THE SARS outbreak last year was not the first time the virus has infected humans. Virologists at Hong Kong University looked at 1000 blood samples taken in 2001, more than a year before the first known cases. Around 2 per cent contained antibodies to the SARS virus, they report online in Emerging Infectious Diseases (vol 10). But the antibodies reacted more strongly with SARS-like coronaviruses from animals than with the virus that caused last year’s outbreaks.
Around 40 per cent of animal traders in Guangdong food markets also have antibodies to the virus. Different strains of the animal virus…
