DES MOINES, Iowa — Public health experts say contact tracing is an essential tool to fight the pandemic. But the amount of people doing case investigation in Iowa might fall short of what’s needed to keep pace with the spread of coronavirus here, according to one analysis from George Washington University.
Contact tracing, or tracking down people who came in close contact with someone who tested positive for COVID-19, isn’t unique to the pandemic. Such infectious disease investigations helped stem the Ebola outbreak in Africa in 2014, and they are used for foodborne illnesses, sexually transmitted infections and the measles.
Experts wrote in a Johns Hopkins University white paper that contact tracing is paramount to safely returning to work and school, and for saving lives.
“The United States must implement a robust and comprehensive system to identify all COVID-19 cases and trace all close contacts of each identified case,” the paper said.
When Gov. Kim Reynolds began re-opening businesses May 1, she cited expanded testing and contact tracing as tools allowing her to loosen restrictions. And as recently as mid-July—with all businesses now allowed to reopen at full capacity and cases on the rise again—she reiterated the importance of case investigations.
“COVID-19 remains active in our state and across the nation and we know testing and contact tracing is key,” she said.
An Iowa Department of Public Health spokeswoman said by email that there are 400 contact tracers in Iowa between the state’s investigators and staff at local public health agencies.
Iowa’s policy is that counties can opt to use the state’s resources instead of their own and 34 counties—including the largest Polk—have chosen to do that for positive cases determined by diagnostic testing. 150 National Guardsmen assist the state with contact tracing, and their federal orders are set to expire in August.
36 counties use state tracers for serology, or anti-body, testing investigations.
“This list changes over time as local need fluctuates,” said Amy McCoy, who handles COVID-19 media relations. “We are actively working on a plan to transition contact tracing efforts from the Guard to department staff. Efforts to hire more contact tracers continue with more coming on board soon.”
McCoy declined to share specifics about hiring efforts.
As of this writing, more than 43,000 Iowans have tested positive for COVID-19 and 844 have died, according to state data.
The number of people tracking down close contracts of Iowans’ infected with coronavirus has increased since the beginning of the pandemic, and so has the state’s testing capacity.
But those levels fall drastically short of at least one estimate that puts the need at about 3,330.
That figure comes from The Fitzhugh Mullan Institute for Health Workforce Equity at George Washington University, which, in partnership with the Association of State and Territorial Health Officials and National Association of County and City Health Officials, created the “Contact Tracing Workforce Estimator” tool which provides an algorithm so states can estimate how many contact tracers they might need.
“There are very few states in the midst of a surge that have adequate capacity,” said Edward Salsberg, who works on project at the Mullan Institute. More than half of the country is seeing a rise in cases, according to data from The New York Times accessed Wednesday.
The estimates from the model are based on the 14-day average of new cases and makes assumptions like a person only having 10 close contacts, which could vary. Salsberg noted that the pool of close contacts is likely larger in states like Iowa where the economy is fully re-open and there is no statewide mask mandate.
The tool also assumes the amount of time it takes to make calls to those contacts and the frequency of follow up. The purpose of the project is to help state and local health officials estimate their needs as accurately as possible based on the unique variables in their communities.
“We’re not saying this is the right number” Salsberg said. “That’s why we developed it as a tool so a locality, a state, a local government could say ‘we know our community, we know how we operate’ and put in their own numbers.”
Dr. Emily Gurley, an epidemiologist at Johns Hopkins University and the instructor of a six-hour online contact tracing training course, echoed that needs fluctuate and there might not be a “magic number" for contact tracers.
“Any individual metric—how many contact tracers you have, or how many cases you found—none of those in and of themselves tells you what the impact is,” Gurley said.
But she emphasized the importance of contact tracing as being one part of a package of interventions to stem the spread.
“In most parts of the country, the number of cases is going up so that tells is that whatever we’re doing in those places is not enough," she said, adding that contact tracing doesn't need to be "perfect" to be effective. Gurley and Hopkins also launched a new course this week aiming to help contact tracing program managers quantify the impacts of their operations—another tool designed to measure contact tracing needs.
NPR used the Contact Tracing Workforce Estimator tool when it surveyed the amount of contact traces state-by-state and published a June report. At the time, the analysis put Iowa's need at 1,316 total tracers and roughly 42 tracers per capita.
When asked about these estimates exceeding Iowa's current capacity of case investigators, McCoy said that the department is focused on "process improvement," which isn't just about hiring additional staff, but using resources more efficiently. She said they didn't know "the criteria or considerations behind the [Mullan Institute] analysis."
"We are working with local public health officials to improve the effectiveness of our contact tracing and to automate some portion of the process," she said in an email. "We’re also working to ensure our efforts are targeted and informed by our data."
In late June, Gov. Kim Reynolds said the state was changing the way it reports coronavirus "recoveries," flagging someone who tested positive as recovered after 28 days, two incubation periods, unless IDPH hears otherwise. Reynolds said they decided to implement the change after follow-up calls from contact tracers were going unanswered.
During a July 7 news conference, Reynolds suggested this change will help the state use contact tracers more efficiently.
"It allows us to use our assets and resources more effectively and really focus on the front end, so we can understand who has been exposed and make them aware so we start to contain the spread of the virus."
Counties using state contact tracers for PCR testing:
Counties using state contact tracers for serology testing: