Malik Peiris from the University of Hong Kong and colleagues studied 50 patients with SARS from five separate outbreak clusters. After identifying a new type of coronavirus from two patients, they subsequently found evidence of virus activity in 90% of the patients compared with 0% for a control group of healthy individuals or those with unrelated illnesses.
The investigators comment that the new virus is not one of the two known human coronaviruses. Nor is it exactly like any of the known animal coronaviruses. Although more genetic analysis needs to be done to be certain, Peiris believes that it may be a new virus which may have originated from animals.
He comments: "This report provides evidence that a virus in the coronavirus family is the etiological agent of SARS. However it remains possible that other viruses act as opportunistic secondary invaders to enhance the disease progression, a hypothesis that needs to be investigated further."
Ann Falsey and Edward Walsh from the University of Rochester, New York, USA, state in an accompanying Commentary: "These findings significantly strengthen the tentative aetiological association reported by other investigators who have also isolated a novel coronavirus from patients with SARS. As other pathogens, such as human metapneumovirus and Chlamydia spp, are identified in SARS patients, it will be important to use control groups to determine their role in causality or as cofactors for severe disease."
Contact:
Professor JSM Peiris, Department of Microbiology, The University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong; T) +852-2855-4888; F) +852-2855-1241; E) malik@hkucc.hku.hk or Mr. Lennon Tsang, Executive Officer, Faculty of Medicine, The University of Hong Kong, 852-2819-2857.
Dr. Ann Falsey, Rochester General Hospital, University of Rochester School of Medicine and Dentistry, Rochester, NY 1462, USA; T) +1-585-922 4055; F) +1-585-922-5380; E) Ann.Falsey@viahealth.org.
Journal
The Lancet