ATLANTA — Tuberculosis kills more than 2.5 million people each year in developing countries, largely because they can’t afford treatment, U.S. health officials said Thursday.

Applying TB rates and population figures, the Centers for Disease Control estimated that 7.1 million new cases occur each year in developing countries, including 5.1 million in East and South Asia and 1.2 million in sub-Saharan Africa. West Asia, North Africa and Central and South America account for 860,000.

More than a third of those patients will die, largely because of poor treatment or no treatment, the CDC said in its weekly report. The estimated number of deaths from TB in the Third World is more than 2.5 million, the Atlanta-based agency said.

“With the possible exception of measles, more persons in developing countries die from TB each year than from any other pathogen,” the CDC said. “Existing diagnostic technology and chemotherapeutic agents can prevent … TB in these countries.”

Tuberculosis, a contagious bacterial infection of the lungs, can be cured in most cases with antibiotic drug treatment.

“The most effective means of reducing transmission of tuberculosis infection, and thus the number of TB cases, is to treat and cure patients,” the CDC said.

But treatment often doesn’t reach patients in poorer countries.

“It’s a combination of things, but clearly, it’s money and resources,” said Dr. Christopher Murray, lead researcher for the CDC report and a research fellow at the Center for Population Studies at the Harvard School of Public Health.