Wired has an article on an open-source tool that is being used to track strains of Covid-19 throughout the world.
"In the case of the Seattle area teenager, genetic data about his strain of Covid-19 was uploaded to Gisaid, a platform for sharing genomic data. Then researchers at Nextstrain made the connection with the earlier patient.
Nextstrain is an open source application that tracks the evolution of viruses and bacteria, including Covid-19, Ebola, and lesser-known outbreaks such as Enterovirus D68 using data sourced largely from Gisaid. Hodcroft and other researchers involved with the project analyze the data shared on Gisaid for mutations and visualize the results. That’s how the team was able to spot the connection between the two Covid-19 cases in Washington."