Concerns over the potential impact of bird flu, and a flu pandemic in humans, have grown over recent weeks.
Sir Liam published the UK's flu preparedness plan this week
Here, England's Chief Medical Officer Sir Liam Donaldson, answers your questions.
Is bird flu lethal to anybody or just those who are elderly or who have chest complaints?
Andrew, Llanymynech, Wales
Bird flu is a disease that affects birds. It is very difficult for the H5N1 (avian or bird flu) virus to pass from birds to humans and the chances of it doing so are low.
So far there have been about 60 deaths worldwide despite the huge numbers of fowl living in close proximity with people in the Far East.
Our concern is that the virus could change and begin to pass easily between humans.
Because such a virus would be a new strain of flu, nobody would have immunity against it and it would make people very ill.
People of every age could be at risk.
What is the precise difference between the 'bird flu' and normal flu? Is it simply a matter of mortality rates?
Stephanie, Cambridge, England
Ordinary seasonal flu (normal flu) occurs every year and affects 10-15% of population.
For most people it is an unpleasant but not life-threatening infection. Most people recover within one or two weeks without requiring medical treatment.
It is not without complications, however, and in an average year there are around 12,000, mainly elderly, people who die from seasonal influenza in England and Wales..
The very young, the older people and those with chronic illness are most at risk of serious consequences from ordinary seasonal flu.
We recommend that people who have these risk factors should have flu vaccinations every year.
They are arranged by GPs who order in the necessary quantities of vaccine every autumn.
In the far east, where bird flu has existed for a while, only a small number of people have actually died as a consequence of contracting this disease. What is the basis for estimating 50,000 could die in this country?
There have been previous pandemics of influenza and they probably started by the mixing of an animal or bird flu virus with a human flu virus to produce a new strain of flu.
Based on advice from independent experts, we are planning on the basis of one in four of the population could become ill.
The estimate of 50,000 deaths was made by looking at fatality rates after the last pandemics in this country, the number of people who die each year from ordinary flu, and the opportunities that we have for minimising the effects of a pandemic.
We have to plan for a range of eventualities and the number of deaths could be higher.
If bird flu mutates into a form that can be passed between humans, is it possible that the mutated virus would be less virulent than the current strain, or is it most likely that the severity would be the same as seen in the recent human cases where it has been contracted from birds?
The high mortality rate in cases in South East Asia may be because only the most serious cases are detected.
We do not know if a pandemic strain, when it occurs, will be more severe or less severe.
It is possible that a pandemic strain will be less severe as it evolves and becomes transmissible between humans.
The number of deaths could be higher
Should the human flu and avian flu meet and mutate into this unknown virus, what are the chances of scientists being able to create a vaccine, and in what kind of time scale?
We are very optimistic that a vaccine will be developed.
But, we can't develop a vaccine before a pandemic starts because we won't know what strain the virus will be.
It is only then that a vaccine can be matched to it.
As soon as a pandemic strain of flu emerges, we will isolate the virus and begin to develop the vaccine.
The vaccine will then need to be manufactured, go through clinical trials and be licensed. This will take between four to six months.
This is an advance on traditional approaches and uses the most modern scientific methods.
We are already taking other steps to make sure we can develop a vaccine as quickly as possible.
We are already taking other steps to make sure we can develop a vaccine as quickly as possible
These include increasing the uptake of seasonal flu vaccine to increase manufacturing capacity so that when we need to make large quantities of pandemic flu vaccine, manufacturers will be able to do so quickly.
We are also developing a library of different flu strains and considering further research into vaccine development.
When the human-to-human version of this virus does become reality, what common sense steps can ordinary people take to keep healthy?
The virus is spread through the air when people cough or sneeze. There are some basic measures you can take to reduce the risk of infection.
- Cover you mouth and nose when you're coughing or sneezing using a tissue wherever possible
- Dispose of dirty tissues promptly and carefully - bag and bin them
- Avoid non essential travel and large crowds of people wherever possible
- Maintain good hygiene - washing hands frequently in soap and water protects against picking the virus up from surfaces and passing it on
- Clean hard surfaces (e.g. kitchen surfaces, door handles etc) frequently, using a normal cleaning product
- Make sure your children follow this advice
There is a lot of talk about potential vaccines and anti viral drugs in case of pandemic outbreak - nobody mentions whether these would be suitable to administer to children. Would they?Edita, London
Yes, we would be able to give anti-viral drugs to children.
Children weighing over 23kg (usually aged seven and over) will be able to be given adult dose capsules for treatment in a flu pandemic.
Children weighing below that amount will need to be referred to a doctor for treatment.
We have ordered part of our antiviral stockpile as a powder so that a special formulation can be made up for these children.
My son is susceptible to breathing problems when he has flu/colds and has been hospitalised with this. What should I do to protect him from this risk? Should I look to have my own stock of Tamiflu for him?
Talk to your GP.
