Impact and Effectiveness of State-Level Tuberculosis Interventions in California, Florida, New York, and Texas: A Model-Based Analysis

Abstract

The incidence of tuberculosis (TB) in the United States has stabilized, and additional interventions are needed to make progress toward TB elimination. However, the impact of such interventions depends on local demography and the heterogeneity of populations at risk. Using state-level individual-based TB transmission models calibrated to California, Florida, New York, and Texas, we modeled 2 TB interventions: 1) increased targeted testing and treatment (TTT) of high-risk populations, including people who are non–US-born, diabetic, human immunodeficiency virus (HIV)-positive, homeless, or incarcerated; and 2) enhanced contact investigation (ECI) for contacts of TB patients, including higher completion of preventive therapy. For each intervention, we projected reductions in active TB incidence over 10 years (2016–2026) and numbers needed to screen and treat in order to avert 1 case. We estimated that TTT delivered to half of the non–US-born adult population could lower TB incidence by 19.8%–26.7% over a 10-year period. TTT delivered to smaller populations with higher TB risk (e.g., HIV-positive persons, homeless persons) and ECI were generally more efficient but had less overall impact on incidence. TTT targeted to smaller, highest-risk populations and ECI can be highly efficient; however, major reductions in incidence will only be achieved by also targeting larger, moderate-risk populations. Ultimately, to eliminate TB in the United States, a combination of these approaches will be necessary.

Policy Implications of Mathematical Modeling of Latent Tuberculosis Infection Testing and Treatment Strategies to Accelerate Tuberculosis Elimination

“…18 Although the effectiveness and cost effectiveness of targeting prevention efforts to specific populations differ by state, 19,20 JHU estimated that targeting LTBI testing and treatment to half of the non-US-born population in these 4 states could lower national TB incidence by 25% to 31% during the next 10 years. 21 LTBI testing and treatment delivered to less numerous populations with higher-than-average TB risk (eg, persons with HIV) was more efficient than LTBI testing and treatment of non-US-born persons but did not substantially reduce TB incidence in the United States. 21 The most-to-least cost-effective populations to test and treat were: persons with HIV, non-US-born persons, persons experiencing homelessness, incarcerated persons, and persons with diabetes.…”

“…21 LTBI testing and treatment delivered to less numerous populations with higher-than-average TB risk (eg, persons with HIV) was more efficient than LTBI testing and treatment of non-US-born persons but did not substantially reduce TB incidence in the United States. 21 The most-to-least cost-effective populations to test and treat were: persons with HIV, non-US-born persons, persons experiencing homelessness, incarcerated persons, and persons with diabetes. 20 JHU concluded that only by providing interventions to non-US-born persons could substantial reductions in TB incidence be made.…”

“…We summarize key results of NEEMA TB modeling activities that have been published or publicly presented and that have programmatic implications for which populations to test, which test to use, and which treatments are most cost effective. [17][18][19][20][21][22][23][24][25] A consensus of NEEMA modeling to date concurs with the aforementioned guidelines and suggests that, for greatest effectiveness and cost effectiveness, targeted testing policies should focus on LTBI testing and treatment among non-US-born persons and persons with HIV, respectively. Testing with an IGRA appears to be most cost effective.…”

“…20 JHU concluded that only by providing interventions to non-US-born persons could substantial reductions in TB incidence be made. 21 CAPE researchers modeled testing of various populations, types of tests, and treatment regimens in California, the state with the highest number of TB cases in the United States. 22 Researchers found that testing of non-US-born persons with medical risk factors for TB progression (HIV infection, tumor-necrosis-factor-alpha inhibitors use, receipt of solid organ transplant) was most cost effective, followed by testing of US-born persons with HIV, non-US-born persons with other medical risk factors (diabetes, end-stage renal disease, smoking), US-born persons with other medical risk factors, and non-US-born persons without medical risk factors.…”

“…JHU published and presented its findings, including those on cost effectiveness of interventions by population and state. 20,21 NEEMA modeling benefited greatly from collaboration with state and local TB staff members. In fact, its success is a direct result of such collaboration.…”