Novel coronavirus and severe acute respiratory syndrome

In today's Lancet, Joseph Peiris and colleagues provide strong evidence that SARS is associated with a novel coronavirus that has not been previously identified in human beings or animals, and begin the process of eliminating the many unknowns from this new syndrome (figure). The investigators used classic viral culture and serological techniques, as well as modern molecular genetic methods, to characterise and to determine the cause of the disease in 50 patients with SARS in Hong Kong. One of the strengths of their report, and an important means of establishing causality, is their analysis of specimens from control patients. None of 40 respiratory secretions from patients with other respiratory diseases contained coronavirus RNA, and none of 200 serum samples from blood donors had serum antibody to this new coronavirus. These findings significantly strengthen the tentative aetiological association reported by other investigators from the Centers for Disease Control and Prevention (CDCP) in Atlanta and from Toronto, who have also isolated a novel coronavirus from patients with SARS.2,3 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.2,4