Reportable diseases are diseases considered to be of great public health importance. Local, state and national agencies (for example, the Centers for Disease Control and Prevention) require that such diseases be reported when they are diagnosed by doctors or laboratories.

This permits surveillance (that is, the collection of statistics on the frequency with which the disease occurs) which in turn allows these agencies to identify trends in disease occurrence, as well as disease outbreaks.

This also allows local agencies such as the Southwest Utah Public Health Department to prepare for possible future outbreaks.