SARS-related virus predating SARS outbreak, Hong Kong.

Using immunofluorescence and neutralization assays, we detected antibodies to human severe acute respiratory syndrome-associated coronavirus (SARS-CoV) and/or animal SARS-CoV-like virus in 17 (1.8%) of 938 adults recruited in 2001. This finding suggests that a small proportion of healthy persons in Hong Kong had been exposed to SARS-related viruses at least 2 years before the recent SARS outbreak.