Scientists taking a first look at the genetics of the bird flu strain
that recently killed two men in China say the virus could be harder to
track than its better-known cousin
H5N1 because it might be able to spread silently among poultry without notice.
scientists said Wednesday that the H7N9 virus seems troubling because
it can generate no symptoms in poultry while seriously sickening humans.
Masato Tashiro, a WHO scientist studying the virus' genetic data, says
the virus also appears to have mutated into a form that enables it to
more easily infect animals such as pigs, meaning they could serve as
hosts that spread the virus more widely among humans.
H7N9 is previously known only to have infected birds.
The preliminary findings need further testing.