Described as widespread outbreaks of infectious diseases, pandemics result in

increased morbidity and mortality over a wide geographical area and cause significant economic, social, and political disruption. Global travel, global integration, urbanisation, changes in land use, and increased exploitation of nature have made pandemics more likely over the past century. Pandemics are therefore judged by their geographical extent rather than the severity of their illness. Example: 2009 Influenza Pandemic, 2003 Severe Acute

Respiratory Syndrome (SARS) Pandemic.

Causes:

• Pandemics have occurred throughout history and appear to be rising in frequency, mainly due to the increasing emergence of viral diseases from animals.
• An outbreak of a pandemic is affected by a combination of spark risk (the  likelihood of the outbreak) and spread risk (the likelihood of the outbreak spreading broadly throughout human populations).
• A few geographical regions with high spark risk, such as Central and West Africa, do not have pandemic preparations comparable to the rest of the world.
• The virus that causes a pandemic most often is influenza.

Effects:

• In pandemics, morbidity and mortality are likely to increase drastically.
• A pandemic can negatively impact the economy through several channels, including fiscal shocks that impact the economy in the short-term, as well as economic growth problems that affect the economy in the long run.
• The adverse effects of pandemics remain primarily attributed to individual behaviour changes, including the aversion of people to work and other public places.
• Some pandemic mitigation measures can lead to significant social and economic disruption.
• The effects of pandemics can be exacerbated in countries that suffer from weak institutions and political instability. State and citizen violence have been a result of outbreak response measures, such as quarantines.

The prevention of pandemics is applicable to two major groups of illnesses. The first are well-known and well-established hazards, including cholera and yellow fever, for which the world has safe, efficient preventative and response plans in place. Pathogens with a high threat level and no known treatments make up the second category. This category contains infectious viruses that could spread through zoonotic spillover, or as a result of unintentional or intentional release.