116 3rd St SE
Cedar Rapids, Iowa 52401
CEDAR RAPIDS - As confirmed COVID-19 cases mount in Iowa, public health officials say they believe the time-intensive practice of contact tracing - a key tool in limiting the spread of infectious diseases - will continue but may be modified or scaled-back.
Contact tracing is a common tool to find cases of a public health disease and isolate it to stop its spread. In the case of the novel coronavirus, officials attempt to trace back how, where and when the person got the virus, and then forward to who that person may have exposed through direct contact so that person can be alerted, monitored for symptoms and instructed to self-isolate if necessary.
Two technology giants - Apple and Google - announced last week they are working together to develop an app that would let owners of smartphones know if they crossed paths with someone infected with the disease. The companies said they hoped to make the tool available to contact tracers by mid-May - two months after COVID-19 was first confirmed in Iowa.
'For most people, in a several day period, you could expose an awful lot of people,” said Patricia Quinlisk, former state epidemiologist and medical director. 'That's why we are recommending social isolation. We are trying to reduce the number of people getting exposed to any other person.”
Quinlisk said because the virus is so new, health officials are still learning its incubation period, how it is being spread and how long it lives in the environment. They don't know all of the answers, she said.
One phenomena being monitored is a 'super spreader” - someone hard to identify or explain - who can unwittingly spread a virus to 10, 20, 30 people or more, Quinlisk said. The typical person may spread a disease to only one or two other people through the normal course of human interactions.
'Right now, my understanding is there is concern that in COVID-19, the super spreader phenomena may be something that's happening,” Quinlisk said. 'I don't know if anybody knows for sure, but that's something that would be of concern, and since you can't just look at somebody and identify that, then you have more stringent actions to stop one person from exposing other people because you don't want to have any super spreader spread.”
As the number of known cases has continued to increase, the work of contact tracing in Iowa has been given to local county public health departments, said Sarah Reisetter, deputy director of the Iowa Department of Public Health.
'We provide them guidance, we communicate with local county health departments regularly, and we provide technical assistance to them should they have questions about how to do this contact tracing,” Reisetter said. 'Local public health agencies do continue to do contact tracing on new cases as they are identified.”
In Johnson County, the public health agency has doubled the number of staff focused on contact tracing. Initially, two disease prevention specialists were leading the process, but two additional staff members have been moved over to help the effort.
Sam Jarvis, community health division manager for Johnson County Public Health, said the agency has active contact tracing efforts for all positive cases of COVID-19 in the county.
While Johnson County has had well over 100 positive cases, at least 30 of those have recovered and are no longer being monitored, he said.
Once a positive case is confirmed, a lab notifies the state and local public health departments. Johnson County officials contact the patient to interview him or her about the illness and exposure risks. Based on this information - the exposures, the symptoms and when symptoms started - the public health workers will identify those contacts with the highest risk, said Jennifer Miller, a Johnson County disease prevention specialist. Staff contacts them and recommends home confinement as they monitor themselves for illness, she said.
Staff have daily contact with the patients who've tested positive to track their illness and determine when they can be advised for release from home confinement, Miller said.
Jarvis said they don't specifically ask if people are abiding by the home confinement recommendation, but it typically is determined as part of conversations.
As cases of community spread occurred in Iowa - cases not linked to a known case or a travel exposure - Johnson County Public Health changed its procedures for contact tracing to focus on those cases at highest risk of spreading.
The procedures were further refined with closures of schools, bars and restaurants and recommendations for social distancing and home confinement, reflecting changes in risk.
'We now focus only on the highest risk individuals to follow up, to track for symptoms and recommend for home isolation,” said Jake Riley, a disease prevention specialist. 'This is because those who had casual contact with someone who tested positive for COVID-19 were at no higher risk than the general public.”
Linn County Public Health has four staff members who devote the majority of their time to contact tracing, and up to five residents at the Cedar Rapids Medical Education Foundation as backup support, said Heather Meador, the clinical branch supervisor for Linn County Public Health.
During the coronavirus outbreak with the push for people to stay home, maintain their distance to others, self-isolate if they are ill and limit group sizes, investigators have been able to be more focused in contact tracing, she said.
While the number of contacts varies from person to person, Meador said, in their investigations 'it has pretty much been their family and their work contacts” that need follow up. Staff follow up with each positive case daily, she said.
Linn County has been the epicenter of COVID-19 in Iowa, and even as case numbers grow, Meador said they would continue contact tracing.
'It may not be as wide as what we are normally able to do, but we will still be doing this because those you are closest to, they need to be notified,” Meador said. 'They need to know to be watching for the signs and symptoms, because again, the more people we can notify that they are a contact that they stay home for 14 days and if they develop symptoms, they're not passing it around the community so this is something that we will not give up on.”
Jarvis and Meador said the practice has been effective, noting they've been able to identify cases through this method although did not have specific data.
Testing can also be part of the contact tracing process. However, the limited availability of test kits has led to focusing tests on only those at highest risk or those with more severe symptoms, Meador said, adding it makes it 'much more difficult to determine the burden of disease within the community.”
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