P1373 — Tracking's Tricky Promises from July 2019 states that although the use of tracking applications by authorities can offer social benefits, examples of the misuse of such applications raise concerns among the general public. Now, under the new circumstances resulting from the emergence of the coronavirus and the rapid worldwide spread of coronavirus disease 2019 (covid-19), the tracking of infected people has become a health-care and safety consideration. The rationale behind tracking people is now more defensible than it was only three months ago, but that fact does not absolve policy makers from weighing the benefits of and concerns about tracking efforts. At present, managing risk is a day-to-day learning experience. Once the covid-19 pandemic has passed, the development of an understanding about where to draw the line in matters pertaining to tracking—for example, what types of tracking are acceptable, which people are permissible to track, and what reasons justify tracking—will be necessary.

Privacy concerns can clash with public-health considerations.

South Korea was one of the countries that the covid-19 outbreak hit fairly early, but the nation reacted quickly and in a very organized fashion. In addition, the government of South Korea decided to track the steps that covid-19 patients took before their diagnosis, and it is using data from GPS phone tracking, credit-card records, surveillance-video information, and patient interviews to develop a map of infected people's movement. A website now enables people in the country to determine whether they may have come in proximity to an infected person. This map is very detailed, but it does not provide the names of infected people. And although many people and civil-rights groups worry about the balance between protecting public health and protecting people's privacy, countries other than South Korea have launched similar tracking efforts. For the sake of privacy, Japan's Ministry of Health, Labour and Welfare (Tokyo, Japan) has been cautious about releasing citizens' travel history; however, some regions of the country have chosen to make public information about covid-19 patients' trips to public places such as gyms, hospitals, and restaurants. Meanwhile, the government of Singapore hosts a website similar to South Korea's that provides the age, sex, occupation, and recent travel history of all the recorded covid-19 patients in Singapore.

As part of tracking efforts, organizations, policy makers, and governments are considering using cell phones to track the movement patterns of covid-19 carriers. Whereas the governments of some countries prioritize public safety over privacy and have implemented cell-phone-based tracking measures, the governments of the United States and many European countries still shy away from implementing such tracking measures. But some researchers have already developed tracking applications that rely on cell-phone data. Indeed, researchers at the University of Cambridge (Cambridge, England) developed such an app about a decade ago. The Cambridge researchers developed the FluPhone mobile app, which asked app users questions to monitor flu-like symptoms and used Bluetooth to keep a record of other mobile devices that came in proximity to the app users. The Cambridge researchers worked with personnel from multiple academic institutions and government agencies in using the data the app collected to develop an understanding of how people interact and how viruses spread. More recently, Massachusetts Institute of Technology (MIT; Cambridge, Massachusetts) MIT Media Lab associate professor Ramesh Raskar and his team developed the Private Kit: Safe Paths app. The app works with the Safe Places geographic-information-system web app that MIT developed to disclose "when and where infected patients were in proximity to others, all while maintaining the privacy of both the patient and the user" (www.media.mit.edu/projects/safepaths/overview). These and similar apps could see beneficial use during the current health crisis, but concerns about privacy make their use controversial.

Clearly, privacy concerns can clash with public-health considerations. Valid reasons to track people exist, but at the same time, the potential for misuse and abuse is very high. Policy makers will need to consider how to deal with this situation, and companies will have to look at the use of technologies to support related applications. Each region has its own way of dealing with the situation, and examining the variety of approaches could provide valuable lessons.

For quite some time, various researchers have been looking at mapping outbreaks and contagion pathways. For example, Alessandro Vespignani—a professor at Northeastern University (Boston, Massachusetts) and director of the university's Network Science Institute—is modeling the processes of contagion in populations and working on predictive tools that enable the analysis of the spatial spread of emerging diseases. Naturally, Dr. Vespignani's research has been catching the attention of other researchers and organizations lately. For example, University of Washington (Seattle, Washington) professor of biostatistics Elizabeth Halloran highlights that Dr. Vespignani and other researchers in the field have possibilities now that they did not have only a short time ago. Publicly available data, advanced computing power, and sophisticated algorithms support research concerning the spread of disease, which will benefit disease-containment efforts. In addition, researchers who study how diseases spread among populations might also learn more about human interactions and how societies operate more generally.

At what point do tracking efforts infringe too much on individuals' privacy and compromise the public's rights and liberties? According to recent media reports, the Israel Security Agency (Tel Aviv, Israel) has started using its technical capabilities to identify people who may have come into contact with covid-19 carriers and then ask them to self-quarantine via text-message notification. The agency is likely using cell-phone-location, credit-card-use, and geolocation data to track people. Although the agency's tracking methods are similar to those that other countries and organizations have implemented, critical observers and opponents of tracking in general will note that a government security service is conducting the tracking in this case, which may concern some people. Another matter that deserves considering is whether a company can or should use customer data that its products collect to track—potentially surreptitiously—a disease during a pandemic. P0908 — Capturing the World from 2016 reports on Kinsa's (San Francisco, California) internet-connected medical thermometers, which send data about users' temperature and symptoms to a mobile app. The company has already used the data it collects to create interactive maps that predicted the flu's spread in the United States, and the data could now aid health officials in tracking the spread of covid-19. In addition, the connected thermometers could send real-time updates about covid-19 developments via the app. Kinsa normally submits the data it collects to peer-reviewed medical journals; however, during the covid-19 pandemic, it will post its data and maps on websites that are accessible to the general public. This use of data could have many benefits but also raises red flags for people who have privacy concerns.