H1N1 Swine Flu – Basic Information

May 2, 2009

Swine Flu – Basic Information

EDU – Swine Flu – Basic Information
Credit to JJackson of Flu Trackers Team

I can see we have a lot of ‘lurkers’ – I hate that term as I think it has pejorative overtones when all it means is readers who have not signed up to comment. Many, I suspect, are relatively new to all things Pandemic flu related and will be confused by the ‘swine flu’ stories appearing in the main stream media (MSM) when up until now ‘bird flu’ has got all the ink. What follows is some background which I hope will help you in understanding this unfolding story.

All flu’s originally come from birds. There are three Types A, B & C and we are only interested in Type A here. They are simple viruses with eight strands of genetic material (RNA) which include instructions for making eleven proteins. Two of these proteins Hemagglutinin (H) & Neuraminidase (N) are used to classify flu’s. There are 16 Hs & 9 Ns giving 144 possible combinations from H1N1 to H16N9 these are called SeroTypes (also known as SubTypes). Flu mutates very rapidly and each of the RNA strands is constantly varying about a theme and these are called Strains. As mentioned, birds are the natural carriers of flu but occasionally one of these strains drifts to a point where it happens to also be capable of infecting a mammal. Normally when this happens it is due to close contact and the story goes no further and the animal is a ‘dead end host’ in that it does not spread the infection to others. On extremely rare occasions the animal does spread to other animals of the same type and if this can be sustained the virus may adapt to its new host species and stop being a bird disease and become a swine or horse or human flu. All three of these animals are now the natural hosts for their own flus. In each case the flu would have originated in birds but, now that it is fully adapted to its new host, would have difficulty transferring back to birds.

Humans have only two Serotypes of Type A seasonal flu which circulate each winter; H1N1 and H3N2. Occasionally others, like H5N1(avian), cause the odd infection in humans but transmission is not sustained. There are also infections from pigs, but again generally in people who work with pigs, and not sustained. H5N1(avian) has caused a steady trickle of human cases since 2003 and as some of these have managed to infect other people the fear was it might make further changes until it could be self-sustaining in humans starting a new pandemic. While we were aware that any non human flu could start a pandemic this was a particularly lethal strain which had shown some human adaption so got a lot of attention.

So much for the background what is happening now?
A new pandemic candidate has emerged this time it is H1N1(swine). H1N1(human) is one of the seasonal flu strains but this is a human adapted flu. There are also H1N1 strains in birds and pigs and they are each adapted to their own host species and normally stay there. Unfortunately a new strain has jumped from pigs into humans and is spreading from human to human. I will use H1N1(sw-hu) as a shorthand for this one as it is now reproducing and spreading in humans but is still genetically very swine like in character. If it gets any better at living in us it may become unstoppable and go pandemic.

What about vaccines and antivirals?

Our immune system has many parts but they can be broadly split into two categories Innate & Adaptive. The Innate system needs no prior knowledge of a pathogen, if it does not recognise it as ‘self’, it attacks – however it is generalised and less effective. The Adaptive part of the system is made up of specialised tools for attacking threats it has met before. If an unrecognised virus appears the Innate system will try and deal with it but you may become quite ill while it builds a targeted Adaptive response. If you have had the disease before then both parts come into play and you are said to have immunity – or partial immunity. In the case of flu it is fighting an evolutionary battle with our immune system and is continuously varying its surface proteins (H & N) to avoid recognition. When we vaccinate someone we are deliberately using something to make the body think it is being attacked by a particular strain so when it meets it again it has a primed Adaptive immunity. After a year flu can change so much that last years infection, or vaccination, may not be enough to protect you. Any swine or avian H1N1 are likely to be such distant cousins that even if you have just had a shot for seasonal H1N1 it probably will not help much, if at all. Unfortunately it takes several months to make reasonable amounts of flu vaccine and you need a sample of the right strain to start. If the WHO decides this H1N1(sw-hu) is going pandemic it would ask all the seasonal flu manufactures to stop production of seasonal flu vaccine and switch to H1N1(sw-hu) vaccine production.

The CDC, in the US, say that H1N1(sw-hu) is susceptible to both Tamiflu and Relenza, the main antiviral drugs, but not to the older ion blockers. Seasonal human H1N1 is largely resistant to the common Tamiflu (tablet), but still suseptible to the less common Relenza (inhaled powder). A further note is that flu has a habit of swapping genetic material with other flus if you get dual infections and this happens more easily if they are similar strains. While H1N1(seasonal) may be far enough away from H1N1(sw-hu) for the vaccine not to work it is close enough for there to be a real danger of it learning Tamiflu resistance in short order.

