Multiplex polymerase chain reaction (PCR) respiratory panels are rapid, highly sensitive tests for viral and bacterial pathogens that cause respiratory infections. In this study, we (1) described best practices in the implementation of respiratory panels based on expert perspectives and (2) identified tools for diagnostic stewardship to enhance the usefulness of testing.

We conducted a survey of the Society for Healthcare Epidemiology of America Research Network to explore current and future approaches to diagnostic stewardship of multiplex PCR respiratory panels.

In total, 41 sites completed the survey (response rate, 50%). Multiplex PCR respiratory panels were perceived as supporting accurate diagnoses at 35 sites (85%), supporting more efficient patient care at 33 sites (80%), and improving patient outcomes at 23 sites (56%). Thirteen sites (32%) reported that testing may support diagnosis or patient care without improving patient outcomes. Furthermore, 24 sites (58%) had implemented diagnostic stewardship, with a median of 3 interventions (interquartile range, 1–4) per site. The interventions most frequently reported as effective were structured order sets to guide test ordering (4 sites), restrictions on test ordering based on clinician or patient characteristics (3 sites), and structured communication of results (2 sites). Education was reported as “helpful” but with limitations (3 sites).

Many hospital epidemiologists and experts in infectious diseases perceive multiplex PCR respiratory panels as useful tests that can improve diagnosis, patient care, and patient outcomes. However, institutions frequently employ diagnostic stewardship to enhance the usefulness of testing, including most commonly clinical decision support to guide test ordering.

Hospital readmission is unsettling to patients and caregivers, costly to the healthcare system, and may leave patients at additional risk for hospital-acquired infections and other complications. We evaluated the association between comorbidities present during index coronavirus disease 2019 (COVID-19) hospitalization and the risk of 30-day readmission.

We used the Premier Healthcare database to perform a retrospective cohort study of COVID-19 hospitalized patients discharged between April 2020 and March 2021 who were followed for 30 days after discharge to capture readmission to the same hospital.

Among the 331,136 unique patients in the index cohort, 36,827 (11.1%) had at least 1 all-cause readmission within 30 days. Of the readmitted patients, 11,382 (3.4%) were readmitted with COVID-19 as the primary diagnosis. In the multivariable model adjusted for demographics, hospital characteristics, coexisting comorbidities, and COVID-19 severity, each additional comorbidity category was associated with an 18% increase in the odds of all-cause readmission (adjusted odds ratio [aOR], 1.18; 95% confidence interval [CI], 1.17–1.19) and a 10% increase in the odds of readmission with COVID-19 as the primary readmission diagnosis (aOR, 1.10; 95% CI, 1.09–1.11). Lymphoma (aOR, 1.86; 95% CI, 1.58–2.19), renal failure (aOR, 1.32; 95% CI, 1.25–1.40), and chronic lung disease (aOR, 1.29; 95% CI, 1.24–1.34) were most associated with readmission for COVID-19.

Readmission within 30 days was common among COVID-19 survivors. A better understanding of comorbidities associated with readmission will aid hospital care teams in improving postdischarge care. Additionally, it will assist hospital epidemiologists and quality administrators in planning resources, allocating staff, and managing bed-flow issues to improve patient care and safety.

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant nosocomial pathogen in the ICU. MRSA contamination of healthcare personnel (HCP) gloves and gowns after providing care to patients with MRSA occurs at a rate of 14%–16% in the ICU setting. Little is known about whether the MRSA isolates identified on HCP gown and gloves following patient care activities are the same as MRSA isolates identified as colonizing or infecting the patient.

From a multisite cohort of 388 independent patient MRSA isolates and their corresponding HCP gown and glove isolates, we selected 91 isolates pairs using a probability to proportion size (PPS) sampling method. To determine whether the patient and HCP gown or gloves isolates were genetically similar, we used 5 comparative genomic typing methods: phylogenetic analysis, spa typing, multilocus sequence typing (MLST), large-scale BLAST score ratio (LSBSR), and single-nucleotide variant (SNV) analysis.

We identified that 56 (61.5%) of isolate pairs were genetically similar at least by 4 of the methods. Comparably, the spa typing and the LSBSR analyses revealed that >75% of the examined isolate pairs were concordant, with the thresholds established for each analysis.

Many of the patient MRSA isolates were genetically similar to those on the HCP gown or gloves following a patient care activity. This finding indicates that the patient is often the primary source of the MRSA isolates transmitted to the HCP, which can potentially be spread to other patients or hospital settings through HCP vectors. These results have important implications because they provide additional evidence for hospitals considering ending the use of contact precautions (gloves and gowns) for MRSA patients.

To determine the utility of the Sofia SARS rapid antigen fluorescent immunoassay (FIA) to guide hospital-bed placement of patients being admitted through the emergency department (ED).

Cross-sectional analysis of a clinical quality improvement study.

This study was conducted in 2 community hospitals in Maryland from September 21, 2020, to December 3, 2020. In total, 2,887 patients simultaneously received the Sofia SARS rapid antigen FIA and SARS-CoV-2 RT-PCR assays on admission through the ED.

