Self-Symptom Checker for COVID-19 Control and Symptom Management

Abstract

Background: Breaking the chain of disease transmission from overseas is necessary to control new infectious diseases such as coronavirus disease 2019 effectively. In this study, we developed a mobile app called Self-Symptom Checker (SSC) to monitor the health of inbound travelers. Methods: SSC was developed for general users and administrators. The functions of SSC include non-repudiation using QR (quick response) codes, monitoring fever and respiratory symptoms, and requiring persons showing symptoms to undergo polymerase chain reaction tests at nearby screening stations following a review of reported symptoms by the Korea Disease Control and Prevention Agency, as well as making phone calls, via artificial intelligence or public health personnel, to individuals who have not entered symptoms to provide the necessary information. Results: From February 12 to March 27, 2020, 165,000 people who were subjected to the special entry procedure installed SSC. The expected number of public health officers and related resources needed per day would be 800 if only the phone was used to perform symptom monitoring during the above period. Conclusion: By applying SSC, more effective symptom monitoring was possible. The daily average number of health officers decreased to 100, or 13% of the initial estimate. SSC reduces the work burden on public healthcare personnel. SSC is an electronic solution conceived in response to health questionnaires completed by inbound travelers specified in the World Health Organization International Health Regulations as a requirement in the event of a pandemic.

INTRODUCTION

  Infectious diseases caused by new viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread rapidly within the closely connected global community due to insufficient scientific evidence on pathogenic mechanisms, misinformation, and clinical pathways in the early stage of transmission, as well as the lack of vaccines and treatment options [1-3]. Vaccines began to be administered in December 2020; however, vaccine breakthrough cases have since increased [4-7]. The worsening situation has resulted in public health systems around the world, from developed countries to low and middle-income countries, reaching their maximum capacity, facing a shortage of resources, healthcare workers [8,9], and seeing a high number of casualties [10]. To prevent the next pandemic or infectious disease outbreak from being as disastrous, scientists, medical experts, policymakers, and businesspersons must, in cooperation with the World Health Organization (WHO), actively develop and utilize non-pharmaceutical interventions [11-13]. The International Health Regulations (IHR) of the WHO state that the health of all inbound travelers must be monitored in the event of a pandemic. However, due to the surge in public health demand, the existing protocol is incapable of functioning effectively in these two aspects. A possible solution can be found in information and communication technology (ICT) [14,15].
  Korea saw its first confirmed case of coronavirus disease 2019 (COVID-19) on January 20, 2020, when scientific information on the virus was very limited [16], and the number of patients rose dramatically in the following month [17]. Korea’s response to COVID-19 is distinct from other countries as ICT has been placed at the forefront.
  since the early days [18,19]. With the growing number of infections, Korea introduced a special entry procedure in February 2020, responding to the pandemic by integrating fever checks and other disease control measures into the existing process [20]. The special entry procedure requires inbound travelers to provide their address in Korea and contact number to ensure that they can be easily contacted if they cross paths with confirmed cases (Figure 1).
  To address the above, the research questions of this study are as follows: (1) Is there an efficient way of maintaining a system that enables quick contact with inbound travelers? (2) Is there a way to efficiently monitor the health of inbound travelers? (3) How can information technology (IT) infrastructure and technology be utilized? The research team developed Self-Symptom Checker (SSC), the first-ever COVID-19 symptom-checking app, which was released in February 2020. It is a pioneering app developed for checking symptoms and detecting infections among inbound travelers to mitigate close contact. This study was the first attempt and a unique experience in developing an app to be used for border control and IHR compliance at the onset of the pandemic.

METHODS

  The research team, comprising the public officials of the Ministry of Health and Welfare and software engineers, prepared use case scenarios for SSC development in early February 2020. The targeted symptoms of health monitoring were the four common symptoms identified by the WHO and the Korea Disease Control and Prevention Agency, such as fever (37.5℃ or higher) or chills, cough, sore throat, respiratory difficulties, or breathlessness (Figure 2) [20]. The user interface was designed to enable users to report their symptoms in a structured manner. Additional symptoms discovered after reporting could also be entered into the system. Ethical approval was not required for this study as it did not involve any human participants.

1. Self-Symptom Checker development environment

  The system was designed in Client-Server architecture. The client operating environment consisted of mobile applications running on Google Android OS or Apple iOS. To manage the data in the integrated system, a personal computer (PC) based application was added. The server operating environment consisted of a server where business logic for SSC is executed, a database server, and a server for information integration between the ministries of the government.

