Lin Y.-C.Cheng C.-Y.Chen C.-P.Cheng S.-H.SUI-YUAN CHANGPO-REN HSUEH2020-06-182020-06-1820201201-9712https://scholars.lib.ntu.edu.tw/handle/123456789/503468We report the case of a patient who had travelled to Japan and who presented mild respiratory symptoms during the COVID-19 outbreak period. There was transient existence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in his oropharynx. The RNA was absent in the six respiratory specimens that were subsequently tested. An anti-SARS-CoV-2 antibody response was absent in the acute and convalescent sera. The reported case indicates that transient colonization of SARS-CoV-2 in the upper respiratory tract is possible without inciting any antibody response against the virus. ? 2020 The Author(s)[SDGs]SDG3antibody; hydroxychloroquine; immunoglobulin G; immunoglobulin M; nucleocapsid protein antibody; unclassified drug; virus RNA; virus antibody; virus RNA; adult; antibody response; Article; case report; clinical article; coronavirus disease 2019; coughing; E gene; human; leukocyte count; male; microbial colonization; oropharynx; rdrp2 gene; real time reverse transcription polymerase chain reaction; Severe acute respiratory syndrome coronavirus 2; throat culture; virus gene; Betacoronavirus; Coronavirus infection; epidemic; genetics; immunology; Japan; pandemic; respiratory system; virus pneumonia; Adult; Antibodies, Viral; Betacoronavirus; Coronavirus Infections; Disease Outbreaks; Humans; Japan; Male; Pandemics; Pneumonia, Viral; Respiratory System; RNA, Viraljournal article10.1016/j.ijid.2020.05.070324706042-s2.0-85085650481