As government officials begin easing restrictions implemented during the early months of the SARS-CoV-2 pandemic, they are looking for new ways to track and slow the spread of the virus. Contact tracing — the practice of identifying those exposed to infected individuals — is part of this effort. For COVID-19, however, public health officials have worked with engineers, cybersecurity experts and technology companies to add a modern twist to this age-old public health tool: smartphone apps.
Historically, contact tracing has happened manually, with humans doing the detective work to find, and break, transmission chains during outbreaks of contagious diseases like measles or HIV. But it’s an imperfect process. Memories can be fallible. And even when manual contact tracing is sufficient for family, friends and co-workers, it often falls short of identifying, for example, contact that occurred while standing in grocery store lines or dining at nearby restaurant tables.
