Positive RT-PCR nasopharyngeal swab in patients recovered from COVID-19 disease: When does quarantine really end? To the Editor , We read with great interest the review by Walsh and colleagues 1 summarising the evidence on the detection pattern and viral load of SARS-CoV-2 over the course of an infection (including any asymptomatic or pre-symptomatic phase), and the duration of infectivity. Even though the authors concluded that the duration of COVID-19 infectivity remains uncertain, this is really an important issue for the international audience. In fact, most of the studies on COVID-19 primarily focused on epidemiological, clinical, biological and radiological characteristics of patients with confirmed SARS-CoV-2 infection. 2 However, only few studies addressed the importance of the follow-up of recovered patients. After the acute phase of SARS-CoV-2 epidemic infection, the Fondazione Policlinico A. Gemelli IRCSS of Rome established a post-acute care service for patients discharged from the hospital. Only the subjects who met the following WHO criteria for hospital discharge and/or discontinuation of quarantine have been admitted to the follow-up: a) subject must be fever-free without fever-reducing medications for three consecutive days; b) subject must show an improvement in any other symptoms, including reduced coughing and shortness of breath; c) at least seven days have passed since the onset of symptoms; d) in addition to these requirements, person must test negative for the SARS-CoV-2 virus twice, with the real-time reverse transcriptase-polymerase chain reaction (RT-PCR) tests for COVID-19 nucleic acid taken at least 24 h apart. If the symptom and testing conditions are met, both WHO and US Centers for Disease Control and Prevention consider the subject officially recovered from COVID-19 disease. 3 During the first week of post-acute care activity, 29 patients recovered from COVID-19 disease were recalled being assessed. 4 , 5 Even though the patients were formally considered recovered from COVID-19 disease, a new RT-PCR test was repeated at the time of post-acute care admission. This study by the Catholic University / Fondazione Policlinico Gemelli IRCCS Institutional Ethics Committee (protocol ID number: 0 0130 08/20). Of the 29 patients who repeated the nasopharyngeal swab, 6 patients (20,6%) tested positive again. All these 6 patients were exposed to the SARS-CoV-2 infection at least one month before (Fig. 1). Three were male and the mean age was 59,0 ± 15,9 years (range from 37 to 78 years). All patients had fever as the onset of the COVID-19 infection. The other most frequently observed symptoms were cough, dyspnea, fatigue and dysgeusia. One patient reported symptoms of conjunctivitis, too. The mean number of days before admission to the hospital was 8,6 ± 3,1. All patients had positive RT-PCR test results at the time of hospital admission and the antero-posterior chest radiograph showing patchy ground-glass