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