RESUMEN
<p><b>OBJECTIVE</b>To understand the risk factors on severe acute respiratory syndrome (SARS) among their contacts and to develop effective strategy for its control.</p><p><b>METHODS</b>Available epidemiological data of SARS cases and close contacts were reviewed and analyzed by SPSS.</p><p><b>RESULTS</b>Out of the 2195 close contacts, 138 (6.3%) were diagnosed as SARS. Among colleagues and classmates of SARS patients, the infection rate was 0.36% versus 31.71% in contacts among families and hospitals, 0.77% in schools. No one was infected among 459 close contacts to SARS in the working unit.</p><p><b>CONCLUSIONS</b>Among close contacts, factors that facilitating transmission would include: time, extent, frequency and place of contact to the patients, as well as factors related to close contacts as way, time of isolation and age. One of the epidemiological characteristics was that SARS were as clustered in the family among those close contacts. It is important to control the spread of SARS through supervision on the close contacts to patients.</p>