Animal-to-Human SARS-associated Coronavirus Transmission?

摘要

To the Editor: Martina et al.reported that domestic cats and ferretsare susceptible to infection by severeacute respiratory syndrome (SARS)–associated coronavirus (SARS-CoV)isolated from a patient infected withSARS. These infected animals couldefficiently transmit the virus to unin-fected animals housed with them (1).This finding is similar to that of SARStransmission in humans in whichSARS-CoV can be quickly spreadfrom person to person through closecontact. Ferrets and domestic cats notonly can be infected by SARS-CoV inthe laboratory, but also can shedSARS-CoV from the pharynx at 2days postinfection and continuingthrough 10 and 14 days postinfection,respectively (1). No clinical signswere observed in six cats that wereinjected with SARS-CoV, whereasthree of six ferrets that were injectedwith SARS-CoV became lethargicwithin 2 to 4 days postinfection, andone of the three ferrets died at day 4postinfection (1,2). This finding indi-cates that domestic cats may not onlybe a useful animal model for evaluat-ing candidate vaccines and drugsagainst SARS (1) but also may begood reservoirs of SARS-CoV.Domestic cats living in the AmoyGardens in Hong Kong, where >100residents contracted SARS in thespring of 2003, were infected withSARS-CoV (1,3). This fact suggeststhat domestic cats can be naturallyinfected with SARS-CoV fromhumans infected with SARS, althoughhow this SARS-CoV transmissionoccurs is unclear. Unfortunately, how-ever, the transmission capability ofthe SARS-CoV strain transmittingfrom domestic animal to human,despite the widely accepted hypothe-sis of the animal origin of SARS-CoV(4–6), cannot be ascertained. If thetransmission of SARS-CoV from ani-mal to human is as easy as that fromhumans to domestic cats, the specula-tion that the outbreak of SARS in theAmoy Garden in Hong Kong wascaused by environmental sources,such as U-traps in bathrooms contam-inated with SARS-CoV (3), weshould reevaluate, because this out-break of SARS in these apartmentsmight also be caused by infected catsor other mammalian hosts