The Case for a Hybrid Approach to Contact Tracing
July 7, 2020
The Case for a Hybrid Approach to Contact Tracing
Traditional Contact Tracing
The concept of contact tracing – a simple, but difficult public health strategy that has successfully combated infectious disease outbreaks globally since the 1930s – has taken on a new definition in the age of COVID-19. It is now being reintroduced and reframed in the media as new app and technology solutions aim to track an infected person’s every move and interaction to prevent the spread of COVID.
The problem with this narrow definition of contact tracing is that the concept isn’t limited to finding the individuals with whom an infected person has had contact. Rather, it’s considered to be part of the full lifecycle management of confirmed cases and the contacts of those people, which also includes:
- Recommendations for isolation or self-quarantine
- Developing a course of action if the infected individual lives with or cares for other people (like family, friends, roommates, etc.)
- The employer’s response to the diagnosis (if the individual was at work and was interacting with other employees)
Notable epidemiologist Crystal Watson told Hopkins Bloomberg Public Health Magazine that contact tracing can reduce suffering and death while the world waits for a COVID vaccine. Fundamentally, contact tracing entails tracking down all the contacts of an infected person and then taking appropriate action to break the chain of transmission, which, in the case of COVID, means a minimum of 10 days in isolation for someone who tests positive, and a 14-day quarantine for those who’ve been in contact with an infected individual.
A traditional contact tracer wouldn’t just want to know who the individual had contact with, they’d also want to know how the infected person is planning to care for their elderly parent if they’re being asked to quarantine, or if the individual has roommates and whether or not they use separate bathrooms. They’ll also want to know how they’re planning to care for their children or buy groceries during their isolation/quarantine period, which could necessitate employer or government assistance.
- Example Scenario #1: An individual tests positive for COVID, so their employer offers to pay for their grocery and/or pharmacy delivery fees so they don’t have to leave their homes during the isolation period to buy food or medicine.
- Example Scenario #2: An individual is notified that they were recently in contact with someone who tested positive for COVID, so their state government provides them with financial aid that they can use to pay for a specialist, nurse, or daycare to mind their loved one(s) while they are quarantined.
There’s a very important social care aspect of contact tracing that is typically carried out in full by public health authorities, but given the increased potential for COVID transmission in the workplace, companies may opt to take on some of that social care responsibility, depending on the nature of the situation, the size of the company, the employee benefits, and where the company feels comfortable drawing the line.
A company may be willing to offer childcare support to a sick employee, for example, but may draw the line if a different sick employee lives with 3 roommates who don’t wear masks, wash their hands, or maintain a safe physical distance from others. The company could determine that the risk to their employee is too far beyond their control, and would then shift responsibility to public health authorities.
Another potential issue with any contact tracing method lies in false negative test results, which are common (the test is more accurate for those with lung infections, because samples are collected from the nose or throat.) It’s also common these days to postpone the tests until the symptoms worsen to minimize chances of getting a false negative or an inconclusive result. False negative tests fly under the radar, as contact tracers would be unable to initiate their investigation without a positive test.
Technology-Based Contact Tracing
“The United States could possibly roll out a mobile contact tracing application that could capture contacts and record their self-reported symptoms… With user permission, an app could also record and store user location for contact tracing and tracking purposes. In addition, a national electronic platform for contact tracing could be developed and potentially synced with existing electronic health records.”
The strategy behind traditional contact tracing is test, trial, and test again. This method was used to control the spread of Ebola, AIDS, measles and other outbreaks, but what makes COVID-19 inherently more difficult to track than other global diseases is its ability to be transmitted asymptomatically and pre-symptomatically. If an infected individual never displays symptoms or feels sick, nobody sees a positive test result. For this reason, contact tracers use a window of two days preceding the initial manifestation of symptoms for purposes of establishing contacts that should quarantine.
