World health report

Executive summary

Obstacles to success

Poverty exposes hundreds of millions of people to the hazard of infectious diseases in their everyday lives. More than 1000 million people live in extreme poverty. Half the world's population lacks regular access to the most needed essential drugs.

Continuing global population growth and rapid urbanization force many millions of city dwellers to live in overcrowded and unhygienic conditions, where lack of clean water and adequate sanitation are breeding grounds for infectious disease.

Migration and the mass movement of many millions of refugees or displaced persons from one country to another as a result of wars, civil turmoil or natural disasters, also contribute to the spread of infectious diseases.

As a result of the economic and social crises still affecting many countries, health systems which should offer protection against disease have, in extreme cases, either collapsed or not even been built. The result is a resurgence of diseases that were once under control or should be controllable, given adequate resources. Disabled by these diseases, some societies are unable to get themselves back on their feet.

Increasing international air travel, trade and tourism result in disease-producing organisms being transported rapidly from one continent to another. Reporting of infectious diseases now poses serious economic threats to trade and tourism. Some countries impose unjustified restrictions on travellers coming from infected countries; others are tempted to conceal information about infections within their own borders. The result is a fragmented, uncoordinated approach to infectious disease control and inadequate global information to allow worldwide monitoring.

Changes in global food trade create new opportunities for infections to flourish. They include the shipment of livestock; new methods of food production, storage and marketing; and altered eating habits.

The effects of climate change may allow some diseases to spread to new geographical areas. Microbes continue to evolve and adapt to their environment, adding antimicrobial resistance to their evolutionary pathways.

For all these reasons, controlling infectious diseases is an imperative global challenge that requires a global response.