Airborne Transmission of SARS CoV
Recombinomics Commentary
March 25, 2005
>> In the first study completed by the Journal of Infectious Diseases, research done in Toronto showed that the SARS coronavirus was detected in the air in a patient's room during the 2003 outbreak in the city.
As well, a study done in Hong Kong shows patients in hospital bays near a SARS patient had a much higher infection rate than patients in distant bays.....
Surfaces where the virus turned up included on a TV remote control, a fridge door in the nurses' station, and on a bed table.
Researchers said that highlighted "the importance of strict adherence to infection control precautions to prevent SARS coronavirus transmission in the health-care setting."
They also concluded that severe acute respiratory syndrome is an "opportunistic airborne infection," in the same class as the common cold. <<.
The above conclusions should not come as a surprise to anyone following the SARS outbreak, who did not take reassuring press release too seriously. Clearly, SARS CoV did not. There were many examples of super-spreaders who infected dozens of people including those in rooms adjacent to 911 at the Metropole Hotel, or passengers seated on flight CA-112 from Hong Kong to Beijing on March 15, 2003.
Under the right circumstances, SARS CoV was quite infectious and the mobilization of resources to control the spread of the virus was clearly justified.
SARS CoV was controllable in part because the symptoms were quite severe and easily recognized, and the virus had a relatively long incubation period. Thus, contact tracing and isolation could effectively manage transmission chains.
Elimination of the animal reservoir in Guangzhou also helped control the re-emergence the following season, although the virus did appear to evolve via recombination into a less virulent strain.
The lessons of the SARS CoV campaign should not be lost in the battle against avian influenza. Transparency has been reduced and the spectrum of clinical presentations for H5N1 is large, which has led to major monitoring and detection shortcomings. Moreover, the incubation time for influenza is considerably shorter than SARS CoV, so control via contract tracing is a greater challenge. In addition, the animal reservoir is endemic to a very large area and not easily controlled, especially in asymptomatic birds that shed high levels of virus.
Bird flu has a markedly higher case fatality rate than SARS CoV, and today's announcement on the five person cluster in Haiphong suggests transmissibility to humans may be improving markedly.
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