Epidemic is a term used to describe a widespread increase in health risks in a population over a short period of time. These risks may be caused by infectious diseases such as cholera and malaria or by non-infectious conditions such as cancer or obesity. Epidemics can have devastating effects on human societies, causing large scale mortality shocks and resulting demographic shifts that can undermine political stability. Severe premodern pandemics, such as the introduction of smallpox to the Americas, were responsible for many social and cultural changes that made indigenous peoples vulnerable to European conquest.
Throughout history, epidemics have been common causes of disease and death. While they are less common today due to cleaner living conditions and improved medicine, outbreaks still occur. The rapid spread of a new type of flu in 1919 and the emergence of AIDS in the 1980s were examples of epidemics. In 2019 a new type of coronavirus, Covid-19, spread worldwide and was considered to be a global pandemic.
An important part of managing a pandemic is rapidly identifying infected individuals and their close contacts. Rapid identification allows people to be isolated, prevented from spreading the virus and treated before they develop severe symptoms. This requires the health care system to have the technical and laboratory capacity to respond quickly to surges of clinical specimens.
The ability to rapidly identify and isolate cases can also have economic consequences. Tracing people, implementing quarantines and isolating infectious patients all require significant staffing and resource commitments that can put strain on health system finances. These costs can be compounded by the need for new facilities and additional supplies of medications and personal protective equipment.