More panic than pandemic

[Guest guest]

http://www.guardian.co.uk/commentisfree/2009/jul/27/swine-flu-pandemic-rates

More panic than pandemic

The way we're collating figures for swine flu is wildly inaccurate and

almost certainly inflating infection rates and public anxiety

Hugh Pennington

Guardian.co.UK, Monday 27 July 2009 13.03 BST

My best wishes to those who have had, and will get, swine flu, and my

profound sympathies to the families of those who have died from it. To them

it is real. But to those responsible for counting cases and designing

defences to protect the population, it is a statistical disease.

Before the virus was discovered in the early 1930s there was no other way to

measure it. Influenza has no unique clinical features. There is no

diagnostic rash. Its symptoms can be caused by a multitude of other microbes

Its activities could only be measured by looking at groups rather than

individuals; studying death rates (making the assumption that a rise in the

winter was due to flu), and counting the number of cases in a community with

" typical " symptoms (likewise assuming that if there was a big rise, its

cause was flu).

But rapid diagnostic laboratory tests came on stream in the 1960s. In the

last two decades their sensitivity and precision has increased enormously.

At the start of the swine flu pandemic they came into their own. Without

them the identification of the virus as new would have taken much longer –

so would the detection of its rapid spread in North America and the

initiation of vaccine development within days thereafter.

But this month health departments in the UK gave up using them on any scale.

They have reverted to the traditional method – primarily counting the

consultations of patients suffering from flu-like symptoms with GPs. The

system relies on reports from sentinel practices which are fed into

statistical formulae to work out the total of " flu " cases across the country

This is how last week's estimate of 100,000 cases in the UK was generated.

In the quiet flu years like those we have enjoyed in recent times this GP

scheme has worked, not by giving a precise estimate of the number of cases,

which it can't because the statistical formulae are full of mathematical

assumptions best described as guesses, but by showing believable trends.

However, swine flu pandemic publicity has been so intense that any measure

relying on calls to doctors from the worried " slightly unwell " (most swine

flu cases are said to be mild) or from people wanting Tamiflu (a drug with a

curative reputation of the kind that is the dream of every advertising

executive) must be challenged, however sophisticated the mathematical models

used to tweak the counts. When the chief medical officer, Sir Liam son

mentions on TV that as many as 65,000 might die it is hard to blame members

of the public for an increase in fear, and it is reasonable to expect a

reduction in their reluctance to have a consultation about a cold. And who

knows what effect the new National Pandemic Flu Service (designed to take

the pressure off GPs) will have on the surveillance system.

The best way to assess the accuracy of diagnosis in sentinel practices is to

get them to send samples from patients for virology. But only 137 English

patients were tested for this purpose last week; 27 were positive. As a

sample supposedly covering the whole nation, this is pathetic. All that can

be said in its favour is that the rest of the UK did no better; 12 tests

were done in Wales (one positive) and 13 in Northern Ireland (one positive).

There are 58 sentinel practices in Scotland. They sent in 50 samples; two

were positive.

Why so few? GPs in the UK have never been enthusiastic users of virology

tests, even the ones that can be used at the bedside to give a result in a

few minutes, and it is likely that the small number of virology laboratories

in the NHS are too busy working up samples from hospital patients to be

shouting about systematic surveillance shortfalls. But the real deficiency

is not a flu one. It is the failure over many years to take infection as

seriously as it deserves. Typical are the struggles of the Health Protection

Agency (which leads the laboratory response to the pandemic) to ensure that

its many budget cuts over the years are as small as possible, and the

long-term decline in medical microbiology teaching and research in our

medical schools.

What next? The CMO said the optimistic estimate of deaths was 20 times less than

his pessimistic 65,000. Such a big range means the experts don't know what is

going to happen. The biggest worry is that the virus might take off on a grand

scale when the schools go back – perhaps targeting the elderly, who have escaped

so far. Maybe the virus will suddenly develop Tamiflu resistance. Time will

tell. But panic should not rule. Put the pandemic into perspective. So far its

lethality is remarkably low. In 1968-69, the mildest pandemic last century, the

virus killed 1,000 in the UK in its first four months.

[Guest guest]

This story should have been tittled A FAIRY TALE IN PIG VIRUS LAND.

