Scotland’s chief veterinary officer (CVO) says best practice biosecurity is the key in the fight against bird flu.

Sheila Voas said Scotland has so far had less of a problem with avian influenza than many other countries and this was down to a combination of ‘people doing a good job and luck and that ought to be acknowledged’.

She said: “That’s one of the reasons I was absolutely delighted Robert Thomson won the Miskelly Award at the NFUS dinner, because although he and I don’t always agree about what to do, I can’t fault him for standing up for the industry and wanting to do the best for them.”

Scotland’s approach to housing orders for commercial flocks, differs from the rest of the UK, but remains under weekly review.

She said: “Housing is a one of a range of factors that may offer some protection to commercial poultry, but it’s only one of a number of factors. Housing of birds, if other biosecurity is absolutely top notch, will provide an additional factor of two to protection, however all the other biosecurity methods give protection of a factor of 44, so housing really is the last thing you can do.

“England, Wales and Northern Ireland chose to house on top of the biosecurity measures that wet we all put in, but their risk profiles were slightly different. England particularly gets more of their birds from the eastern part of the North Atlantic 'flyway' and we believe those birds were more likely to be infected than the ones Scotland gets, which come from Iceland and Greenland.”

Ms Voas added that the Scottish Government had already put in place a requirement for enhanced biosecurity so that feeding and water should be under cover and measures taken to deter wild birds from the range. The housing order issue remains under weekly review by the Scottish Government, however other administrations are considering lifting their housing orders.

Another potential way of fighting bird flu is using vaccines and while some are in circulation and it is feasible to vaccinate certain categories of birds, the CVO said their use can impact trade.

She said: “Vaccines at the moment are suppressive, which means they don’t stop infection, they just reduce the signs and that means you could then be trading in infected birds that could cause a problem elsewhere in non-vaccinated stock.

“There’s work ongoing in developing vaccines that would stop the virus that could be easily administered, because at the moment it is only by injection and given that we slaughter millions of meat chickens every week in this country, that’s a lot of injections.

“A lot of vaccines can be administered to poultry in either food or water, we just haven’t managed to get a flu vaccine that can be done like that yet and it also needs to be effective against the different strains, because the virus changes regularly.”

Concerns have been expressed that bird flu could mutate to infect mammals such as livestock and humans. On this, Ms Voas said: “We have detected some mammals with bird flu, but they have all had very, very close contact, so in Scotland it’s been seals and otters which will have predated on wild bird carcases that have succumbed.

“With the virus, we did gene sequencing and two of the five seals demonstrated a single mutation that made the virus slightly better adapted for survival in mammals. However, in order to spread from mammal to mammal or human to human, there are 10 or 12 mutations that would have to happen, so the likelihood has increased a little, but there’s a long way to go before it becomes something that is spread form human to human and that doesn’t mean it would have severe consequences.

“The majority of people who’ve been infected with bird flu in recent years, notwithstanding a different strain the Middle East 15 years ago, the majority had a very mild disease.”