P109 Infection control policies during the COVID-19 pandemic were effective in limiting morbidity and mortality associated with nosocomial viral transmission at a large NHS respiratory department

IntroductionPrevention of nosocomial transmission was a priority for NHS hospital teams during the SARS-COV-2 pandemic. However, infection control policies were developed in the face of uncertainty about duration of infectivity, routes of transmission, and safety of shared admission spaces. We retrospectively reviewed all hospital admissions to the University Hospitals of Leicester (UHL) respiratory department, which managed more than 30% of UHL patients with a diagnosis of COVID-19 between March 2020 and March 2021to determine the proportion of cases with laboratory evidence of healthcare associated infection (HCAI) and mortality within 28 days of PCR conversionMethodsThis was a retrospective cohort study performed using a bespoke database collating COVID-19 throat swab (TS) PCR results for UHL (COVTRACK). Nosocomial transmission was identified by demonstrating PCR conversions during admission and categorized into definite (conversion time > 14 days) or probable (conversion time 8–14 days). In depth records based analysis was undertaken for patients admitted to respiratory medicine (RM) and deceased within 28 days after conversion.ResultsOut of 10485 patients admitted to the Respiratory Department at UHL, 2054 (19.6%) were COVID-19 spell positive, including 57 with probable (41) or definite HCAI (16). 23 patients (7 with definite HCAI) died within 28 days of PCR conversion (0.22%, of total admitted, 1.1% of COVID19 positive), with 21 (91%) deaths in the 2nd wave. Compared with non-COVID admissions not acquiring nosocomial infection, HCAI was significantly associated with older age (mean difference (95%CI) 11.5 (7.5–15.5) years), length of stay (median LOS 18 Vs 1 day) and multiple ward occupancy (median 3 vs 1 ward);all analyses p<0.001.DiscussionOur analysis suggests HCAI with SARS-COV-2 contributed a very small fraction of COVID-19 related morbidity and mortality at our department and in the majority the trajectory of care was not changed. Despite the high numbers of highly infectious cases during the 1st and 2nd wave, we successfully implemented a suite of infection control measures that effectively mitigated risk. High throughput in admission areas, multiple ward moves, and prolonged hospital stay were significant risk factors associated with HCAI.