2. Information security and protection

  The following measures were implemented for information security and information protection of the SSC. First, personal information could only be collected with the consent of the subject (the individual whose information was being collected), and the collected information was destroyed at the end of the usage period. Second, a web security tool for data encryption and encoding during transmission to ensure safety and an anti-tampering tool for web pages and online certificates were applied to the user application. Third, key information, such as passport numbers, was encrypted in storage. Lastly, the Cyber Security Center of the government monitored the system for intrusions and responded to threats 24 hours a day, 365 days a year.

RESULTS

1. Overview of special entry procedure

  The special entry procedure was implemented on February 4, 2020. SSC, developed to support the special entry procedure, was launched on February 10, and used by inbound travelers from China. The service was expanded to inbound travelers on flights and ships from Hong Kong and Macau from February 12 onwards, followed by Japan on March 9, Europe on March 15, and all countries on March 19. The phone number verification system, which verified the phone numbers of foreigners in Korea, was implemented on March 20. It was applied to all Europeans and Americans on March 27. As of April 1, 2020, the use of SSC was recommended to all inbound travelers, except those admitted to temporary living facilities, and the app was released on the Android and iOS stores.

2. Procedure for disease control stage

  Inbound travelers expected to install SSC, installed the app on their phones, provided passport information by scanning their passports, and verified their phone numbers using short message service (SMS) verification codes. A quick response (QR) code is generated after the local address and other necessary information had been entered. Inbound travelers without mobile phones could fill-up a special declaration form and health survey at the kiosk, where they could take print out of the QR code for entering Korea. A phone call was made to their address of residence to verify whether they could be reached via phone.

3. Self-Symptom Checker page organization

  SSC is composed of six pages: the main page, travel records special declaration page, phone number verification page, self-symptom check page, screening station page, and connection to the Korea Disease Control and Prevention Agency hotline 1339.
  With the expansion of SSC to inbound travelers from all parts of the world, the supported languages increased from Korean, Chinese (simplified, traditional), and English to Japanese, Italian, French, German, Spanish, Russian, Arabic, Indonesian, Malaysian, Thai, Vietnamese, and Portuguese. The users were asked to choose their preferred language at the time of installation, and the app was later improved to automatically detect language settings of the users’ mobile phones (Figure 3).
  When inbound travelers scan their passports using mobile phone cameras, the retrieved information is compared against the passenger and departure details provided by the airlines. Inbound travelers whose identities have been established receive SMS verification codes to check the phone validity of the numbers.
  Since the system operates based on informed consent, inbound travelers provide electronic signatures, confirming that they are aware of SSC functions and privacy policies. QR codes that facilitate identity checks while minimizing exposure of the personal particulars are generated for inbound travelers who agreed to the registration of personal information in SSC and provided valid phone numbers. Tampering with QR codes is prevented through anti-screenshot and real-time clock display functions. Quarantine officers could access information on inbound travelers by scanning their QR codes.

4. Special entry declaration and health survey

  The information retrieved during identity checks was utilized for special entry declarations and health surveys to ensure that the inbound travelers did not have to repeatedly provide the same information. Important information, such as visits to high-risk countries before arrival, the purpose of travel, and experience of symptoms such as fever, cough, sore throat, and breathing difficulties, were reported. By scanning the generated QR codes, the quarantine officers could view the reported information and take the necessary measures. Inbound travelers are classified into those requiring self-quarantine, those requiring facility quarantine, and those exempt from quarantine based on the reported information, and the quarantine officers could give quarantine-related instructions according to this classification (Figure 4).

5. Health monitoring

  Inbound travelers using SSC are asked to check their health at least once a day for 14 days from the date of arrival and report symptoms such as fever, cough, sore throat, and breathing difficulties. The entered health information cannot be modified or deleted, and any change in health is newly registered. Administrators can place in-dividuals reported as healthy on a watch list even if only one symptom is declared. SSC users who fail to report their health status at least once a day receive text messages and mobile phone alerts twice a day.

6. Connection to call centers and consultation management

  The 1339 hotline manages inbound travelers currently in Korea, including newcomers who are not subject to quarantine but excluded those who have since left the country. Health officers are matched to quarantine-exempt inbound travelers based on the languages spoken by the health officers, the number of calls on hold, and the nationality of those exempt from quarantine. A matching change function is available in case inbound travelers are unable to speak languages other than their native language.

7. Artificial intelligence checker

  Inbound travelers report daily, regardless of whether they are experiencing COVID-19 symptoms, for 14 days from the date of arrival via SSC or artificial intelligence (AI) calls. Those who fail to report are given four prompts encouraging them to do so. The first prompt is in the form of a text message or push notification sent by the administrative system. The second prompt is an AI phone call, which records responses into the system if the call is answered. The third prompt, attempted when the phone call is not answered, is a phone call by a health officer of the call center. The fourth prompt is made by contacting family, friends, or acquaintances of inbound travelers. AI check was implemented to address issues such as device compliance, lack of health officers proficient in foreign languages, and the heavy workload of the 1339 hotline (Figure 5).

8. Information linkage

  The system is linked to databases of related ministries to fully utilize information owned by the government and minimize repeated provision of personal particulars by users. The purpose of information linkage is to link only the minimum amount of information needed, and items considered necessary are determined through consultation with the various ministries (Figure 5).

9. Monitoring cases

  Table 1 shows the daily number of monitoring of inbound travelers entering Korea under the special entry procedure over a period of 7 weeks since the release of the SSC app. The number of inbound travelers requiring monitoring averaged a daily 41,813 up to the point where the app was applied to all countries. Assuming a consultation session of 10 minutes by the health officers working 8 hours a day, about 800 health officers and related resources are needed per day. Following the launch of SSC, phone consultation is needed only for in bound travelers who had not installed the app, and the daily average cases dropped to around 5,406 (Table 1). A more effective response was made possible as the daily average number of health officers providing phone consultations decreased to 100, or 13% of the initial estimate.
  Table 2 shows the results of the diagnosis and polymerase chain reaction (PCR) test by the local public health center for 6,447 inbound travelers who responded that they had symptoms for 2 consecutive days. The public health center selected high-risk inbound travelers using the information from SSC or phone consultations and interviewed 981 people. As a result, 744 people were identified as suspected patients. They were tested by PCR and seven people were confirmed to be infected with COVID-19. Table 2 shows the quick identification of high-risk symptomatic cases by SSC, which could then guide the process of the local public health center.
  The successful implementation of SSC led to the development of various systems for disease control in Korea and also motivated countries around the world to actively utilize IT for a more efficient response to COVID-19. Similar apps developed in Korea include the self-quarantine app for symptom management of individuals who have been in close contact with confirmed cases, the self-symptom management app for grade school students and kindergartners, and the smart pass app (QR code) for access to public-use facilities.

 

DISCUSSION

  To block the overseas inflow of the coronavirus amidst the pandemic, the research questions of this study were as follows: (1) Is there an efficient way of maintaining a system that enables quick contact with inbound travelers? (2) Is there a way to efficiently monitor the health of inbound travelers? (3) How can Korea’s outstanding IT infrastructure and technology be utilized?
  Symptom checking apps are widely available to users with acute or chronic conditions as an effective tool to facilitate timely care [21]. The apps have partially alleviated the burden on healthcare professionals during the COVID-19 pandemic, allowing health authorities to triage the suspected cases and support rapid testing and diagnosis [22,23]. The aim to contain the spread of COVID-19 has led to a renewed interest in chatbot-based digital self-symptom management tools, which substitute face-to-face contact and help preserve emergency monitoring & treatment capabilities [24]. Studies from Germany and the United Kingdom demonstrated that it is difficult to confirm the true and real-time status of the epidemic due to the limitations of existing data and monitoring tools. In contrast, apps help obtain on-theground surveillance data on public healthcare or quarantine and offer digital preventive methods in creating/amending healthcare policies [25].
  The COVID-19 symptom monitoring app developed in this study performs daily monitoring of inbound travelers for related symptoms, provides information on health screening stations if symptoms are reported, and guides users who were tested positive in PCR tests to treatment centers and hospitals. Korea utilized its advanced IT to implement the special entry procedure and SSC app, thereby establishing, with minimal resources, an effective disease control and prevention system for inbound travelers from high-risk areas and countries where confirmed cases are not yet being reported. The key innovation in disease control was the automation of phone consultation, which would have required significant human resources to make phone calls to check for symptoms for 14 days from arrival. More than 90% of inbound travelers installed SSC and used it for symptom management. The waiting time in the arrival hall was minimized by providing a link to download SSC in advance, and the app helped to eliminate the risk of potential infection. The app operates based on user consent, and all personal information is thoroughly encrypted and safely deleted after use. Among the inbound travelers, SSC users monitor their symptoms in quarantine facilities or from wherever if not requiring quarantine. A major advantage is that symptoms can be reported by users without making physical contact with medical professionals. The contact-free method of symptom reporting for 14 days minimizes the spread of the disease, which is transmitted through airborne particles when in close proximity with confirmed cases.
  However, statistics on SSC usage show that the installation and response rates are lower for inbound travelers admitted to quarantine facilities than those under active monitoring. This indicates that installing and using SSC are not as necessary when quarantined. In quarantine facilities, symptoms are more likely to be monitored through internal phone calls or directly by the medical staff. The less active use of the app can also be traced to quarantine facilities having well-established services and medical staff attending to the needs of patients. SSC is only successful in early screening if symptoms are shown, and it should be noted that COVID-19 has a high asymptomatic ratio. If COVID-19 infection is determined based on symptoms alone, asymptomatic cases will be overlooked. PCR tests must be performed to reduce the number of false negatives. Therefore, some individuals are quarantined during the incubation period of 14 days. SSC sensitivity is enhanced by conducting PCR tests when inbound travelers in the active monitoring group are excluded from monitoring. Recently, COVID-19-specific contact tracers and SSC have seen an increasing trend in the number of users.
  The SSC app is the first to establish mobile submission of health surveys in response to COVID-19, which is consistent with the mandated health monitoring of inbound travelers during pandemics specified in the IHR by the WHO. The smart system overcomes the limitations of existing disease control measures in two aspects. First, apps have been developed to manage the symptoms of non-communicable diseases, but SSC is the first to be introduced and successfully implemented in airports and ports for preventing the transmission of an infectious disease caused by a novel virus. Second, the burden on administrative staff was significantly reduced due to the replacement of human resources by the app and AI, and the minimized physical contact further contributed to the containment of the disease. This new approach holds great significance for public health, both in theory and practice.
  One limitation of this study can be that SSC was developed and applied only in one country. Further research is needed to determine its effectiveness in other regions and countries. A possible research topic is the quantification of disease control effects of ICT-based non-pharmaceutical approaches. Also the decrease in health personnel following the adoption of SSC is worth examining, and the scope of disease control tasks that can be handled through the integration of SSC and AI. Research on the usability of SSC is essential to enhance user receptiveness and response to the app. Follow-up studies must be performed on changes in symptoms of patients infected by SARS-CoV-2 mutations such as the Delta and Omicron variants. Considering the growing herd immunity and weakened virulence of the virus, researchers can explore whether data retrieved from SSC can be used in time-series analysis.
  Research should be conducted to establish criteria for software upgrades in the event of the release of new scientific information on infectious diseases by WHO. This is expected to improve patient identification since symptom lists are renewed according to the frequency of symptoms associated with novel infectious diseases. New insights into infectious disease management can be gained from research on the integration of vaccine passports. Breakthrough infections have been on the rise after COVID-19 vaccinations, and it will be helpful to analyze symptoms of breakthrough cases, vaccine types, and the number of vaccinations. While SSC has been designed specifically for COVID-19, additional functions can be integrated for it to be developed into a disease-agnostic platform. Voice recognition and braille input should be supported to accommodate users experiencing difficulties with general mobile phone interfaces. If the app can be expanded for use in all parts of the world while ensuring the anonymity of data, it will be an asset in the establishment of disease control policies by WHO and health authorities. This is expected to lay the foundation for the global community to overcome the public health crisis.
  New infectious diseases spread rapidly while there is limited knowledge on their underlying mechanisms, and the lack of accumulated evidence on incubation period, asymptomatic ratio, and clinical pathways make it difficult to contain such diseases using only health monitoring and PCR tests at the time of entry. SSC can significantly enhance health monitoring capacities by automating procedures and lessening the burden on health authorities, especially in the event of a pandemic.

1. Future usability and scalability of Self-Symptom Checker

  The Self-Symptom Checker can easily add symptoms to be monitored, enabling flexible and rapid non-face-to-face monitoring for new infectious diseases. The app has already proven its scalability by being applied to monitoring symptoms of not only overseas arrivals but also those admitted to domestic residential treatment centers. In addition, expanding the function of the app is expected to greatly improve the convenience of overseas arrivals as it will simplify the procedures for submitting quarantine reports and immigration reports necessary for entry.

2. Use of personal information

  There have been no side effects from using the app. In addition, personal information obtained through the use of the app is strictly managed in accordance with the Personal Information Protection Act, and is immediately destroyed when the purpose of preventing infectious diseases is achieved.

 

CONFLICT OF INTEREST

  No potential conflict of interest relevant to this article was reported.

ACKNOWLEDGMENTS

  This research was supported by Korea Evaluation Institute of Industrial Technology funded by the Ministry of Trade, Industry and Energy (grant no., 20012610).

ORCID

Sun-Ju Ahn: https://orcid.org/0000-0002-8325-2312;
Jong Duck Kim: https://orcid.org/0000-0002-8396-4491;
Jong Hyun Yoon: https://orcid.org/0000-0001-9003-4949;
Jung Ha Park: https://orcid.org/0000-0003-3448-726X