Geographic analysis of latent tuberculosis screening: A health system approach

Epidemiology and Clinical Characteristics of Ocular Tuberculosis in the United States, 1993-2019

Background

Data regarding ocular tuberculosis (OTB) in the United States have not been previously reported. We evaluated trends of OTB compared with other extrapulmonary TB (EPTB).

Methods

We estimated the proportion of all EPTB cases (with or without concurrent pulmonary involvement) with OTB reported to the National Tuberculosis Surveillance System during 1993-2019. We compared demographics and clinical characteristics of people with OTB and other EPTB during 2010-2019. P values were calculated by chi-square test for categorical variables and Kruskal-Wallis for continuous variables.

Results

During 1993-2019, 1766 OTB cases were reported, representing 1.6% of 109 834 all EPTB cases: 200 (0.5% of 37 167) during 1993-1999, 395 (1.0% of 41 715) during 2000-2009, and 1171 (3.8% of 30 952) during 2010-2019. In contrast to persons with other EPTB, persons with OTB were older (median, 48 vs 44 years; P < .01), more likely to be US-born (35% vs 28%; P < .01), more likely to have diabetes (17% vs 13%; P < .01), and less likely to have HIV (1% vs 8%; P < .01). OTB was less likely to be laboratory confirmed (5% vs 75%; P < .01), but patients were more likely to be tested by interferon gamma release assay (IGRA; 84% vs 56%; P < .01) and to be IGRA positive (96% vs 80%; P < .01).

Conclusions

Reported OTB increased during 1993-2019 despite decreasing TB, including EPTB; the largest increase occurred during 2010-2019. OTB was rarely laboratory confirmed and was primarily diagnosed in conjunction with IGRA results. More research is needed to understand the epidemiology of OTB to inform clinical and diagnostic practices.

Area-Based Sociodemographic Factors Associated with Latent Tuberculosis Infection in a Low-Prevalence Setting

Area-based sociodemographic markers, such as census tract foreign-born population, have been used to identify individuals and communities with a high risk for tuberculosis (TB) infection in the United States. However, these markers have not been evaluated as independent risk factors for TB infection in children. We evaluated associations between census tract poverty, crowding, foreign-born population, and the CDC's Social Vulnerability Index (CDC-SVI) ranking and TB infection in a population of children tested for TB infection in Boston, Massachusetts. After adjustment for age, crowding, and foreign-born percentage, increasing census tract poverty was associated with increased odds of TB infection (adjusted odds ratio [aOR] per 10% increase in population proportion living in poverty: 1.20 [95% CI, 1.04-1.40]; P = 0.01), although this association was attenuated after further adjustment for preferred language. In separate models, increasing CDC-SVI ranking was associated with increased odds of TB infection, including after adjustment for age and language preference (aOR per 10-point increase in CDC-SVI rank: 1.08 [95% CI, 1.02-1.15]; P = 0.01). Our findings suggest area-based sociodemographic factors may be valuable for characterizing TB infection risk and defining the social ecology of pediatric TB infection in low-burden settings.

Increasing Use Of Interferon Gamma Release Assays Among Children ≥2 Years of Age in a Setting With Low Tuberculosis Prevalence

US guidelines recommend interferon gamma release assays (IGRAs) for diagnosis of tuberculosis infection in children. In this retrospective cohort study, IGRA use in children 2-17 years of age increased substantially between 2015 and 2021. Testing in inpatient/subspecialty settings (vs. primary care), public (vs. private) insurance, lower age and non-English preferred language were associated with increased odds of receiving an IGRA.