2018 State and City TB Report

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Treatment for Latent TB Infection

When a person with infectious TB coughs (sings or talks), droplet nuclei containing M. tuberculosis are expelled into the air. If another person inhales air containing these droplet nuclei, he or she might become infected. However, not everyone infected with TB bacteria develops symptoms of TB. As a result, two TB-related conditions exist: latent TB infection (LTBI) and TB disease.

Figure 11: Percentage of Contacts (to Sputum Acid-Fast Bacilli Smear-Positive TB Patients) Newly Diagnosed with Latent TB Infection Who Began Treatment, United States, 2017

Figure 11: Percentage of Contacts (to Sputum Acid-Fast Bacilli Smear-Positive TB Patients) Newly Diagnosed with Latent TB Infection Who Began Treatment, United States, 2017

Persons with LTBI do not feel sick and do not have any symptoms. They are infected with M. tuberculosis, but do not have TB disease at that time. The only sign of LTBI is a positive reaction to a TB skin test or TB blood test. Persons with LTBI are not infectious and cannot spread TB to others.  However, at some point in their lives, 5–10% of all people with normal immune systems who have LTBI will become sick with TB disease. As previously described, the chances of progression from LTBI to TB disease are higher for persons with weakened immune systems, such as those infected with HIV. LTBI can be treated to prevent the risk of progression to TB disease. Thus, it is important, in terms of accelerating the decline in TB incidence, to measure how many people with LTBI are identified through targeted testing, begin treatment, and complete treatment.

TB programs work to identify persons who are at high risk for LTBI or at high risk for developing TB disease once infected so that they can offer testing and treatment for LTBI. High-risk persons include:

  • Known close contacts of someone with infectious TB disease
  • Persons from regions of the world with high TB incidence
  • Those who work or reside in facilities or institutions with people who are also at high risk for TB.
Figure 12.  Percentage of Contacts (to Sputum Acid-Fast Bacilli Smear-Positive TB Patients) Newly Diagnosed with Latent TB Infection Who Completed Treatment, United States, 2017

Figure 12. Percentage of Contacts (to Sputum Acid-Fast Bacilli Smear-Positive TB Patients) Newly Diagnosed with Latent TB Infection Who Completed Treatment, United States, 2017

Risk factors for developing TB disease once infected include:

  • HIV infection
  • Injection drug use
  • Evidence of prior healed TB disease
  • Diabetes
  • Low body weight

Infants and children under the age of five years are also at higher risk of getting sick with TB disease once infected.

In 2017, the most recent year for which data are available, 11 states and 2 cities met or exceeded the 2025 national target of initiating treatment for 92.0% of people diagnosed with LTBI who were found during contact investigations; 23 states and 1 city were short of the 2025 target but exceeded the national average of 78.5% (Figure 11image icon, Footnotes).

In 2017, 5 states and 2 cities met or exceeded the 2025 national target of treatment completion for 93.0% of people diagnosed with LTBI through contact investigation who started treatment; 23 states and 4 cities were short of the 2025 target but met or exceeded the national average of 79.3% (Figure 12image icon, Footnotes).

Footnotes

Figure 11.  Percentage of Contacts (to Sputum Acid-Fast Bacilli Smear-Positive TB Patients) Newly Diagnosed with Latent TB Infection Who Began Treatment, United States, 2017

The fraction in each parenthesis reports the number of contacts who started treatment out of those contacts newly diagnosed with TB infection.
States/cities are grouped into thirds based on numbers of TB cases reported in 2017.
Baltimore, DC, DE, IA, ID, KS, ME, MT, ND, NE, NH, NM, RI, SD, UT, VT, WI, WV and WY reported 50 or fewer total TB cases in 2017.  Due to the small denominator, data should be interpreted with caution.  Vermont and Wyoming did not report any newly diagnosed LTBI patients.  Data were unavailable for Kansas and Missouri.

Data Source: Aggregate Reports for Program Evaluation as of October 30, 2019

 

Figure 12.  Percentage of Contacts (to Sputum Acid-Fast Bacilli Smear-Positive TB Patients) Newly Diagnosed with Latent TB Infection Who Completed Treatment, United States, 2017

The fraction in each parenthesis reports the number of contacts newly diagnosed with TB infection who completed treatment out of those contacts who started treatment.
States/cities are grouped into thirds based on numbers of TB cases reported in 2017.
Baltimore, DC, DE, IA, ID, KS, ME, MT, ND, NE, NH, NM, RI, SD, UT, VT, WI, WV and WY reported 50 or fewer total TB cases in 2017.
Due to the small denominator, data should be interpreted with caution.  Vermont and Wyoming did not report any newly diagnosed LTBI patients.  Data were unavailable for Kansas and Missouri.

Data Source: Aggregate Reports for Program Evaluation as of October 30, 2019

Page last reviewed: March 6, 2020