Review of Human Emerging Coronaviruses and Animal Coronaviruses
Jyh-Mirn Lai1, Peck-Toung Ooi2
2010 Vol.26 NO.19
Correspondence Author： Jyh-Mirn Lai
Coronaviruses used to be considered as causing only limited and easily recovered infections. So far, three subgroups and at least 16 species of viruses have been found in its family, including the severe acute respiratory syndrome virus (SARS-CoV). Coronaviruses have the largest non-segment positive stranded RNA among all RNA viruses. It is observed as corona-like particles in diameter of about 100nm under an electron microscope. Four major structure proteins; spike, envelope, membrane and nucleocapsid proteins, are synthesized using virus replicase and proteinase. Some coronaviruses have haemagglutinin-esterase protein. Virus particles spread mainly through oral-faeces and respiratory routes. Most of coronaviruses replicate as soon as patients get infected. However, SARS-CoV only replicates after the onset of fever and this presents some difficulties in developing commercial diagnostic kits for SARS-CoV. Setting up suitable criteria for SARS infection is still a concern. Real-time polymerase chain reaction can detect the virus particle within 4 days after onset of fever and immuno-chromatography test kits can detect virus particles and associated antibodies within 10 days after onset of fever. To date, five human coronaviruses have been discovered. The major symptom of HCoV-OC42 infections is diarrhea. HCoV-229E, HCoV-HKU1 and HCoV-NL63 are associated with respiratory infections. The latest one, identified as HCo-NH, is still in argument with the relation of Kawasaki disease.