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Death rates and mutations
I don't want to end the week on an alarming note, and - let's face it - there's been enough alarmist reporting about H1N1 swine flu.
But I would like to draw your attention to a couple of issues which many of you are likely to pick up elsewhere on the web or perhaps in the papers.
The first is a big jump in the global death toll. The World Health Organization said the number of deaths was up around 1,000 on a week ago, reaching at least 7,826 worldwide since the H1N1 virus emerged in April. That should neither surprise nor alarm you. We are now getting into the peak flu season. Seasonal flu kills several hundred thousand very elderly and frail people each year. The difference with swine flu is that the majority of deaths are in the under-65s.
On a more positive note, the WHO said that the epidemic may have peaked in parts of the northern hemisphere. That seems to be the case in the UK and in the United States, which has had several weeks of falling levels of flu.
Secondly, I have picked up via BBC Monitoring that two patients in France, in different hospitals, have died from mutated H1N1 swine flu. (For those who don't know, the BBC monitoring service is based in Caversham in Reading; it listens to news broadcasts from around the world and provides accurate translations.)
The monitoring translation of La Chaine Info Television went like this:
French newsreader: "The health authorities dreaded this. The H1N1 virus is in the process of mutating. The phenomenon reported in Norway has also been detected in France in two deceased patients who were not related in any way and who were in hospitals in two different cities. This mutation could increase the virus's ability to affect certain airways, as well as the lungs."
Read like that, it seems pretty scary, and it is certainly not good news that mutations are occurring. But, as has been pointed out by me and by many of the wise men and women who post comments here, mutations are what we should expect with flu. Flu is an RNA virus in which genetic replication is pretty poor and which makes lots of mistakes. It's the reason that flu viruses drift and the reason we need a new flu jab every winter.
The mutations reported in France have been seen in Norway and in several other countries, and the WHO put out some very clear advice on this recently.
The French mutation has been found in two cities, but we need to know a lot more about it before becoming unduly alarmed. The patients may have been immuno-compromised, making them more susceptible to mutated viruses, and we don't have any evidence that mutated strains are spreading in the wider community.
To sum up, mutation and deaths are sadly unavoidable when it comes to H1N1 swine flu. But this pandemic is still reassuringly mild for the vast vast majority of those infected.
GPs urged to go 'full throttle' in accelerating vaccination
Around one million people in England are now estimated to have been vaccinated against swine flu.
Across the UK, 10 million doses of the vaccine have been distributed to GPs and hospitals.
That one million figure refers to those in the initial priority groups, such as those with chronic asthma, heart and other organ disease, immune problems and pregnant women.
Clearly there is still a long way to go. There are nine million people in the priority groups in England, and around 11.5 million across the UK. Then add to that the three million or more under fives who will be offered the jab after that.
Professor David Salisbury, Director of Immunisation at the Department of Health said he hoped GPs would now be able to accelerate the vaccination process:
"All GPs have now had some vaccine and we are now at the stage of re-stocking them and so the brakes can come off to some extent. We'd like to get the priority groups vaccinated before Christmas, and there will be enough vaccine to do that. GPs don't want to call in patients if they are unsure there have enough vaccine, but now they know they have it in the fridge they can go full throttle."
Professor Salisbury said he wanted doctors to get through the priority groups as quickly as possible so that they could move on to immunising children under five.
Carers for the elderly and disabled will also be entitled to receive the swine flu jab once the initial priority groups have been cleared.
I hope this answers some of the questions many of you have raised about the roll-out of the vaccine.
There are no figures yet for the uptake of vaccine among more than two million front-line health workers.
But Ian Dalton, National Director for Flu Resilience said that "informal conversations" had shown promising levels of uptake. He gave some examples:
• West Midlands Ambulance Service has offered the jab to around 1,000 front line staff and 70% have accepted.
• Guy's and St Thomas' Hospitals have received 2,000 doses and used 1,500 already.
• They have also immunised 4,000 staff against seasonal flu, double the number last year.
So how much swine flu is there in Britain at present? Estimated figures from across the UK suggest cases are falling very slightly but the number of deaths is rising sharply.
Indeed the past week has seen the biggest single rise in deaths since the pandemic began.
UK deaths to date related to H1N1 swine flu: 245
163 England
13 Northern Ireland
46 Scotland
23 Wales
Why are deaths rising if cases are falling? Firstly, remember that weekly estimates for the number of cases of swine flu are probably wildly out (but are useful for showing trends over time).
The latest weekly estimate for England was 46,000 cases of swine flu with a cumulative total of 760,000. But since the Health Protection Agency now reckons that one in five children may have had swine flu, that cumulative figure maybe just a tenth of the real total (and that's just my guess).
I've discussed this apparent contradiction about falling cases and rising death rates earlier this month - something that has been seen in other countries.
It's important to note that there is no evidence that the H1N1 swine flu virus is mutating into something more deadly.
Finally a few graphs - very useful for showing trends. My thanks to the Department of Health and the RCGP for supplying the data:
You can see that the rate of flu is now about average for this time of year but well below the peak we saw in July.
This is a snapshot of the number of patients in hospital in England with suspected swine flu related illness as of 25 November. It's always worth showing this because it's a reminder that while flu is mild for most, for a small minority it can be very serious.
This is the first time I've seen this. It reveals the death toll from swine flu, in England from week to week. You can see that the rate has risen throughout November.
Useful resources:
• Detailed UK weekly epidemiology update
• Swine flu figures for Northern Ireland
• Swine flu figures for Scotland
• Swine flu figures for Wales
Up to a third of children in some areas have been infected
It's been one of the big questions of this pandemic. Just how many of us in Britain have actually had swine flu?
Knowing that would be incredibly useful, as the bigger the proportion infected, the further we are into this pandemic and the less likely there will be a further sting in its tail.
The Health Protection Agency (HPA) has done blood tests of hundreds of children and parents connected to early school outbreaks.
With one school in south west England they tested around 500 people. They found that although around one in 10 children fell ill, three to five times as many got infected and developed antibodies.
After analysing this and other data relating to the number of children being seen by GPs, the HPA has now come up with these interesting estimates:
• Up to one third of children in swine flu hotspots (such as England and the West Midlands) have already been infected with the H1N1 virus.
• Across the UK up to one in five children has had had swine flu.
• About half of those who get infected show no symptoms.
This is all very reassuring. Professor Maria Zambon from the HPA said:
"We didn't get the pandemic that we planned for and you might say that we've been lobbed a soft ball. There hasn't been high case mortality, the virus is sensitive to drugs, and we've been able to make vaccine and roll it out. I am incredibly grateful that we are not dealing with a pandemic of H5 (bird flu)."
Professor Zambon said the virus had had a relatively low impact on older adults and that was probably explained by pre-existing immunity. The HPA has these estimates:
• For those aged over 50 up to four in 10 people have pre-existing protective antibodies to the H1N1 pandemic virus.
• If you are under 50 it falls to around one in 10 of the population.
The professor, who is an acknowledged world expert on flu, did utter a few words of caution. "Influenza is full of mystery and intrigue. It has lots of twists and turns" and she predicted that mutations of the swine flu virus should be expected. She also pointed out that there could still be a substantial outbreak of seasonal flu over winter.
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