Achak Snowy Owl

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H1N1: WHO do not know the gravity of the pandemic

May 2, 2009

Here is a rough personnal translation from France Romandie News.

(©AFP / 02 mai 2009 19h19)

http://www.romandie.com/ats/news/090…7.yhw93yrx.asp

H1N1: WHO do not know the gravity of the pandemic.

GENEVA – WHO “do not know to wich level the H1N1 virus can be grave or mild”, said a responsable of the organisation who has estimate that the evolution of the situation in the next few days in Europe will be determinative.

“The degree of gravity is not fully establish”, declared Dr Michael Ryan, director at the WHO World Wide Network Alert and responses in a pandemic(GOARN).

World Health Organisation (WHO) declared last wednesday alert Phase 5 to emphasize that a pandemic is imminent. The maximum Level 6, that has not yet been declared describe State of Pandemic but not its gravity degree underline Dr Ryan.

The Mexican Government estimate on Friday that the virus was not as aggressive than feared and that the epidemic is in a stabilisation phase with cases count unchanged at 16 deaths in the country.

From the HQ of WHO in Geneva, Dr. Ryan has called to be prudent in the evaluation of the situation.

“When remembering the case of SARS or other epidemics, you can realise how difficult it is to, at this stage of the epidemic to make an precise estimation of the gravity of the disease provoqued by A (H1N1) he emphasized.

“I do not criticise the government of Mexico who has to face a complex situation and who was exceptionnally cooperative when we asked informations, said Dr. Ryan.

The evolution of the situation in Europe in the next few days will allow to determine the extent to wich the mutated virus has propagated in a new continent, sine qua non condition to raise the WHO pandemic alert level at the maximum 6, estimate Dr. Ryan in the press conference.
“Actually, I will reiterate that a pandemic is imminent because we see the disease spreading.

But we have not yet establish a sustain transmission (outside North America). At this stage, we should expect that level 6 be reach but we Hope it will not be he added.

Une transmission “soutenue” signifie que “la maladie se répand profondément dans une population, et pas seulement au sein d’un cercle familial”, a expliqué le Dr Ryan.

Measures taken to treat H1N1 cases among travellers getting in Europe from Mexico or the U.S. seems to have been efficient stated the Director of GOARN.

“At this moment, it would not be recommended in any ways to suggest that these events are not under our control”, he said. “I think that within the next few days will tell us” where the situation will be said Dr Ryan.
“We have no proof of a propagation in a population outside North America” he said.

(©AFP / 02 mai 2009 19h19)

http://www.romandie.com/ats/news/090…7.yhw93yrx.asp

Snowy


Pandemic Preparedness and Updates, May 2nd 2009

May 2, 2009

Pandemic Preparedness and Updates, May 2nd 2009

Doctor Fukuda of WHO statements of yesterday via Canadian Press.

TORONTO — The world may not know for quite some time how the outbreak of swine flu will play out, the scientist leading the World Health Organization’s response to the situation warned Friday. And given that the future path of the virus is unknowable and the possibilities run the gamut from fizzling out to causing a global outbreak of severe disease and death, preparing is the prudent course of action, Dr. Keiji Fukuda told The Canadian Press in an interview.

Snowy Owl’s diary

We cannot say what can happen in the future and therefore we cannot turn away from the information’s on this Public Health crisis but at the same time we must not overreact about it.

WHO has raised the level of alert from 3 to 5 in a week for good reasons. This new virus A H1N1 is complex and has we now can see it can transmit itself trough people in a sustain way (In most countries with cases now, it had spread, person to persons).

So yes the outbreak of this new virus follows the Trail that leads to a pandemic.

Nationals Governments up to now have been wise in not closing borders, viruses do not know borders, and closing them can lead quite fast to shortages of basic supplies.

After studying quite a lot the consequences of mild to worst pandemics, one can only conclude that the most important thing for society as a whole in order to reduce morbidity and mortality is to maintain a Humanitarian Governance, Civil Order, supporting the Health Care Providers and inform people how to cope efficiently in a pandemic.

Because of the bird flu threat (virus H5N1), most of governments have elaborated pandemic preparedness plan, wich is a good news for all of us.

Civil Order, unless govs make inadequate decisions is in the hands of individuals because each and one of us can make a difference.

Just by Hand washing we reduce our risk to become infected thus reducing the burden on the Health Infrastructures. It is efficient, cheap, easy to do and to teach.

Experts do not know yet how severe this outbreak will be. Many factors has to be taken into consideration in order to make a realistic statement on how severe it will be, but up to now, for the short term it looks as if it will be mild.