Rapid antigen results and symptom assessment guided initial patient placement while confirmatory RT-PCR was pending. The sensitivity, specificity, positive predictive values, and negative predictive values of the rapid antigen assay were calculated relative to RT-PCR, overall and separately for symptomatic and asymptomatic patients. Assay sensitivity was compared to RT-PCR cycle threshold (Ct) values. Assay turnaround times were compared. Clinical characteristics of RT-PCR–positive patients and potential exposures from false-negative antigen assays were evaluated.

For all patients, overall agreement was 97.9%; sensitivity was 76.6% (95% confidence interval [CI], 71%–82%), and specificity was 99.7% (95% CI, 99%–100%). We detected no differences in performance between asymptomatic and symptomatic individuals. As RT-PCR Ct increased, the sensitivity of the antigen assay decreased. The mean turnaround time for the antigen assay was 1.2 hours (95% CI, 1.0–1.3) and for RT-PCR it was 20.1 hours (95% CI, 18.9–40.3) (P < .001). No transmission from antigen-negative/RT-PCR–positive patients was identified.

Although not a replacement for RT-PCR for detection of all SARS-CoV-2 infections, the Sofia SARS antigen FIA has clinical utility for potential initial timely patient placement.

To test the feasibility of targeted gown and glove use by healthcare personnel caring for high-risk nursing-home residents to prevent Staphylococcus aureus acquisition in short-stay residents.

Uncontrolled clinical trial.

This study was conducted in 2 community-based nursing homes in Maryland.

The study included 322 residents on mixed short- and long-stay units.

During a 2-month baseline period, all residents had nose and inguinal fold swabs taken to estimate S. aureus acquisition. The intervention was iteratively developed using a participatory human factors engineering approach. During a 2-month intervention period, healthcare personnel wore gowns and gloves for high-risk care activities while caring for residents with wounds or medical devices, and S. aureus acquisition was measured again. Whole-genome sequencing was used to assess whether the acquisition represented resident-to-resident transmission.

Among short-stay residents, the methicillin-resistant S. aureus acquisition rate decreased from 11.9% during the baseline period to 3.6% during the intervention period (odds ratio [OR], 0.28; 95% CI, 0.08–0.92; P = .026). The methicillin-susceptible S. aureus acquisition rate went from 9.1% during the baseline period to 4.0% during the intervention period (OR, 0.41; 95% CI, 0.12–1.42; P = .15). The S. aureus resident-to-resident transmission rate decreased from 5.9% during the baseline period to 0.8% during the intervention period.

Targeted gown and glove use by healthcare personnel for high-risk care activities while caring for residents with wounds or medical devices, regardless of their S. aureus colonization status, is feasible and potentially decreases S. aureus acquisition and transmission in short-stay community-based nursing-home residents.

To evaluate the effect of the burden of Staphylococcus aureus colonization of nursing home residents on the risk of S. aureus transmission to healthcare worker (HCW) gowns and gloves.

Multicenter prospective cohort study.

Residents and HCWs from 13 community-based nursing homes in Maryland and Michigan.

Residents were cultured for S. aureus at the anterior nares and perianal skin. The S. aureus burden was estimated by quantitative polymerase chain reaction detecting the nuc gene. HCWs wore gowns and gloves during usual care activities; gowns and gloves were swabbed and then cultured for the presence of S. aureus.

In total, 403 residents were enrolled; 169 were colonized with methicillin-resistant S. aureus (MRSA) or methicillin-sensitive S. aureus (MSSA) and comprised the study population; 232 were not colonized and thus were excluded from this analysis; and 2 were withdrawn prior to being swabbed. After multivariable analysis, perianal colonization with S. aureus conferred the greatest odds for transmission to HCW gowns and gloves, and the odds increased with increasing burden of colonization: adjusted odds ratio (aOR), 2.1 (95% CI, 1.3–3.5) for low-level colonization and aOR 5.2 (95% CI, 3.1–8.7) for high level colonization.

Among nursing home patients colonized with S. aureus, the risk of transmission to HCW gowns and gloves was greater from those colonized with greater quantities of S. aureus on the perianal skin. Our findings inform future infection control practices for both MRSA and MSSA in nursing homes.

To estimate the risk of transmission of antibiotic-resistant Gram-negative bacteria (RGNB) to gowns and gloves worn by healthcare personnel (HCP) when providing care to residents of community-based nursing facilities to identify the types of care and resident characteristics associated with transmission.

Prospective observational study.

Residents and HCP from 13 community-based nursing facilities in Maryland and Michigan.

Perianal swabs were collected from residents and cultured to detect RGNB. HCP wore gowns and gloves during usual care activities, and at the end of each interaction, these were swabbed in a standardized manner. Transmission of RGNB from a colonized resident to gowns and gloves was estimated. Odds ratios (ORs) of transmission associated with type of care or resident characteristic were calculated.

