Email received November 22 2007 from Dr Ruth Watkins.
I am not sure that one can wait until there are dead and sick turkeys before culling on the most recent dangerous contact. If the same personnel as worked at RPF were going to the latest farm to be culled and working there, that certainly is not biosecurity and virus if not already in the turkey area could be waiting on straw or feed to be introduced. Once turkeys are sick and have died there is much virus about and the risk of further tranmission is the greater.
Vaccination now with 3 weeks to go before immunity in those turkeys is too late.
Sampling large flocks of turkeys etc is difficult. I am not sure how I would go about it. One could sample their water, faeces from from say 10 different sites around their area but one could not sample every live individual. Sick and dead individuals could be sampled. When the turkeys are killed they can then swab each one, and pool the swabs, 10 at a time? I don't know what they do. I doubt when they are killing 1000s of birds they do sample each one. So really it would be very difficult to exclude infection until there were ill birds. (The problem here highlighted by Dr Watkins shows why we are so in need of on-site portable RT-PCR machines that can sample and detect virus within minutes before clinical signs are evident.)
I see no reason why, on an unrelated farm, if it had sick birds should not wait for the report from the lab (PCR faxed) before it was culled out.
Equine influenza in Australia has spread widely in the East and the spread can only be explained in some instances by people taking the virus on their persons (fomites) or on equipment to an uninfected premises. They are changing their status from a country without vaccination to equine influenza to one with vaccination and have ordered millions of doses of vaccine.
When should we vaccinate here against H5N1 in this outbreak? Should it be now or when there is an obvious trigger- infection on an unrelated poultry farm or the infection found in wild birds in East Anglia?
A question I would like to see an answer to is could the human poultry workers on RPF for example carry the virus in their throats without actually being infected as in the case of FMD? Swabs could be taken from all workers before starting them on an anti-viral, Tamiflu. Of course their vaccination in 2008 against current human flu strains is absurd as any co-infection would be now or have already happened.