Tuberculosis — United States, 2021

Thomas D. Filardo, MD; Pei-Jean Feng, MPH; Robert H. Pratt; Sandy F. Price; Julie L. Self, PhD

Disclosures

Morbidity and Mortality Weekly Report. 2022;71(12):441-446. 

In This Article

Abstract and Introduction

Introduction

During 1993–2019, the incidence of tuberculosis (TB) in the United States decreased steadily; however, during the later years of that period the annual rate of decline slowed[1] until 2020 when a substantial decline (19.9%) was observed. This sharp decrease in TB incidence might have been related to multiple factors coinciding with the COVID-19 pandemic, including delayed or missed TB diagnoses or a true reduction in TB incidence related to pandemic mitigation efforts and changes in immigration and travel.[2] During 2021, a total of 7,860 TB cases were provisionally reported to CDC's National Tuberculosis Surveillance System (NTSS) by the 50 U.S. states and the District of Columbia (DC). National incidence of reported TB (cases per 100,000 persons) rose 9.4% during 2021 (2.37) compared with that in 2020 (2.16) but remained 12.6% lower than the rate during 2019 (2.71).* During 2021, TB incidence increased among both U.S.-born and non–U.S.-born persons. The increased TB incidence observed during 2021 compared with 2020 might be partially explained by delayed diagnosis of cases in persons with symptom onset during 2020; however, the continued, substantial reduction from prepandemic levels raises concern for ongoing underdiagnosis. TB control and prevention services, including early diagnosis and complete treatment of TB and latent TB infection, should be maintained and TB awareness promoted to achieve elimination in the United States.

Health departments in the 50 U.S. states and DC report TB cases to CDC based on the Council of State and Territorial Epidemiologists' surveillance case definition, which includes both laboratory and clinically verified cases. For each case, health departments electronically submit a report of a verified TB case to CDC. Midyear U.S. Census Bureau population estimates§ were used to calculate national- and state-level TB incidence per 100,000 persons along with incidence stratified by age groups. Persons with TB were grouped by self-reported race and ethnicity according to federal guidelines. Persons who self-identified as Hispanic were categorized as Hispanic irrespective of self-reported race, persons not identifying as Hispanic were categorized by self-reported race, and non-Hispanic persons who reported more than one race were categorized as "multiple races." Midyear population estimates from the Current Population Survey** were used to calculate incidence by birth origin†† and race/ethnicity. Percent changes in incidence were calculated using unrounded figures.

A total of 7,860 TB cases were reported during 2021, 687 more than during 2020 (7,173) and 1,040 fewer than during 2019 (8,900) (Table 1). From 2020 to 2021, TB incidence (cases per 100,000 population) rose 9.4%, from 2.16 to 2.37, but remained 12.6% lower than during 2019 (2.71). California reported the highest number of cases (1,750), and Alaska reported the highest incidence (7.92). Eighteen states and DC reported the same number or fewer TB cases during 2021 than during 2020; the remaining 32 states reported more cases during 2021 than 2020.

During 2021, 71% of TB cases occurred among non–U.S.-born persons, the same proportion as in 2020 and 2019. Incidence (cases per 100,000 population) among U.S.-born persons increased from 0.71 in 2020 to 0.79 in 2021 and among non-U.S.-born persons from 11.71 in 2020 to 12.16 in 2021 (Figure). Among U.S.-born persons reported as having TB disease, 4% identified as American Indian or Alaska Native (AI/AN), 6% as Asian, 33% as Black, 25% as Hispanic, 2% as Native Hawaiian or other Pacific Islander (NH/OPI), 29% as White, and 1% as multiple races.§§ From 2020 to 2021, TB incidence decreased 0.4% among U.S.-born Black persons and 5.7% among U.S.-born NH/OPI persons and increased among all other U.S.-born groups (including AI/AN [5.0%], Asian [32.6%], Hispanic [16.3%], and White [13.8%] persons) (Table 2). Among non–U.S.-born persons reported as having TB disease, <1% identified as AI/AN, 48% as Asian, 12% as Black, 34% as Hispanic, 1% as NH/OPI, 4% as White, and 1% as multiple races. From 2020 to 2021, TB incidence decreased 8.7% among non–U.S.-born Black persons and 40.3% among non–U.S.-born NH/OPI persons and increased among all other non–U.S.-born groups (including Asian [3.7%], Hispanic [7.9%], and White [4.5%] persons).¶¶ Compared with TB incidence in 2020, incidence during 2021 declined 2.2% among children aged ≤4 years, 0.3% among children and adolescents aged 5–14 years, and 2.9% among persons aged 15–24 years. Incidence increased among adults aged 25–44 years (5.3%), 45–64 years (10.6%), and ≥65 years (13.2%).

Figure.

Tuberculosis disease case counts* and incidence, by patient birth origin§ — United States, 2011–2021
*Case counts are based on data from the National Tuberculosis Surveillance System as of February 9, 2022.
Cases per 100,000 persons. The Current Population Survey provides the population denominators used to calculate tuberculosis incidence according to national origin and racial/ethnic group. https://www.census.gov/programs-surveys/cps.html (Accessed February 9, 2022).
§Cases with unknown origin at birth excluded.

During 2021, among non–U.S.-born persons reported as having TB, 9.3% (507 of 5,456) received a diagnosis <1 year after arrival in the United States, compared with 9.7% (499 of 5,149) during 2020 and an average of 15.6% (996 of 6,377) during 2015–2019. Among non–U.S.-born persons with reported TB during 2021, approximately one third (1,811; 33.2%) had lived in the United States for at least 20 years before receiving a diagnosis, similar to the percentage during 2020 (1,662; 32%), and slightly more than the average of 28% (1,766) during 2015–2019. The proportion of persons who received a diagnosis of TB who had visible acid-fast bacilli on sputum smear microscopy, a marker of infectiousness and more advanced disease, during 2020 (46.4%) and 2021 (48.1%) were higher than the average proportion during 2015–2019 (44.3%).*** When stratified by birth origin, the prevalence of smear positivity among non–U.S.-born persons during 2020 (45.5%) and 2021 (47.8%) were higher than the average during 2015–2019 (42.6%). This increase in smear-positivity was not observed among U.S.-born persons who had received a diagnosis of TB (2021 = 48.2%; 2020 = 48.9%; average 2015–2019 = 48.7%).

*This report is limited to National Tuberculosis Surveillance System data verified as of February 9, 2022. Updated data will be available in CDC's annual TB surveillance report later in 2022.
https://www.cdc.gov/tb/programs/rvct/instructionmanual.pdf
§2021 vintage population estimates were used for 2021 and 2020. 2020 vintage population estimates were used for 2011–2019. https://www.census.gov/programs-surveys/popest/data/tables.html
https://www.census.gov/topics/population/race/about.html
**https://www.census.gov/programs-surveys/cps.html
††Persons born in the United States or a U.S. territory or elsewhere to at least one U.S. citizen parent are categorized as U.S.-born. All other persons are categorized as non–U.S.-born.
§§Persons with missing race or ethnicity data are excluded from calculations of proportions.
¶¶Percent change is not reported for non–U.S.-born AI/AN persons because there were no reported cases during 2020.
***Percentage of positive sputum smears is calculated among persons with a positive or negative sputum smear result; those with unknown results or for whom testing was reported as not performed were excluded.

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