Disjointed Response to Covid-19 Reflected in Approach to Screening, Testing and Contact Tracing
Screening and testing for the Corona virus, and contact tracing those who are infected, are key components of any Covid-19 strategy. Because screening, testing and contact tracing are inter-related it is important to plan for them within the broader context of our overall pandemic response. A national response is required to address this global pandemic. What we have seen instead borders on chaos.
Screening, testing, and contact tracing are part of the larger picture of addressing the Covid pandemic, which includes preventive measures such as isolation of those who have the virus, quarantine for close contacts, minimizing indoor settings with poor ventilation, and proper protective equipment (PPE) for those potentially in contact with the virus. Our individual preventive measures should be a mantra by now; masks, social distancing, and hand washing.
Screening, testing, and contact tracing are linked because if you screen someone for Covid, you will want to test them, and if their test comes back positive you will want to do contact tracing. Contact tracing is important because if we know those who have been in contact with someone who has the infection, we can reduce the chance they transmit it to someone else.
Addressing screening, testing and contact tracing together requires both thinking big enough to get our arms around the issues, while still focusing on our most immediate challenges. Like the activist, “think global- act local.” How might this apply during the Corona crisis? Let’s start by thinking about one of the biggest challenges that has emerged-testing for the virus.
When we look at screening tests used for other health conditions, we find that the most beneficial tests are those that can pick up a disease before it would otherwise be detected, and at a time where health care providers can intervene and change the course of the disease for the better. For example, screening mammograms to detect treatable breast cancers in women between the ages of 50 to 74, and colonoscopy to detect colon cancer in all adults ages 50 to 74 are both recommended by the United States Preventive Services Task Force because their use has been associated with reductions in deaths from cancer in these age groups.
Screening for Covid meets our first requirement for screening because it can identify when someone has the virus before they may be sick or symptomatic, but in contrast to screening for some types of cancer, testing for Covid 19 will not change outcomes for those infected. However, screening for Covid does give us information we can use to lower the likelihood that the person who has Covid or their contacts will infect someone else-if we have an effective contact tracing plan.
We can envision testing strategies ranging from testing everyone who wants to be tested- our current default approach, to only testing those who are high risk or who are sick with symptoms. Before deciding on a testing strategy, one question to ask is, what will be done with the test results once they are received? In the case of Covid, we don’t yet have any treatments except the medications Remdesivir and Decadron which are only available to bend the curve for very ill hospitalized patients, so whether you test negative or positive does not impact the course of the disease for the vast majority of patients.
Screening for Covid in patients and staff in high risk congregate settings such as nursing homes has more value because it can identify patients who need to stay isolated or staff who need to stay home to avoid exposing other patients who are at high-risk of dying if they become infected. It is of less value in the general public because they are less likely than nurses in a skilled nursing facility to be in contact with high risk individuals.
If there are unlimited dollars and adequate numbers of screeners and tests, than it doesn’t matter as much who is tested. But if dollars, screeners, or test supplies are limited, such as is the case now, then a decision should be made to focus screening and testing resources in the highest risk settings. Even testing someone with symptoms may not be needed if supplies are limited, because in many cases it won’t change your treatment recommendations. However, those who are symptomatic are more likely to have the virus and infect others, so we need to tailor our screening and testing and patient advice with our plans for contact tracing.
Lets look more closely at contact tracing. Contact tracing involves contacting both the individual who is infected, known as the index case, as well as close contacts. Ideally, you would be able to isolate individuals who are Covid+ by themselves to keep them from infecting those they live with. In China, this was done by isolating individuals who tested positive in separate living spaces away from families and other contacts during the duration of their infectious period- generally 10 days. This was a response that was managed centrally, with resources provided for separate housing of those infected. In the United States, there are some limited examples of this, such as finding housing for homeless individuals while they were infected with Covid, but not on the scale or with the consistency that occurred in China.
Contact tracing is also done to determine close contacts. Close contacts are the people most likely to have been infected by the person who tested positive. If you live in the same household you are considered a close contact. You are also considered a close contact if you were less than six feet away from the infected individual for more than 15 minutes during the time when they were infectious. The infectious period is two days prior to when the index case tested positive or first developed symptoms through the next 10 days. It takes several days to get your Covid results. Assuming you test positive, by the time a contact tracer speaks to you, they will be questioning you about potential close contacts from the prior week. This includes the two asymptomatic days prior to testing positive or becoming sick, the days it took to have the test completed and the result sent, then through the additional days it takes for the contact tracer to call you, which further depends on their backlog of index cases to call.
The accuracy of identifying who is a close contact is dependent on the information received from the index case. Imagine how difficult it is to remember everyone you might have had close contact with over the last week. Did you have any meetings, go out to dinner, was it for more than 15 minutes and less than six feet away? Does it matter if they had a mask on, or if you were wearing yours? What about schools and classrooms? And then there are the contacts of the contacts, should we worry about them? Each encounter comes with some risk.
