Extrapulmonary tuberculosis in Africa: Molecular analysis of clinical specimens of suspected cases in Northern Ghana

Abstract

Extrapulmonary tuberculosis (EPTB) is a major component of the total tuberculosis cases reported by the World Health Organization. This is a study conducted to compare microscopy and molecular techniques to determine the prevalence of Mycobacterium tuberculosis complex (MTBC) in EPTB patients.Smear microscopy and genotype MTBDRplus line probe assay (LiPA) were applied to concentrated extrapulmonary clinical specimens from different anatomic sites to determine the presence of M. tuberculosis and their susceptibility to isoniazid (INH) and/or rifampin (RIF).A total of 251 specimens comprising 108 (43%) ascitic fluid, 54 (21.5%) pleural aspirate, 24 (9.6%) gastric lavage, 15 (6.0%) pus, 9 (3.6%) synovial fluid, 5 (2%) cerebrospinal fluid, 2 (0.8%) breast aspirate and 34 (13.5%) aspirates from unindicated sites obtained from patients with suspected EPTB attending the Tamale Teaching Hospital were analysed. Microscopically, acid fast bacilli (AFB) were detected in one ascitic fluid and a pus specimen. Using the LiPA, MTBC was observed in four (2.6%) samples; three (3) ascitic fluid and one aspirate.M. tuberculosis complex was confirmed in four (2.6%) patients. The most common specimens suspected of EPTB were ascitic fluid, pleural aspirate and gastric lavage. However, MTBC was predominantly detected in ascitic fluid. This result indicates that the LiPA can improve the detection of EPTB in the region and similar settings globally.