Project Details

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You can view the full text from the H1N1 influenza and pandemic flu themed issue 1 publication details page on the HTA website

An influenza pandemic has recently been declared, involving the novel A(H1N1) influenza virus from Mexico. This has spread to almost 100 countries worldwide in less than two months, causing widespread disease so far in Mexico, USA and Canada. It is highly likely that over the next 12 months, many countries including the UK will be affected by widespread illness. In the UK this wave of intense flu activity is most likely to occur in late autumn 2009.

Very little is known about the new H1N1 pandemic virus (even less than is known about H5N1 ‘bird flu'). For example we do not know how long the virus is excreted by infected humans and how much virus is spread to surfaces and carried in the air. This is very important to know as soon as possible because it affects the advice that will be given to healthcare workers about controlling the spread of infection to themselves and other patients. Similarly we need this information so we can give good quality advice to families who will have to look after each other in their own homes.

The best way to obtain this information is to ask patients who get pandemic flu soon (in August or September) 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 near the patient and sample the air in the room 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. We need to do these studies in children as well as adults because we already know that children seem to hold on to the flu virus for longer and are not very careful with respiratory hygiene!

The study does involve a simple daily nasal swab, and subjects who agree to take part will be inconvenienced to some extent. However the technique of sampling from the nose is quick and not painful so there should be few ethical problems, even in children. Medical care will not be affected in any way. We also believe the public will understand why this work is important.

The team has been performing this kind of work for some time and his well qualified and experienced to carry out the study. Several members of the study team are leading international experts on influenza. The work is very labour intensive and quite costly in terms of laboratory materials because many samples are generated. In addition the pressing need to obtain some preliminary results by early autumn means that additional laboratory and nursing staff are required in the short term.

i) To determine the quantity of infectious virus present on surfaces and in the air, according to time from symptom onset, symptom constellation (e.g. presence of cough or sneeze), distance from source and particle size (in air);
ii) To correlate serial virus shedding in pandemic influenza patients against near-patient environmental contamination (surfaces and air).
iii) To describe virus shedding (quantity of infectious virus) and duration according to important patient sub-groups, notably adults and children, those with mild illness (community patients) and those with more severe disease (hospitalised patients)
iv) To determine if aerosol generating prodcedures are associated with changes in quantity of environmental contamination with live virus either in relation to quantity or particle size, or distance from source.