SARS transmission in Vietnam outside of the health-care setting
To evaluate the risk of transmission of SARS coronavirus outside of the health-care setting, close household and community contacts of laboratory-confirmed SARS cases were identified and followed up for clinical and laboratory evidence of SARS infection. Individual- and household-level risk factors for transmission were investigated. Nine persons with serological evidence of SARS infection were identified amongst 212 close contacts of 45 laboratory- confirmed SARS cases (secondary attack rate 4·2%, 95% CI 1·5–7). In this cohort, the average number of secondary infections caused by a single infectious case was 0·2. Two community contacts with laboratory evidence of SARS coronavirus infection had mild or sub-clinical infection, representing 3% (2/65) of Vietnamese SARS cases. There was no evidence of transmission of infection before symptom onset. Physically caring for a symptomatic laboratory-confirmed SARS case was the only independent risk factor for SARS transmission (OR 5·78, 95% CI 1·23–24·24).(Accepted May 24 2006)
(Published Online July 26 2006)
c1 Medical Epidemiologist, Communicable Disease Surveillance and Response, World Health Organization, 63 Tran Hung Dao Street, Hoan Kiem District, Hanoi, Vietnam. (Email: email@example.com)
1 on behalf of the WHO SARS Investigation Team in Vietnam. The WHO SARS Investigation Team is listed in the Appendix.