Title : Diagnostic performance of real-time PCR kits for the detection SARS-CoV-2 from fecal swab in Covid-19 patient, Rajavithi hospital, Thailand
Abstract:
Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a pandemic disease that can manifest with fever, pneumonia and /or gastrointestinal symptoms with vomiting and diarrhea. Currently, the diagnosis is based on RT-PCR technique in respiratory specimens. Nasopharyngeal swab and throat swab specimens are the gold standard routine method for detection SARS-CoV-2.
Some studies reported that the virus can persist for a long time in feces, and it has been proposed to perform SARS-CoV-2 RT-PCR testing on fecal specimen. Thus, the objective of this study was to evaluate the efficacy of real-time PCR kits to identify SARS-CoV-2 in fecal swab. A total of 41 confirmed Covid-19 patients were enrolled in this study from November 2020 to March 2021 at Rajavithi hospital. Real-time PCR results showed that 33/41 (80.48%) patients detected for SARS-CoV-2 in nasopharyngeal swab and throat swab, while 16/41 (39.02%) detected in fecal swab.
Among the 41 fecal swab samples, we found that 16 samples were detected (16/41), 22 samples were not detected (22/41) and 3 samples were invalid (3/41). Also, we compared with Realtime PCR kits (A, validated by manufacturer) and (B, used in Biomolecular lab, Rajavithi hospital). The sensitivity and positive predictive value (PPV) of real-time PCR kit (B) were 100% and 100%. These results demonstrate that real-time PCR kit was high sensitivity and it can be used for diagnosis of SARS-CoV-2 from fecal swab.
Although, we found that detection rate of SARS-CoV-2 in fecal swab was very low but sensitivity of real-time PCR kit was high. Thus, may be fecal swab could be an alternative specimen for the diagnosis of COVID-19 using Real-time PCR kit in some cases.
Keywords: COVID-19, Real-time PCR kit, SARS-COV-2, Fecal swab
