normal flu although confirmed with the new Swine flu.
Actually the normal flu is also Swine flu, i.e. H1N1. The fear of
pandemic is the Swine flu type A. It has a high rate of fatality in
Mexico, even now.
Normal flu has a fatality rate of 0.1%, 36000 in a population of 300
million. Based on my calculator it is 0.01%.
If you look at the Texas case a 2 weeks ago, there are only 40
confirmed cases but now has 2 deaths. This is 4% based on those who
had shown clear symptoms.
Even for the dangeous Spanish flu in 1918, the infection rate is only
30% so we can expect the current flu, Swine Flu type A(H1N1) to have
similar infection rate.
What it means is that this infection rate is just like normal flu.
That is why people in USA feel that it is just like normal flu because
only 1 in 3 get infected.
Once you are infected, the US cases find that 9 out of 10 only
experience mild cases, similar to normal flu. I am assuming a
symptotic rate of 10%, but fatality rate for Spanish flu is also 10%.
Out of 300 million, 100 million will be infected but only 10% need
hospitalisation, it will mean 10 million people.
In Mexico, 44 deaths for 1019 people currently. Even without
backdating 2 weeks, let us just use 1000 people infected seriously
resulting in 40 deaths which means 4% fatality rate, which is similar
to Texas case of 2 fatalities for 40 confirmed cases about 2 weeks
ago, but now it is 90 cases.
If we take 4% fatality rate, it will be 4 million deaths in USA.
Even if we take the case of 2 fatalities for 100 people in Texas as a
guide, this is 2% resulting in 2 million deaths in USA.
It is true that the cases involve so called chronic cases of asthma
and skin diseases which most people suffer and yet can lead an active
life. 4% out of 10% of 30% is just about 0.12 % of the total which is
a fair guess of the number of people suffering from chronic asthma and
yet still lead an active life.
This is 10 times the number of deaths due to normal flu which is
understandable because normal flu only killed the very old and young.
How do you know that you have acute asthma? I am supposed to be
suffering from one although I can swim and play badminton or other
sports for a short time of course.
The reason is that I cannot blow an asthmatic pipe fully so the doctor
prescribed me steroids to clear my blocked lungs or wind pipe. Since I
believe my so called asthma is more due to lack of physical exercise,
I declined.
Hopefully, this scenario is the correct one which is unlike the cases
in UK where they treat everyone with Tamilflu.
It surely will save us lots of money stock piling Tamilflu. What is
needed is just a good physical exercise in order to strenghthen our
lungs.
http://www.guardian.co.uk/world/2009/may/08/swine-flu-who-advice
Swine flu may be more infectious than we thought – health chief
• Advice will be reviewed if virus continues to spread
• Over-50s might have some immunity to H1N1 strain
* Sarah Boseley, health editor
* The Guardian, Friday 8 May 2009
* Article history
Swine flu may be more infectious than so far appears in the UK and the
current guidance on catching it may have to be changed, the chief
medical officer, Sir Liam Donaldson, warned today.
The World Health Organisation concurred, saying that if unchecked,
swine flu could affect almost a third of the population – 2 billion
people.
Although currently it is only mild, the attack rate of the strain now
affecting 23 countries is around 25-30%, Donaldson said, although he
added that it was possible people over the age of 50 might have some
immunity to the virus.
In the UK, the Health Protection Agency says that only those who have
been within one metre of an infected person for more than an hour are
considered to be at risk. "I think it will be more transmissible than
that when it gets going," said Donaldson. "We may need to look at that
advice."
Anybody with flu-like symptoms is already being told to stay at home
to avoid infecting other people. He said that if flu spreads and
becomes more severe, particularly in the winter months, there will be
concerns about people working at close quarters in offices and
travelling together on tubes, trains and buses.
Donaldson, giving a joint briefing in London with Alan Johnson, the
health secretary, said the top laboratories in the world were still
analysing the flu strain now said to have killed 42 people in Mexico,
which also has 1,112 confirmed cases. "We have to wait another few
weeks for characterisation of the virus," he said.
Last night five swine flu cases were confirmed in Brazil and
Argentina. Brazilian Health Minister Jose Gomes Temporao said four
young adults contracted the flu outside the country - three in Mexico,
and one in Florida. Prior to Thursday, Colombia was the only South
American nation to confirm swine flu with its borders.
In Mexico and in the USA – which Donaldson said was about a month
behind Mexico in the progress of its flu outbreak – the picture looks
different to here, with many more cases apparently transmitted from
one human to another. Only 10 of the 34 cases confirmed in the UK were
actually acquired here.
On the possibility that people over the age of 50 might have some
immunity to the virus, which is of the H1N1 strain, Donaldson said:
"H1N1 has been around a long time. It was a sub-type of the Spanish
flu and is in our current seasonal flu vaccine. The optimistic
interpretation is that the immune systems of the over-50s might have
some memory of the H1N1 of this kind."
He and Johnson defended their handling of the flu outbreak against
critics who say it should be treated just like a mild seasonal flu,
without school closures or the handout of antiviral drugs to contacts
of those who are sick.
"We don't know enough about the illness at this stage. It is very
reassuring that cases so far are not worse. We don't want a situation
where a child is admitted to hospital because of the complications of
flu. As far as children are concerned, I'm very, very cautious. Simply
to allow people to be exposed to it and develop antibodies I don't
think is the right approach."
Johnson said he would rather have egg on his face than deaths on his
hands. "I'd rather be accused of over-hyping something and
exaggerating than not be prepared for a general pandemic that
seriously affected our citizens," he said. The current strategy of
containment justified using "precious antiviral drugs", he said. If it
became widespread or more severe, the strategy would change to reduce
the numbers of people given drugs on a preventive basis. Patients and
their family members would receive drugs, but not others who might
have been in contact.
School closures, on the advice of the Health Protection Agency, were a
necessary part of the containment strategy. Johnson said the public
response to the flu threat had been good, but "now the danger is
complacency".
The government has ordered 227 million face masks and 34 respirators
for health workers and has spent between £400m and £500m on its
stockpile of flu drugs, which is being expanded to cover 80% of the
population from 50% now; £100 million has been committed in contracts
to drug companies Baxter and GlaxoSmithKline to produce a vaccine once
the strain is understood.
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