Why social distancing can slow SARS-CoV-2: Insights from infectious disease epidemiology
Social distancing is a risk reduction measure to interrupt the spread of an infectious agent and is defined as “remaining out of congregate settings, avoiding mass gatherings, and maintaining distance (approximately 6 feet or 2 meters) from others when possible.” Globally, numerous cities, states and countries have enacted policies recommending or requiring social distancing strategies in order to slow the COVID-19 pandemic. Dr. McCoy uses insights from infectious disease epidemiology to explain the rationale behind these recommendations and why some believe that social distancing is the best available strategy to interrupt transmission.
Sandra McCoy is an Associate Professor in the Division of Epidemiology at the UC Berkeley School of Public Health. She studies how social, economic, and cultural forces influence disease transmission and health outcomes. During the past several years, Dr. McCoy has explored these relationships through the lens of HIV infection and reproductive health. Using a diverse array of approaches, her goal is to identify innovative, cost-effective, and scalable strategies to overcome global health challenges. Dr. McCoy has an MPH from the University of Michigan and a PhD in Epidemiology from the University of North Carolina at Chapel Hill. At UC Berkeley, Dr. McCoy teaches introduction to epidemiologic methods and co-teaches a course on the epidemiology and control of infectious diseases.
Natural History of a Pathogen Informs Mitigation and Control Strategies
An important factor in deciding which outbreak mitigation and/or control strategies will be most effective is whether an individual can transmit the virus before or after the development of symptoms. In this infographic, the horizontal bars correspond to the days immediately following an infection. The different colors of the bars represent the stage of infection from the perspective of the virus or the infected person. From the perspective of the pathogen, after a number of days after infection, an individual will transition from noninfectious to being able to infect others (indicated by the transition from yellow to pink). From the perspective of the host, an individual may transition from being asymptomatic to being symptomatic (light green to dark green). Taken together, the timing of these two transitions influences which control strategies might be most effective.