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**JJackson** · August 26, 2006, 09:57 AM

Re: Real-time epidemic forecasting for pandemic influenza

The above graph (taken from the UK pandemic plan) shows an amplitude & duration composite from the three 2000th century pandemics.

**Mingus** · August 26, 2006, 10:21 AM

Re: Real-time epidemic forecasting for pandemic influenza

So from the 1st case reported in UK to the last... 4 month are expected ?
and 1 month to the medical autority to realise the situation is out of control ?

This is for one single wave ? many question

**JJackson** · August 26, 2006, 11:29 AM

Re: Real-time epidemic forecasting for pandemic influenza

Yes an average wave profile derived from three pandemics

**MisterT** · October 13, 2006, 06:54 AM

Re: Real-time epidemic forecasting for pandemic influenza

That's pretty cool information....

It's good to know what you're in for.

**gsgs** · October 13, 2006, 08:13 AM

Re: Real-time epidemic forecasting for pandemic influenza

3 months of isolation would cut most of the risk.
But I wonder, when then isolating people (say 10% of the population)come out after 3 months, wouldn't that give another wave ,
since they are not yet immune ?
Won't you have to stay locked until you get the vaccine ?

I also remember these graphics :

Figure 1

Fig. 1. Epidemic curves as predicted by the model of Stilianakis et al. (34) for parameters characterizing interventions with oseltamivir. [For model equations and parameter values, see the SOM (35).] (A) Number of infected individuals using treatment only (red) or using prophylaxis in addition to treatment (blue) over the first 30 days of the epidemic. The gray line shows the course of the epidemic without any intervention. The solid lines depict the total number of infected individuals, whereas the dashed lines depict the number of individuals infected with resistant virus. The total number of illnesses during the 30-day period is 247, 227, or 26 in the epidemic with no intervention, with treatment, or with prophylaxis, respectively. (We assume that there is no pre-existing immunity in the population.) All symptomatic individuals receive treatment on average 1.4 days after the onset of symptoms. Prophylaxis starts at day 7. (B) Fraction of individuals infected with resistant virus under treatment (red) and prophylaxis (blue). <NOBR>[View Larger Version of this Image (118K JPEG file)]</NOBR>

**Jeremy** · October 13, 2006, 11:09 AM

Re: Real-time epidemic forecasting for pandemic influenza

I thought people might find it interesting that curve that Chikungunya followed in La Reunion was basically the same.

http://www.flutrackers.com/forum/sho...04&postcount=2

The really interesting thing about this outbreak is that it was spread through mosquitos and not direct human-to-human contact.

It appears that once certain conditions are met the curve remains the same.

**Mingus** · October 13, 2006, 11:18 AM

Re: Real-time epidemic forecasting for pandemic influenza

Originally posted by Jeremy

I thought people might find it interesting that curve that Chikungunya followed in La Reunion was basically the same.

http://www.flutrackers.com/forum/sho...04&postcount=2

The really interesting thing about this outbreak is that it was spread through mosquitos and not direct human-to-human contact.

It appears that once certain conditions are met the curve remains the same.

Very strange... It may require a moskitoe excess so it is no more limitative?

**GaudiaRay** · October 13, 2006, 11:59 AM

Re: Real-time epidemic forecasting for pandemic influenza

Originally posted by Jeremy

I thought people might find it interesting that curve that Chikungunya followed in La Reunion was basically the same.

http://www.flutrackers.com/forum/sho...04&postcount=2

The really interesting thing about this outbreak is that it was spread through mosquitos and not direct human-to-human contact.

It appears that once certain conditions are met the curve remains the same.

This thought, Jeremy, is most profound...the curve, when left untenuated, repeats, and repeats. This fact blows away the point mutation argument. It's not random, or else it would not repeat.

**GaudiaRay** · October 13, 2006, 12:14 PM

Re: Real-time epidemic forecasting for pandemic influenza

Originally posted by JJackson

[ATTACH]673[/ATTACH]

The above graph (taken from the UK pandemic plan) shows an amplitude & duration composite from the three 2000th century pandemics.

As I'm sure JJ knows but others newer here don't know, this UK Pandemic Plan chart has been in existence for at least TWO YEARS.

This chart says the pandemic will take 16 weeks. There's a 2 week starting window in which the risk of infection is low enough to get what needs to be done done. After that, the slope of the rising rate of infection is steep.

Lisa the General Practioner (an MD and an engineer) looked at this chart, and (here's where my memory fails me) with an expected 35% infection of the population, at the time window at top of this chart, for 2 weeks, there will be 21% of the population who are sickened. Yes, this is not a joke. It was stunning to see this statistic arise. In addition, those who are caretakers would be overwhelmed and taxed so that they too would leave the workforce.

