Volume 5, Issue 2, December 2010
WOO, Patrick CY
Professor, Department of Microbiology, The University of Hong Kong
Coronavirus study group, International Committee for Taxonomy of Viruses
Introduction
The Coronaviridae family is classified into two subfamilies, Coronavirinae and Torovirinae. Members of the Coronavirinae subfamily are in general referred to as coronaviruses. Phenotypically, coronaviruses are enveloped viruses of 120-160 nm in diameter. Under electronmicroscopy, coronaviruses have a crown-like appearance and the name “coronavirus” is derived from the Greek word κορώνα, which means crown. Genotypically, coronaviruses are positive-sense, single-stranded RNA viruses with genome sizes of about 30 kb, the largest genome size among all RNA viruses. Traditionally, coronaviruses were classified into...