Biomaterial Database

From where did the 2009 'swine-origin' influenza A virus (H1N1) emerge? 2009

Adrian J Gibbs, and John S Armstrong, and Jean C Downie

Australian National University Emeritus Faculty, ACT, Australia. adrian_j_gibbs@hotmail.com

The swine-origin influenza A (H1N1) virus that appeared in 2009 and was first found in human beings in Mexico, is a reassortant with at least three parents. Six of the genes are closest in sequence to those of H1N2 'triple-reassortant' influenza viruses isolated from pigs in North America around 1999-2000. Its other two genes are from different Eurasian 'avian-like' viruses of pigs; the NA gene is closest to H1N1 viruses isolated in Europe in 1991-1993, and the MP gene is closest to H3N2 viruses isolated in Asia in 1999-2000. The sequences of these genes do not directly reveal the immediate source of the virus as the closest were from isolates collected more than a decade before the human pandemic started. The three parents of the virus may have been assembled in one place by natural means, such as by migrating birds, however the consistent link with pig viruses suggests that human activity was involved. We discuss a published suggestion that unsampled pig herds, the intercontinental live pig trade, together with porous quarantine barriers, generated the reassortant. We contrast that suggestion with the possibility that laboratory errors involving the sharing of virus isolates and cultured cells, or perhaps vaccine production, may have been involved. Gene sequences from isolates that bridge the time and phylogenetic gap between the new virus and its parents will distinguish between these possibilities, and we suggest where they should be sought. It is important that the source of the new virus be found if we wish to avoid future pandemics rather than just trying to minimize the consequences after they have emerged. Influenza virus is a very significant zoonotic pathogen. Public confidence in influenza research, and the agribusinesses that are based on influenza's many hosts, has been eroded by several recent events involving the virus. Measures that might restore confidence include establishing a unified international administrative framework coordinating surveillance, research and commercial work with this virus, and maintaining a registry of all influenza isolates.

UI	MeSH Term	Description	Entries
D007251	Influenza, Human	An acute viral infection in humans involving the respiratory tract. It is marked by inflammation of the NASAL MUCOSA; the PHARYNX; and conjunctiva, and by headache and severe, often generalized, myalgia.	Grippe,Human Flu,Human Influenza,Influenza in Humans,Influenza,Flu, Human,Human Influenzas,Influenza in Human,Influenzas,Influenzas, Human
D008800	Mexico	A country in NORTH AMERICA, bordering the Caribbean Sea and the Gulf of Mexico, between BELIZE and the UNITED STATES, and bordering the North Pacific Ocean, between Guatemala and the UNITED STATES.
D009656	North America	The northern continent of the Western Hemisphere, extending northward from the Colombia-Panama border and including CENTRAL AMERICA, MEXICO, Caribbean area, the UNITED STATES, CANADA and GREENLAND. The term often refers more narrowly to MEXICO, continental UNITED STATES, AND CANADA.	Northern America
D009976	Orthomyxoviridae Infections	Virus diseases caused by the ORTHOMYXOVIRIDAE.	Orthomyxovirus Infections,Infections, Orthomyxoviridae,Infections, Orthomyxovirus,Swine Influenza,Infection, Orthomyxoviridae,Infection, Orthomyxovirus,Influenza, Swine,Orthomyxoviridae Infection,Orthomyxovirus Infection
D005060	Europe	The continent north of AFRICA, west of ASIA and east of the ATLANTIC OCEAN.	Northern Europe,Southern Europe,Western Europe
D005585	Influenza in Birds	Infection of domestic and wild fowl and other BIRDS with INFLUENZA A VIRUS. Avian influenza usually does not sicken birds, but can be highly pathogenic and fatal in domestic POULTRY.	Avian Flu,Avian Influenza,Fowl Plague,Influenza, Avian,Avian Influenzas,Flu, Avian,Influenza in Bird,Influenzas, Avian,Plague, Fowl
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001208	Asia	The largest of the continents. It was known to the Romans more specifically as what we know today as Asia Minor. The name comes from at least two possible sources: from the Assyrian asu (to rise) or from the Sanskrit usa (dawn), both with reference to its being the land of the rising sun, i.e., eastern as opposed to Europe, to the west. (From Webster's New Geographical Dictionary, 1988, p82 & Room, Brewer's Dictionary of Names, 1992, p34)
D001717	Birds	Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.	Aves,Bird