Containing COVID-19 outside the isolation ward: the impact of an infection control bundle on environmental contamination and transmission in a cohorted general ward

Abstract

Background During an ongoing outbreak of COVID-19, unsuspected cases may be housed outside of dedicated isolation wards. Aim At a Singaporean tertiary hospital, individuals with clinical syndromes compatible with COVID-19 but no epidemiologic risk were placed in cohorted general wards for COVID-19 testing. To mitigate risk, an infection control bundle was implemented comprising infrastructural enhancements, improved personalprotective-equipment (PPE), and social distancing. We assessed the impact on environmental contamination and transmission. Method Upon detection of a case of COVID-19 in the dedicated general ward, patients and healthcare workers (HCWs) contacts were identified. All patient and staff-close contacts were placed on 14-day phone surveillance and followed-up for 28 days; symptomatic contacts were tested. Environmental samples were also obtained. Findings Over a 3-month period, 28 unsuspected cases of COVID-19 were contained in the dedicated general ward. In 5 of the 28 cases, sampling of the patient’s environment yielded SARS-CoV-2; index cases who required supplemental oxygen had higher odds of environmental contamination (p=0.01). A total of 253 staff closecontacts and 45 patient close-contacts were identified; only 3 HCWs (1.2%, 3/253) required quarantine. On 28-day follow-up, no patient-to-HCW transmission was documented; only one symptomatic patient closecontact tested positive. Conclusion Our institution successfully implemented an intervention bundle to mitigate COVID-19 transmission in a multi-bedded cohorted general ward setting.