Understanding healthcare personnel’s (HCP) contact patterns are important to mitigate healthcare-associated infectious disease transmission. Little is known about how HCP contact patterns change over time or during outbreaks such as the COVID-19 pandemic.

This study in a large United States healthcare system examined the social contact patterns of HCP via standardized social contact diaries. HCP were enrolled from October 2020 to June 2022. Participants completed monthly surveys of social contacts during a representative working day. In June 2022, participants completed a 2-day individual-level contact diary. Regression models estimated the association between contact rates and job type. We generated age-stratified contact matrices.

Three-hundred and sixty HCP enrolled, 157 completed one or more monthly contact diaries and 88 completed the intensive 2-day diary. In the monthly contact diaries, the median daily contacts were 15 (interquartile range (IQR) 8–20), this increased slightly during the study (slope-estimate 0.004, p-value 0.016). For individual-level contact diaries, 88 HCP reported 2,550 contacts over 2 days. HCP were 2.8 times more likely to contact other HCP (n = 1,592 contacts) than patients (n = 570 contacts). Rehabilitation/transport staff, diagnostic imaging technologists, doctors, nurses, mid-level, and laboratory personnel had higher contacts compared with the lowest contact group (Nursing aids). Contact matrices concentrated in working-age populations.

HCP contacts concentrate in their work environment, primarily with other HCP. Their contacts remained stable over time even during large changes to societal contact patterns during the COVID-19 pandemic. This stability is critical for designing outbreak and pandemic responses.

To compare the effectiveness of universal admission testing (UAT) and risk-based testing (RBT) in preventing nosocomial coronavirus disease 2019 (COVID-19) after the implementation of strict infection control measures.

Retrospective multicenter cohort study.

Five community hospitals in Japan.

14,028 adult patients admitted emergently from June 1, 2022, to January 31, 2023.

We calculated crude incidence density rates of community-acquired COVID-19 (positive test ≤4 days postadmission), hospital-acquired COVID-19 (positive test ≥8 days postadmission), total postadmission COVID-19 (all cases of positive test postadmission), and primary cases (sporadic and index cases). A generalized estimating equation model was used to adjust for local incidence (new COVID-19 patients per 100,000 population), single-bed room proportion, and admission proportion of patients older than 65 years.

The weekly local incidence in the study areas was less than 1,800 per 100,000 population (1.8%). Two hospitals implemented RBT and 3 implemented UAT. The median admission testing rate was higher in the UAT group than in the RBT group (95% vs 55%; difference 45.2%, 95% CI, 40.3%–48.8%). Crude and adjusted analyses revealed no significant associations between incidence density rates (IRR; >1 indicates higher incidence with UAT) and admission strategies for any of the outcomes: community-acquired cases (adjusted IRR = 1.23; 95% CI, 0.46–3.31), hospital-acquired cases (1.46; 0.80–2.66), total postadmission COVID-19 (1.22; 0.79–1.87), and primary cases (0.81; 0.59–1.12).

Compared with risk-based testing, universal admission testing may have limited additional benefits in preventing nosocomial COVID-19 transmission during a period of low-moderate local incidence.

To enumerate and describe the effect of whole genome sequencing (WGS) on epidemiological investigations of healthcare-associated transmission of nontuberculous mycobacteria (NTM).

Systematic review.

We performed a literature search using targeted search terms to identify articles meeting inclusion criteria. Data extraction of study characteristics and outcomes was performed by two independent researchers. The primary outcome was the author interpretation of WGS utility in the investigation of suspected healthcare-associated transmission of NTM. The secondary outcome was whether a transmission route was identified through WGS.

Thirty-one studies were included in the final analysis with 28 (90%) concluding that WGS was helpful in transmission investigations and in 19 of these 28 (68%) WGS aided in identifying a transmission route. The most common identified transmission routes were water-borne point sources (10), heater-cooler units (6), patient-to-patient (4), and a healthcare worker (1).

WGS is an informative tool in investigating healthcare transmission of NTM.

To upgrade cleaning and disinfection of patient rooms in a crowded emergency department (ED).

Tertiary referral hospital.

Prospective, 3-component, before-and-after intervention study.

Phase 1 consisted of a 4-week baseline determination of ED patient-room cleanliness, using two means: (1) the fluorescence spray, applied before cleaning and assessed subsequently with an ultraviolet lamp. Results are expressed as % of removed spots/all spots (≥7/10 cleaned spots/room was considered clean; (2) ATP swabs obtained after cleaning, which test for presence of residual organic material; readings <45 were considered clean. Phase 2 consisted of revision and reorganization of established cleaning practices. Phase 3 consisted of adding one cleaning person in afternoon/evening shifts, for 4-weeks, during which room cleanliness was assessed as previously described.

Cleanliness of the 79 patient rooms, for which fluorescence tests were available from before and after cleaning for all three phases of the study, increased from a baseline of 50% ± 35 removed spots/all spots, to 61% ± 36 after the first intervention (CI95 -0.6 – 21, P = 0.54) and to 68% ± 35 after the second intervention (CI95 5 - 31, P = 0.004, as compared to the baseline). Subanalysis showed that evening shifts improved most remarkably, from 47% ± 32 (n = 45), to 60% ± 33 (n = 49) to 76%±29 (n = 29), respectively, from baseline through the second and third phase (P = 0.001). ATP testing appeared less sensitive for assessment of cleanliness but confirmed the assessment by fluorescence for overall cleanliness (CI95 1 - 14, P = 0.018).

