Abstract
Background: Mycobacterium tuberculosis sometimes become resistant to the drugs that are used to treat it. Drug resistant TB (DR-TB) is spread in the same way as drug susceptible TB. DR-TB is a public health crisis. This study aims to find the pattern of drug resistance and correlations between drug resistance and comorbid/non-comorbid conditions in patients with a relapse of TB. Methodology: A cross-sectional study was conducted among 200 HIV-negative relapsed TB patients from 2016-2017 in Mayo Hospital Lahore. The patients’ sputum samples were tested by Ziehl-Neelsen staining to observe acid-fast bacilli. The demographics and medical history of patients was recorded, who were positive for AFB in their sputum samples. Molecular procedure of Gene-Xpert assay was conducted to detect the presence of MTB and rifampicin resistance in the samples. Whereas, the drug susceptibility test (DST) was conducted on the LJ culture medium containing drugs.Results: Out of 200 relapsed TB cases; 97 were comorbid, 99 were non-comorbid. The most prevalent comorbidities were hypertension (42 cases- 43.3%), diabetes (45 cases-46.4%) and hepatitis B (14 cases-14.4%). Among 97 comorbid patients; 37 worked as laborers, 43 earned less than 20,000 PKR and 23 were found to have a history of imprisonment. Whereas in non-comorbid patients; 20 worked as laborers, 28 earned less than 20,000 PKR and 12 had been in prison before. The Gene-Xpert test detected rifampicin resistance (RR) in 20 comorbid (20.6%) and 33 non-comorbid (33.3%) patients. Whereas, the drug susceptibility test (DST) showed that 22 comorbid (22.7%) and 33 non-comorbid (33.3%) patients were RR. A contrast was seen in the results of Gene-Xpert and DST; Gene-Xpert detected 3 cases of RR-negative whereas the same 3 cases were found to be RR-positive on DST. Only 1 case was RR-positive on Gene-Xpert but RR-negative on DST. 17 comorbid patients (17.5%) were diagnosed with MDR-TB and 5 (5.2%) with XDR-TB. Whereas, in non-comorbid patients, there were 26 cases of MDR-TB (26.3%) and 5 cases of XDR-TB (5.1%). There were 2 patients (2.1%) resistant to all drugs.Conclusion: There was a deviation in the results of molecular Gene-Xpert assay compared to the conventional culture methods. Drug resistance was relatively higher in non-comorbid patients than comorbid patients, however, the difference between the two is not very significant.
Distribution Characteristics of Drug Susceptibility Test Results of Tuberculosis and Non-Tuberculous Bacilli in Patients with Opportunistic Infections of AIDS
