Updated 3:40 p.m. ET
Note: This story was updated to include Massachusetts, which began to share contact tracing data on its website on Wednesday.
When everyone who tests positive for coronavirus in your community gets a call from a public health worker asking them about their contacts and those contacts are then asked to quarantine, the process creates a powerful way to keep the virus from spreading.
But contact tracing can do more than that: At scale, the data gathered in those calls also offers vital information about where transmission is happening in a community. That data can drive policy and even guide individuals in assessing what’s more or less safe to go out and do.
NPR has surveyed the health departments of all U.S. states and territories three times about contact tracing capacity — first in April, then again in mid-June, and most recently in late July. The latest survey, done in collaboration with the Johns Hopkins Center for Health Security, also asked states about contact tracing data: what they were gathering and what they’re making public.
The vast majority of states are gathering data from their contact tracing programs, but only 14 respondents reported that the data was posted on a government website. Also, nine states reported that their contact tracing staff numbers were publicly available.
The data that states are gathering includes how many contacts are reached and how quickly and where people were exposed — whether it was in public or at home. The few states analyzing and sharing this data represent “a good start,” says Crystal Watson, senior scholar at the Center for Health Security who collaborated with NPR on the survey. “It’s a little bit scattershot right now.”
What’s needed, she says, is for states to share contact tracing data “more, more widely and more consistently.”
She acknowledges that states are limited by a lack of resources. “Health departments are really stretched to the limit right now, and it’s not a trivial thing to put together the data infrastructure to report [this data] publicly,” Watson says. Some federal guidance on “what states should be aiming to report publicly” could be really helpful, she says.
In the meantime, here are six places already making some of the data gleaned from their contact tracing efforts public, thus illustrating how useful this information can be.