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Executive summaryTesting of asymptomatic patients for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) (ie, “asymptomatic screening) to attempt to reduce the risk of nosocomial transmission has been extensive and resource intensive, and such testing is of unclear benefit when added to other layers of infection prevention mitigation controls. In addition, the logistic challenges and costs related to screening program implementation, data noting the lack of substantial aerosol generation with elective controlled intubation, extubation, and other procedures, and the adverse patient and facility consequences of asymptomatic screening call into question the utility of this infection prevention intervention. Consequently, the Society for Healthcare Epidemiology of America (SHEA) recommends against routine universal use of asymptomatic screening for SARS-CoV-2 in healthcare facilities. Specifically, preprocedure asymptomatic screening is unlikely to provide incremental benefit in preventing SARS-CoV-2 transmission in the procedural and perioperative environment when other infection prevention strategies are in place, and it should not be considered a requirement for all patients. Admission screening may be beneficial during times of increased virus transmission in some settings where other layers of controls are limited (eg, behavioral health, congregate care, or shared patient rooms), but widespread routine use of admission asymptomatic screening is not recommended over strengthening other infection prevention controls. In this commentary, we outline the challenges surrounding the use of asymptomatic screening, including logistics and costs of implementing a screening program, and adverse patient and facility consequences. We review data pertaining to the lack of substantial aerosol generation during elective controlled intubation, extubation, and other procedures, and we provide guidance for when asymptomatic screening for SARS-CoV-2 may be considered in a limited scope.

Respiratory viruses are transmitted via respiratory particles that are emitted when people breath, speak, cough, or sneeze. These particles span the size spectrum from visible droplets to airborne particles of hundreds of nanometers. Barrier face coverings (“cloth masks”) and surgical masks are loose-fitting and provide limited protection from airborne particles since air passes around the edges of the mask as well as through the filtering material. Respirators, which fit tightly to the face, provide more effective respiratory protection. Although healthcare workers have relied primarily on disposable filtering facepiece respirators (such as N95) during the COVID-19 pandemic, reusable elastomeric respirators have significant potential advantages for the COVID-19 and future respiratory virus pandemics. However, currently available elastomeric respirators were not designed primarily for healthcare or pandemic use and require further development to improve their suitability for this application. The authors believe that the development, implementation, and stockpiling of improved elastomeric respirators should be an international public health priority.

Objectives:The primary aim of this study was to assess the epidemiology of carbapenem-resistant Acinetobacter baumannii (CRAB) for 9 months following a regional outbreak with this organism. We also aimed to determine the differential positivity rate from different body sites and characterize the longitudinal changes of surveillance test results among CRAB patients.Design:Observational study.Setting:A 607-bed tertiary-care teaching hospital in Milwaukee, Wisconsin.Patients:Any patient admitted from postacute care facilities and any patient housed in the same inpatient unit as a positive CRAB patient.Methods:Participants underwent CRAB surveillance cultures from tracheostomy secretions, skin, and stool from December 5, 2018, to September 6, 2019. Cultures were performed using a validated, qualitative culture method, and final bacterial identification was performed using mass spectrometry.Results:In total, 682 patients were tested for CRAB, of whom 16 (2.3%) were positive. Of the 16 CRAB-positive patients, 14 (87.5%) were residents from postacute care facilities and 11 (68.8%) were African American. Among positive patients, the positivity rates by body site were 38% (6 of 16) for tracheal aspirations, 56% (9 of 16) for skin, and 82% (13 of 16) for stool.Conclusions:Residents from postacute care facilities were more frequently colonized by CRAB than patients admitted from home. Stool had the highest yield for identification of CRAB.

The household setting has some of the highest coronavirus disease 2019 (COVID-19) secondary-attack rates. We compared the air contamination in hospital rooms versus households of COVID-19 patients. Inpatient air samples were only positive at 0.3 m from patients. Household air samples were positive even without a COVID-19 patient in the proximity to the air sampler.

Not all patients who acquire carbapenemase-producing Enterobacteriaceae (CPE) develop infections by these organisms; many remain only colonized. Of 54 CPE-colonized patients, 16 (30%) developed CPE infections. We identified indwelling urinary catheter exposure, exposure to intravenous colistin, and overseas transfer as variables associated with CPE infection development among colonized patients.

