Seroprevalence of COVID-19 in Taiwan revealed by testing anti-SARS-CoV-2 serological antibodies on 14,765 hospital patients

Hsiang Ling Ho, Fang Yu Wang, Hao Ru Lee, Ya Lan Huang, Chien Liang Lai, Wen Chin Jen, Shie Liang Hsieh, Teh Ying Chou

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


Background: Coronavirus Disease 2019 (COVID-19) has become a worldwide pandemic and affected more than 227 countries or territories, resulting in more than 25 million cases with over 0•85 million deaths, as of September 2, 2020. Taiwan has been successful in countering the COVID-19 outbreak, however, the potential risk for asymptomatic infections and the prevalence rates remain unknown. We aimed to estimate the seroprevalence of COVID-19 in Taiwan via serologically testing hospital patients with neither symptoms indicative of nor positive nucleic acid test for SARS-CoV-2 infection. Methods: Residual specimens from laboratory blood tests for outpatient and emergency department patients visiting a medical centre in Taipei, Taiwan, within one week in May and another in July, 2020, were collected. We used Elecsys Anti-SARS-CoV-2 Assay to screen and further validated cases with high cutoff index by a confirmatory ELISA assay. We also analysed antibody responses against SARS-CoV-2 along disease progression in four nucleic acid test confirmed COVID-19 patients. Findings: Blood samples from a total of 14,765 patients were tested. The unweighted seroprevalence of anti-SARS-CoV-2 antibodies was 0•07% [95% CI, 0•04%-0•13%]; after weighting with the population demographics of Taiwan, the estimated overall seroprevalence was 0•05% [95% CI, 0•02%-0•10%]. Furthermore, based on data of the four COVID-19 cases, the seroconversion dates for IgM were as early as 9 days and that for IgG 11 days after symptoms onset. Interpretation: We screened the anti-SARS-CoV-2 antibodies in a small-scale population-based study and observed an approximately 0•05% seroprevalence of COVID-19, indicating that the current containment protocols emphasising mask wearing, hand washing, social distancing and mandatory quarantine for all incomers are effective in Taiwan. Funding: Taipei Veterans General Hospital, Taipei, Taiwan.

Original languageEnglish
Article number100041
JournalThe Lancet Regional Health - Western Pacific
Publication statusPublished - Oct 2020
Externally publishedYes


  • anti-SARS-CoV-2 serological antibodies
  • COVID-19
  • Pandemic;Taiwan
  • Seroprevalence

ASJC Scopus subject areas

  • Internal Medicine
  • Pediatrics, Perinatology, and Child Health
  • Health Policy
  • Obstetrics and Gynaecology
  • Public Health, Environmental and Occupational Health
  • Geriatrics and Gerontology
  • Psychiatry and Mental health
  • Infectious Diseases


Dive into the research topics of 'Seroprevalence of COVID-19 in Taiwan revealed by testing anti-SARS-CoV-2 serological antibodies on 14,765 hospital patients'. Together they form a unique fingerprint.

Cite this