Which influenzae strain, not of human origin and can cause pandemic
High-Yield Explanation
H5N1 is predominantly a strain in certain species of birds (Avian). In had caused pandemic in human.
Avian influenza (Bird flu)
It is caused mostly by H5 N1 strain of influenza - A. It was detected in Hongkong in 1997 during a pandemic in poultry. It is a pandemic with high mortality rate (60%).
Other types of influenza viruses which have been observed to cause avian influenza are H7 N7 and H9 N2 of influenza-A.
Recently an outbreak of avian influenza was caused by H7 N9 in China, in 2013.
Drug of choice for avian influenza is oseltamivir.
Important facts
H5 N1 strain causes pandemics in birds (avian influenza), but it has not cause frequent pandemics in human as there is no frequent man-to-man transmission.
However, avian H5 N1 is a strain with pandemic potential, since it might ultimately adapt into a strain that is contagious among humans.