This seems to be the best and really only source of information I’ve seen with detailed and frequently updated data on the rate of COVID-19 testing and infections broken down by states within the United States. This is the breakdown by states. This is the daily cumulative update. In each case you have total tests, positives, negatives and pending. In a better world, the CDC or some other government agency would be publishing this information. But that’s not happening.
A few more points about why this is a reliable source.
Everything is moving quickly. I’m not involved with this project. So I can’t vouch for it directly. But I’ve looked at it closely. It’s run by serious, named people. The project combines one started by Jeff Hammerbacher, a data person from the biotech field, and another started by Alexis Madrigal of The Atlantic. They’re both now working together on the joint project. It’s being updated regularly. They’ve published a brief discussion of methodology along with links to state and county sources of information where most of the information is drawn from. There are also helpful notes in a comments field on sources of data and what different states are or are not reporting. (They’re actually looking for volunteers to work on the project.)
I also spoke briefly via Twitter DM with Jeff Hammerbacher to help me understand how the data was collected. As Hammerbacher explained to me, a number of key states with the largest confirmed infections (including California and New York) have stopped releasing numbers of total tests conducted just in the last day or so. (Colorado discontinued and then just restarted the comprehensive data while I was writing this post.) Since states are reporting data unevenly and in some cases without key data that makes the totals only a partial snapshot of what’s happening. So, for example, the total number of tests currently reported on the site – 2806, as I write this – is definitely an undercount, as Madrigal notes here. But all of this information is explained if you drill down into the numbers.
Put that all together and the picture is incomplete and provisional. But that is because the information being released by the states is incomplete and spotty. This is the best (and, again, I think really the only) place where all this information is being drawn together in a rapidly updated and carefully aggregated way.