That flu thing Billp is always trying to talk about

[Bill Peckham]

Hat-tip Pixie at PFI via UK-Bird at FW who found the UK document that underlies the recent story about vaccinating the entire UK population with a pre-pandemic vaccine. This is a UK document but one can assume the same discussions are going on in the US. This document does not address the issue of Tamiflu resistance at all. The other thing to keep in mind is that the numbers are so much larger for the US (UK 60 million population v 300 million in US) and other than private Tamiflu stockpiles there is not any where near enough for Tamiflu prophylactic doses for family members of sick individuals.

The report makes mention of having a vaccine ready for the second wave. But if the virus has mutated once again between the first and second wave, that second wave vax will end up being just another pre-pandemic vaccine.

This is also the first time I've seen open discussion of sever travel restrictions. If it was a high case fatality rate strain then I think it is clear there would be a shut down of international travel and if the strain appeared in North America then there would be an abrupt shut down/slow down of domestic travel. I think this needs to be discussed sooner rather than later in the US in order for people to understand their vulnerability if they are traveling abroad and for families to understand the quick response they would need to get the family back together early in the alert phase - bring kids home from college, etc.. Everything depends on the Case Fatality Rate, I hope the implications of a high CFR receive the attention it deserves in US planning.



November 2007

Pandemic Influenza Scientific Advisory Group (SAG): Subgroup on Modelling

Modelling Summary

http://www.advisorybodies.doh.gov.uk/sagpf/minutes/sag-modelling-summary-nov2007.pdf

Note:

The attached document represents the consensus view of the modelling subgroup of the Pandemic Influenza Scientific Advisory Group. It is not a polished report of the group’s deliberations and conclusions. Rather it is a working document, updated after each meeting of the subgroup, to record the group’s advice in a form which can be immediately used to assist in the formulation of policy. [snip]

Excerpts:

The initial outbreak

What we know:

• If the first incipient pandemic cases are in a rural part of south east Asia, stringent social distance measures, the use of area quarantine and the implementation of a geographically based, large scale, antiviral prophylaxis policy, could contain an outbreak with up to 3 million courses of antivirals for R0 of up to about 2. Even if the strategy fails to contain the disease, it might delay its progress by around a month.

• The practicality of such measures depends on effective local planning to identify cases, provide antiviral drugs and implement quarantine and other social distance measures.

• Regardless of whether the above containment measures prove to be effective, disease surveillance will be required to estimate important disease parameters such as the (age-specific) attack and mortality rates as well as measures of disease severity and descriptions of clinical pattern. It is uncertain exactly how long it will take to derive reasonable initial estimates for these and other parameters. It seems reasonable to assume that, if the disease starts in Asia and takes 2 to 4 weeks to spread to the UK,(see section 2.2), estimates of the mortality rate will be available by the time it reaches the UK. Attack rates are difficult to estimate, so reasonable estimates for these parameters may take longer to derive.

International spread

What we know:

• Having taken 2 to 4 weeks to build up in the country of origin pandemic flu could take as little as 2 to 4 weeks to spread from Asia to the UK, with the peak of the UK epidemic following about 50 days later.

• Imposing a 90% restriction on all air travel to the UK would delay the peak of a pandemic wave by only 1 to 2 weeks. On the other hand a 99.9% travel restriction might delay a pandemic wave by 2 months.

Here are some new thoughts:

• The above delays may be important if there is a substantial seasonal effect on the transmissibility of flu. If there is, it may be possible to “buy” enough time to shift what would otherwise have been a winter outbreak to the spring (or a spring outbreak to the summer), when the lower transmissibility would result in a smaller outbreak. Although this seasonal effect is potentially significant, strong evidence for such an effect has not yet been presented.

• Assuming passengers are screened before travel for clinical symptoms, there is no additional advantage in entry screening. Even preventing those with clinical symptoms from traveling is only likely to delay the spread of the disease by 1 to 2 weeks.

Geographical spread within the UK

• Assume, for the purposes of developing intervention strategies, that the outbreak will spread throughout the UK in less than 2 weeks.