We enrolled 403 residents and their HCP in this study. Overall, 19% of enrolled residents with a perianal swab (n=399) were colonized with at least 1 RGNB. RGNB transmission to either gloves or gowns occurred during 11% of the 584 interactions. Showering the resident, hygiene or toilet assistance, and wound dressing changes were associated with a high risk of transmission. Glucose monitoring and assistance with feeding or medication were associated with a low risk of transmission. Residents with a pressure ulcer were 3 times more likely to transmit RGNB than residents without one (OR, 3.3; 95% confidence interval [CI], 1.0–11.1).

Gown and glove use in community nursing facilities should be prioritized for certain residents and care interactions that are deemed a high risk for transmission.

To determine which healthcare worker (HCW) roles and patient care activities are associated with acquisition of vancomycin-resistant Enterococcus (VRE) on HCW gloves or gowns after patient care, as a surrogate for transmission to other patients.

Prospective cohort study.

Medical and surgical intensive care units at a tertiary-care academic institution.

VRE-colonized patients on Contact Precautions and their HCWs.

Overall, 94 VRE-colonized patients and 469 HCW–patient interactions were observed. Research staff recorded patient care activities and cultured HCW gloves and gowns for VRE before doffing and exiting patient room.

VRE were isolated from 71 of 469 HCWs’ gloves or gowns (15%) following patient care. Occupational/physical therapists, patient care technicians, nurses, and physicians were more likely than environmental services workers and other HCWs to have contaminated gloves or gowns. Compared to touching the environment alone, the odds ratio (OR) for VRE contamination associated with touching both the patient (or objects in the immediate vicinity of the patient) and environment was 2.78 (95% confidence interval [CI], 0.99–0.77) and the OR associated with touching only the patient (or objects in the immediate vicinity) was 3.65 (95% CI, 1.17–11.41). Independent risk factors for transmission of VRE to HCWs were touching the patient’s skin (OR, 2.18; 95% CI, 1.15–4.13) and transferring the patient into or out of bed (OR, 2.66; 95% CI, 1.15–6.43).

Patient contact is a major risk factor for HCW contamination and subsequent transmission. Interventions should prioritize contact precautions and hand hygiene for HCWs whose activities involve touching the patient.

Hospitalized patients with suspected tuberculosis (TB) are placed in airborne isolation until 3 sputum smear samples are negative for acid-fast bacilli (AFB). The Xpert MTB/RIF assay (“Xpert”) nucleic acid amplification test (NAAT) to identify Mycobacterium tuberculosis DNA and resistance to rifampicin is superior to AFB sputum smear microscopy for the diagnosis of TB.

To compare the performance of a single Xpert to AFB smear microscopy for time to airborne infection isolation (AII) discontinuation.

Consecutive patients over 17 years of age in AII for suspected pulmonary TB between October 1, 2014, and March 31, 2016, with leftover respiratory AFB samples were enrolled in this study. A single Xpert was performed on the first available sample. Demographic, clinical, and microbiological data were recorded for each patient. We compared the duration of AII using a single Xpert to AFB smear microscopy under multiple theoretical scenarios using Kaplan-Meier cumulative incidence curves and the log-rank test.

In total, 131 samples were included in our performance analysis of the Xpert, and 114 samples were included in our AII analysis. Overall, 81 patients (65%) were immunosuppressed, of whom 46 (37%) were positive for human immunodeficiency virus (HIV). The sensitivity and specificity of Xpert for diagnosis of M. tuberculosis infection were 67% and 100%, respectively. Xpert was negative in all cases of nontuberculous mycobacteria. Use of a single Xpert reduced AII duration from a median of 67 hours per patient to 42 hours with usual reporting, to 26 hours with direct communication, and to 12 hours with immediate testing.

A single negative Xpert result can reduce AII duration compared to the AFB smear microscopy technique under multiple theoretical scenarios.

Infect Control Hosp Epidemiol 2018;39:590–595

To analyze whether electronically available comorbid conditions are risk factors for Centers for Disease Control and Prevention (CDC)-defined, hospital-onset Clostridium difficile infection (CDI) after controlling for antibiotic and gastric acid suppression therapy use.

Patients aged ≥18 years admitted to the University of Maryland Medical Center between November 7, 2015, and May 31, 2017.

Comorbid conditions were assessed using the Elixhauser comorbidity index. The Elixhauser comorbidity index and the comorbid condition components were calculated using the International Classification of Disease, Tenth Revision, Clinical Modification (ICD-10-CM) codes extracted from electronic medical records. Bivariate associations between CDI and potential covariates for multivariable regression, including antibiotic use, gastric acid suppression therapy use, as well as comorbid conditions, were estimated using log binomial multivariable regression.

After controlling for antibiotic use, age, proton-pump inhibitor use, and histamine-blocker use, the Elixhauser comorbidity index was a significant risk factor for predicting CDI. There was an increased risk of 1.26 (95% CI, 1.19–1.32) of having CDI for each additional Elixhauser point added to the total Elixhauser score.

An increase in Elixhauser score is associated with CDI. Our study and other studies have shown that comorbid conditions are important risk factors for CDI. Electronically available comorbid conditions and scores like the Elixhauser index should be considered for risk-adjustment of CDC CDI rates.

Infect Control Hosp Epidemiol 2018;39:297–301