Background Carbapenem-resistant Enterobacteriaceae (CRE) is an urgent public health threat globally. Limited data are available regarding the epidemiology of CRE in South Florida. We describe the epidemiology of CRE within a large public healthcare system in Miami, FL, the experience with an internal registry, active surveillance testing, and the impact of infection prevention practices. Methods Retrospective cohort study in 4 hospitals from a large healthcare system in Miami-Dade County, FL from 2012 to 2016. The internal registry included all CRE cases from active surveillance testing from rectal and/or tracheal screening occurring in the intensive care units of 2 of the hospitals and clinical cultures across the healthcare system. All CRE cases were tagged in the electronic medical record and automatically entered into a platform for automatic infection control surveillance. The system alerted about new cases, readmissions, and transfers. Results A total of 371 CRE cases were identified. The overall prevalence was 0.077 cases per 100 patient-admissions; the admission prevalence was 0.019 per 100 patient-admissions, and the incidence density was 1.46 cases per 10,000 patient-days. Rates increased during the first 3 years of the study and declined later to a lower level than at the beginning of study period. Conclusions Active surveillance testing and the use of an internal registry facilitated prompt identification of cases contributing to control increasing rates of CRE by rapid implementation of infection prevention strategies.

Background:The association between Clostridioides difficile colonization and C. difficile infection (CDI) is unknown in solid-organ transplant (SOT) patients. We examined C. difficile colonization and healthcare-associated exposures as risk factors for development of CDI in SOT patients.Methods:The retrospective study cohort included all consecutive SOT patients with at least 1 screening test between May 2017 and April 2018. CDI was defined as the presence of diarrhea (without laxatives), a positive C. difficile clinical test, and the use of C. difficile-directed antimicrobial therapy as ordered by managing clinicians. In addition to demographic variables, exposures to antimicrobials, immunosuppressants, and gastric acid suppressants were evaluated from the time of first screening test to the time of CDI, death, or final discharge.Results:Of the 348 SOT patients included in our study, 33 (9.5%) were colonized with toxigenic C. difficile. In total, 11 patients (3.2%) developed CDI. Only C. difficile colonization (odds ratio [OR], 13.52; 95% CI, 3.46–52.83; P = .0002), age (OR, 1.09; CI, 1.02–1.17; P = .0135), and hospital days (OR, 1.05; 95% CI, 1.02–1.08; P = .0017) were independently associated with CDI.Conclusions:Although CDI was more frequent in C. difficile colonized SOT patients, the overall incidence of CDI was low in this cohort.

Many health care systems around the world continue to struggle with large numbers of SARS-CoV-2-infected patients, while others have diminishing numbers of cases following an initial surge. There will most likely be significant oscillations in numbers of cases for the foreseeable future, based on the regional epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Less affected hospitals and facilities will attempt to progressively resume elective procedures and surgery. Ramping up elective care in hospitals that deliberately curtailed elective care to focus on SARS-CoV-2-infected patients will present unique and serious challenges. Among the challenges will be protecting patients and providers from recurrent outbreaks of disease while increasing procedure throughput. Anesthesia providers will inevitably be exposed to SARS-CoV-2 by patients who have not been diagnosed with infection. This is particularly concerning in consideration that aerosols produced during airway management may be infective. In this article, we recommend an approach to routine anesthesia care in the setting of persistent but variable prevalence of SARS-CoV-2 infection. We make specific recommendations for personal protective equipment and for the conduct of anesthesia procedures and workflow based on evidence and expert opinion. We propose practical, relatively inexpensive precautions that can be applied to all patients undergoing anesthesia. Because the SARS-CoV-2 virus is spread primarily by respiratory droplets and aerosols, effective masking of anesthesia providers is of paramount importance. Hospitals should follow the recommendations of the Centers for Disease Control and Prevention for universal masking of all providers and patients within their facilities. Anesthesia providers should perform anesthetic care in respirator masks (such as N-95 and FFP-2) whenever possible, even when the SARS-CoV-2 test status of patients is negative. Attempting to screen patients for infection with SARS-CoV-2, while valuable, is not a substitute for respiratory protection of providers, as false-negative tests are possible and infected persons can be asymptomatic or presymptomatic. Provision of adequate supplies of respirator masks and other respiratory protection equipment such as powered air purifying respirators (PAPRs) should be a high priority for health care facilities and for government agencies. Eye protection is also necessary because of the possibility of infection from virus coming into contact with the conjunctiva. Because SARS-CoV-2 persists on surfaces and may cause infection by contact with fomites, hand hygiene and surface cleaning are also of paramount importance.

Objectives We examined the distribution of reverse transcription polymerase chain reaction (RT-PCR) cycle threshold (CT) values obtained from symptomatic patients being evaluated for coronavirus disease 2019 (COVID-19) to determine the proportion of specimens containing a viral load near the assay limit of detection (LoD) to gain practical insight to the risk of false-negative results. We also examined the relationship between CT value and patient age to determine any age-dependent difference in viral load or test sensitivity. Methods We collected CT values obtained from the cobas severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) assay corresponding to 1,213 combined nasopharyngeal-oropharyngeal specimens obtained from symptomatic individuals that were reported as positive or presumptive positive for SARS-CoV-2. CT values were stratified by SARS-CoV target and patient age group. Results In total, 93.3% to 98.4% of specimens demonstrated CT values greater than 3× the assay LoD, at which point false-negative results would not be expected. The mean of CT values between age groups was statistically equivalent with the exception of patients in age group 80 to 89 years, which demonstrated slightly lower CTs. Conclusions Based on the distribution of observed CT values, including the small proportion of specimens with values near the assay LoD, there is a low risk of false-negative RT-PCR results in combined nasopharyngeal-oropharyngeal specimens obtained from symptomatic individuals.

