Analyzing the course of the A(H1N1) influenza epidemic of 2009 in Finland

The pandemic of A(H1N1) influenza virus (‘the swine flu’) has drawn attention from both scientists and the media. It has been estimated that the swine flu pandemic caused 1,600,000 influenza cases and 14,000 deaths worldwide, including 9,000 influenza cases in Finland. In this research we study the relation of Finnish A(H1N1) influenza strains and the strains isolated in all other countries. We address the following questions: to what extent Finnish strains are specific to Finland? Is the geographical neighborhood reflected in the evolution of the virus? We conclude that Finnish strains are similar to other strains; however this similarity is lower during the peak of the pandemic. We show that phylogenetic distance between Finnish strains and strains from neighbor countries are not less that and that the neighbor countries have not played a specific role in the evolution of the influenza.