When all those who test positive for coronavirus in your community receive a call from a public health worker asking them about their contacts, and those contacts are asked to quarantine, this can be a powerful way to do not spread the virus.
But contact tracking can do more than that: On a scale, the data collected on those calls also provides vital information about where broadcasting is taking place in a community. This data can guide policy, and even guide individuals in assessing what is more or less certain to come out and do in their communities.
NPR has surveyed health departments of all US states and territories three times to ask about contact traceability ̵1; first in April, then again in mid-June, and finally in late July. . The latest survey, conducted in collaboration with the Johns Hopkins Center for Health Safety, also asked states about contact tracking data: what they were collecting and what they are making public.
Most states are collecting data from their contact tracking programs, but only 13 respondents reported that the data was posted on a government website. Eight states reported that the number of their contact staff for tracking was available to the public.
Records of data being collected include how many contacts were made and how quickly and where people were exposed – whether he was out in public or at home. Some states analyzing and sharing this data represent “a good start,” says Crystal Watson, a senior researcher at the Center for Health Safety who collaborated with NPR in the survey. “It’s a little scattered now.”
What it needs, she says, is for states to share contact tracking data “more, more widely and more consistently.”
She acknowledges that states are limited by a lack of resources. “Health departments are actually lying on the border now, and it’s not a trivial thing to put together the data infrastructure to report [this data] publicly, “says Watson. Some federal guidelines on” which states should aim to report publicly “can be really helpful, she says.
Meanwhile, here are six countries that are already making public some of the data collected from their contacts tracking efforts, which illustrate how useful this information can be.
1. New Jersey: Almost half of the cases refuse to give contact names
In its COVID data panel, the New Jersey contact tracking tab focuses on contact capacity for tracking and staffing, and even staff breakdown by county.
“The data I see here on the number of contact trackers and the effectiveness of contact tracking is truly fabulous,” says Watson. “It really helps you understand how many people – contacts in particular – are being reached and notified and the time at which it is happening.”
The speed and completeness of contact tracking is essential to its effectiveness. If 100% of new cases were to be achieved within 24 hours of diagnosis, and 100% provided a complete list of close contacts, this could curb transmission dramatically.
But in reality, public health workers do not have that level of success. In New Jersey, these data show that public health workers reached only 44% of new cases within 24 hours, and nearly half of those who arrived refused to provide contacts.
“I know they probably aim higher than they are earning right now,” Watson says. “Although we have also seen some modeling that suggests that even at those levels, contact tracking can provide a huge benefit in transmission control.”
2. Louisiana: Bars, Day Care and Casinos – Details on Where Broadcasting is taking place
Louisiana does not show much raw data or graphics, but it does have a very useful list of settings where explosions are happening and how many cases are arising from those explosions.
“The data that Louisiana is providing about COVID-19 outbreaks is unique because it breaks down pretty granular data about [likely] the location of the broadcast or exposure, “says Watson.
LDH.LA.gov/Screenshot by NPR
This level of detail can be really valuable for policymakers who are trying to decide on targeted restrictions on gatherings or business, without closing everything. While some other states throw information about broadcasting from “community spread” or “social environments,” Louisiana is much more accurate for countries.
It’s useful, says Watson, to see that in Louisiana, “gyms, for example, have not contributed [to outbreaks] approximately as many bars. “Beyond leadership 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 to Surge Staff
Maryland has a very detailed view of how tracking contacts are going in the state. “It shows how many cases and contacts have been entered into the system, how many cases and contacts have been successfully reached and completed their interview,” says Watson. “It helps us get a better idea of the volume that Maryland is looking to track and the effective achievement of contact tracking programs.”
The data show that the Maryland contact tracking workforce has been able to call about 90% of new cases within 24 hours, except for about a week in mid-July. Katherine Feldman, who heads the contact tracking at the Maryland Department of Health, told DCist this week that “a few weeks ago … when case charges escalated, we identified a need to increase [contact tracing staff], and we did “
The data also show that – as in New Jersey – only about half of the cases provide information about their contacts.
To address the widely reported public health trust problem that may contribute to these numbers, Maryland also has photographs and evidence from people who have been tracked. Todd Poorman writes: “I’m grateful for the contact tracker from the health department who called me to check in. Every single day I was quarantined. […] There is a lot of stigma out there, but fear keeps us away. “We have to overcome the fear and work together.”
4. Washington DC: The Unknown Transmission Exceeds the Known
DC was one of the first jurisdictions to share this type of data, Watson says. The County COVID panel currently displays two types of contact tracking data: How many contacts have been reached within 48 hours, and what percentage of new cases arise from quarantined people.
If most new cases arise from people who are already a known contact, this can provide assurance that the public health system is at the forefront of transmission. In DC, data show that only 4.5% of cases arise this way – far from the goal of 60%.
DC.gov/ Screen presence by NPR
In other words, 95.5% of new cases were previously unknown to the health department.
“It really shows how much community broadcasting we still have,” says Watson. “It’s really useful to know that we both probably need to bring the broadcast down, in general, and [we need to] continue to improve contact tracking effectiveness “.
5. Delaware: Tracking phone numbers is a challenge
Delaware offers a kind of narrative walk of the contact tracking process, from a new case being identified, to contacts that themselves end up proving positive. The numbers are paired with explanations of what they indicate and why.
“Not everyone who was reached was interviewed right away,” notes read next to a figure show that 17% of contacts reached did not complete the interview, and then she lists some possible reasons, including a contact that is too busy talking or hard of hearing He also notes that 27% of cases and 43% of contacts were missing phone numbers, and that “new attempts to get and verify phone numbers are being explored”.
Delaware.gov/Screenshot by NPR
“I like that they have summary statistics ahead,” Watson says, noting that the percentage of contacts reached, the average number of contacts per case, and cases with known exposure in another case are highlighted. The percentage of known exposure cases is 25%, much higher in Delaware than in DC, which is at around 4%. (It’s tricky to make these kinds of comparisons, though, without standardized metrics.)
“I also love the way they open up the process and provide data and explanations at every step,” Watson says. “It shows how difficult it is to have contact with people, but also how much work the health department is doing to make it happen.”
6. North Dakota: The spread of the community goes beyond the transmission of families
North Dakota was originally a way out in terms of contact tracking staff, according to the first NPR survey in state health departments. In the latest survey published in early August, NPR analysis revealed that the state currently does not have enough staff to find contacts to pursue new issues.
Now, the state appears to be using contact tracking data to identify sources of exposure for new cases.
“Their bucket is kind of wide,” Watson says. “Interestingly it is interesting that community broadcasting is higher than close contact contact”, as close internal contact is believed to be the main driver of COVID broadcasting. More specifics – as in the Louisiana eruption data – can help explain what these buckets mean in real life, she says.