Transmission Cycle of SARS-CoV-2

The COVID-19 infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), progressed to a global pandemic and led to millions of deaths worldwide over the years since its COVID-19 origin. Coronavirus transmission is a zoonotic spillover, which means that virus transmission can occur from a vertebrate animal to a human host. The CoV genome underwent continuous recombination and evolution, which resulted in interspecies transmission and the virus' recurrent emergence as a pandemic. The SARS-CoV-2 infection primarily results in respiratory symptoms, like pneumonia, that range from mild to severe in severity, along with alveolar injury ultimately leading to acute respiratory distress syndrome (ARDS) and death. This chapter outlines the SARS-CoV-2 transmission pathways, how the disease spreads by infected people, and the consequences for the prevention and control of infection, both inside and outside healthcare facilities. This section also covers modes of transmission like horizontal, fomite, fecal-oral, nosocomial, and animal-to-human transmission of SARS-CoV-2.

Keywords: COVID -19, Modes of transmission, SARS-CoV-2, Transmission cycle.