Comments on: The End of Pandemic Severity http://72.10.34.174/vss/2009/05/the-end-of-pandemic-severity/ An ARC Collaboration Thu, 20 May 2010 03:21:29 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: Lyle Fearnley http://72.10.34.174/vss/2009/05/the-end-of-pandemic-severity/comment-page-1/#comment-39875 Lyle Fearnley Sat, 16 May 2009 02:03:00 +0000 http://anthropos-lab.net/vss/?p=433#comment-39875 Very interesting. In addition, transmissibility itself cannot be reduced to a property of the virus. I have been following this in the case of SARS epidemiology and the problem of 'superspreaders', that is, unevenly distributed individuals with exceptionally large number of transmitted infections, which threatens the possibility of calculating a meaningful Ro. There is not a consensus on whether superspreading is the result of a peculiarity of the SARS virus alone, or, more likely, a combination of viral properties and patterns of sociability and immunity. So it would be interesting to see WHO move towards a concept of 'zones of virulence' incorporating properties of the virus, patterns of sociability, immunity (the concept of which could also be complicated to include extra-biological factors) and governmental capacity (i.e. capacity to impose isolation, capacity to provide ventilators, re: Andy's last post) in the mapping of a differential severity. Very interesting. In addition, transmissibility itself cannot be reduced to a property of the virus. I have been following this in the case of SARS epidemiology and the problem of ‘superspreaders’, that is, unevenly distributed individuals with exceptionally large number of transmitted infections, which threatens the possibility of calculating a meaningful Ro. There is not a consensus on whether superspreading is the result of a peculiarity of the SARS virus alone, or, more likely, a combination of viral properties and patterns of sociability and immunity. So it would be interesting to see WHO move towards a concept of ‘zones of virulence’ incorporating properties of the virus, patterns of sociability, immunity (the concept of which could also be complicated to include extra-biological factors) and governmental capacity (i.e. capacity to impose isolation, capacity to provide ventilators, re: Andy’s last post) in the mapping of a differential severity.

]]> By: alakoff http://72.10.34.174/vss/2009/05/the-end-of-pandemic-severity/comment-page-1/#comment-39818 alakoff Thu, 14 May 2009 15:35:15 +0000 http://anthropos-lab.net/vss/?p=433#comment-39818 Note, in the story below, that the shift is from focusing on virulence alone to focusing on two other categories: "vulnerability" (of the population) and "capacity" (of country's public health system). ----- WHO foresees problems with pandemic severity index Lisa Schnirring * Staff Writer May 13, 2009 (CIDRAP News) – A World Health Organization (WHO) official today signaled that the agency is stepping back from plans to develop a way to grade pandemic severity, because its experts believe severity will vary from place to place, making the development of a severity index difficult and its use impractical. Sylvie Briand, acting director of the WHO's Global Influenza Programme, told reporters at a media briefing today that the agency's technical experts have discussed a severity index several times, and they understand that pandemic severity is a key piece of information that governments use in response planning. But even within the same country, severity can vary among regions and during different waves of illness. "Having one indicator to describe all these varieties of situations was not very helpful," Briand said. She said severity is based on three components: the virulence and transmissibility of the virus, the vulnerability of the population, and the capacity of a country to fight the disease. All three components can vary across countries and pandemic waves, Briand said. "This is why it's hard to have an index." The WHO is gathering as much information as possible to help countries assess their vulnerability and fight the disease, she said. Instead of issuing a severity index, the WHO will base its guidance on a concept paper, issued on May 11, that outlines key severity issues and indicators that help countries assess their own vulnerability to the virus. In the May 11 statement about severity, the WHO said the novel H1N1 influenza virus seems to be more contagious than seasonal flu, but typically causes "very mild illness" in otherwise healthy people. The statement also said that most people, with the possible exception of older groups, are likely to have little or no immunity to the virus. Briand repeated that the WHO pandemic alert phases refer to geographic spread and transmission patterns, but not severity. The WHO will continue to look at severity assessment. "In terms of linking, necessarily, phases with severity, let's see if it's useful, but it's probably not so useful," she said. Note, in the story below, that the shift is from focusing on virulence alone to focusing on two other categories: “vulnerability” (of the population) and “capacity” (of country’s public health system).

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WHO foresees problems with pandemic severity index

Lisa Schnirring * Staff Writer

May 13, 2009 (CIDRAP News) – A World Health Organization (WHO) official today signaled that the agency is stepping back from plans to develop a way to grade pandemic severity, because its experts believe severity will vary from place to place, making the development of a severity index difficult and its use impractical.

Sylvie Briand, acting director of the WHO’s Global Influenza Programme, told reporters at a media briefing today that the agency’s technical experts have discussed a severity index several times, and they understand that pandemic severity is a key piece of information that governments use in response planning. But even within the same country, severity can vary among regions and during different waves of illness.

“Having one indicator to describe all these varieties of situations was not very helpful,” Briand said.

She said severity is based on three components: the virulence and transmissibility of the virus, the vulnerability of the population, and the capacity of a country to fight the disease. All three components can vary across countries and pandemic waves, Briand said. “This is why it’s hard to have an index.”

The WHO is gathering as much information as possible to help countries assess their vulnerability and fight the disease, she said. Instead of issuing a severity index, the WHO will base its guidance on a concept paper, issued on May 11, that outlines key severity issues and indicators that help countries assess their own vulnerability to the virus.

In the May 11 statement about severity, the WHO said the novel H1N1 influenza virus seems to be more contagious than seasonal flu, but typically causes “very mild illness” in otherwise healthy people. The statement also said that most people, with the possible exception of older groups, are likely to have little or no immunity to the virus.

Briand repeated that the WHO pandemic alert phases refer to geographic spread and transmission patterns, but not severity. The WHO will continue to look at severity assessment. “In terms of linking, necessarily, phases with severity, let’s see if it’s useful, but it’s probably not so useful,” she said.

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