Transmission of SARS-CoV-2: an update of current literature

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent for the 2019 coronavirus disease (COVID-19) pandemic, has caused a public health emergency. The need for additional research in viral pathogenesis is essential as the number of cases and deaths rise. Understanding the virus and its ability to cause disease has been the main focus of current literature; however, there is much unknown. Studies have revealed new findings related to the full transmission potential of SARS-CoV-2 and its subsequent ability to cause infection by different means. The virus is hypothesized to be of increased virulence compared with previous coronavirus that caused epidemics, in part due to its overall structural integrity and resilience to inactivation. To date, many studies have discussed that the rationale behind its transmission potential is that viral RNA has unexpectedly been detected in multiple bodily fluids, with some samples having remained positive for extended periods of time. Additionally, the receptor by which the virus gains cellular entry, ACE2, has been found to be expressed in different human body systems, thereby potentiating its infection in those locations. In this evidence-based comprehensive review, we discuss various potential routes of transmission of SARS-CoV-2—respiratory/droplet, indirect, fecal-oral, vertical, sexual, and ocular. Understanding these different routes is important as they pertain to clinical practice, especially in taking preventative measures to mitigate the spread of SARS-CoV-2.