Transmission of SARS-CoV-2 without close contact – a systematic review of real-world case studies

Research program: 
The challenge: 

Since SARS-CoV-2 was first reported in December 2019 in Wuhan, China, more than 420 million cases and 5.9 million deaths worldwide have been reported as of 23 February 2022. With such a rapid proliferation, understanding the transmission of SARS-COV-2 has been crucial. The predominant theories of SARS-COV-2 transmission have focused on short-ranged transmission, particularly spread from person to person via respiratory droplets or infected surface contact. However, the role of long-range airborne transmission in the spread of COVID-19 has become a topic of interest. Current level of evidence has led to the World Health Organization (WHO) acknowledging the role of aerosols in both short- and long-range transmission. The number of studies which have demonstrated indoor transmission of SARS-CoV-2 without possibility for direct or close contact in multiple settings have been increasing.

The project: 

The aim of this project is to determine the following: a) The different scenarios reported for long-range transmission of COVID-19 in the literature; b) To assess if there is a difference in the attack rate for delta variant and other variants of concern in long-range transmission.

The method: 

We conducted a systematic review of real-world cases of SARS-COV-2 transmission occurring without close contact, seeking to update previous reviews. The protocol for this meta-analysis was registered with PROSPERO (CRD42022302083) and followed the steps outlined in Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA).

The results: 

This project is due for completion in 2022. Data collection and synthesis are currently ongoing.

The impact: 

The resulting knowledge would directly impact on policy decisions regarding adequate mitigation measures to be implemented for reduction of spread of disease in indoor settings.

Project contact: 
PhD Student/ Research Assistant