Spread among, and impact on, the UK population

• The UK case fatality rate (CFR) for previous pandemics was of the order of 0.2 to 2%. In contrast, recent estimates of the case fatality rate for H5N1 avian flu are of the order of 50%. Based on historical pandemics a ‘reasonable worst case’ for a pandemic would be a CFR of 2.5%. Even if the estimates for H5N1 avian flu are overestimates for a version of the virus adapted for efficient human to human transmission, an H5N1 pandemic would be expected to be towards the higher end of the range of historically observed CFRs.

• A pandemic with a CFR above 2.5% cannot be ruled out. {this seems obvious yet the CDC planning scenarios stop at a 2% CFR}

• For previous pandemics, the overall clinical attack rate (cumulative across all waves) has been of the order of 25 to 35% in the UK. A reasonable upper bound for the cumulative clinical attack rate would appear to be 50%. The worst case scenario would be a single wave pandemic with a clinical attack rate of 50%. The proportion of the population infected would be higher:estimates of the proportion of infected individuals who go on to become clinical cases range from 50 to 67%.

• If pandemic flu were to reach the UK, the main intervention would be the treatment of clinical cases with antiviral drugs. However, antiviral prophylaxis of the household contacts of these cases could have a more marked impact on the disease. Such household prophylaxis would be more effective in mitigating and delaying the progress of the epidemic but this would require an anti-viral stockpile of at least twice the size currently available.

• Prior vaccination with a poorly matched (pre-pandemic) vaccine and antibiotic treatment of those with complications would also be important in controlling the overall impact on hospitalizations and deaths.

• Stockpiling enough antivirals to treat 75% (rather than 25%) of the UK population would allow the above antiviral intervention to be augmented to one involving both treatment of all cases and prophylaxis of their household contacts. Combining this augmented antiviral intervention with vaccination of 100% (rather than 40%) of the population, together with the use of antibiotic drugs for complications, could be sufficient to limit the number of cases, hospitalizations and deaths to the levels of the targeted strategy (when fully effective) even if one component intervention is ineffective. (The US numbers are antivirals stockpiled to treat 50 million - trying for 76 million - and no antiviral stockpile for prophylactic doses)

• In addition to the medical countermeasures of vaccine, antivirals and antibiotics, various social distance measures might be used to reduce interpersonal contacts and hence the progress and extent of the epidemic. Two such measures are school closures and restrictions on mass gatherings.

• The impact of closing schools, especially without any antiviral intervention, depends critically on the mixing between children and adults. Different plausible models give results suggesting between a 10% and 30% reduction in peak. In either case the reduction in the total number of cases is the range of 10%. Most of this reduction (in the total number of cases) would be in school age children, where the reduction in the number of clinical cases might be as high as 50%. School closure is therefore most usefully employed if children are particularly badly affected.

• Closing schools as an adjunct to antiviral treatment, might reduce the peak of the epidemic by an additional 10% (e.g. taking the most optimistic case, from a 30% reduction in the peak to 40%). The total number of clinical cases might also be reduced by 10%. Again most of this reduction would be in school age children, where the reduction in the number of clinical cases might be as high as 50%.

• Little direct evidence is available on the effects of canceling large public events. However, the results might be expected to be similar to those for closing schools, albeit on a considerably more limited scale. Some benefit might be expected for those who attend the events but very little for the overall community.

• The estimated impact of antiviral treatment and household prophylaxis assumes treatment within 24 hours of the first symptoms and that those with clinical symptoms are treated at home. Greater delay or the greater mixing of those with clinical symptoms will reduce the impact of any antiviral policy.

• Absenteeism directly due to illness would be expected to peak at between 15-17% for two to three weeks at the height of the epidemic. This corresponds to a 50% attack rate but employers should be advised to plan to this rate to take account of local geographical and temporal variation.

