Longitudinal, virological, and serological assessment of hospitalized COVID-19 patients

J Neurovirol. 2022 Feb;28(1):113-122. doi: 10.1007/s13365-021-01029-0. Epub 2022 Jan 7.

Abstract

Here we described the virological and serological assessment of 23 COVID-19 patients hospitalized and followed up in Milan, Italy, during the first wave of COVID-19 pandemic. Nasopharyngeal (NPS), anal swabs, and blood samples were collected from 23 COVID-19 patients, at hospital admission, and periodically up to discharge, for a median time of 20 days (3-83 days). RNA was isolated and tested for SARS-CoV-2 by qRT-PCR; anti-SARS-CoV-2 IgM and IgG antibody titers were evaluated in serum samples by ELISA. SARS-CoV-2 genome was detected in the NPS swabs of the 23 patients, at the admission, and 8/19 (42.1%) were still positive at the discharge. Anal swabs were positive to SARS-CoV-2 RNA detection in 20/23 (86.9%) patients; 6/19 (31.6%) were still positive at discharge. The mean time of RNA negative conversion was 17 days (4-36 days) and 33 days (4-77 days), for NPS and anal swabs, respectively. SARS-CoV-2-RNA was detected in the blood of 6/23 (26.1%) patients. Thirteen/23 (56.5%) and 17/23 (73.9%) patients were seropositive for IgM and IgG, respectively, at the admission, and the median IgM and IgG levels significantly (p < 0.05) increased after 13 days. Although the limited cohort size, our report provides evidence that SARS-CoV-2 is shed through multiple routes, with important implications in healthcare settings.

Keywords: Anal swabs; Anti-SARS-CoV-2 antibodies; Blood; Nasopharyngeal swabs; SARS-CoV-2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Viral
  • COVID-19* / diagnosis
  • Humans
  • Immunoglobulin G
  • Immunoglobulin M
  • Pandemics
  • RNA, Viral / genetics
  • SARS-CoV-2

Substances

  • Antibodies, Viral
  • Immunoglobulin G
  • Immunoglobulin M
  • RNA, Viral