Purpose
This Aggregate Reports for Tuberculosis Program Evaluation (ARPE) report summarizes national contact investigation efforts related to tuberculosis (TB) cases diagnosed in 2021 as well as summary data from the period 2017-2020.
About the report
Follow-up examination and treatment of contacts to patients with tuberculosis (TB) is a national TB prevention and control priority in the United States.
Each year, TB programs report results of their contact investigation activities to CDC by entering the data into the Aggregate Reports for Tuberculosis Program Evaluation (ARPE) form via the National Tuberculosis Indicators Project performance-monitoring tool.
ARPE data provide the only national level data on contact investigations and are reported in three categories:
- Sputum smear-positive
- Sputum smear-negative/culture-positive
- Other
The data are also used by awardees as a tool to evaluate and coordinate TB prevention activities.
Data summary
In 2021, 7,882 TB cases were reported in the United States. Of these, 3,320 were AFB smear-positive and 1,420 were AFB smear-negative, culture-positive. The number of sputum acid-fast bacillus (AFB) smear-positive TB cases identified in 2021 (3,320) were fewer than the annual number identified during 2017-2019 (range: 3,364 - 3,481) but higher than those identified in 2020 (2,879).
Elicitation of contacts
Similarly, the number of contacts elicited declined in 2021 (27,202) as compared to any year in the period 2017-2020 (range: 35,915-53,783). The percentage of cases with contacts elicited in 2021 (3,050; 91.9%) was also lower than the annual percentages achieved during the period 2017-2020, with all years falling below the 2025 National Performance Target of 100%. Declines in the number and percentage of cases with contacts elicited in 2021 as compared to prior years might be related to the COVID-19 epidemic, so caution should be exercised when interpreting that data.
Evaluation of contacts
Evaluation of contacts to smear-positive cases in 2021 (76.2%) also remained below the 2025 National Performance Target of 94% but was similar to levels of performance achieved annually during the period 2017-2020 (range: 75.7% -80.6%).
Diagnosis and treatment of latent TB infection
Among the 27,202 contacts elicited to smear-positive cases in 2021, 4,438 (21.4%) were diagnosed with latent TB infection. Of those, 73.7% (3,272) initiated treatment and 81.2% (2,657) of those completed treatment. The 2021 latent TB infection treatment initiation percentage (73.7%) was lower than that achieved annually between 2017-2020 (range: 75.8%-77.8%). Treatment completion percentages were similar throughout the period of 2017-2021 (range: 76.8%-81.2%). Performance for both latent TB infection treatment initiation and completion remains below the 2025 National TB Performance Targets of 92% and 93%, respectively.
Additionally, among persons diagnosed with latent TB infection and determined to be contacts of smear-positive TB cases in 2021, contacts choosing to stop treatment for any reason accounted for 32.4%, while contacts lost to follow-up accounted for 43.5%.
Appendix A: Sputum smear-positive TB cases
Appendix A. Counts and Indices for Investigation of Sputum Acid-fast Bacillus (AFB) Smear-Positive TB Cases, 2017-2021A
| Cases and Contacts | 2017 | 2018 | 2019 | 2020 | 2021 |
|---|---|---|---|---|---|
| Cases for investigation | 3,364 | 3,398 | 3,481 | 2,879 | 3,320 |
| Cases, no contacts | 247 | 187 | 193 | 206 | 270 |
| Number of contacts | 51,447 | 53,783 | 51,419 | 35,915 | 27,202 |
| Evaluated | 41,489 | 42,302 | 38,942 | 28,095 | 20,738 |
| TB disease | 416 | 352 | 345 | 317 | 381 |
| Latent TB infection | 6,428 | 6,044 | 5,587 | 4,229 | 4,438 |
