Detection Of SARS-CoV-2 In Various Clinical Specimens Of Hospitalized Latvian COVID-19 Patients

Background and Aims. Even though COVID-19 and SARS-CoV-2 infection is generally associated with respiratory symptoms, this virus is able to cause extrapulmonary manifestations, as the
expression of the cell entry receptor of SARS-CoV-2 can be detected in various tissues. We aimed to explore the detection of SARS-CoV-2 in various clinical specimens collected from hospitalized COVID-19 patients. Materials and methods Nasopharyngeal swab, peripheral blood, urine and fecal samples were collected from COVID-19 patients hospitalized at Latvian Centre of Infectious Diseases in the first few days of hospitalization. Blood plasma and peripheral blood mononuclear cells (PBMCs) were isolated. SARS-CoV-2 was detected, and the viral load determined using commercially available
quantitative real-time PCR kit. Results Overall, SARS-CoV-2 was detected in all types of clinical
specimens collected. Highest number of SARS-CoV-2 positive samples were observed among the
swab samples, closely followed by fecal samples (69.6 % and 55.1% respectively). Statistically higher
viral loads were detected in fecal samples as compared to the swabs (46204 [IQR: 5424.0-3919660.0]
vs 6004 [IQR: 468.3- 32859.0] viral copies/ml, p=0.0009). Few patients even had more than three
SARS-CoV-2 positive samples, with one harboring SARS-CoV-2 in all of the analyzed samples.
Clinical data analysis revealed this patient to have multiple chronic health problems, and that he had
deceased from COVID-19 complications. Interestingly, most of the patients harboring SARS-CoV-2 in
PBMC samples, had very low or undetectable IgG and IgM antibody titers. Conclusions SARS-CoV-2
infection seems to have an extrapulmonary distribution, as it could be detected in all of the sample
types analyzed. Clinical significance of the multiple sample SARS-CoV-2 detection remains to be
elucidated