Cross-sectional Evaluation of Mycobacterial Associations with Lung Disease and Its Associated Factors

Abstract

Background: Nontuberculous mycobacteria (NTM), a diverse group of environmental organisms rapidly proliferating in water, soil, and dust, are becoming a common cause of clinical disease. This study analyzed patient data from two major hospitals in Faisalabad, Pakistan, to improve early detection of NTM lung disease and to guide clinical practice in seeking earlier and quicker intervention.  

Methods: A retrospective cross-sectional study was conducted from January 2020 to December 2021, using the records of 294 tuberculosis patients at Allied Hospital and DHQ Hospital, Faisalabad. Non-probability convenience sampling was used for sample collection and sample size was collected using OpenEpi 3.0.0.  Data from patients with NTM lung disease were checked. The diagnosis was based on criteria defined by the ATS/IDSA (a clinical, radiological and microbiological evidence). Testing of specimens (sputum, BAL fluid, puncture fluid) was conducted using AFB smear, culture (MGIT 960) and species identification by molecular techniques. Chi-square, Wilcoxon tests and logistic regression were performed using SPSS version 26.0.p<0.05 was considered as significant.

Results: There were 294 patients (147 males; 147 females); median age 61 years, 77.2% had bronchiectasis. The most frequently identified species was the Mycobacterium avium-intracellulare complex (MAC 56.1%) followed by M. kansasii (19%) and M. abscessus (15.3%).   Sputum cultures had the highest positivity rate (87.4%), outperforming BAL fluid (80.3%) and puncture fluid (61.5%).

Conclusion: The M. avium-intracellulare complex is the most common NTM species found in patients in these hospitals. The signs of expectoration, gender and bronchiectasis increased likelihood of BAL culture positivity, which aids in diagnosis.