• For a typical organization additional absenteeism due to those who need to stay at home to look after ill children might increase absenteeism from 15-17% to 20%. (This seems odd - the CDC planning scenario assumes 40 - 50% absenteeism because of those caring for the sick, watching kids home from school and raw fear. If it was a high CFR then I'm not sure what level of absenteeism we'd see but it'd be above 50% for long stretches)

Policy questions:

• How would the response change for an extreme pandemic (i.e. with a CFR above the historical range i.e. up to 2.5%) (first time I've seen a .gov document asking the question. No answers or further discussion but at least they're acknowledging the scenario)

The second wave

What we know:

• Some supplies of vaccine specific to the pandemic virus may be available for a second or third wave of a pandemic - if they arise. Of the three pandemics of the 20th Century only that of 1918/19 generally produced second waves and thus in only one of these pandemics would a specific vaccine be of value in controlling the pandemic. (The second wave of1968/9 in the UK was a special case.)

• It is expected that vaccine will start to become available approximately 4-6 months after the start of the pandemic. Even if there is time to produce some vaccine before the start of the second wave, there may not be time to produce a large amount of vaccine, which may take an additional 10-12 months.

• The impact of vaccination with a pandemic-specific vaccine, if it were available, is entirely dependent on the timing and size of any second and subsequent waves in relation to the fist wave and hence inherently difficult to estimate.

• If strategies controlling the epidemic are successful (i.e. complete coverage with pre-pandemic vaccine coupled with household prophylaxis) widespread vaccination with the pandemic specific vaccine will be necessary to provide sufficient population immunity to allow suspension of antiviral interventions.

Annex 1: Advised planning assumptions

Up to 50% of the population ill (with serological rates up to 80-85%). Of which, from 10% up to 25% are expected to have complications, half of these bateriological. (With possibly as little a 35% overlap between the ‘at risk groups’ and those who actually get complications.)

Peak illness rates of 10 - 12% (in new cases per week - of the population) in the peak fortnight.

Absences rates for illness reach 15-20% in the peak weeks (at a 50% overall attack rate, assuming an average 7 working day absence for those without complications, 10 for those with, and some allowance for those at home caring for children.)

Case hospitalization demand rates in the range 0.55% to 4% with an average six day length of stay.

- but, of which 25% would, if the capacity existed, require intensive care for 10 days.

Case fatality rates in the range 0.4% to 2.5%.

[kitkatz]

I bet the committees on this go on forever and nothing has been done to prepare for the worst scenario.  Probably a lot like herding cats.

[Bill Peckham]

Govt to double stockpile of flu drugs
Web posted at: 11/25/2007 4:50:17
Source ::: THE TIMES
LONDON • The emergency stockpile of flu drugs will be doubled in Britain so that half of the population is covered in the event of a pandemic, Alan Johnson, the Health Secretary, announced yesterday.

An extra 15m doses of Tamiflu, an antiviral drug that is the main defence against a pandemic, will be ordered at an anticipated cost of about £150m, after ministers accepted that supplies are too low to ensure that the maximum number of lives are saved.

The new pandemic plan, details of which were first revealed by The Times, will allow the government to give the drug preventively to families of infected people, which according to scientists is the best way to contain the virus. The existing stockpile, which has 14.6m doses, is sufficient only for treating patients. Britain will now have comparable stockpiles to France and Australia and double the stores held by Germany and the United States.

snip

http://www.timesonline.co.uk/tol/news/uk/article2924970.ece

(ht JWB at PFI)

[Bill Peckham]

I bet the committees on this go on forever and nothing has been done to prepare for the worst scenario.  Probably a lot like herding cats.

Much will depend on the particulars of the virus but that will be the same everywhere. It will really depend on your zip code and the preparation of yourself and your neighbors. And luck.

[okarol]

My husband said we should try to get some Tamiflu. However, it used to be available by prescription, but so many restrictions have been put on it that it may be impossible to get now. Last year they limited which pharmacies could sell it and who could purchase it, not sure if those rules are still in effect.

And now there's this:

FDA: Flu Drugs Affecting Kids' Behavior
FDA Wants Warnings About Possible Bizarre Behavior in Kids That Get 2 Widely Used Flu Drugs
The Associated Press

 WASHINGTON Nov 24, 2007 (AP)

Government health regulators recommended adding label precautions about neurological problems seen in children who have taken flu drugs made by Roche and GlaxoSmithKline.

