The Centers for Disease Control and Prevention has started a telephone survey to identify the extent of chronic disease syndrome (search) in Georgia.

The survey will allow the federal health agency to estimate the extent the syndrome in Georgia and in the United States, the agency said in a statement.

About 800,000 people in the United States have chronic disease syndrome or similar illnesses. Minorities and people with low incomes appear to be affected by the syndrome more often than others, the CDC said.

The survey will interview 17,000 randomly selected households in Georgia. More detailed interviews will be conducted to those who have the syndrome's symptoms, which includes a severe and debilitating fatigue (search), and those who appear to have the illness will be given free medical and lab evaluations.

Residents of DeKalb, Fulton, Bibb, Houston, Baldwin, Bleckley, Crawford, Jones, Macon, Monroe, Peach, Twiggs and Wilkinson counties will be interviewed for the study.

The CDC first started researching chronic disease syndrome two decades ago after investigating an outbreak of an unknown illness characterized by debilitating fatigue among residents of Incline Village, Nev. The agency has conducted a series of studies on CFS since 1988. The cause of CFS remains unknown, the CDC said.