Background: The Coronavirus disease 19 (COVID-19) is a highly transmittable viral infection that initiated in
Wuhan, China and has spread around the world. The high prevalence and spread ways of COVID-19 have become an international challenge that requires careful consideration. We aimed to review the current evidence of COVID-19 transmission
Methods: This study was a systematic review that was done to identify current evidence on transmission modes of COVID19. We searched selected keywords in six important databases to discover related sources on the main objective of the study.
To identify studies meeting the inclusion criteria, the authors screened the titles and abstracts of retrieved documents. The
appropriate articles were selected and their results were discussed to make the final inclusion.
Results: We identified five potential transmission modes of COVID-19 including airborne, droplet, contact with contaminated surfaces, oral and fecal secretions. Furthermore, some studies have pointed out other modes of virus transmission,
such as person to person, and direct contact with animals.
Conclusion: Droplet and contact with contaminated surfaces were the most frequent transmission modes of COVID-19. Fecal excretion, environmental contamination, and fluid pollution might contribute to a viral transmission. The possibility of
fecal transmission of COVID-19 has implications, especially in areas with poor sanitation and the environmental pollution
can be caused by patients with SARS-CoV-2 through respiratory droplets and feces, subsequently, the human environment
will change to a potential medium of virus transmission.