The Food and Drug Administration on Friday released its safety review of Roche's Tamiflu and Glaxo's Relenza. Next week, an outside group of pediatric experts is scheduled to review the safety of several such drugs when used in children.

FDA began reviewing Tamiflu's safety in 2005 after receiving reports of children experiencing neurological problems, including hallucinations and convulsions.

Twenty-five patients under age 21 have died while taking the drug, most of them in Japan. Five deaths resulted from children "falling from windows or balconies or running into traffic."

There have been no child deaths connected with Relenza, but regulators said children taking the drug have shown similar neurological problems.

While FDA said it isn't clear whether the problems are directly related to the drugs, it recommends adding language about the possible side effects to labeling for physicians who prescribe Tamiflu and Relenza.

Besides being a drug side effect, the agency said the behaviors alternately could result from an unusual strain of flu or a rare genetic reaction to the drug.

Company representatives were not immediately available for comment.

http://abcnews.go.com/Health/wireStory?id=3907721

[Bill Peckham]

I think Tamiflu is much more widely used in Japan than in any other country - my understanding is that it is used prophylacticly to prevent/treat seasonal flu so I'm not sure how significant a contraindication these reports represent.  In the event of an event I'd want to have Tamiflu available, which means I will have to get it now. I'll see if I can get it through normal channels in December.

Tamiflu is just one of many items you'd want to have on hand - over the counter flu remedies and symptom relievers will also be in short supply.

[okarol]

I have thought about the recent swine flu news - especially because we are in California and there have been a couple cases (although not fatal, thankfully.) Immunosuppressed and dialysis patients are particularly at risk, and while I am not panicking unnecessarily, I am trying to learn more. Avoiding crowds is all I have heard so far, but beyond that there is no preventative measures offered. Hopefully it will run it's course.
Here is a pretty good overview about Swine Flu http://www.webmd.com/cold-and-flu/news/20090421/swine-flu-faq - it does say that the flu is sensitive to Tamiflu, (but as mentioned before, there can be side affects.)
Bill - were you ever able to get some Tamiflu?

[G-Ma]

I just read about the swine flu and did not know that it's a mixture of swine, bird and human virus which is not a good thing...Tamiful seems to one of few meds working but even that supply is short when you look at the number of people in Mexico Ciity that may need it before it comes further into the US..if it does...hopefully not.  Just my thought.

[okarol]

From Bill's blog:


April 24, 2009
Dialysis unit preparedness for novel influenza strains: Are we ready for Swine Flu?

Bill Peckham

The CDC is reporting 8 cases of influenza in San Diego and Texas and the New York Times is reporting swine flu concerns in Queens NY. This is worrisome news because this strain of influenza is novel. Novel means that no one has prior immunity to this strain of H1N1 influenza because it's new. Since it's new it has the potential to get more people sick then would normally get sick in the flu season which in the Northern Hemisphere is from about November to March, but you can get the flu throughout the year and a novel strain can spread rapidly often in waves.

Pandemonium2 I've written 32 posts categorized "Pandemic" as it relates to dialysis. I've tried to engage at various planning levels - that's me biting my lip behind the guy talking (page three at this PDF link) at a county planning exercise last year. I've been thinking about this for a while (my first pandemic post was almost exactly three years ago) mostly in regard to the H5N1 "bird flu" influenza virus. I don't think we are as prepared as we should be for an influenza pandemic no matter which flavor.

The experts always said that the next pandemic could be any type of influenza the only requirement is for there to be a new genetic form of influenza that passes easily among humans. The H1N1 cases in the US reported to date have not caused any death (deaths have been reported in Mexico but at this point things are not at all certain) so let's hope that what's know as the Case Fatality Rate is very low. The CDC considers a pandemic to be be severe if the CFR is 2%. This will be an important number to watch.

