SARS-CoV-2 not Detected in the Nasopharyngeal Sample but in Bronchoalveolar Lavage Fluid.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection typically relies on reverse transcription-polymerase chain reaction (RT-PCR) technology. However, there is a certain rate of missed detection of SARS-CoV-2 in nasopharyngeal samples, particularly among immunosuppressed individuals.

Methods: In this case, SARS-CoV-2 was detected in nasopharyngeal swabs and bronchoalveolar lavage fluid (BALF) using RT-PCR. Pulmonary imaging was performed using computed tomography (CT). Patient clinical data were retrieved from the Laboratory Information System (LIS).

Results: SARS-CoV-2 was negative in two nasopharyngeal tests of the patient, but was finally detected in BALF, confirming that the lung lesions were infected by SARS-CoV-2.

Conclusions: In the post-epidemic era, it is necessary to use BALF to identify SARS-CoV-2 infection in cases where other factors have been ruled out in immunosuppressed individuals with pulmonary infections, especially when the nasopharyngeal test yields a negative result.