| • Started treatment | 4,952 | 4,583 | 4,271 | 3,290 | 3,272 |
| • Completed treatment | 3,804 | 3,623 | 3,423 | 2,600 | 2657 |
| • Treatment outcome unknown/missing | 231 | 366 | 283 | 335 | 263 |
| Reason | 2017 | 2018 | 2019 | 2020 | 2021 |
|---|---|---|---|---|---|
| Contacts stopping treatment (n) | 917 | 594 | 565 | 355 | 352 |
| Active TB developed | 7 (0.8%) | 6 (1.0%) | 4 (0.7%) | 2 (0.6%) | 2 (0.6%) |
| Adverse effect of medicine | 53 (5.8%) | 51 (8.6%) | 47 (8.3%) | 40 (11.3%) | 41 (11.6%) |
| Contact chose to stop | 304 (33.1%) | 256 (43.1%) | 185 (32.7%) | 114 (32.1%) | 114 (32.4%) |
| Contact lost to follow-up | 415 (45.2%) | 190 (32.0%) | 249 (44.1%) | 145 (40.8%) | 153 (43.5%) |
| Contact moved (follow-up unknown) | 67 (7.3%) | 35 (5.9%) | 38 (6.7%) | 27 (7.6%) | 22 (6.2%) |
| Death | 6 (0.7%) | 4 (0.7%) | 8 (1.4%) | 5 (1.4%) | 8 (2.3%) |
| Provider decision | 65 (7.1%) | 52 (8.7%) | 34 (6.1%) | 22 (6.2%) | 12 (3.4%) |
| Evaluation Indices (%) | 2017 | 2018 | 2019 | 2020 | 2021 |
|---|---|---|---|---|---|
| Contact elicitation (%) | 92.7% | 94.5% | 94.5% | 92.8% | 91.9% |
| Contacts per case (N, Average) | 15.3 | 15.8 | 14.8 | 12.5 | 8.2 |
| Contact evaluation (%) | 80.6% | 78.7% | 75.7% | 78.2% | 76.2% |
| TB disease (%) | 1.0% | 0.8% | 0.9% | 1.1% | 1.8% |
| Latent TB infection (%) | 15.5% | 14.3% | 14.3% | 15.1% | 21.4% |
| Latent TB infection treatment initiated (%) | 77.0% | 75.8% | 76.4% | 77.8% | 73.7% |
| Latent TB infection treatment completed (%) | 76.8% | 79.1% | 80.1% | 79.0% | 81.2% |
Figure 1: Proportion of TB patients with contacts elicited
National objective
Increase the proportion of TB patients with positive acid-fast bacillus (AFB) sputum-smear results who have contacts elicited to 100.0% by 2025.
Indicator
Percent of sputum AFB smear-positive TB cases with contacts elicited
Cohort
- Sputum AFB smear-positive TB cases are counted in the cohort period of interest.
- Records with a variable(s) for which exclusion criteria cannot be assessed are included in the analytic cohort.
Data sources
- ARPEs (Contacts) fields, a1 (Sputum smear+ Cases for Investigation), b1 (Sputum smear+ Cases with No Contacts)
- Sputum AFB smear-positive TB cases with contacts elicited = Number of sputum AFB smear-positive TB cases for investigation - Number of sputum AFB smear-positive cases with no contacts.
Calculation
[(Number of sputum AFB smear-positive TB cases with contacts elicited) / Cohort] x 100.
Figure 2: Evaluation of contacts
National objective
Increase the proportion of contacts to sputum AFB smear-positive TB cases who are examined for infection and disease to 94.0% by 2025. Contacts are counted as evaluated if they have been tested and examined to the point where a final determination of diagnosis is either latent TB infection or TB disease.
Indicator
Percent of contacts to sputum AFB smear-positive TB cases examined for infection and disease
Cohort
Contacts to sputum AFB smear-positive TB cases counted in the cohort period of interest. Records with a variable(s) for which exclusion criteria cannot be assessed are included in the analytic cohort.
Data sources
ARPEs (Contacts) fields, c1 (Number of Contacts to Sputum smear+ Cases), d1 (Contacts to Sputum smear+ Cases Evaluated)
Calculation
[Number of contacts to sputum AFB smear-positive TB cases evaluated/ Cohort] x 100.
Figure 3: Latent TB infection treatment initiation
National objective
Increase the proportion of contacts to sputum AFB smear-positive TB cases diagnosed with latent TB infection who start treatment to 92.0% by 2025.
Indicator
Percent of contacts to sputum AFB smear-positive TB cases diagnosed with latent TB infection who started treatment. Contacts are counted as having started treatment after taking the first dose of a treatment course.