I'll need to go back and read some of my past posts but generally this is a big deal and we can hope that it is just a wake up call and not the event we've been fearing.

http://www.billpeckham.com/from_the_sharp_end_of_the/2009/04/dialysis-unit-preparedness-for-novel-influenza-strains.html

[RightSide]

According to medical history, there have been an average of three pandemics per century.  In the 20th century, we had pandemics in 1918, 1957, and 1968, each caused by a major antigenic shift like we're worrying about now.  (As a teenager, I got caught by the 1968 Hong Kong flu.  It was nasty.  I survived it, but 35,000 other Americans didn't.)

Since the last pandemic, we've been lucky for 41 years--but our luck can't hold forever.

As regards in-center hemodialysis, a simple safety precaution is for everyone in the center--EVERYONE--to wear masks as long as they are there.  Doctors, nurses, techs, patients, everybody.   I'm sure that most hospitals will implement similar precautions.

But we're hardly the only ones at risk.  There have already been cases where one flu sufferer traveling on an airliner infected most of the others on board.  If a severe pandemic strikes, and you're a frequent flier, good luck to you.

[Wallyz]

Yeah- once its pandemic stage the best  strategy is isolation with mask, hand washing, etc.
I think the Mexican governemtn is doing pretty well, trying to hit the center of the pandemic with Tamaflu, and trying to isolate people.  I know that if the epicenter was America, people would be both panicking , suing to be let out of isolation and demading that tamaflu be distributed on a lottery system, with a healthy black market.

[Bill Peckham]

We need to watch what happens in the next few days. The containment strategy is no longer in play - the spread is too advanced if it is in NYNY and Kansas and Ottawa, on and on. We should expect a steady stream of case reports, the incubation period seems to be towards the short end of the scale so the next few days will be very telling.

There are two key numbers we need to know
 RO: how many people each person infects. If RO is less than 1 then the transmission chain peters out; if RO is 2 or higher the numbers will balloon.
 The case fatality rate. I assume the low CFR in the US is due to the availability of Tamiflu. There isn't that much Tamiflu stockpiled, and what is stockpiled is single use stockpiles, I don't know of anyone with 400 doses to last the entire PanFlu year.

And that is the problem for dialysis - if it is a pandemic then we are in for a Panflu year and waves of illness. The vulnerability of incenter dialyzors is the issue of being regularly in a room full of people for hours at a time - surgical masks protect others from you, they do not protect you from others. You'd need N-95 or better masks to protect yourself from others. Other than me does anyone have hundreds of N-95 masks stockpiled? And the larger issue for dialyzors is our huge supply needs and resource consumption. Just where exactly do you think people on dialysis rank on community planing priorities? http://www.billpeckham.com/from_the_sharp_end_of_the/2008/05/where-does-dial.html

Right now I am not so worried about next week as I am about next November. But I am considering starting a resource conservation strategy. I'll make my decision tomorrow.

[Bill Peckham]

I have thought about the recent swine flu news - especially because we are in California and there have been a couple cases (although not fatal, thankfully.) Immunosuppressed and dialysis patients are particularly at risk, and while I am not panicking unnecessarily, I am trying to learn more. Avoiding crowds is all I have heard so far, but beyond that there is no preventative measures offered. Hopefully it will run it's course.
Here is a pretty good overview about Swine Flu http://www.webmd.com/cold-and-flu/news/20090421/swine-flu-faq - it does say that the flu is sensitive to Tamiflu, (but as mentioned before, there can be side affects.)
Bill - were you ever able to get some Tamiflu?

My dialysis provider is planning to operate and using Tamiflu is part of that strategy.

[Bill Peckham]

I think this post, in this thread still has the sort of mitigation strategy that dialysis units must have under consideration.
http://ihatedialysis.com/forum/index.php?topic=2272.msg43535#msg43535

How would each of you answer these questions?

• If member of patient household has flu what should be done?
• If patient presents with symptoms what should be done?
• If patient is confirmed with symptoms what should be done?