The swiftness of the reaction of the Mexican Government on NPI (Non Pharmaceutical Interventions), closing of schools, stopping mass gathering, etc..  seems to have help to slow down the spread. But despite this, yesterday almost a million Mexicans left Mexico city because almost everything is close and people had two choices, SIP (Sit in Place) being patient and autonomous for another five days or get out of there to get medicine, food or for other reasons. On this matter we can expect a rise of cases in a week.

We can already observe how important it is to make sure that we have a couple of week of water, non perishable food, critical medicine and make a plan if our school and Day Care centers close for a week or two. There is NOW a window of opportunity for citizens to prepare. Governments are quite prepared but what about businesses, Community groups and local Services ?

Snowy


WHO – Doctor Fukuda statements May 1st 2009

May 2, 2009

CP Exclusive: WHO says prepping for a bad pandemic has to be considered

http://www.google.com/hostednews/canadianpress/article/ALeqM5j1PQOzI0HN6NoxZzXVvpgsJvklfg

TORONTO — The world may not know for quite some time how the outbreak of swine flu will play out, the scientist leading the World Health Organization’s response to the situation warned Friday.

And given that the future path of the virus is unknowable and the possibilities run the gamut from fizzling out to causing a global outbreak of severe disease and death, preparing is the prudent course of action, Dr. Keiji Fukuda told The Canadian Press in an interview.

snip

Fukuda defended the WHO’s call to arms, saying the world cannot know at this point what this new virus has in store.

“And so if we go ahead and we spend a fair amount of time getting ready and it remains mild and not so many people die or get seriously ill from it, then we are lucky and we should just be happy,” Fukuda, the WHO’s acting assistant director general of health security and environment, said from Geneva.

“If on the other hand it turns very severe and we have simply stopped preparing and we haven’t pushed ahead with the preparations . . . that would really be the worst of all possibilities.”

“To have had an opportunity to really do something and then to have lost it and then to have a significant number of people get really sick and to die – that would really be the worst of all possibilities.”

snip

In many ways, this virus is acting like a garden variety flu – and not a very bad one at that. The problem is, there is virtually no way to gauge its future behaviour by its present actions, Fukuda said.

Influenza is notoriously unpredictable. The RNA viruses mutate continuously. Flu dogma is constantly being rewritten. People who’ve spent years studying the virus marvel at its ability to confound; this out-of-left-field emergence of a swine flu outbreak serves as a perfect example of that.

“It’s just amazing how often you are so completely taken by surprise by flu,” Fukuda said with wonder in his voice.

snip

“There’s no way we can predict it, no way we can know, even if it disappears, that it’s not going to reappear later on,” Fukuda said. “So it really takes a significant amount of time to know whether that would happen or not.”

-The virus could cause a mild pandemic.

Too little is yet known about the dynamics of flu viruses for anyone to be able to predict which of these possibilities is most likely, though given the efficiency of spread to date Fukuda thinks fizzling out is unlikely.

That uncertainty is what is driving the WHO and governments to respond with such aggression to this outbreak.

“We are trying to sound a note that the situation is serious, but there are things that you can do and we ought to do them,” Fukuda said.

“We are not trying to present an overblown picture about the dangers or anything. But you know, we are very mindful of the historical patterns in the past and the different effects in different populations and the ability of this virus just to change for reasons we don’t understand or in ways that we can’t predict.”

He said he doesn’t worry about the public seeing this as a “crying wolf” situation, should the outbreak fizzle out or cause only a mild pandemic.

“If you explain things in the right way, this situation can be understood,” he insisted.

“And so it’s really: How do we convey the situation in a way which people can understand there’s a lot of uncertainty in it, and there are definitely choices to be made about how we approach things?

“But there are also some very serious considerations that have to be taken into account. And that is one of the things that we are wrestling with to steer the right course for this.”


Comments on H1N1 from The Lancet

May 1, 2009

Comments on H1N1 from The Lancet

Swine influenza: how much of a global threat?

Free registration rquired at

http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(09)60826-6/fulltext?_eventId=login
Excerps

The public should expect further deaths from this swine influenza outbreak. The Lancet certainly expects the number of those infected to increase and the spread of infection to expand.

Therefore, all recommendations made so far should be seen as provisional.

We are passing through an unstable period in this outbreak’s evolution.

Every member of the public has a part to play in limiting the risk of a full-blown pandemic.

Vigilance, and not alarm, is needed, with readiness to self-isolate oneself at home if an influenza-like illness develops.

Such home isolation, combined with other measures of social distancing, are most likely to stop the spread of swine influenza.

These actions could buy the necessary time to boost stockpiles of antivirals and develop a vaccine against this virus, which will inevitably take months rather than weeks to prepare and distribute.

So far, the rapid responses by governments and international agencies have triggered effective mechanisms to protect the public.

But the vital role and responsibility of the individual should not be ignored.

Snowy Owl


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May 1, 2009

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