The bird flu virus causing an outbreak in Turkey appears to be changing, according to researchers studying samples from infected patients there.
Three mutations have so far been found. Scientists believe two of these make it easier for the virus to infect humans. Combined, these two mutations could also make it easier for the virus to spread between humans.
The effect of the third mutation is unclear. Further details of all three are given in this article in Nature.
Alan Hay, director of a World Health Organization influenza laboratory in the United Kingdom, says that the virus would probably need further mutations to enable efficient human-to-human transmission.