Here, Nextstrain analyzed 723 publicly shared COVID-19 genomes. By comparing these viral genomes to each other, they can characterize how COVID-19 is moving around the world.

In this report, it is highlight that the virus has been introduced and is circulating in many parts of the globe. Knowing if and to what degree COVID-19 circulates locally and how mitigation measures can slow this spread requires a good knowledge of the local outbreak dynamics. This, in turn, requires widespread testing. This emphasizes the importance of rapid testing with a strong focus on slowing local transmissions.

Every week a situation report is updated. In the In this week's updates, it is reported:

• Evidence for travel-related introductions to many parts of the world.
• Many places with recent introductions can expect to see cases expand in 4-8 week timeframe. They should prepare now.
• Many places that have recently implemented social distancing measures can expect to see cases continue to accumulate in the short-term, but new cases will likely plateau and decline in the medium-to long-term.
• Testing for both active infections and recovered individuals will be vital for coping with this epidemic.