A pandemic is a disease outbreak in people that spreads across countries or continents. It affects more people Pandemic Risk Definition and takes more lives than an epidemic which remains limited to one city, region, or country.
The scientific evidence reviewed in this workshop report demonstrates that pandemics are becoming more frequent, driven by a continued rise in the underlying emerging disease events that spark them. Without preventative strategies, pandemics will emerge more often, spread more rapidly, kill more people, and affect the global economy with more devastating impact than ever before.
PMID: 19565018 Influenza A viruses are highly infectious respiratory pathogens that can infect many species. Birds are the reservoir for all known influenza A subtypes; and novel influenza viruses can emerge from birds and infect mammalian species including humans.