During the 1918 flu pandemic, swine flu was 1st considered to be a disease related to human influenza. In the beginning it was considered that swine influenza virus only affects among the pig population world wide.Actually swine flu is a Type A influenza virus which causes regular outbreak of flu in pigs,but is rarely fatal and not affects the human race.But fom the late December of 2005, 12 cases of human infection due to swine flu was reported by the US Centre for disease cental and Prevention.But thing began to really detoriate from the late April 2009,when there was an outbreak of more than a thousand cases of swine flu infections in humans in Mexico.The incident was suspected to have 86 deaths.The WORLD HEALTH ORGANIZATION considered the event to have ”Pandemic Potential”.Six cases of swine flu were reported on 26th April, 2009 in Canada - four students in Nova Scotia and two in British Columbia. Although the six case were very mild but the number of cases increased to 19 within a short span of 3 days time.