Recorded presentation

Gabriel M Leung, MD, MPH¹, Pui-Hong Chung, MBBS, MRCP², Thomas Tsang, MBBS, FHKAM², Wilina Lim, MBBS, FRCPath², Steve KK Chan, BSc¹, Patsy Chau, MStat¹, Christl A Donnelly, DSc³, Azra G Ghani, DPhil³, Christophe Fraser, DPhil³, Steven Riley, DPhil³, Neil Ferguson, PhD³, Roy M Anderson, PhD³, Yuk-lung Law, MBBS², Tina Mok, MBBS², Tonny Ng, MBBS², Alex Fu, MBBS², Pak-Yin Leung, MBBS², JS Malik Peiris, MBBS, DPhil⁴, Tai-Hing Lam, MD, MSc¹, and Anthony J Hedley, MD, FFPH¹. (1) School of Public Health, University of Hong Kong, Faculty of Medicine Building, 21 Sassoon Road, Pokfulam, Hong Kong, +852-2819-9209, gmleung@hku.hk, (2) Hong Kong Department of Health, Wu Chung House, Wanchai, Hong Kong, (3) Department of Infectious Disease Epidemiology, Imperial College, London, ., London, United Kingdom, (4) Department of Microbiology, University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong

Major questions about the transmissibility of SARS-CoV in the community setting and the full clinical spectrum of disease remain unanswered. During the 2003 epidemic in Hong Kong 3,107 asymptomatic close contacts of SARS cases were identified, 1,776 (57%) of whom were recalled for serological testing. Only two out of 1,068 who consented to testing (0.19%, exact 95% confidence interval 0.02-0.67%) were positive for SARS-CoV IgG antibody. The findings indicate that SARS usually manifests as a florid clinical syndrome and only rarely as a subclinical infection, and that at present wild animal species are the only significant natural reservoirs of the virus. The very low seropositivity in this high exposure group suggests that rapid identification and isolation of cases, together with effective treatment, may offer better strategies for the prevention and control of outbreaks than the development of vaccine and mass vaccination programs.

Learning Objectives:

• To recognize the critical role of serosurveys in ascertaining natural reservoirs of SARS coronovirus.
• To understand how field epidemiology and laboratory services can produce critical infection control intelligence, using SARS as an example.

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.

Recorded presentation