Emerging infectious diseases.

Over the last two decades, there has been the emergence of previously unknown infectious diseases and the re-emergence of diseases thought to be in decline. This is the result of social, economic, political and ecological factors, and the interactions of organisms, hosts and the environment. In recent years, Australia has experienced a number of significant outbreaks of emerging diseases such as bat paramyxovirus and Escherichia coli O111, and there has been a resurgence of vaccine-preventable diseases. Australia is implementing a National Communicable Disease Surveillance Strategy in response to this public health threat. The Strategy, similar initiatives in other countries, and enhanced international cooperation will contribute to the global response to emerging diseases.