Prevalence of tuberculosis, multidrug resistant tuberculosis and associated risk factors among smear negative presumptive pulmonary tuberculosis patients in Addis Ababa, Ethiopia

Abstract

Background The diagnoses of active smear negative PTB, remains difficult. As a result, treatment is often carried out empirically relaying on clinical criteria. The distribution and magnitude of smear negative PTB, smear negative MDR-TB and associated factors in the same day diagnosis strategy are not clearly known in the study area. Therefore, this study aimed to determine the prevalence of TB, MDR-TB and associated risk factors among presumptive smear negative pulmonary tuberculosis patients in Addis Ababa, Ethiopia. Methods Analytic cross sectional study design was used. A total of 418 smear negative presumptive pulmonary TB patients were enrolled from selected health facilities since August 01, 2017 to January 5, 2018. Sputum samples were examined by Ziehl Neelsen microscopy, Xpert MTB/RIF assay and Culture. Drug susceptibility testing was performed by line probe assay and BACTEC MGIT 960 system. These laboratory tests were performed in Ethiopian Public Health Institute, National TB Reference Laboratory. Data was analyzed by SPSS Ver.20. Results From the total of 418 enrolled patients, 27 (6.5%) were Xpert MTB/ RIF and 26 (6.4%) were culture confirmed smear negative PTB patients. The positivity rate among male and female was 10.2 and 3.5% ( p = 0.005) respectively. From 26 culture positive isolates 3 (11.54%) were MDR TB; from MDR-TB confirmed isolates 2/23 (8.7%) were among new and 1/3 (33.3%) was among retreatment smear negative presumptive pulmonary TB patients. All Rifampicin resistant smear negative pulmonary TB isolates by Xpert MTB/ RIF assay were found to be MDR TB and 7/26 (26.9%) isolates were INH mono resistant. History of migration found to be a potential factor for developing smear negative pulmonary TB. Conclusion In this study a significant proportion of smear negative pulmonary TB was diagnosed. Furthermore, a high smear negative multi drug resistant (MDR) TB and other mono drug resistant TB prevalence was confirmed. Due to the limitations of smear microscopy which is used as a primary diagnostic tool, these TB strains are missed to be diagnosed and transmission continues in the community.

Characteristics of pulmonary multidrug-resistant tuberculosis patients in Tigray Region, Ethiopia: A cross-sectional study

“…The WHO data indicates that 6–10% of new TB cases and 13–60% of cases in previously treated patients are MDR [ 21 ]. The overall proportion of MDR-TB observed in our study was higher compared to previous studies conducted in Addis Ababa, Ethiopia [ 22 , 23 ], northwest Ethiopia [ 24 , 25 ], Jigjiga in the Somali Region [ 9 ] and the Oromia Region [ 26 ], which showed an overall prevalence of MDR-TB of 11.5%, 5.6%, 10.2%, 1.8%, 1.8% and 4.7%, respectively. The finding was also higher than the study done in China [ 27 ], Kenya [ 28 ], Tanzania [ 29 ], India [ 30 ], Vietnam [ 31 ], Lima Peru [ 32 ], Dalian China [ 33 ] and northeastern China [ 34 ], where the overall MDR-TB prevalence was estimated at 11.3%, 4.8%, 6.3%, 5.6%, 6.9%, 6.6%, 10.1%, 8.7%, respectively.…”

Prevalence of Tuberculosis by GeneXpert Method in Karnali Academy of Health Sciences Teaching Hospital, Jumla, Nepal

“…Rifampicin-resistant MTB isolates detected by GeneXpert were strong predictors of MDR-TB. [13] Although the numbers of MTB/RR i.e. 4 (4.16%) in the present study were less than in similar studies in Ethiopia.…”

“…[10] But higher as compared to other studies with a prevalence of 5.3%, 7.2%, 6.5%. [11][12][13] Out of 805 participants, 457 (57%) males and 348 (43%) females were tested for GeneXpert test. We found a high prevalence rate of TB infection in males (14.66%) as compared to females (8.33%) which was in agreement with a study conducted in the National Tuberculosis Center, Bhaktapur, Nepal (27.55% male, 25% female).…”

Trends of Mycobacterium tuberculosis and rifampicin resistance in Adigrat General Hospital, Eastern zone of Tigrai, North Ethiopia

“…Besides, a drug resistance (DR-TB) sentinel report in 2013 showed the MDR-TB prevalence of 2.3% among new and 17.8% among previously retreated TB cases in Ethiopia [ 6 ] .In the same year, there was notification of 119, 592 new TB cases and enrollment of 597 DR-TB cases [ 7 ]. Furthermore, a number of studies have shown the prevalence of Mycobacterium tuberculosis with rifampicin resistance Ethiopia ranged from 4.7–18.3% [ 5 , 8 – 11 ]. Mutations region of 81 base pairs (bp) of the rpoB gene has been found in about 96% of rifampicin (RMP) resistant Mycobacterium tuberculosis [ 8 , 9 ].…”