Challenges in Management of Pulmonary Tuberculosis in Patients with Silicosis

Dear Editor, Silico-tuberculosis is a worldwide problem that is common among persons having prolonged and significant exposure to crystalline silica in occupational settings.[1] These patients are at increased risk of relapse of disease and may require extension of tuberculosis treatment in view of poor drug penetration and extensive lesions. We conducted a prospective observation study among pulmonary tuberculosis cases having occupational exposure of silica dust and radiological features suggestive of silicosis. Among 65 such cases, the mean age was 42.43 ± 15 years (age range 21–66 years) with male-to-female ratio of 20:1. The sputum smear microscopy for acid-fast bacilli was positive in 24.5% cases. In 81.5% cases, Mycobacterium tuberculosis was detected in sputum examination for cartridge-based nucleic acid amplification test (CBNAAT)/line probe assay test. The remaining 18% cases were clinically diagnosed on suggestive clinical-radiological presentation. All patients were initiated on standard 6-month antituberculosis treatment under the national tuberculosis elimination program. In 69.3% cases, the treatment outcome was favorable (38.4% subjects completed their treatment successfully, and 30.8% subjects were cured). 30.7% cases showed unfavorable treatment outcome (6.2% subjects had treatment failure, and about 24.6% subjects died during the course of their illness on treatment). Rupani[2] also observed 2.3 times (95% confidence interval 1.6–3.4) higher odds of unfavorable treatment outcome of tuberculosis among silicosis patients than those without silicosis. About 27.6% patients in the present study required extension of tuberculosis treatment for another 3 months based on their poor clinical, radiological response, and unsatisfactory microbiological profile (positive sputum smear microscopy) at the end of 6 months following daily regular antituberculosis treatment. A controlled trial in Hong Kong among silico-tuberculosis patients observed a 22% relapse rate for those receiving 6 months of antituberculosis treatment compared to only 7% relapse rate among those receiving treatment for 8 months.[3] The result of the present study and others available in English literature indicates treatment challenges among pulmonary tuberculosis patients having concomitant silicosis in view of higher risk of treatment failure, relapse, and mortality, apart from persistent symptoms among such patients. Although relapse of tuberculosis among study subjects could not be assessed, this study, based on specified indications, provided extended duration of tuberculosis treatment for subset of such patients to achieve a favorable radiological and/or microbiological response. Active surveillance, early diagnosis, and effective treatment approaches are need of the hour to combat the dual challenge of silico-tuberculosis. Research quality and ethics statement This study was approved by the Institutional Ethics Committee (J L N Medical College, Ajmer # 338/Acad-III/MCA/2023). The authors followed applicable EQUATOR Network guidelines during the conduct of this research project. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.