Bird flu mutation could lead to pandemic

Scientists have warned that the bird flu virus H5N1 could evolve into a strain which would be able to spread between humans rapidly.

Researchers from the Erasmus Medical Centre in the Netherlands identified five genetic alterations which would enable the virus to spread to lethal pandemic proportions.

An agency based in the United States unsuccessfully attempted to ban the research, which has been published in the Science journal.

The agency said that releasing the study to the general public could provide dangerous information to terrorists.

Prof Ron Fouchier, however, told the BBC that the reason the data has been published is to try and encourage scientists to look into possible vaccinations.

"We hope to learn which viruses can cause pandemics and by knowing that we might be able to prevent them by enforcing strict eradication programmes," he said.

The H5N1 virus has led to the death of millions of birds but can be transmitted to people who have close contact with the animals.

However, the number of global deaths from the disease have been quite small (just 332 since 2003), the World Health Organisation (WHO) revealed.

Scientists, though, are concerned that one day it could mutate into a form which would be able to spread between people when they cough and sneeze like normal influenza can.

Five key differences were found between bird flu and normal flu and it was reasoned that they were the mutations needed for a virus to become airborne.

They then genetically engineered those changes and added them to the H5N1 virus, testing the results by monitoring the spread caused by coughing and sneezing in ferrets.

Researchers from the University of Cambridge then took the study to the next step by testing 3,000 strains of bird flu that just two of the mutations are needed to make it airborne.