In spite of the number and effectiveness of modern antibiotics, infectious diseases remain a significant health problem within the US.  Many organisms which cause human disease have become resistant to the antibiotics which once controlled them, and for others antibiotics have never been completely effective.

Especially dangerous are the subgroup of infections that can spread efficiently from person to person, because these have the capacity to produce rapid outbreaks of disease affecting many people at once.  Concerns about such outbreaks involve the potential for natural outbreaks (pandemic influenza, SARS, HIV/AIDS) and also bioterrorism (smallpox, tularemia, and other conceivable agents).

Surveillance for communicable infectious diseases and their control has always been a central concern for Public Health officials at all levels.  This will continue to be true for the foreseeable future.