Poverty and high viral load are associated with worse outcomes among COVID-19 patients.We included patients admitted to Froedtert Health between March 16 and June 1, 2020. SARS-CoV-2 viral load was proxied by cycle-threshold values. To measure poverty, we used Medicaid or uninsured status and residence in socially disadvantaged areas. We assessed the association between viral load and length of stay and discharge disposition, while controlling for demographics and confounders.Higher viral load was associated with longer length of stay (coefficient -0.02; 95% CI, -0.04 to 0.01; P = 0.006) and higher likelihood of death (coefficient -0.11; 95% CI, -0.17 to -0.06; P 0.001). Poverty, residence in disadvantaged areas, and race were not.This study confirms a relationship of viral load with in-hospital death, even after controlling for race and poverty.

Background Treatment of asymptomatic bacteriuria (ASB) is recommended in pregnant women and prior to urologic procedures with anticipated mucosal disruption. However, there is still insufficient evidence of the usefulness of treating ASB prior to urologic procedures. Therefore, the aim of this study was to ascertain the risk of infections in patients undergoing urologic surgery based on the presence of ASB. Methods We conducted a cohort study among patients undergoing urologic surgery at a single center located in Medellin, Colombia. All patients were screened for ASB prior to their procedures. Patients were evaluated for the development of any postoperative infectious complications for up to 30 days after the procedure. Results A total of 149 patients were included in this cohort. Incidence of ASB was 14.8%. Thirteen patients (8.72%) developed infectious complications: 3 (13.64%) with ASB and 10 (7.87%) without ABS. Factors associated with postoperative infectious complications included urologic cancers (hazard ratio [HR], 5.26; 95% confidence intervals [CI], 1.24-22.37), urologic interventions in the preceding 3 months (HR, 3.72; 95% CI, 1.02-13.51), and use of antibiotics 3 months prior to surgery (HR, 3.83; 95% CI, 1.01-15.49). Presence of ASB was not associated with postsurgical infectious complications (HR, 1.02; 95% CI, 0.26-3.96). Conclusions There was no association between ASB and postoperative infectious complications. There were other factors associated with infectious complications, such as urologic cancer, previous history of urologic manipulation, and antibiotic use.

Inflammatory bowel disease (IBD) andThis retrospective cohort included IBD patients who presented with acute onset of gastrointestinal symptoms and aA total of 71 patients were included. Eighty-four percent of the tests were EIA(-) and among the EIA(-) 88% were treated with antibiotics. Outcomes between EIA(+) and EIA(-) were not significantly different in terms of recurrences, admissions, changes to IBD medications or complications. Outcomes were also similar when comparing those who received antibiotic therapy to those who did not.Our cohort did not demonstrate a significant difference in outcomes between EIA(+) and EIA(-)

Asymptomatic SARS-CoV-2 infections are often difficult to identify because widespread surveillance has not been the norm. Using time-series analyses, we examined whether COVID-19 rates at the county level could predict positivity rates among asymptomatic patients in a large health system. Asymptomatic positivity rates at the system level and county-level COVID-19 rates were not associated.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) asymptomatic infections may play a critical role in disease transmission. We aim to determine the prevalence of asymptomatic SARS-CoV-2 infection at 2 hospital systems in 2 counties in Wisconsin. The SARS-CoV-2 prevalence was 1% or lower at both systems despite the higher incidence of coronavirus disease 2019 (COVID-19) in Milwaukee County.

Previously, we showed that disinfection of sink drains is effective at decreasing bacterial loads. Here, we report our evaluation of the ideal frequency of sink-drain disinfection and our comparison of 2 different hydrogen peroxide disinfectants.