Cohort
Contacts to sputum AFB smear-positive TB cases who have newly diagnosed latent TB infection, counted in the cohort period of interest. Records with a variable(s) for which exclusion criteria cannot be assessed are included in the analytic cohort.
Data Sources
ARPEs (Contacts) fields, f1 (Contacts to Sputum smear+ Cases with Latent TB Infection), g1 (Contacts to Sputum smear+ Cases Diagnosed with Latent TB Infection Who Started Treatment)
Calculation
[Number of contacts diagnosed with latent TB infection who started treatment/ Cohort] x 100.
Figure 4: Latent TB infection treatment completion
National objective
For contacts to sputum AFB smear-positive TB cases who have started treatment for latent TB infection, increase the proportion who complete treatment to 93.0% by 2025.
Indicator
Percent of contacts to sputum AFB smear-positive TB cases who complete treatment.
Cohort
Contacts to sputum AFB smear-positive TB cases with newly diagnosed latent TB infection and have started treatment are counted in the cohort period of interest. Records with a variable(s) for which exclusion criteria cannot be assessed are included in the analytic cohort.
Data sources
ARPEs (Contacts) fields, g1 (Contacts to Sputum smear+ Cases Diagnosed with Latent TB Infection Who Started Treatment), h1 (Contacts to Sputum smear+ Cases Diagnosed with Latent TB Infection Who Completed Treatment)
Calculation
[Number of contacts diagnosed with latent TB infection who completed treatment / Cohort] x 100
Figure 5: Number of contacts to AFB smear-positive TB cases
Appendix B. Sputum smear-negative, culture-positive TB cases
Appendix B. Counts and Indices for Investigation of Sputum AFB Smear-Negative, Culture-Positive TB Cases, 2016-2020A
| Cases and Contacts | 2017 | 2018 | 2019 | 2020 | 2021 |
|---|---|---|---|---|---|
| Cases for investigation | 1,827 | 1,903 | 1,784 | 1,343 | 1,420 |
| Cases, no contacts | 312 | 258 | 257 | 205 | 251 |
| Number of contacts | 14,101 | 13,589 | 12,679 | 8,831 | 8,120 |
| Evaluated | 11,628 | 10,713 | 9,908 | 6,940 | 6,254 |
| TB disease | 72 | 72 | 63 | 66 | 78 |
| Latent TB infection | 1,320 | 1,428 | 1,147 | 901 | 872 |
| • Started treatment | 893 | 958 | 747 | 567 | 527 |
| • Completed treatment | 703 | 744 | 606 | 413 | 428 |
| • Treatment outcome unknown/missing | 46 | 40 | 32 | 91 | 41 |
| Reason | 2017 | 2018 | 2019 | 2020 | 2021 |
|---|---|---|---|---|---|
| Contacts stopping treatment (n) | 144 | 174 | 109 | 63 | 58 |
| Active TB developed | 1 (0.7%) | 4 (2.3%) | 2(1.8%) | 0 (0%) | 0 (0%) |
| Adverse effect of medicine | 17 (11.8%) | 21 (12.1%) | 13 (11.9%) | 12 (19.0%) | 5 (8.6%) |
| Contact chose to stop | 49 (34.0%) | 71 (40.8%) | 38 (34.9%) | 25 (39.7%) | 21 (36.2%) |
| Contact lost to follow-up | 44 (30.6%) | 54 (31.0%) | 42 (38.5%) | 20 (31.7%) | 25 (43.1%) |
| Contact moved (follow-up unknown) | 15 (10.4%) | 10 (5.7%) | 6 (5.5%) | 2 (3.2%) | 3 (5.2%) |
| Death | 1 (0.7%) | 2 (1.1%) | 4 (3.7%) | 2 (3.2%) | 3 (5.2%) |
| Provider decision | 17 (11.8%) | 12 (7.0%) | 4 (3.7%) | 2 (3.2%) | 1 (1.7%) |
| Evaluation Indices (%) | 2017 | 2018 | 2019 | 2020 | 2021 |
|---|---|---|---|---|---|
| Contact elicitation (%) | 82.9% | 86.4% | 85.6% | 84.7% | 82.3% |
| Contacts per case (N, Average) | 7.7 | 7.1 | 7.1 | 6.6 | 5.7 |
| Contact evaluation (%) | 82.5% | 78.8% | 78.1% | 78.6% | 77.0% |
| TB disease (%) | 0.6% | 0.7% | 0.6% | 0.9% | 1.2% |
| Latent TB infection (%) | 11.4% | 13.3% | 11.6% | 12.9% | 13.9% |
| Latent TB infection treatment initiated (%) | 67.7% | 67.1% | 65.1% | 62.9% | 60.4% |
| Latent TB infection treatment completed (%) | 78.7% | 77.7% | 81.1% | 72.8% | 81.2% |
Appendix C: Other*
Appendix C. Counts and Indices for Investigation of Other* Cases, 2017-2021A
* Other: Contact investigations not captured in investigating sputum AFB smear-positive or sputum AFB smear-negative, culture-positive. For example: Associate-contact or source-case investigations done because of a child with TB disease.
