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Card-based system, designed to monitor asymptomatic persons, helps limit COVID-19 spread


This article by Dr. Keith Lau is published in the journal, Coronaviruses, 2020

The COVID-19 pandemic has had an adverse impact on the global economy. Researchers around the globe have been working hard to find ways to stop the spread of the disease either in the form of drugs or SOP changes that revolve around guidelines given by the WHO for maintaining hygiene and social distancing norms. The challenge of stopping the spread is especially challenging as many individuals who are exposed to the novel SARS coronavirus do not show the symptoms of COVID-19 and risk exposing non-infected individuals.

Researchers are now using GIS and IT systems to find ways to monitor populations and the movement of infected individuals to track the spread of the disease and efficiently tackle problems arising due to exposure to the novel coronavirus.

A team of researchers based in Hong Kong have devised a system to track asymptomatic individuals through the use of anonymous transit smart cards and terminals. The proposed system is connected to a central database of infected individuals maintained by the medical authorities. The location and movement of individuals is tracked by this system and it issues an alert in case they check in at a location where others are visiting. Non-infected individuals are flagged as asymptomatic carriers if they have been detected at a location where infected individuals have also been present. Through a combination of metrics such as gathering size and infection rates, the system calculates an index (called the alert level) by comparing the changes in the number of persons listed as infected individuals and asymptomatic individuals over the previous days. The alert level is designed to give an idea of the severity of the spread of the infection. The alerts issued by the system can be used to issue warnings to non-infected persons about a possible risk of COVID-19 infection in a specific location and also to block the entry of suspected carriers at a terminal.

The system has received recognition as a top solution for tourism destinations from the UN World Tourism Organization (UNWTO) in the recent Healing for Destinations tourism solutions contest. The system is in use in elderly homes, wet markets, public schools and restaurants in Hong Kong.

"The spread of COVID-19 is a mathematical problem."Explains Keith Lau, who is one of the principal researchers on the project. "By monitoring asymptomatic individuals and limiting the participation of individuals in large gatherings, we can see a reduction in exponential growth of cases, and this is reflected in our data. Our system makes it easy for local authorities to identify problems during pandemics such as the COVID-19 pandemic and invest their resources appropriately to minimize impacts on economic trade."

The team's research has been published in the first volume of the new journal Coronaviruses, published by Bentham Science Publishers.

The article is open access (free-to-download) for limited time period of three months. To get access to the full-text article, please visit: