In late January 2020, the Taiwanese government established a centralized quarantine center to screen and monitor COVID-19 infections in international travelers who had visited countries with a declared COVID-19 outbreak [5]. On March 30, 2020, the government of Taiwan arranged a special charter flight to evacuate Taiwanese travelers who had become stranded in Hubei, China, and return them to Taiwan. Upon arrival in Taiwan, the travelers proceeded to one of the largest national centralized quarantine centers, Taipei Yangmingshan, for the mandatory 14-day quarantine period. The Yangmingshan quarantine center included six quarantined wards on three floors.

This cohort study included all the passengers of the charter flight, who were subsequently followed up until their discharge from the quarantine center or until April 15. This study was approved by the Institutional Review Board of Taipei City Hospital (no. TCHIRB-10904014-E).

The body temperature of the Taiwanese travelers was checked at the international airport in China, and individuals with fever were not allowed to board the charter flight. All travelers were required to disinfect their hands with alcohol-based hand sanitizer at the boarding port and to wear personal protective equipment (PPE) provided by the Taiwanese government, which included a face mask and medical gown. Meals were not provided during the flight to avoid cross-infection between passengers.

Upon arrival at the international airport in Taiwan, National Defense chemical troops used a 1:10 diluted sodium hypochlorite solution (5000 ppm) to disinfect the travelers’ luggage. The travelers then proceeded to the Yangmingshan quarantine center for the 14-day quarantine period. They were required to record their body temperature twice daily with a thermometer that was provided to them. Additionally, daily meals were delivered to the individuals’ rooms, and janitors used a 1:10 diluted sodium hypochlorite solution to clean the quarantine center once daily.

During admission to the Yangmingshan centralized quarantine center, the travelers were screened for COVID-19 using a real-time reverse transcriptase–polymerase chain reaction (RT-PCR) test. If an individual tested positive for COVID-19, they were transferred to a hospital for medical isolation and treatment.

Travelers’ clinical symptoms were recorded twice daily by their primary care nurses via telephonic communication. If an individual developed fever or became ill, a multidisciplinary team (MDT) consisting of 15 medical workers used telehealth to assess the traveler’s condition.

The telehealth system at the Yangmingshan quarantine center was developed based on a popular social media app called LINE, which is a freeware app operated by the NAVER Corporation in South Korea. The LINE-based telehealth system established two-way communication between the MDT and 217 quarantined travelers. Through a unique ID, the quarantined individuals were invited to join an official LINE group in which the quarantined travelers could report their symptoms to the MDT members. When the MDT members received a message regarding a quarantined traveler’s symptoms, the MDT members initiated a one-to-one video call through LINE to clinically evaluate the patient. The MDT members collaboratively discussed the traveler’s condition during the telehealth session and provided appropriate management and treatment interventions for the traveler. If a quarantined traveler presented with fever or shortness of breath, they were transferred to the hospital for further treatment.

The personnel who were responsible for overseeing the travelers’ quarantine at the Yangmingshan quarantine center included the MDT, police officers, janitors, a logistics group, and administration staff. The MDT consisted of 3 physicians, 10 nurses, a pharmacist, and a psychologist. Three physicians, including a general practitioner, a pediatrician, and a cardiologist, gave treatment advice according to the traveler’s condition during the telehealth session. The 10 nurses were responsible for taking care of the travelers during 12-hour day and night shifts in the six quarantined wards. The nurses communicated daily with the quarantined travelers to evaluate their clinical condition and record their body temperature. The pharmacist delivered medications to ill quarantined travelers. Physicians and nurses wore PPE when examining the travelers in person.

The police officers were responsible for the security of the travelers at five sentry points and ensured that all travelers obeyed the COVID-19 quarantine rules and completed the 14-day mandatory quarantine order. In total, 18 police officers were divided into three groups, with one leader in each group. The three groups of police officers worked in 12-hour day and night shifts. Three janitors were responsible for environmental disinfection in the six quarantined wards, and one janitor was responsible for two quarantined wards on one floor. The logistics group, composed of 10 people, was responsible for meal preparation and ensuring that sufficient supplies were provided to the 217 travelers during the 14-day quarantine.

The cost of the quarantine for the travelers at the Yangmingshan quarantine center was covered by the disaster reserve of the national Ministry of Health and Welfare, which included payment of the MDT, nonmedical personnel, and telehealth services as well as the provision of PPE.

First, the participants’ demographic data were analyzed. Continuous data are presented as mean (SD), and two-sample t tests were used for comparisons between groups. Categorical data were analyzed with Pearson chi-square tests where appropriate. A P value <.05 was considered to indicate statistical significance.

A timeline infographic was used to display the progression of clinical symptoms in hospitalized travelers. The labor and overall costs of the quarantine were calculated according to the disaster reserve data from the Taiwan Ministry of Health and Welfare. All data management and analyses were performed using SPSS 19.0 (IBM Corporation).

Our sample comprised 217 Taiwanese travelers who were stranded in Hubei, China, due to the COVID-19 pandemic and who returned to Taiwan on March 30, 2020 (Figure 1). The mean age of the sample was 30.0 years (SD 19.4), and 130 of the 217 subjects (59.9%) were female. All travelers tested negative for COVID-19 by an RT-PCR throat swab upon admission to the Taipei Yangmingshan quarantine center. During the 14-day quarantine, 28 of the 217 travelers (12.9%) underwent telehealth consultations due to illness.

