HEALTH experts in Bolton say they are not surprised some cases of bird flu are resistant to the anti-viral drug being used to treat it.

Two patients suffering from the virus in Vietnam died after failing to respond to treatment with the drug Tamiflu, which is being stockpiled by health authorities across the UK, including Bolton, in case of a pandemic.

But public health specialist Graham Munslow said: "This isn't a great surprise. The strain of avian flu in the Far East has not yet mutated into human-to-human form and is still very much related to poultry.

"This is mild bad news, but it's being tested against a virus that isn't affecting humans."

In the event of a bird flu pandemic, it is estimated 70,000 people in Bolton would be affected.