MAGNITUDE OF MYCOBACTERIUM TUBERCULOSIS AND ASSOCIATED FACTORS AMONG CLINICAL SAMPLES SENT FOR GENEXPERT AT SAINT PAUL HOSPITAL MILLENNIUM MEDICAL COLLEGE, ADDIS ABABA, ETHIOPIA: A RETROSPECTIVE CHART REVIEW

Abstract

Abstract Background: Tuberculosis (TB) remains a critical global public health challenge, with significant morbidity and mortality worldwide. Rapid and accurate detection of Mycobacterium tuberculosis (MTB) is essential for effective management, particularly in both pulmonary and extrapulmonary TB cases. The GeneXpert MTB/RIF assay enables simultaneous detection of MTB and rifampicin resistance from various clinical specimens. Despite its wide utilization in Ethiopia, limited evidence exists regarding TB positivity rates across different sample types and the socio-demographic, clinical, and laboratory factors associated with positive results and drug resistance at St. Paul’s Hospital Millennium Medical College (SPHMMC). Understanding these patterns is crucial for optimizing diagnostic strategies and guiding patient management and TB control programs. Objective: To determine the positivity rates of tuberculosis and the associated socio demographic, clinical, and laboratory factors among CSF, pleural fluid, peritoneal fluid, and sputum samples tested using GeneXpert at SPHMMC. Methods: A cross-sectional study was conducted using GeneXpert test records from January 2024 to December 2024. All eligible CSF, pleural, peritoneal, and sputum samples with complete demographic, clinical, and laboratory data were included. Data was extracted using a pretested data abstraction format, covering sample type, GeneXpert result, rifampicin resistance, patient age, sex, HIV status. The data was then entered and analyzed using SPSS version 27. Descriptive statistics summarized TB positivity rates and rifampicin resistance. Associations between TB positivity and covariates were assessed using chi-square tests and multivariate logistic regression, with a p-value <0.05 considered statistically significant. Result: A total of 501 clinical samples were analyzed, with a mean patient age of 38.2 years (SD = 21.24). The overall GeneXpert MTB positivity rate was 5.2% (26/501). Among the MTB-positive cases with available resistance data (n=25), the rifampicin resistance rate was 4.0% (1/25). Bivariate analysis showed no statistically significant association between patient sex and MTB positivity ($p = 0.115$), with females showing a positivity rate of 7.0% and males 3.5%. The type of clinical specimen was highly associated with positivity ($p < 0.001$); while sputum samples had a 3.0% positivity rate, non-sputum samples (FNAC, CSF, peritoneal, and pleural fluids) demonstrated higher positivity rates ranging from 20% to 50%. The positivity rate was highest among HIV-positive patients (11.8%). 73% of the samples had unknown HIV status which was the most significant finding of the study. Conclusion: The study demonstrates a 5.2% TB positivity rate at SPHMMC. Non-sputum specimen types were identified as significant predictors of positive results, underscoring the utility of GeneXpert MTB/RIF for rapid diagnosis beyond pulmonary TB. The rifampicin resistance rate of 4.0% necessitates continued vigilant surveillance. These findings highlight the need for targeted screening in high-risk groups and the importance of improving integrated TB/HIV documentation to enhance clinical management and public health interventions. In comparison, findings of this study showed lower positivity rates than previous studies done at st. Paul and significantly lowere rates than national and WHO studies which shows progressiely better TB control over the past few years. Keys: Tuberculosis, GeneXpert MTB/RIF, Ethiopia, Rifampicin Resistance, Extrapulmonary TB, SPHMMC.