17 October, 2005 - Published 01:39 GMT

Bird Flu - the plain facts. Just how dangerous is it for humans?

Romanian authorities are carrying out a further cull of birds in an effort to prevent the spread of avian flu.

The same viral strain, known as H5N1, has killed birds in Turkey and is linked with more than sixty human deaths in Asia. If it mutates, scientists are worried it could cause a human flu pandemic. Microbiologist Hugh Pennington sorts the facts from fiction.