[G-Ma]

Thought provoking questions Bill.  I think it's important we all think about all the what ifs.
Member of household..in my case I'm alone but can't allow my g daughter to come over every day like she wants if anyone in her house is ill..they know it just has to be this way.
If patient presents...I will talk to Dr immediately..request Tamiflue..I would think some sort of isolation at dialysis..I'm also going to question my center about this.
If symptoms confirmed I know CDC and state have to be notified and specific isolation procedures I would think.
Another point I have to look at is the fact that Saul generally goes to Mexico City, Chihuahua and the villages his family lives in either before a visit with me or during and he many times comes home ill with something the family has and then I get sick so I know there will need to be some talks about him needing to make a decisiion on who he visits or more importantly the need for him to know how this flu could affect him or me.  He had questioned thiis yesterday and I had not read a lot yet so today I'll be able to talk to him aout this, thanks to Bill and all of you.    I'm looking forward to seeing other thoughts.     

[okarol]

The Obama administration today declared a public health emergency. Here's the news story:

http://ihatedialysis.com/forum/index.php?topic=13619.0 Swine Flu Outbreak Triggers Public Health Emergency

[RightSide]

Summer pandemics can be milder, because folks are out of doors in fresh air more often, and don't spread the virus in confined areas so much.

However, in 1918, that flu pandemic hit in two waves:  First a milder one in the summer, and then the really bad virulent one in the following winter.  So even if the swine flu pandemic is contained this summer, we're not out of the woods yet.  The CDC will almost certainly include this flu strain in the flu shots to be given out this fall.  MAKE SURE YOU GET ONE!!!  A second-wave pandemic this coming winter is a real possibility.

[Bill Peckham]

The WHO Raises Alert to Phase 5; Pandemic Is Imminent
http://www.who.int/mediacentre/news/statements/2009/h1n1_20090429/en/index.html

Human to human transmission and widely spread geographically. We should expect them to raise it to level six by Friday.

Someone is going to have make a very tough call in the next couple weeks. We don't have the production capacity to make two vaccines at once.

If you make the vaccine for the H1N1 virus then you can't get out a vaccine for the seasonal flu. Something to consider is that this years seasonal flu picked up resistance to Tamiflu so we have expect that next year's strain of seasonal flu will also have Tamiflu resistance.

Do you make the seasonal vaccine or do you make a vaccine for the new H1N1 strain? I wouldn't want to be the one to make the decision.

[MandaMe1986]

The Obama administration today declared a public health emergency. Here's the news story:

http://ihatedialysis.com/forum/index.php?topic=13619.0 Swine Flu Outbreak Triggers Public Health Emergency

Bush has 9/11 when he first came into office and now Obama has this.  In a way this is giving us a chance to see what people say about Obama.  I personally feel bad for the guy, this could get out of hand very quickly.

[paul.karen]

This is a great reason to secure our borders.

Remember when people use to come to america via ellis island.  If they were sick they were turned away or quarantined.
Obamas thoughts are.  Well it is here so why secure the borders.  Is he even for real??
With that kind of logic well nuff said.

[paris]

Have you seen what the border patrol has been doing the past week or two?  If you even look like you might sneeze, you can't cross the border.   The problem is more with vacationers bringing it back.  My neice and her husband are in Mexico this week. They planned their trip months ago.  I'll  be glad when they are back.    In this age of travel, any disease will spread quickly.  100 years ago, we stayed home.  Now someone can be in Mexico, fly to France and be back in the US before he even shows signs of flu.   I just keep washing my hands a lot!!

[MandaMe1986]

I kinda agree with Obama on this one.  You know it is here, and at this point it is us spreading it.  And like Paris said it is more with people who were visiting who are bringing it back.

[jbeany]

I think Obama's line of thought was more of - securing the borders won't stop it anyhow, but will do further damage to an already bad economy.

[kitkatz]

At least our minds are off the lousy economy now.

[okarol]

Regarding face masks - as Bill has said - most surgical masks protect others from you, they do not protect you from others. You'd need N-95 or better masks to protect yourself from sick people - yesterday our local pharmacy was able to get a box of 12 for Jenna, so it isn't impossible ... yet, anyway.