Emerging Nidovirus Infections

Abstract

This chapter discusses emerging nidovirus infection, such as severe acute respiratory syndrome (SARS). It is well known that some animal coronaviruses (e.g., feline infectious peritonitis virus and transmissible gastroenteritis virus) cause fatal infections in their hosts. However, relatively little attention had been focused on human coronaviruses (e.g., human coronavirus 229E [HCoV-229E] and HCoVOC43) before the SARS era. This is partly explained by the fact that these human coronaviruses (and even recently identified human coronaviruses, with the exception of SARS coronavirus [SARS-CoV]) were associated primarily with mild enteric and respiratory diseases in healthy individuals. The genome of SARS-CoV is that of a typical coronavirus. The genome of coronavirus is a single, positive-stranded RNA, approximately 29.7 kb in length. The SARS outbreak highlighted the importance of multidisciplinary research and of cooperation between multiple laboratories in tackling emerging diseases. Much basic and clinical research on coronaviruses has been triggered by this outbreak. The SARS pandemic also led to the search for novel coronaviruses in humans and animals, resulting in the identification of at least two new human and several new animal coronaviruses within the last 4 years. As more and more coronaviruses that are phylogenetically distinct from classical group 1 to 3 viruses are discovered, an alternative classification system of coronaviruses will need to be considered.