In the early days of COVID – amid shelter-in-place orders and other efforts to flatten the curve – Apple and Google announced a partnership to develop a technology-based contact tracing solution, which has had several problems: “The rigid policing of a common framework has tied governments’ hands around the world, offering no flexibility to adapt to scientific advice on these unprecedented solutions for the global pandemic.”
Apple and Google aren’t the only ones with issues. The U.K.’s National Health Service (NHS) officially abandoned efforts to implement a centralized technology-based contact tracing solution after “spending three months and millions of pounds on technology that experts had repeatedly warned would not work.”
Manual contact tracing outcomes tend to be more productive and valuable (especially if they’re required by law), and the problem with relying exclusively on bluetooth and geolocation-based contact tracing is that the technology is simply inaccurate when it comes to identifying the nuances between different levels of physical contact, typically defined as such:
- Direct Contact: 1 second of hand-shaking, hugging, sports contact, accidentally bumping into someone, etc.
- Close Contact: 15+ minutes at a distance of less than 6 feet apart
- Proximate Contact: 1+ hours of sharing the same space, but not being right next to someone, like an office meeting, a movie theater, small social gatherings, etc.
While Bluetooth Low Energy (BLE) is a suitable technology to detect proximity, its application to COVID contact tracing isn’t mature and is likely to be unreliable. For example, it would be prone to false positives in scenarios where thin walls separate people that were never actually in contact. It’s also likely to give false negatives for direct contacts that lasted less than the sampling period (sampling is required to preserve the device’s battery).
False positives waste valuable contact tracing resources, while false negatives can lead to more infections. The technology could be useful as a way to “seed” the memory of a person who would explicitly confirm the contacts, but that would require relaxing very stringent privacy aspects of the protocol. Some health agencies in Europe have attempted to implement this without using Google and Apple’s contact tracing APIs, but their apps performed very poorly, especially in regards to battery life and ability to detect proximity while in the background.
Finally, the biggest issue with technology-based contact tracing methods is that people don’t like using them, or don’t want to. The apps, most of which are voluntary, need a significant number of users if they’re ever going to be effective, and there’s a large portion of people who won’t download them for various reasons ranging from privacy concerns to inconvenience.
A Hybrid Approach to Contact Tracing
Traditional contact tracing methods may have proven success rates, but there are also benefits to implementing technology-based solutions that can assist contact tracing efforts by securely collecting employee health monitoring data and notifying HR managers of positive cases so they can initiate the contact tracing lifecycle – either themselves, or with help from a health authority (depending on the size of the company and the nature of the work) – in order to prevent the spread before it gets out of control.
OSHA laws make employers responsible for recording cases of COVID-19 (see OSHA – Revised Enforcement Guidance for Recording Cases of Coronavirus Disease 2019). The following analysis at Employer Liability and Defenses from Suit for COVID-19-Related Exposures in the Workplace from Gibson Dunn indicates that employers should be able to rely on worker compensation statutes to avoid direct liability to employees, but it also highly recommends protective measures in the workplace.
Protecting employee health should be a top priority for businesses during these difficult times. Additionally, since using a contact tracing health monitoring solution is a clear protective measure for COVID-19 risk, it ends up being the best factual defense to any potential employee or class action lawsuit alleging claims related to COVID-19 exposure.
In lieu of apps that automate the full lifecycle of contact tracing from start to finish – often with mixed results – a health monitoring solution that also incorporates contact tracing capabilities can be far more effective. By incorporating technology-based solutions with traditional contact tracing methods, companies can act quickly on positive cases to prevent other employees’ exposure while also demonstrating their commitment to employee health, compliance, and avoiding liability associated with bringing people back to work safely.
How Evident Helps
Evident’s Health Status solution facilitates secure and private collection and analysis of employee health data so that they can make informed business decisions around bringing employees back to work safely. The new contact tracing feature immediately notifies human resources professionals or managers about employees with high risk health status results (e.g. fever, high temperatures, exposure to someone who’s tested positive for COVID, etc.) so they can either initiate their own contact tracing lifecycle manually, or contact health authority professionals to initiate a more formal process for contact tracing.