Current flu virus may be 100% swine in origin
This intriguing notice posted to the International Society for Infectious Diseases by Columbia University researchers suggests that the current swine flu outbreak may be a “reassortment” (i.e. rearrangement) of existing swine flu viruses and not a swine, avian, and human influenza combo:
The preliminary analysis using all the sequences in public databases (NCBI) suggests that all segments are of swine origin. NA and MP seem related to Asian/European swine and the rest to North American swine (H1N2 and H3N2 swine viruses isolated since 1998). There is also interesting substratification between these groups, suggesting a multiple reassortment. We are puzzled about sources of information that affirm that the virus is a reassortment of avian, human and swine viruses. It is true that the H3N2 swine virus from 1998 and 1999 is a triple reassortant, but all the related isolates are found since then in swine.
We’ll see if this analysis holds up and it certainly doesn’t guarantee that the outbreak will be any easier to contain, but it does suggest that the current flu — at the moment — is not the triple-threat that it was reported to be. Stay tuned…