Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Apr;12(2):54-63.
doi: 10.24171/j.phrp.2021.12.2.02. Epub 2021 Apr 29.

COVID-19 transmission: a rapid systematic review of current knowledge

Panagiotis Mourmouris  1 , Lazaros Tzelves  1 , Christiana Roidi  1 , Anastasia Fotsali  1
Affiliations

COVID-19 transmission: a rapid systematic review of current knowledge

Panagiotis Mourmouris et al. Osong Public Health Res Perspect. 2021 Apr.

Abstract

Objective: The objective of this study was to identify the potential and definite sources of transmission of coronavirus disease 2019 (COVID-19).

Methods: Due to time constraints and the acute nature of the pandemic, we searched only PubMed/Medline from inception until January 28, 2021. We analyzed the level of evidence and risk of bias in each category and made suggestions accordingly.

Results: The virus was traced from its potential origin via possible ways of transmission to the last host. Symptomatic human-to-human transmission remains the driver of the epidemic, but asymptomatic transmission can potentially contribute in a substantial manner. Feces and fomites have both been found to contain viable virus; even though transmission through these routes has not been documented, their contribution cannot be ruled out. Finally, transmission from pregnant women to their children has been found to be low (up to 3%).

Conclusion: Even though robust outcomes cannot be easily assessed, medical personnel must maintain awareness of the main routes of transmission (via droplets and aerosols from even asymptomatic patients). This is the first attempt to systematically review the existing knowledge to produce a paper with a potentially significant clinical impact.

Keywords: Airborne particulate matter; COVID-19; Pathogen transmission.

PubMed Disclaimer

Conflict of interest statement

Conflicts of Interest

The authors have no conflicts of interest to declare.

Figures

Figure 1.
Figure 1.
Flowchart of the study.
See this image and copyright information in PMC

References

    1. World Health Organization (WHO) Geneva: WHO; 2021. Coronavirus disease 2019 (COVID-19): weekly epidemiological update on Covid 19 [Internet] Mar 23 [cited 2021 Mar 30]. Available from: https://www.who.int/publications/m/item/weekly-epidemiological-update-on....
    1. Yen MY, Schwartz J, Chen SY, et al. Interrupting COVID-19 transmission by implementing enhanced traffic control bundling: implications for global prevention and control efforts. J Microbiol Immunol Infect. 2020;53:377–80. - PMC - PubMed
    1. Ong SW, Tan YK, Chia PY, et al. Air, surface environmental, and personal protective equipment contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from a symptomatic patient. JAMA. 2020;323:1610–2. - PMC - PubMed
    1. Bai Y, Yao L, Wei T, et al. Presumed asymptomatic carrier transmission of COVID-19. JAMA. 2020;323:1406–7. - PMC - PubMed
    1. Wells GA, Shea B, O'Connell D, et al. Ottawa: Ottawa Hospital Research Institute; 2021. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses [Internet] [cited 2021 Mar 1]. Available from: http://www.ohri.ca/programs/clinical_epidemiology/oxford.asp.