The increase in the life expectancy of the population in Europe over the last 150 years is largely due to the decline in mortality of infectious diseases. It has succeeded in stopping the major pandemas such as plague, cholera and smallpox. At the same time, tuberculosis, the most common cause of death, is now under control.
Improved social and hygienic conditions are the main causes, but the prevention and treatment of infections has also been of great importance. Despite this, infectious diseases remain the main cause of death in developing countries, and the most common cause of death among children and adolescents globally.
The spectrum of infectious diseases is not stable.
Since 1980, the HIV pandemic has cost the lives of 40 million people. The outbreak of SARS in 2003 threatened to develop into a pandemic, but was brought under control. Ebola in West Africa 2013-2016 cost 11,000 people their lives. Influenza still poses a pandemic threat which, in the worst case, could cause a disaster of even greater proportions than the Spanish flu in 1918/19.
A number of factors make the risk of pandememias in the future greater than before.
The growing traffic, tourism and trade, and the high population growth of the world's major slums, increase the risk of infectious diseases spreading rapidly. The development of antibiotic resistance poses a particular problem.
It is therefore important, also in the future, to have a strong preparedness for communicable diseases and epidemics.