Objective:Describe the epidemiological and molecular characteristics of an outbreak ofKlebsiella pneumoniaecarbapenemase (KPC)–producing organisms and the novel use of a cohorting unit for its control.Design:Observational study.Setting:A 566-room academic teaching facility in Milwaukee, Wisconsin.Patients:Solid-organ transplant recipients.Methods:Infection control bundles were used throughout the time of observation. All KPC cases were intermittently housed in a cohorting unit with dedicated nurses and nursing aids. The rooms used in the cohorting unit had anterooms where clean supplies and linens were placed. Spread of KPC-producing organisms was determined using rectal surveillance cultures on admission and weekly thereafter among all consecutive patients admitted to the involved units. KPC-positive strains underwent pulsed-field gel electrophoresis and whole-genome sequencing.Results:A total of 8 KPC cases (5 identified by surveillance) were identified from April 2016 to April 2017. After the index patient, 3 patients acquired KPC-producing organisms despite implementation of an infection control bundle. This prompted the use of a cohorting unit, which immediately halted transmission, and the single remaining KPC case was transferred out of the cohorting unit. However, additional KPC cases were identified within 2 months. Once the cohorting unit was reopened, no additional KPC cases occurred. The KPC-positive species identified during this outbreak includedKlebsiella pneumoniae,Enterobacter cloacaecomplex, andEscherichia coli. blaKPCwas identified on at least 2 plasmid backbones.Conclusions:A complex KPC outbreak involving both clonal and plasmid-mediated dissemination was controlled using weekly surveillances and a cohorting unit.

We reviewed seminal papers and recently published articles discussing multiple aspects of infection prevention applied to Clostridioides (formerly Clostridium) difficile infection (CDI). We identified hot topics including the importance of understanding the gut microbiome in CDI and its implications from an infection prevention perspective, the increasing role of antibiotic stewardship including testing stewardship in preventing and mitigating CDI, and the increasing role of clinical decision support systems to improve early diagnosis and decrease inappropriate testing. In addition to established infection prevention interventions, CDI control will be achieved by a combination of gut microbiome manipulation, personalized medicine based on host and agent genome analysis, and a combination of antimicrobials and testing stewardship by leveraging progressively sophisticated electronic decision systems. Automated environmental decontamination systems are not routinely recommended at this time.

Objectives Evidence suggests that quality, location, and staffing levels may be associated with COVID-19 incidence in nursing homes. However, it is unknown if these relationships remain constant over time. We describe incidence rates of COVID-19 across Wisconsin nursing homes while examining factors associated with their trajectory during five months of the pandemic. Design Retrospective cohort study. Setting/Participants Wisconsin nursing homes. Methods Publicly available data from June 1, 2020 to October 31, 2020 were obtained. These included facility size, staffing, Five-star Medicare rating score and components. Nursing home characteristics were compared using Pearson Chi-square and Kruskal-Wallis tests. Multiple linear regressions were used to evaluate the effect of rurality on COVID-19. Results There were a total of 2,459 COVID-19 cases across 246 Wisconsin nursing homes. Number of beds (P

The primary aim of this study was to assess the epidemiology of carbapenem-resistant Acinetobacter baumannii (CRAB) for 9 months following a regional outbreak with this organism. We also aimed to determine the differential positivity rate from different body sites and characterize the longitudinal changes of surveillance test results among CRAB patients.Observational study.A 607-bed tertiary-care teaching hospital in Milwaukee, Wisconsin.Any patient admitted from postacute care facilities and any patient housed in the same inpatient unit as a positive CRAB patient.Participants underwent CRAB surveillance cultures from tracheostomy secretions, skin, and stool from December 5, 2018, to September 6, 2019. Cultures were performed using a validated, qualitative culture method, and final bacterial identification was performed using mass spectrometry.In total, 682 patients were tested for CRAB, of whom 16 (2.3%) were positive. Of the 16 CRAB-positive patients, 14 (87.5%) were residents from postacute care facilities and 11 (68.8%) were African American. Among positive patients, the positivity rates by body site were 38% (6 of 16) for tracheal aspirations, 56% (9 of 16) for skin, and 82% (13 of 16) for stool.Residents from postacute care facilities were more frequently colonized by CRAB than patients admitted from home. Stool had the highest yield for identification of CRAB.

Current recommendations by the Centers for Disease Control and Prevention suggest placing patients with carbapenem-producing Enterobacteriales (CPE) in contact precautions, but there is no consensus on the appropriate duration of precautions.We aimed to evaluate predictors for prolonged CPE carriage and median clearance time.Patients with first isolated CPE identified from 2012-2016 were followed for clearance of CPE using at least two rectal or tracheal aspirate surveillance cultures and clinical cultures during intensive-care-unit admission. Predictors associated with prolonged CPE carriage were assessed using Cox proportional-hazards.Out of 75 eligible patients, 25 (33%) cleared their CPE-carrier status; median time to clearance was 80 days (Range, 16-457). Patients who were immunocompromised, had mechanical ventilation exposure, or exposure to carbapenems had 66%, 66%, and 86% (HR, 0.34, 0.34, and 0.14, respectively [P-value.05]) lower probability of clearing compared to those immunocompetent of without such exposures. Patients with CPE isolated from more than one body site had a 5.3 times higher probability of clearing their CPE-carrier status (P-value.001).Patients immunocompromised, with mechanical ventilation exposure, or exposure to carbapenems had higher risk for prolonged CPE carriage. Infection prevention programs should consider these predictors as part of their assessment of discontinuing contact precautions among CPE carriers to prevent horizontal transmission and outbreaks within healthcare facilities.

