Cases of swine flu, which has killed people in Mexico, have been confirmed around the world. With experts scrambling to develop a vaccine, there is concern at the potential for a pandemic affecting millions of people.
Since the beginning of human civilizations humans are affected by so many contagious diseases. Plague, malaria, cholera, pneumonia, dengue and small pox are some the diseases caused by virus & bacteria infection.
The latest threat to humanity is the swine flu caused by a virus. The first case was reported at mexico in late april 2009. The US was the second country to report swine flu death. World Health Organization has announced today the spread of virus a phase five 'Pandemic'. Here is the wikipedia definition for pandemic.
A pandemic (from Greek παν pan all + δήμος demos people) is an epidemic of infectious disease that spreads through populations across a large region; for instance a continent, or even worldwide.
According to the World Health Organization (WHO), a pandemic can start when three conditions have been met:
* Emergence of a disease new to a population.
* Agents infect humans, causing serious illness.
* Agents spread easily and sustainably among humans.
A disease or condition is not a pandemic merely because it is widespread or kills many people; it must also be infectious. For instance, cancer is responsible for many deaths but is not considered a pandemic, because the disease is not infectious or contagious.
You can learn more about swine flu from this BBC link: Learn more about swine flu