The southern U.S. had the nation's lowest five-year survival rate among those diagnosed with HIV or AIDS in 2003-2004, according to new research.

Fifteen percent of people diagnosed with HIV and 27 percent of those diagnosed with AIDS in that year had died within five years of diagnosis.

Nine southern states (Alabama, Florida, Georgia, Louisiana, Mississippi, North and South Carolina, Tennessee and Texas) are hit disproportionately hard by HIV/AIDS. Patients in this region tend to be younger, more rural, African-American and female. They are also more likely to attribute their HIV infection to heterosexual sex.

"This research documents the dire consequences that having an HIV diagnosis in the Deep South region has for too many individuals," said Duke University law professor Carolyn McAllaster, who directs the Southern HIV/AIDS Strategy Initiative (SASI) and the law school's AIDS/HIV and Cancer Legal Project.

The research team included the Center for Health Policy and Inequalities Research at the Duke Global Health Institute, SASI, the Centers for Disease Control and Prevention and the University of North Carolina School of Public Health. Their findings appear in the December 2014 edition of the Journal of Community Health.

Differences between U.S. regions in demographic characteristics and transmission risk did not explain the higher death rate among persons living with HIV in the targeted Southern states, indicating that other factors contribute to this disparity.

Lead author Susan Reif of the Duke Global Health Institute said a number of factors likely contribute to the differences in outcomes seen among individuals living with HIV in the Deep South, including poverty, lower levels of education and insurance coverage, social stigma associated with the disease, and racism.

"These differences are crucial to consider when creating strategies to address HIV/AIDS in this region," Reif said. "Clearly greater investment and focus are required to address the unique nature of the HIV/AIDS epidemic in the South."