Does avian bird flu have different strains?
The avian bird flu is known to have 15 different strains. Of these, the H5N1 strain is the one that is infecting humans and causing widespread death. Variations have been found even within the H5N1 strain with slight differences being seen in different countries that became affected by the outbreak. Moreover, all of these strains were different to those seen in the past. Pakistan recently announced discovery of cases of the H-7 and H-9 in poultry, but no cases of these strains being passed to humans.
