A narrative review of tuberculosis in the United States among persons aged 65 years and older.

Tuberculosis (TB) is a preventable infectious disease that confers significant morbidity, mortality, and psychosocial challenges. As TB incidence in the United States (U.S.) decreased from 9.7/100,000 to 2.2/100,000 from 1993 to 2020, the proportion of cases occurring among adults aged 65 and older increased. We conducted a review of published literature in the U.S. and other similar low-TB-burden settings to characterize the epidemiology and unique diagnostic challenges of TB in older adults. This narrative review also provides an overview of treatment characteristics, outcomes, and research gaps in this patient population. Older adults had a 30% higher likelihood of delayed TB diagnosis, with contributing factors such as acid-fast bacilli sputum smear-negative disease (56%) and non-classical clinical presentation. At least 90% of TB cases among older adults resulted from reactivation of latent TB infection (LTBI), but guidance around when to screen and treat LTBI in these patients is lacking. In addition, routine TB testing methods such as interferon-gamma release assays were two times more likely to have false-negative results among older adults. Advanced age was also often accompanied by complex comorbidities and impaired drug metabolism, increasing the risk of treatment failure (23%) and death (19%). A greater understanding of the unique factors of TB among older adults will inform clinical and public health efforts to improve outcomes in this complex patient population and TB control in the U.S.

Tuberculosis Disease Among Adults Aged 65 Years and Older: Alameda County, California, 2016-2019.

Background: Older adults aged ≥65 years old represent an increasing proportion of tuberculosis (TB) cases in the United States, but limited evidence exists on the characteristics and treatment outcomes that differentiate them from younger adults. Methods: We evaluated Alameda County TB surveillance data from 2016 to 2019 and abstracted public health charts for older adult TB cases. Clinical presentation and treatment outcomes were compared in older and younger adults (15-64 years), and multivariable logistic regression was conducted to assess risk factors for TB treatment noncompletion among older adults. Results: Of 517 TB cases, 172 (33.2%) were older adults and 101 were ≥75 years old. Compared to younger adults, older TB cases were more likely to be non-US-born, and have diabetes. For diagnosis, older adults were more likely to have negative interferon-gamma release assays (24.6% vs 16.0%; P = .01) and were less likely to have cavitary disease (18.6% vs 26.7%; P < .001). One third of older adults experienced an adverse event; older adults were less likely to complete TB treatment (77.7% vs 88.4%; P = .002) and were more likely to die during TB treatment (16.3% vs 2.9%; P < .01), especially among those ≥75 years old, who had a mortality rate of 22.9%. In multivariable analysis, dementia was significantly associated with treatment noncompletion (adjusted odds ratio, 5.05; 95% confidence interval, 1.33-20.32; P = .02). Conclusions: Diabetes, negative diagnostic tests, and poor treatment outcomes were more prevalent in older adult TB cases. A greater understanding of their TB presentation and comorbidities will inform interventions to improve outcomes among older adults.