Mathematical assessment of Canada's pandemic influenza preparedness plan

[mixin]

Mathematical assessment of Canada's pandemic influenza preparedness plan
AB Gumel, M Nu?o, G Chowell

OBJECTIVE: The presence of the highly pathogenic avian H5N1 virus in wild bird populations in several regions of the world, together with recurrent cases of H5N1 influenza arising primarily from direct contact with poultry, have highlighted the urgent need for preparedness and coordinated global strategies to effectively combat a potential influenza pandemic. The purpose of the present study was to evaluate the Canadian pandemic influenza preparedness plan.

PATIENTS AND METHODS: A mathematical model of the transmission dynamics of influenza was used to keep track of the population according to risk of infection (low or high) and infection status (susceptible, exposed or infectious). The model was parametrized using available Canadian demographic data. The model was then used to evaluate the key components outlined in the Canadian plan.

RESULTS: The results indicated that the number of cases, mortalities and hospitalizations estimated in the Canadian plan may have been underestimated; the use of antivirals, administered therapeutically, prophylactically or both, is the most effective single intervention followed by the use of a vaccine and basic public health measures; and the combined use of pharmaceutical interventions (antivirals and vaccine) can dramatically minimize the burden of the pending influenza pandemic in Canada. Based on increasing concerns of Oseltamivir resistance (wide-scale implementation), coupled with the expected unavailability of a suitable vaccine during the early stages of a pandemic, the present study evaluated the potential impact of nonpharmaceutical interventions (NPIs) which were not emphasized in the current Canadian plan. To this end, the findings suggest that the use of NPIs can drastically reduce the burden of a pandemic in Canada.

CONCLUSIONS: A deterministic model was designed and used to assess Canada's pandemic preparedness plan. The study showed that the estimates of pandemic influenza burden given in the Canada pandemic preparedness plan may be an underestimate, and that Canada needs to adopt NPIs to complement its preparedness plan.

http://www.pulsus.com/journals/abst...964&isuKy=778&isArt=t&fromfold=Current Issue&

 

[gsgs]

Re: Mathematical assessment of Canada's pandemic influenza preparedness plan

is this good news or bad news ?
Well, PIs and NPIs can both be very effective, so I think it's
good news.

Antivirals are more effective than vaccines (in Canada)
But don't rely on Tamiflu alone because of resistance

 

[tropical]

Re: Mathematical assessment of Canada's pandemic influenza preparedness plan

"RESULTS: The results indicated that the number of cases, mortalities and hospitalizations estimated in the Canadian plan may have been underestimated ...
CONCLUSIONS: A deterministic model was designed and used to assess Canada's pandemic preparedness plan. The study showed that the estimates of pandemic influenza burden given in the Canada pandemic preparedness plan may be an underestimate, and that Canada needs to adopt NPIs to complement its preparedness plan."

From the above (study), seems bad news - because the Canada pandemic preparedness plan was build on understimated premises - which give underestimated planned measures - it must adopt the suggested changes.

 

[gsgs]

Re: Mathematical assessment of Canada's pandemic influenza preparedness plan

this "may have been" doesn't really mean much, as long
as they give no clue, how likely it is. How likely a pandemic with more
clinical cases.

Any such estimate "may have been" underestimated.
Or overestimated.

 

[tropical]

Re: Mathematical assessment of Canada's pandemic influenza preparedness plan

The actual stage is probably the usual premised 2%CFR.

We'll see if the actual bf CFR is realy 60%, or it is drasticaly deminished by (Indo) proclamed "milions" of people with bf antibodies and esigue simptoms.

 

[mixin]

Re: Mathematical assessment of Canada's pandemic influenza preparedness plan

I forgot this important part:

The Meltzer model does not include the potential impact of antivirals drugs, public health measures, or an effective vaccine. These estimates, therefore, may over-estimate the potential impact in Canada; they are provided here for planning purposes only and to raise awareness regarding potential health impacts.

So the persons who modeled the plan thought it was probably an over-estimate while those doing the mathematical assessment believe it may be an under-estimate.

 

[gsgs]

Re: Mathematical assessment of Canada's pandemic influenza preparedness plan

mild to moderate severe with no vax or anitvirals:
0.4% will die

severe with no interventions:
2% may die

 

[mixin]

Re: Mathematical assessment of Canada's pandemic influenza preparedness plan

And they assume the majority cases will occur during the first wave
leaving many with immunity for the next waves.

 

[tropical]

Re: Mathematical assessment of Canada's pandemic influenza preparedness plan

Like I said previously:
"the usual premised 2%CFR".

"For a severe pandemic with no interventions:
up to 10% may be hospitalized and 2% may die."

That would not be understimated only if the Dr. Nid. theory is right - that 50% of the populations is actualy bf infected in the afected areas.

The Canada's plan hospitalized people are only 10% - because of lack in hospital capacity in an serious event, probably.
Instead it must be much more higher.

"Individuals who recover from illness caused by the pandemic strain will be immune to further infection by that strain."

If we detract the word "that", the recovered will NOT be immune to OTHER strains evolved further from the initial (after passing so much humans, like is with seasonal flu) when the 2nd/3d wave come - it's supposed even by the WHO guideline papers.