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

Abstract

Introduction 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, 1,766 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 1,171 (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<0.01), more likely to be U.S.-born (35% vs 28%, p<0.01) and to have diabetes (17% vs 13%, p<0.01), and less likely to have HIV (1% vs 8%, p<0.01). OTB was less likely to be laboratory confirmed (5% vs 75%, p<0.01) but patients were more likely to be tested by interferon gamma release assay (IGRA; 84% vs 56%, p<0.01) and IGRA positive (96% vs 80%, p<0.01). Conclusion Reported OTB increased during 1993–2019 despite decreasing TB, including EPTB; the largest increase occurred during 2010–2019. OTB was rarely laboratory confirmed and primarily diagnosed in conjunction with IGRA results. More research is needed to understand the epidemiology of OTB to inform clinical and diagnostic practices.