The best way to obtain this information is to ask patients who get pandemic flu soon (in August, September and October) to help us by agreeing to give a daily nose swab sample for just over one week so we can see how much virus is in the nose day by day and how quickly this disappears. At the same time we will take samples from hard surfaces in a patient's room or home and sample the air using a special filter device. We can then work out how much virus is being excreted, how long the 'danger period' is, whether surfaces are more or less important than the air that we breathe (in terms of catching the virus) and if we can advise on a 'safe distance' from the patient, beyond which there is relatively little chance of catching the illness.