Alfred Croucher (China hand) has a very interesting article on how SARS was spread to Hong Kong from China. Some of it is speculative, but still interesting.
It is said the Index patient, a medical doctor from Guangzhou knew he had something highly infectious and got a visit to HK approved, ostensibly to attend a relative's wedding but with the real purpose of seeking expert treatment. Sadly he booked himself into the Kowloon Metropole first and actually attended the wedding before submitting himself to medical examination at the Kwongwah Hospital. His traces at the Metropole caused an extensive outbreak, as did his attendance at the wedding.
After the wedding he booked himself into the Kwongwah Hospital while warning the staff he may have a highly infectious disease. The staff there immediatly took appropriate measures and as a result no infections resulted from his stay. But Kwongwah is not by any means a specialist in infectious diseases so they arranged for the Index patient to be transferred to the Prince of Wales (POW), one of the top hospitals which specialises in infectious diseases.
At POW the staff, in their hubris, are said to have dismissed the warnings from Kwongwah and even the director examined the patient without appropriate precautions. As a result he and many other staff died while no-doubt passing on the disease to other patients.
The whole article is worth a read, particularly the discussion as to why the disease has been very easily spread in Hong Kong hospitals but not United States hospital (US hospitals have much better hygiene, and may already be taking precautions for possible germ warfare.