Background During the first three months of the COVID 19 pandemic, our facility cared for an influx of patients. At the peak, the daily census exceeded 200 patients with COVID 19. Surveillance for healthcare acquired infections (HAIs) continued throughout this time. Despite the acuity of the patients and the frequent use of antibiotics, the rates of Clostridioides difficile lab ID (CDI) events remained relatively stable. We sought to determine the validity of this rate. Methods To determine if cases of CDI were missed, we compared the 3-month rate per 10,000 patient days in 2020 to the same time-period in 2019 (March, April, and May). The number of tests ordered during the two periods was also compared. Additionally, the Doctor of Pharmacy from our antibiotic stewardship team reviewed all orders for oral Vancomycin to determine if empiric CDI treatment was initiated without confirmatory testing. Results The CDI rate for the 3 months in 2019 was zero compared to 0.48 per 10,000 patient days during the peak of the pandemic. The number of tests increased in the 2020 period to 17.5 per 10,000 patient days versus 15.8 in the 2019 period. Three patients received oral Vancomycin, each of whom had valid indications. Conclusions Based on this data, CDI cases were not underreported. We speculate that the lack of an increase in CDI rates may be attributed to: Increased hand hygiene by staff – compliance increased to 91 % in 2020 compared to 83 % in 2019,enhanced attention to cleaning and high level disinfection, and Improved adherence to use of personal protective equipment.

Background: Accurately tracing nosocomial transmission of coronavirus disease 2019 (COVID-19) is critical to developing effective infection prevention policies. Given the high prevalence and variable incubation period of SARS-CoV-2 infection, the utility of traditional contact tracing is limited. We describe a nosocomial outbreak in which whole-genome sequencing (WGS) was pivotal to identifying the primary case. Methods: This study was conducted at a New York City academic hospital. The index case was identified on August 13, 2020, and the last case on September 9, 2020. Hospital policy required all inpatients to be screened for COVID-19 on admission by SARS-CoV-2 molecular amplification testing. All healthcare workers (HCWs) were required to wear masks and eye protection for patient care. After a patient (patient 1), who tested SARS-CoV-2 negative on admission, was positive on preprocedure screening on hospital day 9, contact tracing was initiated. Two patients (patients 2 and 3) and 13 HCWs with high-risk exposures (HREs) to patient 1 were quarantined and referred for testing. Additional surveillance testing was performed on 18 inpatients and 84 HCWs on the affected unit. Patients 2 and 3 and 3 HCWs (HCW-1, -2, and -3), only 1 of whom had a high-risk exposure to patient 1, tested positive. WGS was performed to further investigate this outbreak. Results: The outbreak variant (clade 20A) was found in samples from 6 patients and 2 HCWs. Patients 2 and 3 were roommates of patient 1 in the 2 days before patient 1’s positive test, and they did not consistently wear masks in the room. HCW-1 placed a peripheral IV in patient 1 the day before patient 1’s positive test without wearing eye protection. Four additional cases in this cluster (patients 4–6 and HCW-4) were identified by surveillance WGS of positive tests. A review indicated that patient 1 was located ~3 m (~10 feet) away from patient 4 in the emergency department (ED) for 6 hours on hospital day 1, when the admission SARS-CoV-2 test from patient 4 was not positive. No epidemiologic link was found to patient 5 or 6 or HCW-4. The specimen from HCW-2 was inadequate for WGS. The specimen from HCW-3 was not linked to this cluster. Conclusions: This complex nosocomial outbreak highlights the importance of WGS in understanding transmission events. Patient 4 was not identified by traditional contact tracing but was linked to patient 1 and was recognized as the primary case through WGS, having likely infected patient 1 in the ED. Based on these findings, we focused our corrective actions on more promptly isolating suspected COVID-19 cases in the ED, increasing inpatient masking, and improving HCW adherence to universal eye protection.Funding: NoDisclosures: None