Isolation versus quarantine and alternative measures to control emerging infectious diseases.

In the past 25 years, the world has witnessed the emergence and re-emergence of many infectious diseases. In the early stages of their emergence, isolation and quarantine may be the only and last resort to effectively control infectious diseases when we are confronted with limited or no knowledge of a newly identified and previously unknown contagious disease, which causes a serious public health threat either locally or internationally. The article traces back the origins of isolation and quarantine; defines precisely the terms isolation and quarantine as they are currently used in the modern era; compare and contrast these terms; identifies some of the harmful consequences of applying quarantine measures; highlights considerations for the use of isolation and quarantine; and identifies alternative measures adopted by the world health community to respond to emerging and re-emerging health threats.