Serology of severe acute respiratory syndrome: implications for surveillance and outcome

J Infect Dis. 2004 Apr 1;189(7):1158-63. doi: 10.1086/380397. Epub 2004 Mar 16.


Background: Severe acute respiratory syndrome (SARS) is a novel infectious disease. No information is currently available on host-specific immunity against the SARS coronavirus (CoV), and detailed characteristics of the epidemiology of SARS CoV infection have not been identified.

Methods: ELISA was used to detect antibody to SARS CoV. Reverse-transcriptase polymerase chain reaction was used to detect SARS CoV RNA. T cells in peripheral blood of patients were quantified by flow cytometry.

Results: Of 36 patients with probable SARS CoV infection, 30 (83.3%) were positive for IgG antibody to SARS CoV; in contrast, only 3 of 48 patients with suspected SARS CoV infection, 0 of 112 patients with fever but without SARS, and 0 of 96 healthy control individuals were positive for it. IgG antibody to SARS CoV was first detected between day 5 and day 47 after onset of illness (mean +/- SD, 18.7+/-10.4).

Conclusion: Detection of antibody to SARS CoV is useful in the diagnosis of SARS; however, at the incubation and initial phases of the illness, serological assay is of little value, because of late seroconversion in most patients.

MeSH terms

  • Adult
  • Antibodies, Viral / blood
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Flow Cytometry
  • Humans
  • Immunoglobulin G / blood
  • Immunoglobulin G / immunology
  • Immunoglobulin M / blood
  • Immunoglobulin M / immunology
  • Immunophenotyping
  • Male
  • RNA, Viral / blood
  • Reverse Transcriptase Polymerase Chain Reaction
  • SARS Virus / genetics
  • SARS Virus / immunology
  • SARS Virus / isolation & purification*
  • Severe Acute Respiratory Syndrome / immunology*


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