article_snippet: H7N9 could be expected to persist and spread beyond the region.'
article_snippet: 2013, the H7N9 appeared to die down - aided in large part by .
article_snippet: about how The H7N9 virus, one of several strains of bird flu known to be able to infect humans re-emerged, how The H7N9 virus, one of several strains of bird flu known to be able to infect humans might develop, and how The H7N9 virus, one of several strains of bird flu known to be able to infect humans .
article_snippet: of H7N9 over 15 cities across five provinces in China.
article_snippet: By collecting and sequencing a large number of samples, they . found that the H7N9 virus is mutating frequently, acquiring .
article_snippet: genetic changes that might increase the H7N9 virus pandemic potential.
article_snippet: findings were interesting but did not necessarily show the H7N9 . was changing in ways that made the H7N9 more likely to develop into a . pandemic flu strain.
article_snippet: the H7N9 virus emerged in humans in March 2013. 
article_snippet: the H7N9 virus has since then infected at least 571 people in China, Taipei, Hong Kong, Malaysia and Canada, killing 212 of at least 571 people in China, Taipei, Hong Kong, Malaysia and Canada . '
article_snippet: So far, the overall risk associated with the H7N9 virus has .
article_snippet: Yi Guan's team, however, said Yi Guan's team analysis pointed to a . need for heightened vigilance of H7N9 and for curbing direct .