COVID-19: The CIDRAP Viewpoint Part 4: Contact Tracing for COVID-19: Assessing Needs, Using a Tailored Approach

ABSTRACT

From the Introduction: In situations involving major outbreaks or high rates of endemic disease, contact tracing is most effective either early in the course of an outbreak or much later in the outbreak when other measures have reduced disease incidence to low levels. In the latter instance, contact tracing is more manageable and can be used to eliminate remaining small foci of infection. Contact tracing, for example, was key in the late stages of the smallpox eradication program and has played an important role toward global polio eradication. [...] While contact tracing can be a valuable public health tool, its success depends on certain characteristics of the pathogen;the epidemiology of the disease involved;the thoroughness and follow-up of the contacts identified;the availability of rapid testing, preventive treatment and/or a vaccine;and the acceptance and effectiveness of quarantine for those potentially incubating an infection and of isolation for those found to be infected. Characteristics of the pathogen that influence the potential success of contact tracing include the routes of transmission (such as via aerosol, contaminated surfaces, or bodily fluids), the incubation period, the serial interval (the time between contact with a primary case and development of symptoms in a secondary case), the asymptomatic ratio (the percentage of infected people who remain completely asymptomatic during the course of their illness), the timeframe that people can transmit the disease before they develop symptoms, and the degree to which asymptomatic people can transmit the pathogen.Public health;Public health surveillance;Epidemiology;COVID-19 (Disease)