**1. Introduction**

Coronavirus Infectious Disease-19 (hereafter referred to as COVID-19), is a respiratory syndrome caused by the SARS-CoV-2 virus that began with an outbreak in Wuhan City, China, in December 2019; since then, it has spread rapidly worldwide [1,2]. In Korea, the 31st patient with COVID-19 was confirmed in Daegu City on 19 February 2020; after that, the disease spread nationwide and prompted the Korean government to raise the infectious disease crisis alert to "serious" on 23 February 2020 [1]. On 12 March, the WHO declared COVID-19 to be a pandemic [3]. COVID-19 has a high basic reproduction number (R0) of 1.9–6.5; however, ~81% of patients are asymptomatic or have mild symptoms [4]. The most common symptoms are fever, fatigue, and a dry cough, although a considerable number of patients report anosmia (loss of the sense of smell) [5].

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**Citation:** Lee, K.-M.; Ko, H.-J.; Lee, G.H.; Kim, A.-S.; Lee, D.-W. A Well-Structured Follow-Up Program is Required after Recovery from Coronavirus Disease 2019 (COVID-19); Release from Quarantine is Not the End of Treatment. *J. Clin. Med.* **2021**, *10*, 2329. https://doi.org/ 10.3390/jcm10112329

Academic Editor: Michele Roccella

Received: 2 April 2021 Accepted: 24 May 2021 Published: 26 May 2021

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**Copyright:** © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

At the time of writing, Korea has reported >70,000 confirmed cases and >100 million infections; more than 2 million deaths have been reported worldwide and the numbers continue to rise. The number of confirmed cases and the number of people released from quarantine after full recovery is also increasing rapidly [1]. According to the Center for Disease Control and Prevention, release from quarantine is allowed under the following circumstances: absence of fever without the need for antipyretic drugs; improved clinical symptoms for a minimum period of 72 h at 10 days post-onset; and two negative COVID-19 (polymerase chain reaction, (PCR)) tests with an interval of at least 24 h [1]. Since March 2020, when the number of confirmed cases in Korea increased rapidly, the number of patients that recovered began to rise; as of 29 January 2021, the number of recovered patients had reached 66,503, which was seven times that in quarantine [1].

Patients who recover from an infectious disease may experience several sequelae. For example, severe acute respiratory syndrome (SARS) was prevalent in China from 2002 to 2004, and those who recovered had significant psychological problems lasting up to three months post-discharge. Problems included a marked deterioration in quality of life, post-traumatic stress disorder, depression, and anxiety [6]. Furthermore, 44.1% of patients complained of post-traumatic stress disorder even at four months post-discharge [7]. For patients hospitalized in an intensive care unit (ICU) due to severe disease, physical quality of life functions were significantly affected [6], Similarly, ~36% of patients with Middle East Respiratory Syndrome (MERS) reported sequelae such as pulmonary fibrosis even after successful discharge [8]. Therefore, data from patients who recovered from SARS and MERS suggest that COVID-19 is highly likely to have physical or psychological sequelae; indeed, COVID-19 leads to additional health problems such as respiratory symptoms, cognitive impairment, anxiety, depressive symptoms, insomnia, denial, anger, and posttraumatic stress [9,10]. Thus, patient care with psychological support after discharge is an important factor to consider.

An unusual aspect of COVID-19 is that people released from quarantine can test positive again. In China, several such cases have been reported [11,12]. In Korea, many people tested positive for COVID-19 within a short period after viral clearance. The Central Clinical Committee regards this phenomenon as being caused by genetic material from the remaining "dead virus" rather than by a live virus [13]. However, because the period of reconfirmation after a negative virus PCR test varies from 4 to 17 days [12], and re-infection, but not re-confirmation, after recovery is possible [14], there is no question that patients need appropriate care and screening for the recurrence of symptoms, even after discharge.

However, unlike programs designed to increase diagnosis and survival rates, care programs for recovered COVID-19 patients returning to the community are insufficient. Daegu Metropolitan city and Gyeongsangbukdo province had >75% of confirmed COVID-19 cases in Korea; this is because the virus spread via some local religious groups from February to April 2020, the initial period of disease spread in Korea. As mentioned above, the number of patients released from quarantine exceeds the number of new diagnoses; therefore, the proportion of recovered patients in Daegu city and Gyeongsangbukdo province was the highest in Korea [1]. Thus, the Daegu—Gyeongsangbukdo branch of the Korean Family Medicine Association developed a follow-up health consultation program for patients that recovered from COVID-19: 20 family-medicine faculties, in co-operation with Daegu and the Daegu Medical Association, volunteered to begin providing consultations for those who agreed to participate in the program. To the best of our knowledge, this program is the first of its kind in the world. This study investigated the need for, and the results of, a well-structured follow-up program for people who recovered from COVID-19.