The workload associated with contact tracing is also immense. First, they must contact the infected individual, then identify and record for each Covid+ patient all the names and dates and times of close contacts, as well as contact information for each of these contacts. Add in the geographic element to help pinpoint the locations where the contact occurred to determine where the virus might have spread, and you can see why each each initial interview of a Covid+ individual can take an hour to complete, assuming you are able to contact them in the first place. Then there is the remaining work, including contacting each close contact to educate them, as well as to monitor them for symptoms.
The craziness of contact tracing increases as the number of positive cases rises. For infections like meningitis or ebola, which are rare and deadly, it makes sense to hunt down all contacts, particularly when there are antibiotics that can prevent infections in contacts as is the case for meningitis. Early in an outbreak with limited number of cases we are in a better position to provide contact tracing that can help us get ahead of the disease and stop the thread of transmissions through isolation of those with the condition and quarantine of the limited number of contacts. When there are hundreds of positive cases a day in a community, and each case may have 5–10 close contacts or more close contacts, the workload escalates rapidly to the point where responding to positive cases is slowed. When there is any amount of backlog with contact tracing, you reduce its effectiveness with each passing moment because until they are notified, close contacts will remain in the community without knowing they may be potential carriers of the virus. Clear guidance on how much information to collect is needed for our contact tracers to stay on top of their case loads, and the guidance itself will need to be updated as the number of cases and the resources required to address them changes.
Assuming we have done the screening and testing, identified the positive cases and advised them to isolate for at least 10 days, agreed upon a definition for close contacts and identified close contacts, what do we then say to close contacts? Again there are nuances in the message. If you happen to work in a hospital or work with the police or fire departments you are considered an essential worker. In that case even if you were exposed to a Covid+ patient, you would be allowed to return to work while monitoring for symptoms. On the other hand, “non-essential” close contacts would be advised to quarantine- ie stay at home and away from others for 14 days. Staying at home for 14 days is very restrictive and challenging, not only for the individual in quarantine, but also for those they live and work with. Each quarantine order for those in close contact with the index case sends ripples of hardship throughout the community.
What would effective management of contact tracing look like? It would involve relying on the recommendations of experts. Fortunately, there are some of the best in the world at the CDC. Contact tracers in cities, counties, and states, would be able to turn to definitive guidance on what length of time and what distance away from a Covid+ individual is considered close contact. There would be additional guidance on key variables such as indoor versus outdoor settings, whether either party was wearing a mask, how to handle group or congregate settings such as jails, schools, places or worship, and in-person meetings, and there would be clear expectations on the frequency and the intensity of followup.
A clear and consistent definition of a close contact, coupled with the means to identify and track close contacts, would be linked to meaningful guidance for close contacts that is realistic and achievable, and to support for social services that may be needed to ensure that the recommendations can be carried out. The recommendations would be nuanced enough so that smaller outbreaks might have different protocols from larger outbreaks, and the guidance would be linked to funding and support for the number of contact tracers and managers and IT equipment to efficiently carry out the assigned tasks.
The dynamic nature of this pandemic demands thoughtful decision-making and adjustments in strategies. Contact tracing is just one tiny piece of the crisis brought on by Covid-19. We must also ensure an adequate medical response for those who become very sick, and address the economic safety net for those negatively impacted by Covid-19. Nor is Covid-19 our only challenge. We must also deal with the dramatic changes to our work places and jobs as we rapidly enter the digital world, while climate change issues lurk close at hand. But it does illustrate how difficult the decisions are that we face, and how badly we need leadership and management to see our way through this.
What would we expect of a leader during this time of crisis? They would respect and understand the magnitude of the challenge we face due to the Covid-19 pandemic, and they would accept the responsibility to lead the charge against the pandemic. They would bring together those in the best position to address the pandemic, and they would provide them with the resources they needed. Because this is a global epidemic with sweeping consequences affecting all 50 states, we need this leadership and management at the federal level to ensure that screening, testing, and contact tracing resources and efforts are coordinated across the country efficiently and effectively.
What we have witnessed in the battle against Covid 19 is what happens when we do not take action at the proper level, either because we fail to recognize the scope of the task or because we do not know what to do. We can’t get our arms around the pandemic because we aren’t fighting it as a nation. We need clear and consistent messages, not only on the most important steps we can take to reduce spread, including masks, social distancing, and face washing, but also on the types of nitty-gritty questions that we have raised about contact tracing and close contacts. The ramifications of these recommendations in terms of both workload and staffing for tracers, as well as the consequences on the lives of those who are identified as close contacts, must be considered. All very challenging, but all also doable. The alternative is huge additional expenditures, more shelter in place, or an ever-growing pandemic.
Dr John Zweifler is a family physician with decades of experience in medical director roles, patient care, medical education, and managed care. He now works part-time as a medical consultant with the Fresno County Department of Public Health. He is also a physician consultant with The Terry Group, and is the author of the e-books, “Tipping Health Care in the Right Direction” and “Pop Health”
He can be contacted at The Terry Group John.zweifler@terrygroup.com
