Local and state case reporting to national and international epidemiological agencies such as the CDC and WHO is vital in the tracking of infectious disease.

Public health agencies must play a major role in disease education and surveillance, as well as in the work to limit the spread of infectious diseases in their local populations by enforcing guidelines established to insure the purity of water supplies and reduction of food-borne illness among food suppliers and restaurants.  These agencies also should work to reduce the number of disease-carrying vectors such as mosquitoes and ticks, as well as the reservoirs such as rodents and wild animals that come into contact with members of the public.