Detection of Mycobacterium tuberculosis and rifampicin resistance using the Xpert MTB/RIF assay among suspected tuberculosis patients at a tertiary-care hospital in Southern Punjab, Pakistan: a cross-sectional study

Abstract Background Drug-resistant tuberculosis remains an important concern in high-burden settings, where delayed identification of resistance can complicate treatment and infection-control decisions. This study examined MTB detection by Xpert MTB/RIF and the frequency of molecularly detected rifampicin resistance among presumptive TB patients in a tertiary-care hospital in Southern Punjab, Pakistan. Methods A descriptive cross-sectional study was conducted in the Department of Microbiology, Combined Military Hospital, Multan, between 1 January and 31 December 2024. We included 170 adults aged 18–75 years with clinical or radiological findings suggestive of pulmonary or extrapulmonary TB. Clinical specimens were examined with the Xpert MTB/RIF assay. MTB detection and rifampicin resistance were summarized using frequencies, percentages and 95% confidence intervals. Results The 170 participants had a mean age of 45.8 ± 10.2 years; 95 (55.9%) were male and 75 (44.1%) were female. Pulmonary specimens accounted for 114 (67.1%) samples and extrapulmonary specimens for 56 (32.9%). MTB was detected in 136/170 participants (80.0%; 95% CI 73.2–85.8%). Detection was 96/114 (84.2%) in pulmonary specimens and 40/56 (71.4%) in extrapulmonary specimens. Among the 136 Xpert MTB-positive cases, rifampicin resistance was detected in 16 (11.76%; 95% CI 6.9–18.4%), while 120 (88.24%) had no molecular evidence of rifampicin resistance. The reported comparisons showed no statistically significant association between rifampicin resistance and age (p = 0.42) or sex (p = 0.68). Conclusions Xpert MTB/RIF identified MTB in a substantial proportion of presumptive TB patients and simultaneously identified rifampicin resistance in a subset of MTB-positive cases. The findings support rapid molecular testing in this clinical setting, but the single-centre design and absence of comprehensive drug-susceptibility testing restrict the extent to which the results can be generalized or used to characterize the wider resistance profile.