Characteristics of tuberculosis in elderly adults: A multicenter French study

The incidence of tuberculosis (TB) remains high in elderly adults in France. Immunosenescence and comorbidities challenge both diagnosis and treatment in this population. Recent data describing TB characteristics and outcomes in the elderlies are scarce. We aimed to describe clinical and microbiological features of TB in the elderly population and to identify factors associated with 2-year mortality.

We conducted a retrospective multicenter study including patients aged ≥ 75 years who were diagnosed with TB between 2010 and 2020 across 18 centers. A multivariate analysis was used to identify factors independently associated with 2-year mortality.

A total of 295 patients were included: mainly born in France (57%). Immunosuppression was rare (9.8%). Fever and cough were uncommon, while weight loss was the most frequent symptom (60.3%), significantly associated with diagnostic delays. Pulmonary TB was the predominant form (63.1%) with higher culture positivity observed in this group and in the oldest patients. Isoniazid resistance was rare (5.2%). Standard quadritherapy was the most common initial regimen and was not associated with higher rates of adverse events. At two-year follow-up, overall mortality was 31.3%. In multivariate analysis, mortality was significantly associated with severe renal failure, living in nursing home or long-term care facilities, and weight loss at presentation.

This study highlights the atypical presentation of TB in elderly adults and the continued use of standard quadritherapy despite low drug resistance. Weight loss, though nonspecific, appears to be the most prognostic symptom and is associated with delayed diagnosis and higher mortality.