Background: The COVID-19 pandemic has disproportionately affected nursing home residents, and emerging evidence suggests quality, location, resident demographics, and staffing levels may be related to COVID-19 incidence within facilities. We describe the distribution of COVID-19 cases in Wisconsin nursing homes from January 2020 to October 2020, the effect of rural versus urban locations on COVID-19 incidence, and the temporal changes in COVID-19 incidence. Methods: We constructed a database using the Center for Medicaid and Medicare Services’ (CMS) publicly available data. Variables obtained per facility included location, number of beds, ownership type, average census, 5-star ratings (overall, quality, health, staffing, and nurse staffing categories), number of COVID-19 cases, resident Medicaid/Medicare share, area deprivation index, and social vulnerability index. Nursing homes were divided into tertiles based on total COVID-19 cases for descriptive analysis (zero cases, 1–7 cases, >7 cases). Demographic and clinical variables were reported as frequencies, mean (standard deviation) or median (interquartile range). We compared groups using the Pearson χ2 test and the Kruskal-Wallis test. COVID-19 incidence rates were calculated by dividing the number of COVID-19 cases by monthly occupied bed days and multiplied by 10,000. Results: From January 1, 2020, to November 1, 2020, in total, 3,133 SARS-CoV-2–confirmed cases were reported among 248 (70.5%) nursing homes. Urban location (P = .027), overall 5-star rating (P = .035), number of beds (p < 0.001), and average count of residents per day (p < 0.001) were associated with a greater number of COVID-19 cases. Temporal analysis showed that the highest incidence rates of COVID-19 in NHs were observed from January to May and in October 2020 (11.36 and 30.33 cases per 10,000 occupied-bed days, respectively). Urban NHs experienced higher incidence rates until September, then incidence rates among rural facilities surged (Fig.1A). In the first half of the year, NHs with lower quality scores (1-3 stars) had a higher COVID-19 incidence rate; however, in August this trend reversed, and facilities with higher quality scores (4-5 stars) showed the highest incidence rates (Fig.1B). Fig. 2 shows a temporal depiction of the shift from urban to rural settings. Conclusions: Higher COVID-19 incidence rates during the first 5 months of the pandemic were observed in urban, larger facilities with lower 5-star rating. By the end of the year, nursing homes in rural areas and those with higher quality ratings had the highest incidence rates.Funding: NoDisclosures: None

Background: The gold standard for diagnosis of COVID-19 has been SARS-CoV-2 detection by reverse-transcriptase-quantitative polymerase chain reaction (RT-qPCR), which provides a semiquantitative indicator of viral load (cycle threshold, Ct). Our research group previously described how African American race and poverty were associated with an increased likelihood of hospitalization due to COVID-19. We sought to characterize the relationship between Ct values and clinical outcomes while controlling for sociodemographic factors. Methods: We conducted a cross-sectional study of SARS-CoV-2–positive patients admitted to Froedtert Health between March 16 and June 1, 2020. Ct values were obtained by direct interrogation of either cobas SARS-CoV-2 or Cepheid Xpert Xpress platforms. Patient demographics, comorbidities, symptoms at admission, health insurance, and hospital course were collected using electronic medical records. A proxy for socioeconomic disadvantage, area-deprivation index (ADI), was assigned using ZIP codes. Multivariate models were performed to assess associations between Ct values and clinical outcomes while controlling for ADI, race, and type of insurance. Results: Overall, 302 patients were included. The mean age was 60.89 years (SD, 18.2); 161 (53%) were men, 177 (58%) were African Americans; and 156 (51%) had Medicaid or were uninsured. Of the 302 inpatients, 158 (52%) required admission to the ICU, 199 (65.9%) were discharged to home, 49 (16.2%) were discharged to a nursing home, and 54 (17.9%) died. Lower Ct values (higher viral load) were associated with Medicaid or lack of insurance (coefficient, −2.88, 95% confidence interval [CI], −4.96 to −0.79, P = .007) and age >60 years old (coefficient, −2.98, 95% CI −4.87 to −1.08, P = .002). Contrary to what was expected, higher CT values (lower viral load) were associated with higher ADI scores (coefficient, 2.62, 95% CI, 0.52–4.85; P = .017). However, when patients were stratified into low, medium, and high ADI, those with Medicaid or no insurance had the lowest mean Ct values (23.3, 25.9, and 27.6, respectively) compared to Medicare or other insurance (Figure 1). Body mass index (odds ratio [OR], 1.04; 95% CI, 1.02–1.07; P = .001) and male sex (OR, 2.15; 95% CI, 1.28–3.60; P = .004) were independently associated with ICU admission. Every increase of a CT point (OR, 0.90; 95% CI, 0.85–0.95; p 60 years old (OR 2.62, 95% CI; 1.14-6.04; p=0.023) was associated with death. Conclusions: In this cross-sectional study of adults tested for COVID-19 in a large midwestern academic health system, lower Ct values were independently associated with poverty and age >60 years old.Funding: NoDisclosures: None

