Credited to Hong Kong. Laboratories in Germany (Drosten and colleagues) and at the US Centers for Disease Control and Prevention (Ksiazek and colleagues) identified the same coronavirus independently within weeks, and CDC guidance cites those papers. The Hong Kong group is described as the first to isolate the virus.
How it began
In early 2003 an outbreak of severe acute respiratory syndrome was reported in Hong Kong. A group led by Malik Peiris at the Department of Microbiology of the University of Hong Kong at Queen Mary Hospital, working with clinicians at Princess Margaret, Pamela Youde Nethersole Eastern, Kwong Wah and Queen Elizabeth hospitals and the Government Virus Unit, studied 50 patients from more than five separate linked clusters. In March 2003 they isolated a virus of the family Coronaviridae from two patients. Their report appeared in The Lancet dated April 19, 2003.
How it works
The team analyzed case notes, chest X-rays and laboratory tests of nasopharyngeal aspirates and blood sera. Virus from patient samples was grown in fetal rhesus kidney cells. Infected cells were then fixed and used in an immunofluorescence test to detect antibodies in patients' blood, and a reverse-transcriptase PCR test specific for the virus was built. With these two tests, 45 of the 50 SARS patients showed evidence of infection with the virus, and none of the control samples from patients with other diseases did.
How it spread
The agent was sequenced soon after it was isolated. A review of the pandemic notes that the new virus grew in Vero cells, unlike other human coronaviruses, which helped laboratories work with it. Groups in Germany and at the United States Centers for Disease Control and Prevention published their own identifications of the same coronavirus in 2003, and the CDC guidance on SARS cites those papers for the cause of the disease.
What changed first
The paper concluded that the coronavirus might be the primary agent of the disease. Its serological and molecular tests allowed a definitive laboratory diagnosis for the first time and let researchers ask whether other factors affected how the illness progressed. The clinical data also described the disease: patients aged 23 to 74, with fever, chills, muscle pain and cough, and worse outcomes among older patients and household contacts.
What lasted
The virus is now known as SARS-CoV-1. The Hong Kong work was part of the evidence that a coronavirus was the cause of the syndrome, and the approach of virus culture followed by specific antibody and PCR tests set the pattern for the laboratory diagnosis of SARS.