| Contacts | 2017 | 2018 | 2019 | 2020 | 2021 |
|---|---|---|---|---|---|
| Number of contacts | 7,930 | 10,667 | 8,309 | 5,620 | 8,079 |
| Evaluated | 6,755 | 8,837 | 6,207 | 4,293 | 6,118 |
| TB disease | 62 | 69 | 66 | 65 | 85 |
| Latent TB infection | 724 | 820 | 796 | 515 | 749 |
| • Started treatment | 532 | 577 | 551 | 344 | 425 |
| • Completed treatment | 428 | 493 | 457 | 283 | 338 |
| • Treatment outcome unknown/missing | 25 | 18 | 24 | 12 | 32 |
| Reason | 2017 | 2018 | 2019 | 2020 | 2021 |
|---|---|---|---|---|---|
| Contacts stopping treatment (n) | 79 | 66 | 70 | 49 | 55 |
| Active TB developed | 4 (5.1%) | 1 (1.5%) | 0 (0%) | 0 (0%) | 0 (0%) |
| Adverse effect of medicine | 5 (6.3%) | 9 (13.6%) | 14 (20.0%) | 6 (12.2%) | 4 (7.3%) |
| Contact chose to stop | 31 (39.2%) | 18 (27.3%) | 27 (38.6%) | 18 (36.7%) | 25 (45.4%) |
| Contact lost to follow-up | 26 (33.0%) | 26 (39.4%) | 21 (30.0%) | 19 (38.8%) | 22 (40.0%) |
| Contact moved (follow-up unknown) | 8 (10.1%) | 5 (7.6%) | 5 (7.1%) | 4 (8.2%) | 3 (5.5%) |
| Death | 0 (0%) | 1 (1.5%) | 0 (0%) | 0 (0%) | 0 (0%) |
| Provider decision | 5 (6.3%) | 6 (9.1%) | 3 (4.3%) | 2 (4.1%) | 1 (1.8%) |
| Evaluation Indices (%) | 2017 | 2018 | 2019 | 2020 | 2021 |
| Contact evaluation (%) | 85.2% | 82.8% | 74.7% | 76.4% | 75.7% |
| TB disease (%) | 0.9% | 0.8% | 1.1% | 1.5% | 1.4% |
| Latent TB infection (%) | 10.7% | 9.3% | 12.8% | 11.9% | 12.2% |
| Latent TB infection treatment initiated (%) | 73.5% | 70.4% | 69.2% | 66.8% | 56.7% |
| Latent TB infection treatment completed (%) | 80.5% | 85.4% | 82.9% | 82.3% | 79.5% |
- Reporting jurisdictions: 50 U.S. states, Washington D.C., Puerto Rico, and eight large city jurisdictions (Los Angeles, CA; San Francisco, CA; San Diego, CA; Chicago, IL; Baltimore, MD; New York City, NY; Philadelphia, PA; Houston, TX). Missouri and Kansas did not report in 2017 and 2018. Nebraska and the Virgin Islands did not report in 2018. Iowa did not report in 2020. Vermont did not report in 2019 and 2021. Data shown in tables and figures are up to date as of July 28, 2023.