Background: Asymptomatic SARS-CoV-2 infections play a crucial role in viral transmission. However, they are often difficult to identify given that widespread surveillance has not been the norm. We sought to determine whether COVID-19 rates reported at the county level could predict the positivity rates for SARS-CoV-2 among asymptomatic patients tested in a large academic health system. Methods: This observational study was conducted from April 23, 2020, to December 10, 2020, at Froedtert Health (FH) system, the largest academic health system in Wisconsin. On April 23, 2020, FH implemented SARS-CoV-2 surveillance among all consecutive admissions not suspected of COVID-19, all patients scheduled for elective procedures and deliveries, and all asymptomatic patients with known exposures. Samples were processed by the FH laboratory using molecular methods (RT-PCR). To obtain the daily number of newly confirmed COVID-19 cases in Milwaukee County, we accessed the Wisconsin Department of Health Services publicly available COVID-19 database. For the purpose of this study, COVID-19 rates were defined as the percentage of positive tests among all daily tests performed at the county level, while SARS-CoV-2 positivity rates were the percentage of positive tests among all daily surveillance tests performed at FH among asymptomatic patients. The association between COVID-19 rates in Milwaukee County and asymptomatic rates at FH were assessed using an autoregressive moving average time series analysis. To examine the association between these rates, we fitted a seventh-order autoregression for the residuals based on autocorrelation function and partial autocorrelation function plots of the residuals from linear regression. Results: From April 23, 2020, to December 10, 2020, there were 2,347 new asymptomatic infections detected at FH and 75,196 new COVID-19 cases reported in Milwaukee County. Figure 1 shows the time-series plot of asymptomatic SARS-CoV-2 positivity rates at FH and Figure 2 shows COVID-19 rates in Milwaukee County. As the COVID-19 rate in Milwaukee County increased by 1 unit, the asymptomatic infection rate in FH decreased by 0.024 unit (95% CI, −0.053 to 0.004; P = .095) after accounting for autocorrelation over time. Thus, there was no association between these rates. Conclusions: The positivity rates among asymptomatic patients at a large medical center were not predicted by the positivity rate at the county level. This finding suggests that the epidemiology at a county level may be determined by pockets in the population who may not interact, and thus not affect, the positivity rates among asymptomatic patients served by a hospital system within the county.Funding: NoDisclosures: None

Not all patients who acquire carbapenemase-producing Enterobacteriaceae (CPE) develop infections by these organisms; many remain only colonized. Of 54 CPE-colonized patients, 16 (30%) developed CPE infections. We identified indwelling urinary catheter exposure, exposure to intravenous colistin, and overseas transfer as variables associated with CPE infection development among colonized patients.

The association between Clostridioides difficile colonization and C. difficile infection (CDI) is unknown in solid-organ transplant (SOT) patients. We examined C. difficile colonization and healthcare-associated exposures as risk factors for development of CDI in SOT patients.The retrospective study cohort included all consecutive SOT patients with at least 1 screening test between May 2017 and April 2018. CDI was defined as the presence of diarrhea (without laxatives), a positive C. difficile clinical test, and the use of C. difficile-directed antimicrobial therapy as ordered by managing clinicians. In addition to demographic variables, exposures to antimicrobials, immunosuppressants, and gastric acid suppressants were evaluated from the time of first screening test to the time of CDI, death, or final discharge.Of the 348 SOT patients included in our study, 33 (9.5%) were colonized with toxigenic C. difficile. In total, 11 patients (3.2%) developed CDI. Only C. difficile colonization (odds ratio [OR], 13.52; 95% CI, 3.46-52.83; P = .0002), age (OR, 1.09; CI, 1.02-1.17; P = .0135), and hospital days (OR, 1.05; 95% CI, 1.02-1.08; P = .0017) were independently associated with CDI.Although CDI was more frequent in C. difficile colonized SOT patients, the overall incidence of CDI was low in this cohort.

