sentence: New infections occur at a rate of one per second.
sentences_before: Experts believe that one third of the world population is infected with 'M. tuberculosis'.
sentences_after: In 2007, about 13.7 million chronic cases were active globally. The number of tuberculosis cases has been decreasing since 2006, and new cases have decreased since 2002.
concept_name: new infection
headings: Tuberculosis Prevalence
categories: Diseases caused by bacteria Pulmonology