Molecular advances in the cell biology of SARS-CoV and current disease prevention strategies

Stark, Caren J; Atreya, CD

The virus has been isolated from wild animals (Himalayan palm civets and raccoon dogs) found in the animal markets of Guangdong, China [17] . The actual natural reservoir for SARS-CoV is still unknown. Once transmitted to humans, SARS-CoV appears to evolve to facilitate to human-human transmission. Sequence analysis of different SARS-CoV isolates from early in the epidemic show deletion events occurring in open reading frame 8 (Orf 8) [18] . Identical deletions in Orf 8 have also been seen in animal coronaviruses supporting the idea that SARS-CoV was introduced to humans via an animal intermediate. In addition to deletion events occurring early and late in the epidemic, a slowing of missense mutations is seen over time, with the most extensive changes occurring in the S protein during the early stages of the outbreak [18] . This suggests the virus has undergone some level of adaptation but has ultimately stabilized at a time in the epidemic where SARS-CoV has become more virulent. Deciphering the evolutionary passage of this virus will undoubtedly provide valuable information on preventing future outbreaks.