Detection of viable SARS-CoV-2 in deep respiratory specimens despite negative nasopharyngeal SARS-CoV-2 RT-PCR: Occult COVID-19 as an unsuspected cause of pulmonary infiltrates in immunocompromised patients. (2022)

• Record Type: Journal Article
• Authors: Wee, Liang En; Tan, Jing Yuan; Ko, Karrie Kwan-Ki; Wan, Wei Yee; Lai, Deborah Chooi Mun; Oon, Lynette Lin Ean; Tan-Garcia, Alfonso; Yeong, Joe Poh Sheng; Pena, Angela Maria Takano; Lim, Tony Kiat Hon; Conceicao, Edwin Philip; Venkatachalam, Indumathi; Wijaya, Limin; Tan, Thuan Tong
• Is Part Of: IDCases. Volume 30(2022)
• Publication Date: 2022
• Subjects: SARS-CoV-2 -- COVID-19 -- Viral antigen -- Relapse -- Immunocompromise -- Rituximab -- Occult COVID-19; Communicable diseases -- Periodicals; Communicable Diseases -- Case Reports; Communicable Diseases -- Periodicals; Communicable diseases; Periodicals; 616.9
• DOI: 10.1016/j.idcr.2022.e01611
• Languages: English
• ISSNs: 2214-2509

Abstract

Abstract: Background: Prolonged shedding/relapse of COVID-19 infection has been reported, particularly in patients who received anti-CD20 agents (eg. rituximab). However, cases of occult COVID-19, in which SARS-CoV-2 persistence in lung parenchyma is diagnosed despite clearance from nasopharyngeal (NP) specimens, are uncommon. Case summary: We describe two cases of occult COVID-19 in immunocompromised patients. Both patients had received rituximab previously. Both cases initially presented as ground-glass infiltrates on lung imaging; the diagnosis was originally not suspected due to repeated demonstration of negative SARS-CoV-2 from NP specimens, and alternative etiologies were originally considered. Persistence of SARS-CoV-2 in lung parenchyma, however, was demonstrated on bronchoalveolar lavage (BAL) specimens; additionally, isolation of viable SARS-CoV-2 virus and detection of SARS-CoV-2 nucleocapsid and spike-protein antigen in lung tissue on immunohistochemistry close to 3-months from primary infection strongly suggested ongoing viral persistence and replication as a driver of the lung parenchymal changes, which resolved after antiviral treatment. Discussion: Occult COVID-19 can be a cause of unexplained ground-glass infiltrates on lung imaging; negative NP samples do not rule out SARS-CoV-2 persistence and invasive sampling must be considered. The unsuspected presence of viable virus on BAL, however, highlights that procedurists perfoming aerosol-generating-procedures during an ongoing pandemic wave must also practise appropriate infection-prevention precautions to limit potential exposure.