Are the symptoms of bird flu the same as "normal" influenza? If so, why is it apparently so deadly when most of us (except the very vulnerable) are able to withstand the normal effects of flu with the help of a little medication? David Hutchinson, Bradford

The official teaching, such as is promulgated by the Ministry of Health, is that the symptoms of avian flu will be similar to those of standard epidemic flu. Symptoms such as we all suffer from time to time. Doctors are predicting a pandemic. This seems inevitable unless the spread of avian flu can be halted by immunisation, its rate of transmission having first been slowed by the use of prophylactics to contain minor outbreaks. An epidemic becomes a pandemic (a world wide epidemic) because the virus is new to humans’ immune system and we have no resistance to it. As you have suggested the usual people who are most at risk from disaster following an attack of flu are those who are very young, over 65 or immuno compromised because of chronic disease or the drugs being taken to treat chronic disease.

There are some differences between avian flu H5N1 and the usual flu that have already been noticed. Whereas in ordinary epidemics it is the old and the young and the infirm who succumb most readily, in the Far East the death rate from avian flu was initially highest among fit older children and those of working age. The reason for this may well be that active children are used to help care for the hens or ducks, and their response is less to do with their resistance to infection, and more to do with the jobs they have to do, including scrambling around the hen house. It is the size of the viral load that their immune system has had to cope with that has been crucial.

Research published in the last week or two have suggested that the lethal nature of bird flu when caught by humans is because the virus has a predilection for attacking cells deep in the lower respiratory system, in the furthest reaches of their lungs. Ordinary flu, according to this theory, initially has a greater predilection for cells higher in the respiratory system.

Another theory to account for the high death rate and for its effect on those who are usually less vulnerable is that the initial infection may cause such a gross immune response that the effect of this can itself be dangerous.

Is it true that traditional treatments for flu, such as paracetamol, etc, have no effect whatsoever on bird flu? Sandra Black, Manchester

Paracetamol or aspirin (aspirin in adults but never in anyone under 16), plenty of fluids and rest is usually enough to treat flu unless there is secondary infection. These treatments paracetamol, aspirin, cough medicines and even a hot toddy do nothing to cure flu or alter its clinical course, they only ease its symptoms. It is not the symptoms of avian flu that causes international concern, but the likely outcome of the disease, and the casualty rate. We don’t need painkillers and anti inflammatories to relieve the aches and pains, headaches and coughs but anti virals to alleviate the damage the virus is doing, so that our patients will be more likely to survive.

Above all we need to produce a vaccine to make it less likely that too large a proportion of the population will catch the avian flu or that if they do catch it they will not develop it as badly as some of those who have caught it in the Far East.

How will the medical services cope if there is a pandemic - presumably there will not be enough drugs to go round. Do doctors and GPs already have access to supplies. If so, how will they be distributed to patients? Deborah Noble, Kendal

Emergency services won’t be able to cope unless far more money is spent in preparing for a possible pandemic. Good medicine, and the fighting of disease, follows some of the same principles that are taught in military academies. Potential officers have it drilled into them that they should think of the worst possible scenario, and plan accordingly. Just as we spent millions over the last fifty years on developing tanks and air craft that never had to be used in traditional war fare, and billions on nuclear weapons, that have never been released against an enemy so should we now spend a few millions extra now in safe guarding our countrymen and women against another possible, and potentially equally lethal enemy. This is no time for cuts, we didn’t count the cost during the second half of the twentieth century when preparing to defend ourselves against the risk (no more than that) of a nuclear war, nor should we now be counting the cost in preparing to defend ourselves against the inevitable onslaught of H5N1 flu.

There will not be enough drugs to go round. There are two possible lines of treatment. Anti viral agents (Tamiflu and Relenza) useful in modifying the attack if used early, and as a prophylactic by giving to contacts to prevent spread. There about ten million people who are considered at risk from ordinary flu each winter and in need of immunisation. These are the people who should have Tamiflu or Relenza at the first sign of flu.

