Coronavirus Replication and Reverse Genetics
The Coronaviridae family is included in the Nidovirales order together with the Arteriviridae and Roniviridae. Possibly the first recorded coro- virus-related disease was feline infectious peritonitis in 1912. However, - til the late 1960s the coronaviruses were not recognized as pathogens - sponsible for human diseases (common cold), and it was in 2003 when - man coronaviruses (HCoVs) received worldwide attention with the em- gence of the severe and acute respiratory syndrome (SARS), produced by a coronavirus (SARS-CoV), that has infected more than 8,000 people in 32 countries, killing about 10%. The increase in research on coronaviruses soon led to the discovery of another human coronavirus (HCoV-NL63), which is prevalent in 7% of hospital patients and has been associated with bronchiolitis and, possibly, conjunctivitis. Coronaviruses have been identified in mice, rats, chickens, turkeys, pigs, dogs, cats, rabbits, horses, cows, and humans. Coronaviruses are - sociated mainly with respiratory, enteric, hepatic, and central nervous s- tem diseases. In humans and fowl, coronaviruses primarily cause upper respiratory tract infections, while porcine and bovine coronaviruses est- lish enteric infections that result in severe economic losses. HCoVs are - sponsible for 10%–20% of common colds, and have been implicated in gastroenteritis, high and low respiratory tract infections, and rare cases of encephalitis. HCoVs have also been associated with infant necrotizing - terocolitis and are tentative candidates for multiple sclerosis.