Frieden, Thomas R.Local health departments generally do a good job of monitoring and controlling conditions that killed people in the United States 100 years ago. Yet noncommunicable diseases, which accounted for less than 20% of US deaths in 1900,1 now account for about 80% of deaths.2 Our local public health infrastructure has not kept pace with this transition. Health departments must continue to handle traditional public health priorities as well as emerging infectious diseases. They must also increasingly address terrorism detection, preparedness, and response. But it is even more urgent that they adjust to the epidemiological transition from communicable to chronic disease. All too many are asleep at the switch.Public HealthChronic Illness & DiseasesPracticechronic diseaseprevention and controlpublic healthsurvellianceenvironmental interventionsArticle