There are also nine million people (this figure has never been confirmed) that the government considers should have priority because their work is of national importance. These people also need immediate anti virals if infected, or antivirals prophylactically so that they can keep working.

Neither of these two groups makes any allowance for the need to have emergency treatment that might be used in an effort to control an outbreak after individual cases. No allowance has been made for this group.

We have only fourteen million doses of anti virals on order, and they won’t be available for many months. This is certainly not enough to protect every vulnerable person and essential workers. What about the rest, the other forty million Britons? We are allegedly worse prepared than other western countries.

Vaccines are not yet available because it is said that the perfect vaccine can’t be produced until the pandemic starts. There are varying views on this and many think that a vaccine that gives some protection against H5N1 might be better than nothing. We shouldn’t be thinking of laying in four million doses but enough for everyone. Cheaper than a nuclear submarine but more likely to be useful.

Who are the most at risk from catching bird flu? Are the elderly and children particularly at risk, or is it just as deadly for everybody? Name and address withheld

My bet is that the elderly and children will be most at risk and that the high mortality in those of working age in the Far East is related to their close contact with hens as a result of their occupation.

Is it possible to catch avian flu by eating poultry affected with the virus? Matt Howland, London

Government advice about this has been optimistic, and perhaps slightly less than realistic, in order to avoid panic and a detrimental effect on agriculture (which we all want to do but not at the expense of accuracy). Cooking chicken or ducks so that they are well done will kill the virus. Obviously no form of stuffing should be used that tends to cool the inside of the bird and render it less sterile. Barbecues are notoriously bad at cooking meat right through.

The greater danger arises from the preparation of the bird, rather than when eating it. Chickens for cooking are nearly always contaminated by faeces, which is further spread by disembowelling them before cooking. The contamination extends to the cook’s hands, cooking surfaces, kitchen utensils and other uncooked food in which the chicken comes in contact. The strictest hygiene, including constant hand washing, is essential

We keep a few wild chickens and are obviously concerned that they may become infected. In terms of our day-to-day handling of the birds, should we be taking any extra precautions? What are the early symptoms we should be looking out for? Janet Tuttle, Suffolk

We will be all unlikely to catch avian flu H5N1 from the hens until the virus mutates. So far there has been mutation but it has been only minimal. So far as the hens are concerned infection from migrating wild birds is always a possibility. The hens should already be fed under cover. If there are outbreaks of H5N1 in Britain your few hens should be kept in a shed.

It is nearly that time of the year when the swallows will return and nest around the house. We have always regarded them as beneficial in keeping the mosquito population down, but now I wonder if we should discourage them? John Lord, Bowen Island, Canada

No. Encourage them. Swallows are already threatened. However you are quite right in supposing that outbreaks in this country might spread from wild birds migrating in the spring from Africa, as we were from winter birds arriving from the Balkans and Eastern Europe. The expectation is that affected birds will die on route, but this reasoning was also applied to autumnal and winter migrations, but even so cases were reported in Germany, Italy and in France.

Following your article on psittacosis, is it possible that if you keep pet birds such as parrots you will be exposing yourself and your children at a greater risk of bird flu? Name and address withheld

So long as the parrot or canaries are protected from contact with wild birds all will be well.

What is the scientific basis for estimates of deaths from a global bird flu pandemic of a few millions? The death rate of those infected so far is about 50 per cent, so if the virus became readily transmissible one would expect global deaths to be hundreds of millions, surely? Julian La Vey, London

Nobody know the true risk. All are estimates. The present estimates are very optimistic “to avoid causing panic.” The assumption is that once the virus mutates it will become more infectious to humans but less lethal. This has been the case in other flu pandemics, including the Spanish flu of 1918. In truth nobody knows how the genetic kaleidoscope is going to settle down after it has been shaken by mutation. It may be that there is no change in the viruses virulence or infectiousness, it might be that either of these or both might become less dangerous to humans, or that one or the other might be much more dangerous. We don’t know. Time alone will tell and in my opinion we should obey the command of my squadron leader during my national service training and think of the worst, and prepare for it.