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June 8, 2005

Diagnosis of Latent Tuberculosis Infection: Measure for Measure

Author Affiliations

Author Affiliation: Department of Epidemiology and Biostatistics and the Tuberculosis Research Unit, Case Western Reserve University School of Medicine, Cleveland, Ohio.

JAMA. 2005;293(22):2785-2787. doi:10.1001/jama.293.22.2785

In 2003, the World Health Organization reported 8.8 million cases of tuberculosis (TB) worldwide, nearly half of them presenting with an infectious form of disease, and resulting in 1.7 million deaths from TB. Since TB transmission occurs before diagnosis in the index case, even when an optimal TB control program is in place,1 new and undiagnosed cases are the driving force behind the current TB epidemic. If each new TB case in 2003 infected up to 10 susceptible contacts2 before diagnosis, up to 40 million new infections could have occurred worldwide that year alone. Since TB has a long period of latent infection, these new infections added to the pool of existing infections, which represents a source for potential TB cases in the years, and even decades, to come. One strategy for global TB control would be to implement an effective screening program in high-risk populations that would identify individuals with latent TB infection and treat them to prevent disease.