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 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.