The Spectrum of Severe Acute Respiratory Syndrome–Associated Coronavirus Infection

20 April 2004 | Volume 140 Issue 8 | Pages 614-619

Background: Whether subclinical or atypical presentations of severe acute respiratory syndrome (SARS) occur and whether clinical judgment is accurate in detecting SARS are unknown.

Objectives: To describe the spectrum of SARS coronavirus infection in a large outbreak and to compare diagnoses based on clinical judgment with the SARS coronavirus test.

Design: Secondary analysis of prospectively collected clinical data and archived serum.

Setting: A SARS screening clinic of a university hospital in the New Territories of Hong Kong.

Patients: 1221 patients attending the clinic between 12 March 2003 and 12 May 2003.

Measurements: SARS coronavirus serology.

Results: 145 of 553 (26%) patients had serologic evidence of SARS coronavirus infection. Of 910 patients who were managed without hospitalization, only 6 had serologic evidence of SARS. Five of the six patients had normal chest radiographs, and four had symptoms such as myalgia, chills, coughing, and feeling feverish. With the SARS coronavirus serologic test as the gold standard, the clinical diagnosis of probable SARS at hospitalization had a sensitivity of 0.96 (95% CI, 0.91 to 0.98) and a specificity of 0.96 (CI, 0.92 to 0.97).

Limitations: Follow-up serologic samples were not obtained from almost half of the patients because they declined further testing. Some people living in the community who were infected but who had minor or no symptoms might not have visited the clinic.

Conclusions: There is little evidence of widespread subclinical or mild forms of SARS coronavirus infection. Clinical diagnoses during the outbreak were reasonable and resulted in appropriate triaging.

Editors' Notes Context Severe acute respiratory syndrome (SARS) is a rapidly progressive pneumonia, but do some infected patients have only mild or no symptoms? Contribution A total 1100 patients had serologic tests when evaluated at a SARS clinic in Hong Kong at the time of the 2003 epidemic. Of 910 patients who were managed without hospitalization, 6 patients had serologic evidence of SARS. Five of the 6 patients had normal chest radiographs, and 4 patients had symptoms such as myalgia, chills, coughing, and feeling feverish. Cautions Although this study suggests few cases of subclinical SARS during the 2003 outbreak, patients were self-referred rather than identified through community surveillance. –The Editors

 

Author and Article Information

From The Chinese University of Hong Kong, Hong Kong.

Acknowledgments: The authors thank the staff of the Department of Accident and Emergency for their dedication during the SARS crisis and for diligently ensuring the highest possible level of data capture. They also thank their research nurse, Ms. Paulina Mak, for her tireless efforts that extended beyond her contractual commitments.

Potential Financial Conflicts of Interest: None disclosed.

Requests for Single Reprints: Timothy H. Rainer, MD, Accident and Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Rooms 107/113, Trauma and Emergency Centre, Prince of Wales Hospital, 30–32 Ngan Shing Street, Shatin, NT, Hong Kong; e-mail, rainer1091{at}cuhk.edu.hk.

Current Author Addresses: Dr. Rainer: Accident and Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Rooms 107/113, Trauma and Emergency Centre, Prince of Wales Hospital, 30–32 Ngan Shing Street, Shatin, NT, Hong Kong.

Drs. Chan, Hui, Tam, Sung, and Cameron and Ms. Ip, Mr. Lee, Mr. Smit, Mr. Wu, and Mr. Ahuja: The Chinese University of Hong Kong, Prince of Wales Hospital, 30–32 Ngan Shing Street, Shatin, NT, Hong Kong.

Author Contributions: Conception and design: T.H. Rainer, P.K.S. Chan, D. Smit, P. Cameron.

Analysis and interpretation of the data: T.H. Rainer, P.K.S. Chan, M. Ip, N. Lee, P. Cameron.

Drafting of the article: T.H. Rainer, M. Ip, N. Lee, D. Smit, A. Wu, A.T. Ahuja, J.J.Y. Sung, P. Cameron.

Critical revision of the article for important intellectual content: T.H. Rainer, N. Lee, D.S. Hui, D. Smit, A. Wu, A.T. Ahuja, J.S. Tam, J.J.Y. Sung, P. Cameron.

Final approval of the article: T.H. Rainer, M. Ip, N. Lee, D.S. Hui, D. Smit, A. Wu, A.T. Ahuja, J.S. Tam, J.J.Y. Sung, P. Cameron.

Provision of study materials or patients: T.H. Rainer, N. Lee, D. Smit, A.T. Ahuja, J.J.Y. Sung.

Statistical expertise: T.H. Rainer.

Administrative, technical, or logistic support: P.K.S. Chan, J.S. Tam.

Collection and assembly of data: T.H. Rainer, D. Smit.