article_snippet: A wave of H7N9 bird flu in .
article_snippet: The H7N9 virus, one of several strains of bird flu known to . be able to infect humans, has persisted, diversified and spread .
article_snippet: The H7N9 virus, one of several strains of bird flu known to be able to infect humans emerged in humans in March 2013.
article_snippet: A wave of H7N9 bird flu in China that has spread into people may have the potential toemerge as a pandemic strain in humans .
article_snippet: A wave of H7N9 bird flu in China that has spread into people has since then infected at least 571 people in China, Taipei, .
article_snippet: A large number of new genetic variants of The H7N9 virus, one of several strains of bird flu known to be able to infect humans have .
article_snippet: all these mutations that are accumulating as The H7N9 virus, one of several strains of bird flu known to be able to infect humans persists .
article_snippet: potential of The H7N9 virus, one of several strains of bird flu known to be able to infect humans?
highlights_snippet: The H7N9 virus, one of several strains of bird flu known to be able to infect humans, has persisted, diversified and spread in chickens across China .
  
highlights_snippet: Unless control measures are put in place, The H7N9 virus, one of several strains of bird flu known to be able to infect humans will spread,
highlights_snippet: The H7N9 virus, one of several strains of bird flu known to be able to infect humans warn .