title: Cluster of SARS among medical students exposed to single patient, Hong Kong.
abstract: 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.
authors.affiliation: 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
authors.forename: Tze-wai
authors.initials: TW
authors.lastname: Wong
authors.forename: Chin-kei
authors.initials: CK
authors.lastname: Lee
authors.forename: Wilson
authors.initials: W
authors.lastname: Tam
authors.forename: Joseph Tak-fai
authors.initials: JT
authors.lastname: Lau
authors.forename: Tak-sun
authors.initials: TS
authors.lastname: Yu
authors.forename: Siu-fai
authors.initials: SF
authors.lastname: Lui
authors.forename: Paul K S
authors.initials: PK
authors.lastname: Chan
authors.forename: Yuguo
authors.initials: Y
authors.lastname: Li
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Bresee
authors.forename: Joseph J Y
authors.initials: JJ
authors.lastname: Sung
authors.forename: Umesh D
authors.initials: UD
authors.lastname: Parashar
mesh_terms: 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
chemical_list: D000336:Aerosols