Environment contamination and intra-hospital spread of COVID-19 in a tertiary care Hospital in Taiwan

Abstract

Background: The role of environmental contamination in COVID-19 transmission within hospitals is still of interest due to the significant impact of outbreaks globally. However, there is a scarcity of data regarding the utilization of environmental sampling for informing infection control measures during SARS-CoV-2 outbreaks. Methods: This retrospective study analyzed incident event investigations conducted at a single center from May 1, 2021, to August 31, 2021. Investigations were initiated following the identification of a COVID-19 confirmed case (referred to as the index case) who had stayed in a hospital area outside the dedicated COVID-19 ward/bed and without specific COVID-19 precautions. Measures to prevent intra-hospital spread included contact tracing, adjusted testing policies, isolation of confirmed cases, quarantine of close contacts, environmental disinfection, and PCR testing of environmental samples. Results: Among the 18 incident events investigated, the index case was a healthcare personnel in 8 events, a patient in 8 events, and a caregiver in 2 events. The median number of confirmed COVID-19 cases within 14 days was 13 (IQR, 7–31) for events with SARS-CoV-2 RNA detected on environmental surfaces, compared to only one (IQR, 1–1.5) for events without surface contamination (P = 0.04). Environmental contamination was independently associated with a higher number of COVID-19 cases (P < 0.001). Conclusion: This study highlights environmental contamination as an indicator of the severity of incident events and provides a framework for incident event management, including a protocol for environmental sampling. Implementing these measures can help prevent the spread of COVID-19 within healthcare facilities.

Keywords

• SARS CoV-2
• Fomite transmission
• Indirect contact transmission
• Incident event
• Outbreak investigation