When all coronavirus positive people in your community receive a call from a public health officer asking them about their contacts and those contacts are then asked to quarantine. It can be an effective way to stop the virus from spreading.
But contact tracking can do more than that: On a large scale, the data collected during those calls also provides vital information about where transmission takes place in a community. That data can drive policy and even guide individuals to evaluate what is more or less safe to get out and do in their communities.
The NPR surveyed health departments of all US states and territories three times to ask about exposure tracking ̵1; first in April, then again in mid-June, and the most recent was late July. The latest survey, conducted in partnership with the Johns Hopkins Center for Medical Security, also asked states about contact tracking data: what they’re collecting. crosses and what they are publicizing.
The majority of states are collecting data from their contact tracking programs, but only 13 respondents reported that the data was posted on government websites. Eight states report that their contact tracking staff numbers have been made public.
The status of the data being collected includes how many contacts are reached, how fast and where people are exposed – whether it’s in public or at home. Crystal Watson, senior scholar at the Center for Health Security, who collaborated with NPR on the survey, said several states that analyzing and sharing this data show “a good start”. “It’s a bit fragmented now.”
It is essential for states that share contact tracking data “more, more widely, and more consistently,” she said.
She admits that states are limited by a lack of resources. “The medical departments are really stretching to the limit right now, and aggregating the data infrastructure for reporting is no small feat. [this data] Some federal guidelines on “what states should move toward public reporting” could be really helpful, she said.
In the meantime, here are six places that have made some data available from their contact tracking efforts, illustrating how helpful this information is.
1. New Jersey: Nearly half of all cases refuse to provide a contact’s name
In its COVID data dashboard, New Jersey’s contact tracking tab focuses on contact tracking capabilities and employee count, even breaking down staff by county.
“The data I’m seeing here on the number of contact traces and the effectiveness of relationship tracing is really amazing,” said Watson. “It really helps you understand how many people – contacts in particular – are being reached and informed and when it’s happening.”
The speed and completeness of contact tracking are key to its effectiveness. If 100% of new cases are reached within 24 hours of diagnosis and 100% provide a complete list of close contacts, that could significantly limit transmission.
But in reality, public health workers have not achieved that level of success. In New Jersey, these data showed that public health workers had access to only 44% of the new cases within 24 hours, and nearly half of them refused to provide a contact.
“I know they might be aiming higher than what they’re getting right now,” Watson said. “Although we have seen some patterns that show that even at those levels, contact tracing can have a great benefit in line control.”
2. Louisiana: Bars, Day Cares, and Casino – Details of where the transmission took place
Louisiana doesn’t show a lot of raw data or graphs, but it does have a very helpful list of settings where outbreaks are occurring and how many cases arise from those outbreaks.
“The data Louisiana is providing on COVID-19 outbreaks is unique because it breaks down quite detailed data about [likely] Watson said.
LDH.LA.gov/Screenshot by NPR
This level of detail can be really valuable to policymakers who are trying to decide targeted restrictions on aggregation or business without shutting things down. While some other states provide information about transmission from “public out” or “social contexts,” Louisiana is much more site-accurate.
Watson said, it’s helpful to be able to see that in Louisiana, “for example, the gyms didn’t contribute [to outbreaks] almost equal to the bars. “In addition to driving policy, that kind of information can also help individuals decide where they want to go and how to keep themselves safe.
3. Maryland: Know when a Surge employee is needed
Maryland has a very detailed view of how contact tracking is occurring in the state. “This shows how many cases and contacts are being entered into the system, how many cases and contacts are successfully accessed and completed their interview,” said Watson. “This gives us a better idea of both the volume Maryland is currently tracking and the effective reach of contact tracking programs.”
Data show that Maryland’s contact-tracking workforce was able to call about 90% of new cases within 24 hours, except for about a week in mid-July. Katherine Feldman, head of liaison tracking at the Maryland Department of Health, told DCist this week that “a few weeks ago … as the number of cases increased, we determined there was a need to increase. [contact tracing staff], and we did. “
The data also shows that – as in New Jersey – only about half of the cases are providing information about their contacts.
To address the widely reported public health belief issue that may contribute to these numbers, Maryland also includes photos and testimonials from people who have been followed. Todd Poorman wrote: “I am very grateful to the contact follower from the health department who called me in for a checkup, every day I was on segregation. […] There is a lot of stigma out there, but fear holds us back. We need to overcome our fears and work together. “
4. Washington DC: Unspecified transmission exceeds known levels
Watson says that DC is one of the first jurisdictions to share this type of data. The District COVID dashboard now displays two types of contact tracking data: How many contacts were contacted within 48 hours, and what percentage of new cases arise from those in quarantine. .
If most new cases arise from known people, it can be ensured that the public health system is always at the forefront of transmission. In DC, data showed that only 4.5% of cases arose this way – away from the 60% target.
DC.gov/Screenshot by NPR
In other words, 95.5% of the previous new infections were not known to health authorities.
“It really shows just how much we still get from the community,” said Watson. “It’s really helpful to know that we both probably need to offload, in general, and [we need to] Continue to improve contact tracking efficiency. “
5. Delaware: Tracking phone numbers is a challenge
Delaware provides a kind of contact tracking narrative, from a new case being identified, to all the contacts who themselves test positive. The numbers are paired with explanation of what they show and why.
“Not everyone who was approached was interviewed immediately,” the note read next to a number shows that 17% of the contacted did not complete the interview and then it became paralyzed. listed a number of possible reasons, including some contacts too busy to talk to or hearing difficulties. It also notes that 27% of cases and 43% of contacts lack a phone number and “new attempts to retrieve and authenticate a phone number are being explored.”
Delaware.gov/Screenshot by NPR
“I like that they have summary statistics first,” Watson said, noting that percentage of contacts reached, average number of contacts per case, and known cases associated. related to another case are highlighted. The proportion of cases with known exposures is 25%, much higher in Delaware than in DC, at about 4%. (However, it’s difficult to make these kinds of comparisons without standardized metrics.)
“I also like the way they run the process and provide data and explanation at each step,” Watson said. “It shows how difficult it is to get in touch with people, but also shows how much work the medical department is doing to get it going.”
6. North Dakota: Community spread transcends domestic transmission
According to the NPR’s first survey of state health departments. In the latest survey published in early August, NPR analysis found that the state currently does not have enough contact follow-up staff to update new cases.
Now, the state appears to be using contact tracking data to determine the source of exposure for new cases.
“Their team is very broad,” said Watson. “It is interesting that community transmission is higher than close contact”, since close home contact is often thought to be the main cause of COVID transmission. She says more specifics – as in the Louisiana outbreak data – could help explain what these groups mean in real life.