Factors Associated with SARS-CoV-2 Repeat Positivity - Beijing, China, June-September 2020

Siqi Li; Xiaoli Wang; Li Li; Yang Pan; Siyuan Yang; Dawei Tan; Ying Shen; Peng Yang; Naor Bar-Zeev; Yaling Hu; Jacky M Jennings; Simin Li; Linghang Wang; Quanyi Wang

doi:10.46234/ccdcw2022.017

Factors Associated with SARS-CoV-2 Repeat Positivity - Beijing, China, June-September 2020

China CDC Wkly. 2022 Feb 4;4(5):88-95. doi: 10.46234/ccdcw2022.017.

Authors

Siqi Li^{1

2}, Xiaoli Wang^{1

3

4}, Li Li⁵, Yang Pan^{1

3

4}, Siyuan Yang⁶, Dawei Tan⁵, Ying Shen¹, Peng Yang^{1

4}, Naor Bar-Zeev², Yaling Hu⁷, Jacky M Jennings⁸, Simin Li⁹, Linghang Wang⁵, Quanyi Wang^{1

3

4}

Affiliations

¹ Beijing Center for Disease Prevention and Control, Beijing, China.
² Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
³ Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China.
⁴ School of Public Health, Capital Medical University, Beijing, China.
⁵ Emergency department of Infectious diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, China.
⁶ Laboratory of Infectious Diseases Center of Beijing Ditan Hospital, Capital Medical University, Beijing, China.
⁷ Sinovac Biotech Co, Ltd, Beijing, China.
⁸ Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, MD, USA.
⁹ Yiducloud (Beijing) Technology Co., Ltd, Beijing, China.

Abstract

Introduction: Repeat positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) following COVID-19 initial viral clearance (re-positivity) poses a public health management challenge. The objective was to determine factors associated with neutralizing antibody (Nab) level and re-positivity among patients infected with a single strain SARS-CoV-2.

Methods: During a single strain SARS-CoV-2 cluster in Beijing, China, longitudinal individual clinical, virological, and immunological data were collected from 368 infections from June 13 to September 22, 2020. Factors associated with Nab level and re-positivity were analyzed using generalized estimating equations.

Results: A total of 353 (96%) SARS-CoV-2 infections had demographic, clinical, and laboratory data available. Among the 353 infections, 55 (15.5%) were re-positive, and blood draws were taken from 346 individuals (98.0%) during hospitalization and/or during the follow-up period. Symptoms were milder for the second-time admission for the re-positives, although 36.4% of re-positives presented with radiographic appearance of pneumonia manifestation. Compared to non-re-positive patients, NAb titers were lower among re-positives; NAb was positively associated with clinical severity. Samples from the lower respiratory tract manifested higher viral load than that from the upper respiratory tract. Multivariable analysis showed re-positivity was positively associated with being female [odd ratio (OR)=1.7, 95% confidence interval (CI) 1.1-2.8] and being aged <18 years (OR=5.2, 95% CI 1.5-18.1); having initially asymptomatic infection (OR=13.7, 95% CI 1.6-116.3); and negatively associated with a higher NAb level (OR=0.9, 95% CI 0.5-1.7).

Conclusions: NAb may be important for sustained viral clearance. Lower respiratory tract infection was associated with higher viral load among all infections when compared to upper respiratory tract infection. Continuous lower respiratory and intermittent upper respiratory viral shedding among COVID-19 infections may occur.

Keywords: COVID-19; Neutralizing antibody; Repeated positivity; Viral load.

Copyright and License information: Editorial Office of CCDCW, Chinese Center for Disease Control and Prevention 2022.

Grants and funding

This work was supported by the National Key Research and Development Program of China (2020YFA0707600), the National Key Research and Development Program of China (2020YFC0840800), Beijing Talent Project (2020A50) and National Key R&D Program of China (2021ZD0114103)