Tuberculosis in the United States, 2019: A Record Low, but a Slow Decline

The United States has pursued the elimination of tuberculosis (TB) since 1989, by quickly finding and treating cases and testing people exposed to them to stop further spread. The strategy worked: TB incidence has fallen by approximately two-thirds since then. But progress has slowed in recent years, and CDC’s provisional data for 2019 show why.

The 2019 numbers

• 8,920 new cases, 1.1% fewer than in 2018 — the lowest count ever reported
• 2.7 cases per 100,000 people, down 1.6% — the lowest rate on record
• an average decline of 2.1% a year during 2012–2019, slower than during 2007–2012

State rates ranged from 0.2 per 100,000 in Wyoming to 8.1 in Alaska. Nine states — Alaska, California, Georgia, Hawaii, Maryland, New Jersey, New York, Texas and Washington — and the District of Columbia were above the national rate. California, Florida, New York and Texas still accounted for about half of all cases.

Born abroad, infected long ago

6,322 cases (70.9%) were in people born outside the United States, whose TB rate was 15.5 times that of U.S.-born people.

TB cases and rates by national origin, 2007–2019. Image from CDC’s report.

Among people born abroad, rates were highest in Asian (25.7) and Native Hawaiian or Pacific Islander (25.1) people, followed by Black (19.5), Hispanic (10.2) and American Indian or Alaska Native (5.3) people, and lowest in white people (3.1). The top five countries of birth were:

Among U.S.-born people, rates were highest in Native Hawaiian or Pacific Islander (3.5) and American Indian or Alaska Native (3.4) people, then Black (2.5), Hispanic (1.6) and Asian (1.6) people, and lowest in white people (0.4).

HIV and drug resistance

• HIV status was known for 87.3% of cases; 4.9% of them had HIV, rising to 7.8% among people aged 25–44.
• In 2018 (the latest year with complete data), 102 of 6,746 tested cases (1.5%) were multidrug-resistant — 88 of them in people born abroad, and 83 in people with no earlier TB episode. There was one case of extensively drug-resistant TB.

Why progress has slowed

The elimination strategy works best against recent transmission — and a shrinking share of U.S. cases comes from that. About 80% now result from reactivation of latent TB infection (LTBI): an infection acquired years earlier, often outside the United States, that later turns into active disease.

That calls for a broader strategy that puts more emphasis on finding and treating latent TB — without weakening efforts to stop transmission, or the country risks another resurgence like that of the late 1980s and early 1990s.

• The U.S. Preventive Services Task Force and CDC recommend routine latent TB screening for people at higher risk, such as those who have lived in countries where TB is more common or in homeless shelters or correctional facilities.
• Screening and treating these groups compares favorably, in effectiveness and cost, with accepted preventive care such as mammography and statins, so it should be a routine part of primary care for people at elevated risk.
• Fear of side effects has held treatment back. New CDC and National Tuberculosis Controllers Association guidelines recommend short, rifamycin-based regimens, which are less toxic and more often completed than isoniazid alone.
• Partnerships with health care providers, including private providers, are essential.

Limits: the 2019 figures are provisional, rates rest on estimated populations, rates for small groups swing more from year to year, and complete drug-resistance data take longer because TB bacteria grow slowly.

Sources

Based on Schwartz NG, Price SF, Pratt RH, Langer AJ, "Tuberculosis — United States, 2019," MMWR Vol. 69, No. 11, CDC; a work of the United States government in the public domain. The report gives two different average yearly declines for 2007–2012 (6.7% and 6.4%), so neither is stated here.