Negative Nasopharyngeal and Oropharyngeal Swabs Do Not Rule Out COVID-19
Poramed Winichakoon, Romanee Chaiwarith, Chalerm Liwsrisakun, Parichat Salee, Aree Goonna, Atikun Limsukon, Quanhathai Kaewpoowat
Abstract
C oronavirus disease 19 (COVID-19) has become the Public Health Emergency of International Concern.A diagnosis is made by the detection of a novel virus or genetically similar coronavirus by molecular assay in clinical specimens (1).Nasopharyngeal and oropharyngeal (NP/OP) samples are commonly used as a screening tool.Here, we reported a case of COVID-19 pneumonia diagnosed from bronchoalveolar lavage (BAL) fluid that initially had negative tests from NP/OP swabs.On 21 January 2020, a 28-year-old previously healthy Chinese man presented to Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand, with a 3-day history of high-grade fever and malaise.He also complained of rhinorrhea and cough, which had already resolved.He traveled from Jinzhou, China, to Chiang Mai on 15 January 2020 by trains and airplanes, with a brief transit in Wuhan, China.After his full itinerary was identified, his case was reported to the local government health agency as a patient under investigation for COVID-19.He was admitted to an airborne infection isolation room, and NP/OP swabs were obtained.