FSIS samples food products for a number of pathogens and protects the food supply by retaining or recalling products. FSIS inspects for conditions and collects samples to test for many diseases such as rabies, tuberculosis, brucellosis, and pseudorabies which can be transmitted to humans. The USDA's animal health infrastructure and mission is, in part, built on the important task of excluding and rapidly responding to the introduction of these pests and diseases. Interstate movement and transport of infected and exposed animals are regulated in an effort to stop further spread of the diseases. Surveillance begins with accurate diagnosis and requires open lines of communication among doctors, scientists, and government officials.
Evaluation requires epidemiologic and laboratory based investigations.
Disease control requires that public health infrastructures are in place and that resources are available to procure and distribute medical supplies, such as drugs and vaccines. Significant improvements can be made in surveillance and response to international epidemics, if U.S. agencies are granted mandates and authority to make the most effective use of U.S. expertise in public health. Sometimes the informal global surveillance and response system for infectious diseases works very well, however, sometimes it does not - as the following examples illustrate.