.

Retrospective cohort study.

Eight medical and surgical intensive care units (ICUs) in 4 academic medical centers.

Traditional surveillance (by hospital staff) and computer algorithm surveillance were each compared against a retrospective audit review using a random sample of blood culture episodes during the period 2004–2007 from which an organism was recovered. Episode-level agreement with audit review was measured with κ statistics, and differences were assessed using the test of equal κ coefficients. Linear regression was used to assess the relationship between surveillance performance (κ) and surveillance-reported BSI rates (BSIs per 1,000 central line–days).

We evaluated 664 blood culture episodes. Agreement with audit review was significantly lower for traditional surveillance (κ [95% confidence interval (CI)] = 0.44 [0.37–0.51]) than computer algorithm surveillance (κ [95% CI] [0.52–0.64]; P = .001). Agreement between traditional surveillance and audit review was heterogeneous across ICUs (P = .001); furthermore, traditional surveillance performed worse among ICUs reporting lower (better) BSI rates (P = .001). In contrast, computer algorithm performance was consistent across ICUs and across the range of computer-reported central line–associated BSI rates.

Compared with traditional surveillance of bloodstream infections, computer automated surveillance improves accuracy and reliability, making interfacility performance comparisons more valid.

Infect Control Hosp Epidemiol 2014;35(12):1483–1490