Background The key epidemiological drivers of Clostridioides difficile transmission are not well understood. We estimated epidemiological parameters to characterize variation in C. difficile transmission, while accounting for the imperfect nature of surveillance tests. Methods We conducted a retrospective analysis of C. difficile surveillance tests for patients admitted to a bone marrow transplant (BMT) unit or a solid tumor unit (STU) in a 565-bed tertiary hospital. We constructed a transmission model for estimating key parameters, including admission prevalence, transmission rate, and duration of colonization to understand the potential variation in C. difficile dynamics between these 2 units. Results A combined 2425 patients had 5491 admissions into 1 of the 2 units. A total of 3559 surveillance tests were collected from 1394 patients, with 11% of the surveillance tests being positive for C. difficile. We estimate that the transmission rate in the BMT unit was nearly 3-fold higher at 0.29 acquisitions per percentage colonized per 1000 days, compared to our estimate in the STU (0.10). Our model suggests that 20% of individuals admitted into either the STU or BMT unit were colonized with C. difficile at the time of admission. In contrast, the percentage of surveillance tests that were positive within 1 day of admission to either unit for C. difficile was 13.4%, with 15.4% in the STU and 11.6% in the BMT unit. Conclusions Although prevalence was similar between the units, there were important differences in the rates of transmission and clearance. Influential factors may include antimicrobial exposure or other patient-care factors.

Key Points Question Is an individual’s location of residence associated with asymptomatic carriage of toxigenic Clostridiodes difficile? Findings In this cohort study of 3043 adult participants admitted to the hospital, patients who lived closer to livestock farms had a higher likelihood of carrying toxigenic C difficile at the time of hospital admission. Meaning Clostridioides difficile is acquired not only in hospitals but also in the community setting. Livestock farms may expose people to higher loads of C difficile via runoff water and to substances that disrupt the intestinal microbiome, placing them at higher risk of C difficile colonization., Importance Clostridioides difficile infection is the most frequent health care–associated infection in the United States. However, exposure to this organism might occur outside the health care setting. Objective To examine whether exposure to environmental factors, such as livestock farms, is associated with a higher probability of being colonized with C difficile at hospital admission. Design, Setting, and Participants This retrospective cohort study was conducted from May 1, 2017, to June 30, 2018, at a teaching-affiliated hospital in Milwaukee, Wisconsin. All consecutive patients underwent C difficile screening using a nucleic acid amplification test at hospital admission. Data analyses were performed from July 2018 to October 2019. Exposures The distances from patient residence to the nearest livestock farms, meat processing plants, raw materials services, and sewage facilities were measured in addition to risk factors previously evaluated in other studies. Main Outcomes and Measures The main outcome was a positive result on C difficile screening tests performed within 72 hours of hospital admission. Results A total of 3043 patients admitted to the hospital were included in the final analysis. Of those, 1564 (51.4%) were women and 2074 (68.9%) were white, with a mean (SD) age of 62.0 (15.9) years; 978 patients (32.1%) were admitted to hematology-oncology units. At first admission, 318 patients (10.4%) were detected through testing as C difficile carriers. Multivariable logistic regression analyses were performed on a stratified sample of patients based on hematology-oncology admission status. These analyses indicated that although patients admitted to hematology-oncology units were 35% more likely to be colonized with C difficile, no significant association existed between their sociodemographic and economic characteristics or health care and environmental exposures and the likelihood of a positive C difficile test result. In contrast, among patients admitted to non–hematology-oncology units, comorbidities increased the likelihood for colonization by more than 4 times; women had 60% greater colonization than men, and a history of recent hospitalization (ie, within the preceding 6 months) increased the likelihood of colonization by 70%. Residential proximity to livestock farms were all significantly associated with a higher likelihood of a positive C difficile test result. Residential proximity to livestock farms more than doubled the probability of C difficile colonization in patients admitted to non–hematology-oncology units. Conclusions and Relevance A shorter distance between residence and livestock farms was associated with C difficile colonization. Knowledge of the epidemiology of C difficile in the community surrounding the hospital is important, as it has potential implications for the incidence of hospital-onset C difficile infection., This cohort study examines whether environmental factors, such as residential proximity to livestock farms, are associated with the probability of toxigenic Clostridiodes difficile carriage in patients at the time of hospital admission.