If your son is thought to be someone at risk of the effects of flu, your GP will be able to advise about vaccination or other preventive measures.
Does the winter flu jab protect against the new strain of the virus at all and is it safe to eat eggs or chicken meat in the affected areas?
Rafal, Glencormack, Ireland
The ordinary seasonal flu vaccine helps to protect against ordinary seasonal flu. It offers no protection against avian flu.
It is safe to eat poultry but you should make sure that it is cooked properly
If there were a new pandemic strain emerging, new vaccine would need to be developed and manufactured to protect against the pandemic strain of flu.
It is very difficult to contract 'bird flu' (H5N1) virus.
At the moment there is no bird flu in the UK. It is safe to eat poultry but you should make sure that it is cooked properly.
Imports to the UK of chicken from affected areas have been banned.
For changes to this advice, you should monitor the Food Standards Agency's website.
A lot of companies offer the flu jab to all employees indiscriminately. Should one have it simply because it is on offer? What are the long term risks of having the jab if you are not in a high-risk group?
We already have well established arrangements for vaccination against seasonal flu and our programme is one of the most effective in Europe.
We recommend seasonal vaccination for all those over 65 or those who suffer from illnesses that put them at higher risk from flu - such as asthma, diabetes or serious heart or lung conditions.
If you are someone who has been recommended to have flu vaccination, please make sure you have made your appointment with your GP practice.
If your company offers flu vaccine and you want more advice, talk to your GP. Influenza vaccine has a very good safety record.
What is the government doing to ensure that health staff will be adequately protected, to convince them it is safe to go to work?
We want to make sure that the NHS is as well prepared as it can be to respond to a flu pandemic.
We have seen how well our NHS responds to other emergency situations such as terrorist attacks and train crashes. We need to make sure they can respond just as well in the face of a flu pandemic.
The NHS will not only have to cope with an increase in the number of patients but it is inevitable that some frontline health workers themselves will fall ill.
We think that if the H5N1 virus changed and became a pandemic strain of flu, this vaccine could offer some limited protection
In the unlikely event of a pandemic occurring before the stockpile of anti-virals is complete, front line health workers will be given priority.
These drugs could help to reduce the severity of the symptoms.
Healthcare workers who are working closely with infected patients will be provided with face masks and will be asked to wash their hands regularly to help slow the spread of infection.
We are also purchasing 2-3 million doses of H5N1 vaccine. This is a vaccine which protects only against the virus which is currently affecting birds (which may not be the eventual pandemic 'flu strain that emerges).
We think that if the H5N1 virus changed and became a pandemic strain of flu, this vaccine could offer some limited protection.
We would consider giving it to healthcare workers to help protect them.
Should the problems with bird flu prevent holidaying in Asia, Thailand for example?
There are no travel restrictions for persons travelling to Vietnam or other affected countries.
However, for those travelling to Vietnam and Thailand we recommend that they:
- Avoid visiting live animal markets and poultry farms
- Avoid contact with surfaces contaminated with animal faeces
- Do not attempt to bring any live poultry products back to the UK
- Keep an eye on the Foreign Office travel advice for any changes (http:// www.fco.gov.uk)
I would like to know what measures are to be taken against wild birds, should the bird flu develop in the UK?
The response to any outbreak depends wholly on the particular circumstances.
However, any measures taken by the government would be based on a risk assessment and be proportionate.
The evidence so far shows that only people who have been in very, very close contact with infected birds have caught the disease
The Department for Environment, Food and Rural Affairs (DEFRA) would carry out a risk assessment to establish risk to any nearby poultry flocks.
DEFRA and the Veterinary Laboratories Agency would work with the local health authorities and the local health protection unit to assess the risk associated with contact with wild birds.
Even if H5N1 is detected there would be a low risk to the public.
The evidence so far shows that only people who have been in very, very close contact with infected birds have caught the disease.
We have two hens which we keep in a coop in the garden. Is it wise to keep them, or should we get rid of them? If so, how should they be disposed of?
Don't get rid of them. Simply follow DEFRA's advice:
- Feed and water your birds indoors to avoid contamination by wild birds and other animals
- Make sure your premises are tidy and clean. Spilled feed, litter and standing water attract wild birds and vermin
- Control vermin
- Make sure your clothes, footwear and hands are clean, before and after contact with birds
- Supply clean, fresh drinking water
- Be vigilant
- Look out for signs of disease. Mortality, falling egg production and respiratory distress may be early signs of a disease problem
- If you suspect disease, act quickly and consult your vet. Bird flu is a notifiable disease and must be reported to your local Divisional Veterinary Manager
Is there any risk of domestic cats getting this disease if they catch infected wild birds? What would be the risk of a person catching it from an infected bird brought in by a cat?
There is no evidence that any type of bird flu has passed from avian species to cats.
So even in the unlikely event that the reported dead birds had died from flu, the risk to your cat would be extremely low.
Cases of dog flu have been recorded in the US, but in this case the virus is believed to have originated from horse flu.