________________________________

From: Sue <mum2mishka@...>

undisclosed-recipients@...

Sent: Monday, July 27, 2009 9:18:04 AM

Subject: More panic than pandemic

 

http://www.guardian.co.uk/commentisfree/2009/jul/27/swine-flu-pandemic-rates

More panic than pandemic

The way we're collating figures for swine flu is wildly inaccurate and

almost certainly inflating infection rates and public anxiety

Hugh Pennington

Guardian.co. UK, Monday 27 July 2009 13.03 BST

My best wishes to those who have had, and will get, swine flu, and my

profound sympathies to the families of those who have died from it. To them

it is real. But to those responsible for counting cases and designing

defences to protect the population, it is a statistical disease.

Before the virus was discovered in the early 1930s there was no other way to

measure it. Influenza has no unique clinical features. There is no

diagnostic rash. Its symptoms can be caused by a multitude of other microbes

Its activities could only be measured by looking at groups rather than

individuals; studying death rates (making the assumption that a rise in the

winter was due to flu), and counting the number of cases in a community with

" typical " symptoms (likewise assuming that if there was a big rise, its

cause was flu).

But rapid diagnostic laboratory tests came on stream in the 1960s. In the

last two decades their sensitivity and precision has increased enormously.

At the start of the swine flu pandemic they came into their own. Without

them the identification of the virus as new would have taken much longer –

so would the detection of its rapid spread in North America and the

initiation of vaccine development within days thereafter.

But this month health departments in the UK gave up using them on any scale.

They have reverted to the traditional method – primarily counting the

consultations of patients suffering from flu-like symptoms with GPs. The

system relies on reports from sentinel practices which are fed into

statistical formulae to work out the total of " flu " cases across the country

This is how last week's estimate of 100,000 cases in the UK was generated.

In the quiet flu years like those we have enjoyed in recent times this GP

scheme has worked, not by giving a precise estimate of the number of cases,

which it can't because the statistical formulae are full of mathematical

assumptions best described as guesses, but by showing believable trends.

However, swine flu pandemic publicity has been so intense that any measure

relying on calls to doctors from the worried " slightly unwell " (most swine

flu cases are said to be mild) or from people wanting Tamiflu (a drug with a

curative reputation of the kind that is the dream of every advertising

executive) must be challenged, however sophisticated the mathematical models

used to tweak the counts. When the chief medical officer, Sir Liam son

mentions on TV that as many as 65,000 might die it is hard to blame members

of the public for an increase in fear, and it is reasonable to expect a

reduction in their reluctance to have a consultation about a cold. And who

knows what effect the new National Pandemic Flu Service (designed to take

the pressure off GPs) will have on the surveillance system.

The best way to assess the accuracy of diagnosis in sentinel practices is to

get them to send samples from patients for virology. But only 137 English

patients were tested for this purpose last week; 27 were positive. As a

sample supposedly covering the whole nation, this is pathetic. All that can

be said in its favour is that the rest of the UK did no better; 12 tests

were done in Wales (one positive) and 13 in Northern Ireland (one positive).

There are 58 sentinel practices in Scotland. They sent in 50 samples; two

were positive.

Why so few? GPs in the UK have never been enthusiastic users of virology

tests, even the ones that can be used at the bedside to give a result in a

few minutes, and it is likely that the small number of virology laboratories

in the NHS are too busy working up samples from hospital patients to be

shouting about systematic surveillance shortfalls. But the real deficiency

is not a flu one. It is the failure over many years to take infection as

seriously as it deserves. Typical are the struggles of the Health Protection

Agency (which leads the laboratory response to the pandemic) to ensure that

its many budget cuts over the years are as small as possible, and the

long-term decline in medical microbiology teaching and research in our

medical schools.

What next? The CMO said the optimistic estimate of deaths was 20 times less than

his pessimistic 65,000. Such a big range means the experts don't know what is

going to happen. The biggest worry is that the virus might take off on a grand

scale when the schools go back – perhaps targeting the elderly, who have

escaped so far. Maybe the virus will suddenly develop Tamiflu resistance. Time

will tell. But panic should not rule. Put the pandemic into perspective. So far

its lethality is remarkably low. In 1968-69, the mildest pandemic last century,

the virus killed 1,000 in the UK in its first four months.