Our data demonstrate that a two-step intervention significantly improves cleaning in a busy ED.

SARS-CoV-2 asymptomatic surveillance testing (AST) is a common strategy to minimize the risk of nosocomial infection in patients and healthcare personnel. In contrast to admission screening, post-admission AST was less widely adopted.

This study describes the diagnostic yield of post-admission serial SARS-COV-2 testing in hospitalized patients at a large cancer center with mostly double-occupancy rooms.

Retrospective cohort study design. Post-admission SARS-CoV-2 tests were examined over a 18 month study period. Positive results were reviewed to determine true hospital-onset infections using a combination criteria of screening all sample cycle threshold (Ct) values >30, results of non-concordant repeat testing, and clinical symptoms.

Post-admission serial testing of 15,048 hospitalized patients during an 18-month study period at a tertiary care cancer center detected hospital-onset infection in 1.6% (n = 245 patients). Among all hospital-onset positive SARS-CoV-2 RNA tests, 13% were clinically false positive. Most true infections were mild to moderate in severity.

In summary, post-admission serial testing in a high-risk setting is a low-yield strategy with several unfavorable effects and should no longer be routinely applied.

Antimicrobial resistance is increased by antibiotic overuse, so it’s crucial for stewardship programs to monitor and control their use. Pneumonia, particularly prevalent among older adults in Japan, is requiring higher rates of medical treatment. This study aimed to develop an improved method for benchmarking broad-spectrum antibiotic use in the empiric treatment of pneumonia in older adult inpatients by applying the “smoothed” observed-to-expected (O/E) ratio which adjusts for hospital-level variations and minimizes the effect of extreme values.

Using nationwide data from the Diagnosis Procedure Combination research group, pneumonia patients between April 1st 2018 and March 31st 2020 were analyzed. The primary outcome was the smoothed O/E ratio of the broad-spectrum antibiotic use for hospitals. It was calculated from the predicted values of broad-spectrum antibiotic use that were obtained through multilevel logistic regression using patient characteristics as predictors from data clustered by hospitals. The analysis investigated the risk-adjusted use of broad-spectrum antibiotics among hospitals.

A total of 244,747 patients from 958 hospitals were included, with a mean age of 81 (±8.30) years. The proportion of broad-spectrum antibiotic use was 35.3% (n = 86,316). The prediction model showed a C-statistic of 0.722. There was a noticeable variation in the O/E ratio among hospitals with values ranging from 0.13 (95% CI: 0.09–0.20) to 2.81 (95% CI: 2.64–2.97).

Using a risk-adjusted smoothed O/E ratio, we assessed the use of broad-spectrum antibiotics across hospitals, identifying those with high O/E ratios that may indicate a need for improvement.

Clinical trials for assessing the effects of infection prevention and control (IPC) interventions are expensive and have shown mixed results. Mathematical models can be relatively inexpensive tools for evaluating the potential of interventions. However, capturing nuances between institutions and in patient populations have adversely affected the power of computational models of nosocomial transmission.

In this study, we present an agent-based model of ICUs in a tertiary care hospital, which directly uses data from the electronic medical records (EMR) to simulate pathogen transmission between patients, HCWs, and the environment. We demonstrate the application of our model to estimate the effects of IPC interventions at the local hospital level. Furthermore, we identify the most important sources of uncertainty, suggesting areas for prioritization in data collection.

Our model suggests that the stochasticity in ICU infections was mainly due to the uncertainties in admission prevalence, hand hygiene compliance/efficacy, and environmental disinfection efficacy. Analysis of interventions found that improving mean HCW compliance to hand hygiene protocols to 95% from 70%, mean terminal room disinfection efficacy to 95% from 50%, and reducing post-handwashing residual contamination down to 1% from 50%, could reduce infections by an average of 36%, 31%, and 26%, respectively.

In-silico models of transmission coupled to EMR data can improve the assessment of IPC interventions. However, reducing the uncertainty of the estimated effectiveness requires collecting data on unknown or lesser known epidemiological and operational parameters of transmission, particularly admission prevalence, hand hygiene compliance/efficacy, and environmental disinfection efficacy.

Concerns about penicillin-cephalosporin cross-reactivity have historically led to conservative prescribing and avoidance of cephalosporins in patients with penicillin allergy labels, potentially causing suboptimal outcomes. Recent evidence suggests a lower risk of cross-reactivity, prompting a reassessment of alert systems.

To assess the impact of limited penicillin cross-reactivity alerts on outpatient cephalosporin use and the incidence of adverse reactions in a healthcare setting.

This retrospective cohort study compared cephalosporin prescribing and adverse reactions in patients labeled as penicillin-allergic before and after limiting penicillin cross-reactivity alerts in the electronic medical record at a large academic medical center.

Among 17,174 patients (8,131 pre- and 9,043 post-implementation), there was a statistically significant increase in outpatient cephalosporin prescribing by 8% (P < .001). The use of alternative antibiotic classes decreased. There was no statistically significant increase in adverse events pre- and post-implementation (0.036%–0.058%, P = .547), and no severe events were attributable to cross-reactivity. The alert modification reduced alerts by 92% (P < .001).

The reduction of penicillin-cephalosporin cross-reactivity alerts was associated with increased cephalosporin use, without a significant increase in adverse reactions. This demonstrates that the practice is safe and decreases alert burden.