Cluster of SARS among medical students exposed to single patient, Hong Kong.
We studied transmission patterns of severe acute respiratory syndrome (SARS) among medical students exposed exclusively to the first SARS patient in the Prince of Wales Hospital in Hong Kong, before his illness was recognized. We conducted a retrospective cohort study of 66 medical students who visited the index patient's ward, including 16 students with SARS and 50 healthy students. The risk of contracting SARS was sevenfold greater among students who definitely visited the index case's cubicle than in those who did not (10/27 [41%] versus 1/20 [5%], relative risk 7.4; 95% confidence interval 1.0 to 53.3). Illness rates increased directly with proximity of exposure to the index case. However, four of eight students who were in the same cubicle, but were not within 1 m of the index case-patient, contracted SARS. Proximity to the index case-patient was associated with transmission, which is consistent with droplet spread. Transmission through fomites or small aerosols cannot be ruled out.
Wong
Tze-wai
TW
Departmentof Community and Family Medicine, The Chinese University of Hong Kong, School of Public Health, Prince of Wales Hospital, Hong Kong Special Administrative Region, People's Republic of China. twwong@cuhk.edu.hk
Lee
Chin-kei
CK
Tam
Wilson
W
Lau
Joseph Tak-fai
JT
Yu
Tak-sun
TS
Lui
Siu-fai
SF
Chan
Paul K S
PK
Li
Yuguo
Y
Bresee
Joseph S
JS
Sung
Joseph J Y
JJ
Parashar
Umesh D
UD
D000328:Adult; D000336:Aerosols; D015331:Cohort Studies; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D017758:Infectious Disease Transmission, Patient-to-Professional; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D045169:Severe Acute Respiratory Syndrome / Q000453:epidemiology* / Q000635:transmission*; D013337:Students, Medical; D014691:Ventilation
D000336:Aerosols