Temporary Isolation Wards During COVID-19 Pandemic Prove Effective Against Transmission Risk

Temporary isolation wards were used continually throughout 2021, during a surge in community transmission driven by the COVID-19 Delta variant, but were the wards effective in keeping down environmental transmission?

In Singapore, when the airborne infection isolation rooms (AIIRs) created to hold COVID-19 patients were overflowed with patients, prefabricated containers and other temporary shelters housed patients stricken with the disease. Recently, a study was conducted to discover whether those areas were successful at containing environmental transmission over a longer period of time.

The study published today in American Journal of Infection Control (AJIC), titled, “Environmental contamination and evaluation of health care-associated SARS-CoV-2 transmission risk in temporary isolation wards during the COVID-19 pandemic, ” covers the results. Infection Control Today® (ICT®) spoke with Ian Wee, MRCP, associate consultant, Department of Infectious Diseases, Singapore General Hospital, and lead author, about the study in an exclusive interview.

ICT®: A summary of the key findings and why they are important.

Ian Wee, MPharm(Clin Pharm): At our institution, a large tertiary hospital in Singapore, pre-pandemic a purpose-built 50-bedded isolation ward (IW) was available, comprising single and cohort airborne infection isolation rooms (AIIRs). However, the substantial increase in demand for AIIRs during the COVID-19 pandemic rapidly outstripped the number of AIIRs available, and COVID-19 patients were housed in temporary isolation wards converted from general ward rooms, or in a 50-bedded temporary isolation ward comprising prefabricated containers. These temporary isolation wards saw sustained usage throughout 2021, during a surge in community transmission driven by the SARS-CoV-2 delta-variant. We therefore sought to assess SARS-CoV-2 environmental contamination/transmission risk associated with such temporary isolation wards over a prolonged period of usage.

The key findings were as follows: A total of 355 environmental swabs were collected; 22.4% (15/67) of patients had at least 1 positive environmental sample. Patients housed in temporary isolation ward rooms constructed from prefabricated containers (adjusted-odds-ratio, aOR = 10.46, 95%CI = 3.89-58.91, P = 0.008) had greater odds of detectable environmental contamination, with positive environmental samples obtained from the toilet area (60.0%, 12/20) and patient equipment, including electronic devices used for patient communication (8/20, 40.0%). A single cluster of COVID-19 infections amongst health care workers was reported in the temporary isolation ward constructed from prefabricated containers; however, health care-associated transmission was deemed unlikely based on whole-genome-sequencing and epidemiological investigations.

Our findings are crucial given the potential for sustained usage of temporary isolation wards during succeeding pandemic waves driven by more transmissible SARS-CoV-2 variants.

ICT®: What is the practical application for the key findings for infection preventionists from this study?

IW: During the ongoing coronavirus disease 2019 (COVID-19) pandemic, requirements for airborne infection isolation rooms AIIRs to safely manage patients with COVID-19 has often resulted in demand outstripping existing capacity. Given the significant cost and time required to construct permanent structures with AIIR capabilities, various workarounds have been proposed to create temporary isolation wards, including conversion of preexisting hospital wards, erection of temporary structures, or conversion of non-medical facilities. However, evaluation of the capability of such temporary isolation wards to safely manage COVID-19 cases is significantly lacking; largely because these temporary isolation wards were often introduced at the pandemic peak to provide surge-capacity and resources for detailed evaluation were unavailable. Our findings showed that no health care-associated transmission was detected in temporary isolation wards over 18-months of prolonged usage, demonstrating capacity for sustained use during succeeding pandemic waves.

ICT®: What results surprised you, if any?

IW: It was encouraging to find that no health care-associated transmission of COVID-19 was detected in temporary isolation wards over 18-months of prolonged usage. Design of temporary isolation wards to incorporate better engineering-controls and allow more effective cleaning and other infection-prevention measures, remains critical, as compliance with personal-protective-equipment may not be absolute given unfamiliarity and fatigue, resulting in potential health care-associated transmission in areas with significant soilage from contaminated fomites.

ICT®: What, if any, future research will there be related to this one?

IW: Air sampling was not performed in the temporary isolation ward constructed from prefabricated containers as its compact nature made setting up of necessary instrumentation challenging and there were concerns that air sampling equipment could impede the entry of resuscitative equipment in the event of a medical emergency within the confined space. In future, if the opportunity permits, we would like to revisit this.

The study can be found here.