November 29th, 2010
Building E, Room E1
2.30 p.m.

Antonio Scalari
Master student
Functional Genomics
University of Trieste

Influenza is one of the most important respiratory infection of humans and occurs as seasonal (winter) epidemics in temperate regions. Of the three genera of influenza viruses (Influenzavirus, family: Orthomyxoviridae), the Influenza A virus, apart from concurring in the onset of seasonal epidemics, is associated with occasional large scale global pandemics. Influenza pandemics have been among the largest and deadliest epidemics in history and among these the most acknowledged , in twentieth century, is the so called Spanish influenza, occured in 1918-1919.
A pandemic originates from a single event of genetic reassortment (antigenic shift) in a subtype or between more subtypes of Influenza A virus. This event occurs in mixed infections in animal reservoirs and may results in the appearance of new strains with dramatic changes in virulency and antigenicity. After the pandemic of 1918, others occured, the last of which is been that broken out in april 2009 in Mexico , caused by an A/H1N1 subtype virus. Molecular epidemiology, through genetic sequencing of strains isolated in different times and places and through phylogenetic analysis, studies the origin and the molecular evolution of viruses, compares them with viral types associated with previous epidemics and pandemics and can discover new mutations wich are significant for therapy, vaccines formulation and forecast of the spread of future outbreaks.
Keywords: Influenza A virus, pandemic, antigenic shift, molecular evolution

Modificato.