As food for thought, what is not anticipated yet is that it will not be a 20% or even 40% absentee rate, but with 21% of the populace infected, there will be 40 to 60% absenteeism, simply to caretake the ill, and the rest of the folks may very well have reasons to avoid human interaction as well.

Please dwell on this chart and conjure your own expectation of its consequences.

**Laidback Al** · October 13, 2006, 12:29 PM

Re: Real-time epidemic forecasting for pandemic influenza

I would like more discussion about these epidemic curves and graphs. The graph posted by JJackson is the average wave profile of all of the waves of three 20th century pandemics.

1. So, is this the best predictor model of the duration of a potential H5N1 pandemic (at least the first wave)?

2. Can the amplitude of the graph be considered the attack rate at any given point along the time line?

From the graphs posted by gsgs, the higher the R0 (the reproduction number) the shorter the duration of the wave without any intervention. However, with intervention, the curve flattens and the duration is extended.

3. Would this mean that at any given point in time, with interventions, fewer individuals would be sick, although the overall attack rate for the pandemic would not change?

4. Rephrasing gsgs's question, Is a prepper who can self-isolate for 4 months more likely to survive a wave with a shorter duration (i.e. high R0) and no suitable interventions for any of the population? Or, once preppers comes out of hibernation, will they become infected and be the last few cases at the tail end of the curve?

5. None of these data address how many waves there might be in a future pandemic or the intensity of any individual wave, its this correct?

**hawkeye** · October 13, 2006, 12:34 PM

Re: Real-time epidemic forecasting for pandemic influenza

How will we be able to clearly identify this window?

[QUOTE name=GaudiaRay]This chart says the pandemic will take 16 weeks. There's a 2 week starting window in which the risk of infection is low enough to get what needs to be done done. After that, the slope of the rising rate of infection is steep.[/QUOTE]

**Laidback Al** · October 13, 2006, 01:16 PM

Re: Real-time epidemic forecasting for pandemic influenza

Originally posted by hawkeye

How will we be able to clearly identify this window?

Retrospectively, only.

**under the radar** · October 13, 2006, 01:24 PM

Re: Real-time epidemic forecasting for pandemic influenza

Originally posted by Mingus

So from the 1st case reported in UK to the last... 4 month are expected ?
and 1 month to the medical autority to realise the situation is out of control ?

This is for one single wave ? many question

single wave

**under the radar** · October 13, 2006, 01:56 PM

Re: Real-time epidemic forecasting for pandemic influenza

Comments in blue:

Originally posted by Laidback Al

I would like more discussion about these epidemic curves and graphs. The graph posted by JJackson is the average wave profile of all of the waves of three 20th century pandemics.

1. So, is this the best predictor model of the duration of a potential H5N1 pandemic (at least the first wave)? average duration of wave and percentage of total (for the wave) of sick people doctor visits, hospitalizations and deaths from pandemic illness for each week of wave

2. Can the amplitude of the graph be considered the attack rate at any given point along the time line? sort of. If you take the total of all the sick people, doctor visits, hospitalizations and deaths for the entire wave, and if you know the total for each week, you can determine the percent of the total. That is what the curve represents. Percentage of the total by week.

From the graphs posted by gsgs, the higher the R0 (the reproduction number) the shorter the duration of the wave without any intervention. However, with intervention, the curve flattens and the duration is extended.

3. Would this mean that at any given point in time, with interventions, fewer individuals would be sick, although the overall attack rate for the pandemic would not change? Yes, that's correct

4. Rephrasing gsgs's question, Is a prepper who can self-isolate for 4 months more likely to survive a wave with a shorter duration (i.e. high R0) and no suitable interventions for any of the population? More likely to avoid infection. Survival would depend not only on avoidance of infection, but also consequences of the magnitude (extent - based on case attack rate - and duration- based on case fatality rate) of social disruption and infrastructure collapse. Cummulatively, both during and after the pandemic. Or, once preppers comes out of hibernation, will they become infected and be the last few cases at the tail end of the curve? If a prepper comes out of SIP at the end of a wave, there is a much lower risk of infection, however there is still a risk, until the virus runs out of enough hosts, either through enough of the hosts becoming vaccinated, or enough of the hosts becoming immune.

5. None of these data address how many waves there might be in a future pandemic or the intensity of any individual wave, its this correct? True. That would really depend on the case attack rate and the case fatality rate of the virus.

#4 edited for clarification
#4 edited again for further clarification