IJSR International Journal of Scientific Research 2277 - 8179 Indian Society for Health and Advanced Research ijsr-10-6-35539 Original Research Paper Transmission of Coronavirus Disease-19 through Asymptomatic and Pre-symptomatics is a Challenge to Containment: A Retrospective Observational study. Parul Sinha Dr. Dr. Nisha Patidar Dr. June 2021 10 6 01 02