Table 1 shows the characteristics of quarantined travelers who were and were not evaluated with telehealth. There was no significant difference in the age or sex of the quarantined travelers who were and were not evaluated with telehealth. Three travelers had fever and underwent clinical assessment using telehealth during the 14-day quarantine period.

The symptoms and management of quarantined travelers receiving telehealth care were recorded during the 14-day mandatory quarantine (Multimedia Appendix 1). The most common symptoms requiring telehealth consultations in quarantined travelers were fever (n=3), diarrhea (n=3), toothache (n=3), and skin rashes (n=3). Of the 217 travelers, 3 (1.4%) developed fever during the 14-day quarantine period and were hospitalized after a telehealth assessment.

Of the 28 quarantined travelers evaluated with telehealth, one traveler with diabetes presented with dizziness and weakness on the fifth day and was suspected to be hypoglycemic during the telehealth clinical evaluation. The patient’s blood glucose test indicated a level of 75 mg/dl when health care workers wearing PPE visited this individual.

Figure 2 shows the progression of clinical symptoms in three hospitalized travelers. One traveler developed fever and illness 2 days after quarantine, and two additional travelers developed fever 3 days after being admitted to the centralized quarantine center. Chest x-rays of all three patients were negative for pneumonia. Moreover, a second round of SARS-CoV-2 testing by RT-PCR throat swab was negative for COVID-19 in all three individuals. They were subsequently discharged from the hospital on April 5 and returned to the Yangmingshan quarantine center to complete the mandatory quarantine.

Table 2 shows the labor and overall cost incurred during the 14-day mandatory quarantine. The major personnel consisted of police officers (n=18), followed by the MDT (n=15). Moreover, the major expense was the labor cost of the MDT (US $72,334, 37.30%), followed by police officers (US $66,427, 34.25%) and the cost of PPE (US $16,016, 8.26%). The total cost incurred during the 14-day quarantine was US $193,938, which equated to US $894 per traveler.

This cohort study reports a model for the screening and quarantining of international travelers who visited countries with a declared COVID-19 outbreak. All travelers tested negative for COVID-19 during the 14-day mandatory quarantine period. Three travelers with fever were hospitalized after the telehealth assessment, and subsequent tests for COVID-19 were negative for all three patients. The total costs during the quarantine were US $193,938, which equated to US $894 per individual. Our study demonstrates that strict infectious control measures, proactive screening, and an MDT integrated with the use of telehealth contributed to the successful quarantine of international travelers while remaining cost-effective for containing the spread of COVID-19.

Quarantine is an effective strategy to control and prevent COVID-19 outbreaks [9]. However, monitoring individuals in quarantine is essential to provide prompt management and early detection of COVID-19 cases. By establishing a line of communication between health care workers and quarantined individuals, telehealth can provide timely assessment of quarantined individuals and fast-track the hospitalization of people who develop symptoms of COVID-19. Although telehealth has not been widely adopted in monitoring COVID-19 infections in quarantined individuals, one study in China [15] used a telehealth system to monitor 188 home-quarantined individuals; it was found that 74 individuals (39.4%) were infected with SARS-CoV-2. Moreover, 6 of the 74 confirmed COVID-19 cases (8.1%) were hospitalized after the telehealth assessment [15]. Our study used telehealth to monitor COVID-19 infections in 217 international travelers during the 14-day mandatory quarantine. Three travelers with fever were hospitalized after the telehealth assessment, and subsequent tests for COVID-19 were negative for all three patients. Because telehealth can assist in providing timely assessment and does not delay hospitalization of quarantined individuals, our study suggests that it is imperative to adopt telehealth to monitor COVID-19 infections in this population.

Our report is among the first to analyze the cost-effectiveness of an enforced quarantine program. We found that the total cost of a 14-day quarantine for 217 international travelers was US $193,938, equating to US $894 per traveler. Although none of the 217 Taiwanese travelers tested positive for SARS-CoV-2 during the 14-day mandatory quarantine period, this study highlights the importance of screening and immediately quarantining returning international travelers because of the high risk of COVID-19 in this population [16]. The quarantine strategy in our report is also corroborated by a recent study [14], in which it was reported that the quarantine strategy is efficient in curbing the COVID-19 outbreak, and its relative efficacy increases when supplemented with other measures designed to reduce disease transmission.

LINE-based telehealth can provide timely assessment and care for patients who require it. During the COVID-19 surge, LINE-based telehealth could provide care for nonsevere COVID-19 cases in hospitals [13], and health care workers can provide timely assessment and management of patients with COVID-19 through the telehealth system and reduce the transmission of SARS-CoV-2 in health care facilities [11].

The present study has two limitations. First, our study did not compare the cost-effectiveness of a 14-day quarantine for high-risk COVID-19 individuals. In this cohort study, none of the 217 Taiwanese travelers tested positive for SARS-CoV-2 during the 14-day mandatory quarantine period. As SARS-CoV-2 is highly contagious [17], it is imperative to screen and quarantine travelers who have visited countries with a declared COVID-19 outbreak. Second, the external validity of our findings may be a concern because all our patients were Taiwanese. The generalizability of our results to other non-Asian ethnic groups requires further verification. However, our findings suggest new avenues for future research.

This prospective cohort study reports an enforced quarantine program integrated with a telehealth system to monitor COVID-19 infection in quarantined individuals. Telehealth not only provided timely management of quarantined individuals with illness but also reduced the risk of COVID-19 infection in health care workers. Our study suggests that it is imperative to screen and quarantine international returning travelers to reduce the nationwide spread of COVID-19.