Mycobacterium tuberculosis: Overcoming one obstacle on the road to elimination

The interferon-gamma release assay is a blood test that has a greater specificity than TST and requires only one visit. A positive test is seen in both latent TB infection and TB disease. There is no cross-reaction with BCG. This is the ideal test for prior BCG recipients and others who are unlikely to return for TST readings and are at least 5 years of age.

A chest radiograph is required to differentiate latent TB infection from TB disease. Latent TB infection is diagnosed when there is an absence of parenchymal disease, opacification, or intrathoracic adenopathy.

Treatment of latent TB infection versus TB disease is beyond the scope of this article. Consultation with an infectious disease expert is recommended.

For additional information and resources, go to www.cdc.gov/tb, and for a sample TB risk assessment tool, go to www.cdc.gov/tb/publications/ltbi/appendixa.htm.

As we mark the passing of another World TB Day, we have one goal – to identify, screen, and treat children and adolescents at risk for latent TB infection and help eliminate future cases of TB disease.
 

Dr. Word is a pediatric infectious disease specialist and director of the Houston Travel Medicine Clinic. She said she had no relevant financial disclosures.