Shelby County is home to less than 15 percent of the state's residents but almost 40 percent of its 14,000-plus HIV/AIDS patients, a fact that drew a visit Wednesday from the Department of Health and Human Services' assistant secretary for health. "This is a completely preventable epidemic," Dr. Howard K. Koh said prior to taking part in a community meeting at East High School. Koh's visit was part of a campaign launched by the Obama administration to fight HIV/AIDS, particularly its disproportionate impact on certain demographic groups. "This is a critical area because we have a million people infected in the nation," Koh said, adding that "some very basic work" remains to be done. Discrimination is hampering efforts to control the spread of the virus, said Health Department Director Yvonne Madlock: "Many people may choose not to know their status to avoid dealing not only with the disease but the stigma associated with the disease."