April 8-10

Three research groups publish results which suggest that a novel coronavirus might be the etiologic agent of SARS (Peiris, Drosten, Ksiazek).

Using serological tests and a reverse-transcriptase polymerase chain reaction (RT-PCR) specific for the new virus, one group of researchers found that 45 out of 50 patients with SARS, but none of the controls, had evidence of infection with the virus (Peiris). Electronmicroscopic examination of cultures reveals ultrastructural features characteristic of coronaviruses. With specific diagnostic RT-PCR primers, several identical nucleotide sequences are identified in 12 patients from several locations; a finding which is consistent with a point source outbreak (Ksiazek). High concentrations of viral RNA of up to 100 million molecules per milliliter are found in sputum (Drosten).