kent nickell
Well-known member
I was just reading "SARS How a global epidemic was stopped" (WHO, Western Pacific Region) 2006. It seems to be an informative, well-written book authored by 34 international experts who were personally involved in the epidemic. I thought I'd mention some of the points that stood out to me.
First was the strange epidemiology of the disease characterized by superspreaders. Most SARS cases did not transmit the infection to others, but super-spreading events, loosely defined as infecting at least 20 others occured in Guangdong, Hong Kong, Beijing, an airline flight from Hong Kong to Beijing, Hanoi, Singapore, and Taiwan. The overall Ro was estimated at 3. Hospitals were sites of transmission amplification, and the main site for SARS transmission. At Scarborough Hospital in Toronto, 100 staff members fell ill, many of them seriously, forcing the hospital to close. Transmission in public buildings, schools, or open-air settings was not reported.
I found a few aspects of the SARS outbreak worrisome in relation to a possible H5N1 pandemic. First was that in SARS transmission appeared to occur only in symptomatic cases. This gave infection control procedures such as quarantine and isolation much more of a chance to work. If H5N1 turns out to be more of a 'regular influenza' we will likely see at least a few days of asymptomatic spread. Countries may have a false sense of security for how well these measures appeared to work in SARS. Also SARS appeared to spread predominanty by close contact and large droplet transmission and rarely aerosolization which appeared to occasionally be artificially induced by medical procedures.
Second was the enormous economic impact of the travel advisories. For example Hong Kong was placed on a travel advisory for about 3 months and it cost them billions of dollars in lost business leaving the city teetering on the brink of its third recession in six years. This was repeated in other countries and especially coupled with the apparent succes of infection control measures noted above could also lead to complaceny and reluctance to transparenty report cases.
Some of the other issues were also very interesting. Both the USA and UK were briefly called 'affected areas' with possible secondary cases. At one point Shanghai announced strict SARS measures, more stringent than those recommended by WHO, including a 14-day quarantine period for travelers arriving from affected areas.
Also an interesting footnote from Chapter 1 SARS Chronology when discussing the 27 imported cases to the US , "Very little information was made available about the details of the situation in the USA during the outbreak"
First was the strange epidemiology of the disease characterized by superspreaders. Most SARS cases did not transmit the infection to others, but super-spreading events, loosely defined as infecting at least 20 others occured in Guangdong, Hong Kong, Beijing, an airline flight from Hong Kong to Beijing, Hanoi, Singapore, and Taiwan. The overall Ro was estimated at 3. Hospitals were sites of transmission amplification, and the main site for SARS transmission. At Scarborough Hospital in Toronto, 100 staff members fell ill, many of them seriously, forcing the hospital to close. Transmission in public buildings, schools, or open-air settings was not reported.
I found a few aspects of the SARS outbreak worrisome in relation to a possible H5N1 pandemic. First was that in SARS transmission appeared to occur only in symptomatic cases. This gave infection control procedures such as quarantine and isolation much more of a chance to work. If H5N1 turns out to be more of a 'regular influenza' we will likely see at least a few days of asymptomatic spread. Countries may have a false sense of security for how well these measures appeared to work in SARS. Also SARS appeared to spread predominanty by close contact and large droplet transmission and rarely aerosolization which appeared to occasionally be artificially induced by medical procedures.
Second was the enormous economic impact of the travel advisories. For example Hong Kong was placed on a travel advisory for about 3 months and it cost them billions of dollars in lost business leaving the city teetering on the brink of its third recession in six years. This was repeated in other countries and especially coupled with the apparent succes of infection control measures noted above could also lead to complaceny and reluctance to transparenty report cases.
Some of the other issues were also very interesting. Both the USA and UK were briefly called 'affected areas' with possible secondary cases. At one point Shanghai announced strict SARS measures, more stringent than those recommended by WHO, including a 14-day quarantine period for travelers arriving from affected areas.
Also an interesting footnote from Chapter 1 SARS Chronology when discussing the 27 imported cases to the US , "Very little information was made available about the details of the situation in the USA during the outbreak"