Prolonged shedding of severe acute respiratory syndrome coronavirus 2 in patients with COVID-19

Emerg Microbes Infect. 2020 Dec;9(1):2571-2577. doi: 10.1080/22221751.2020.1852058.


Following acute infection, individuals COVID-19 may still shed SARS-CoV-2 RNA. However, limited information is available regarding the active shedding period or whether infectious virus is also shed. Here, we monitored the clinical characteristics and virological features of 38 patients with COVID-19 (long-term carriers) who recovered from the acute disease, but still shed viral RNA for over 3 months. The median carrying history of the long-term carriers was 92 days after the first admission, and the longest carrying history was 118 days. Negative-positive viral RNA-shedding fluctuations were observed. Long-term carriers were mostly elderly people with a history of mild infection. Infectious SARS-CoV-2 was isolated from the sputum, where high level viral RNA was found. All nine full-length genomes of samples obtained in March-April 2020 matched early viral clades circulating in January-February 2020, suggesting that these patients persistently carried SARS-CoV-2 and were not re-infected. IgM and IgG antibodies and neutralizing-antibody profiles were similar between long-term carriers and recovered patients with similar disease courses. In summary, although patients with COVID-19 generated neutralizing antibodies, they may still shed infectious SARS-CoV-2 for over 3 months. These data imply that patients should be monitored after discharge to control future outbreaks.

Keywords: COVID-19; SARS-CoV-2; long-term carrier; prolonged shedding; transmission risk.

MeSH terms

  • Adult
  • Aged
  • Antibodies, Neutralizing
  • Antibodies, Viral / blood
  • COVID-19 / virology*
  • Carrier State
  • Female
  • Genome, Viral
  • Humans
  • Immunoglobulin G / blood
  • Immunoglobulin M / blood
  • Male
  • Middle Aged
  • RNA, Viral / isolation & purification
  • SARS-CoV-2 / physiology*
  • Sputum / virology
  • Virus Shedding*


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

Grants and funding

This work was funded by National Science and Technology of China (grant numbers 2020YFC0861100 and 2020YFC0840900 to PZ), the Natural Science Foundation of China (excellent scholars grant numbers 81822028 and 82041013 to PZ), and the Strategic Priority Research Program of the CAS (grant number XDB29010204 to PZ).