The SARS-CoV-2 virus has infected hundreds of millions of people and caused millions of deaths worldwide. Reports of racial and ethnic disparities regarding both rates of infection of the SARS-CoV-2 virus and morbidity of the coronavirus disease-19 (COVID-19) contain profound differences depending on the population. A previous study found an independent and positive association between the Black/African American race and positive COVID-19 testing results in Milwaukee County, WI, while adjusting for age, sex, socioeconomic status, and comorbidities (Munoz-Price. et al, 2020, JAMA Network). Our previous study revealed that patients with COVID-19 who developed hypertriglyceridemia during their hospitalization were associated with a 2.3 times higher mortality rate, after adjusting for age, gender, body mass index, history of hypertension and diabetes (Dai. et al, 2021, manuscript accepted by Journal of Clinical Lipidology). Additionally, adverse blood clotting events is one of the major causes of death for patients with COVID-19. In this study, we investigated the correlation between racial/ethnic groups and mortality, along with potential correlations between hypertriglyceridemia and adverse blood clotting events in hospitalized patients with COVID-19 (ICD10CM:U07.1). De-identified data from 1,441 hospitalized patients diagnosed with COVID-19 between March 2020 and June 2021 were extracted using the Medical College of Wisconsin Clinical Research Data Warehouse. Vital, demographic, and diagnostic information were used for the statistical analysis, specifically: age, gender, body mass index (BMI), race/ethnicity, thrombosis diagnosis and laboratory test results for triglyceride. The thrombotic events included were presence of disseminated intravascular coagulopathy, deep vein thrombosis, myocardial infarction, pulmonary embolism, and stroke diagnosed during their hospitalization. Hypertriglyceridemia was characterized as triglyceride levels greater than 150 mg/dL, with a baseline variable being the first occurrence of hypertriglyceridemia (baseline), and the peak variable being the highest manifestation of hypertriglyceridemia during hospitalization (peak). A binary logistic regression model showed that non-white Hispanic and Asian patients both had a higher correlation with mortality than white patients, with odds ratios (OR) of 4.1 [95% CI (2.2-7.9), p < 0.001] and 4.2 [95% CI (1.8-9.8), p < 0.001], respectively, after adjusting for age, BMI, and sex (Figure A). Additionally, the regression analysis showed that peak hypertriglyceridemia developed during hospitalization was correlated with a 1.8 times higher mortality in the entire inpatient cohort [95% CI (1.2-2.9), p < 0.01], after adjusting for age, sex, and BMI and independent of obesity. Furthermore, myocardial infarction [OR = 1.5, 95% CI (1.-2.5), p < 0.05] and pulmonary embolism [OR = 2.0, 95% CI (1.1-4.1), p < 0.05] were also correlated with a higher mortality, after adjusting for age, BMI, and sex (Figure B). The peak hypertriglyceridemia developed during hospitalization correlates with the incidence of thrombotic events with a borderline significance [OR= 1.5, 95% CI (0.9-2.1), p = 0.05] after adjusting for BMI, age, and sex. Further analysis revealed that non-white Hispanic patients had the highest frequencies of peak hypertriglyceridemia (triglyceride > 150 mg/dL) occurrence during hospitalization than the other race/ethnicity groups (Figure C). On the other hand, 22% of non-white Hispanics had at least one diagnosis of thrombotic event during hospitalization, which was the lowest incidence of thrombosis among all race/ethnicity groups (Figure D). In our current retrospective study of inpatients with COVID-19, race/ethnicity, peak hypertriglyceridemia developed during hospitalization, and thrombosis are independently associated with mortality. The peak hypertriglyceridemia developed during hospitalization is positively correlated with the incidence of thrombosis. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Antimicrobial resistance (AMR) remains one of the leading global health threats. This study compared antimicrobial resistance patterns among E. coli isolates from clinical uropathogenic Escherichia coli (UPEC) to hospital wastewater populations and throughout an urban wastewater treatment facility - influent, pre- and post-chlorinated effluents. Antibiotic susceptibility of 201 isolates were analyzed against eleven different antibiotics, and the presence of twelve antibiotic resistant genes and type 1 integrase were identified. AMR exhibited the following pattern: UPEC (46.8%) > hospital wastewater (37.8%) > urban post-chlorinated effluent (27.6%) > pre-chlorinated effluent (21.4%) > urban influent wastewater (13.3%). However, multi-drug resistance against three or more antimicrobial classes was more prevalent among hospital wastewater populations (29.7%) compared to other sources. E. coli from wastewaters disinfected with chlorine were significantly correlated with increased trimethoprim-sulfamethoxazole resistance in E. coli compared to raw and treated wastewater populations. blaCTX-M-1 group was the most common extended spectrum beta-lactamase in E. coli from hospital wastewater (90%), although UPEC strains also encoded blaCTX-M-1 group (50%) and blaTEM (100%) genes. Among tetracycline-resistant populations, tetA and tetB were the only resistance genes identified throughout wastewater populations that were associated with increased phenotypic resistance. Further characterization of the E. coli populations identified phylogroup B2 predominating among clinical UPEC populations and correlated with the highest AMR, whereas the elevated rate of multi-drug resistance among hospital wastewater was mostly phylogroup A. Together, our findings highlight hospital wastewater as a rich source of AMR and multi-drug resistant bacterial populations.

We report patient-to-patient transmission of Enterobacter hormaechei isolates with reduced susceptibility to ceftazidime-avibactam due to production of KPC-40, a variant of KPC-3 with a two-amino-acid insertion in the Ω-loop region (L167_E168dup). The index patient had received a prolonged course of ceftazidime-avibactam therapy, whereas the second patient had not received the agent and still became colonized with the KPC-40-producing strain. The complex dynamics of KPC (Klebsiella pneumoniae carbapenemase) described here highlight several key diagnostic and therapeutic considerations.