We found that the TB burden was lower than previously thought, which may indicate better programme performance. However, a high proportion of TB among young persons suggests that TB is circulating in the community and that there is a need for more efforts to limit the spread of TB disease.

Early detection of multidrug-resistant Mycobacterium tuberculosis (MDR-TB) is of primary importance for both patient management and infection control. Optimal methods for identifying drug-resistant Mycobacterium tuberculosis in a timely and affordable way in resource-limited settings are not yet available. This study prospectively evaluated a low-technology but rapid drug susceptibility testing method, the microscopic observation drug susceptibility assay (MODS), in the concurrent detection of M. tuberculosis and its susceptibilities to isoniazid and rifampin (two drugs defining multidrug-resistant M. tuberculosis) directly from sputum specimens. Sputum samples were collected from 262 smear-positive TB patients in Addis Ababa, Ethiopia. To undertake MODS, 100 l of decontaminated samples was inoculated into a 24-well plate containing 1 ml of 7H9 broth with and without appropriate drugs. The assay uses an inverted-light microscope to detect characteristic mycobacterial growth in liquid culture. Of 262 smear-positive patients, MODS detected 254 (96.9%) and culture in Löwenstein-Jensen medium detected 247 (94.3%) (P ‫؍‬ 0.016). For the 247 cultures, the sensitivity, specificity, and accuracy of MODS for detecting MDR-TB were 92.0, 99.5, and 98.8%, respectively, using the method of proportion as a reference (concordance, 98.8%; kappa value, 0.932). Results for MODS were obtained in a median time of 9 days. MODS is an optimal alternative method for identifying MDR-TB in a timely and affordable way in resource-limited settings.Tuberculosis (TB), once in decline, is now experiencing a resurgence fueled in part by the human immunodeficiency virus (HIV)/AIDS pandemic. Multidrug-resistant Mycobacterium tuberculosis (MDR-TB), defined as resistant to at least isoniazid (INH) and rifampin (RIF), is complicating TB control efforts in several low-and middle-income countries. A critical mass of resistance seen in high-burden countries has great potential not only to halt the progress of TB control but also to reverse it (34). Implementation of additional strategies, such as reducing transmission by detecting cases earlier and improving infection control in settings with shared-air spaces, is urgently needed (29). Optimal methods for identifying drugresistant M. tuberculosis in a timely and affordable way in resource-limited settings are not yet available. The currently available drug susceptibility testing (DST) methods with solid media are inexpensive but slow and laborious and cannot meet such a demand. Liquid automated commercial systems (13,14,20,28), such as the BACTEC MGIT 960 (Becton Dickinson, Sparks, MD), are rapid but require heavy, expensive equipment, have high running costs, and are technically complex. Molecular genetic methods (16,17,22,29) are fast but too expensive and require well-trained manpower in order to be used in resource-poor settings. In addition, not all mutations conferring resistance to anti-TB drugs are known. Several lowtechnology methods (1,2,8,10,26,30,32) are also available. Most are indirect D...

BackgroundThe identification of circulating TB strains in the community and drug sensitivity patterns is essential for the tuberculosis control program. This study was undertaken to identify M. tuberculosis strains circulating in selected communities in Ethiopia as well as to evaluate the drug sensitivity pattern of these strains.MethodThis study was a continuation of the Ethiopian National TB Prevalence Survey that was conducted between 2010 and 2011. Culture-positive isolates of M. tuberculosis from previous study were typed using region of difference (RD) 9-based polymerase chain reaction (PCR) and spoligotyping. Drug sensitivity testing was conducted using the indirect proportion method on Lowenstein-Jensen media.ResultAll 92 isolates were confirmed as M. tuberculosis by RD9-based PCR and spoligotyping of 91 of these isolates leds to the identification of 41 spoligotype patterns. Spoligotype revealed higher diversity (45 %) and among this 65.8 % (27/41) were not previously reported. The strains were grouped into 14 clusters consisting of 2–15 isolates. The dominant strains were SIT53, SIT149 and SIT37 consisting of 15, 11, and 9 isolates, respectively. Our study reveals 70 % (64/91) clustered strains and only 39.1 % (25/64) occurred within the same Kebele. Further assignment of the strains to the lineages showed that 74.7 % (68/91) belonged to Euro-American lineage, 18.6 % (17/91) to East Africa Indian lineage and the remaining 6.5 % (6/91) belonged to Indo-oceanic lineage. Valid drug susceptibility test results were available for 90 of the 92 isolates. Mono-resistance was observed in 27.7 % (25/90) and poly-resistance in 5.5 % (5/90) of the isolates. Moreover, multi-drug resistance (MDR-TB) was detected in 4.4 % of the isolates whilst the rest (60/90) were susceptible to all drugs. The highest level of mono-resistance, 26.6 % (24/90), was observed for streptomycin with majority (91.1 %) of streptomycin mono-resistant strains belonging to the Euro-American lineage.ConclusionIn this study, the strains of M. tuberculosis circulating in selected sites of Ethiopia were identified along with the drug sensitivity patterns. Thus, these findings are useful for the TB Control Program of the country.

Purpose Advances in molecular tools that assess genes harboring drug resistance mutations have greatly improved the detection and treatment of drug-resistant tuberculosis (DR-TB). This study was conducted to determine the frequency and type of mutations that are responsible for resistance to rifampicin (RIF), isoniazid (INH), fluoroquinolones (FLQs) and second-line injectable drugs (SLIDs) in Mycobacterium tuberculosis (MTB) isolates obtained from culture-positive pulmonary tuberculosis (TB) patients in the central, southeastern and eastern Ethiopia. Patients and Methods In total, 224 stored culture-positive MTB isolates from pulmonary TB patients referred to Adama and Harar regional TB laboratories between August 2018 and January 2019 were assessed for mutations conferring RIF, INH, FLQs and SLIDs resistance using GenoType ® MTBDRplus (MTBDRplus) and GenoType ® MTBDRsl (MTBDRsl). Results RIF, INH, FLQs and SLIDs resistance-conferring mutations were identified in 88/224 (39.3%), 85/224 (38.0%), 7/77 (9.1%), and 3/77% (3.9%) of MTB isolates, respectively. Mutation codons rpoB S531L (59.1%) for RIF, katG S315T (96.5%) for INH, gyrA A90V (42.1%) for FLQs and WT1 rrs (100%) for SLIDs were observed in the majority of the isolates tested. Over a 10th of rpoB mutations detected in the current study were unknown. Conclusion In this study, the most common mutations conferring drug resistance to RIF, INH, FLQs were identified. However, a significant proportion of RIF-resistant isolates manifested unknown rpoB mutations. Similarly, although few in number, all SLID-resistant isolates had unknown rrs mutations. To further elucidate the entire spectrum of mutations, tool such as whole-genome sequencing is imperative. Furthermore, the expansion of molecular drug susceptibility testing services is critical for tailoring patient treatment and preventing disease transmission.

IntroductionThe diagnostic accuracy of Xpert MTB/RIF is well documented but underutilization is a major challenge in most high burden countries. This appears to be linked with insufficient knowledge of health professionals of using the tool. However, this has not been well studied.ObjectiveOur objective was to assess the knowledge of health professionals on Xpert MTB/RIF assay and associated factors in detecting TB/TB drug resistance.MethodsAn institution based cross–sectional study was conducted from April 4 to June 5, 2015, in Addis Ababa that involved 209 healthcare providers working in TB clinics. Structured questionnaire through self-administered interview technique was used to collect the data. We asked them about Xpert on whether they are aware of its place in TB diagnosis, when and for whom it shall be used, its role in treatment monitoring, result interpretation and patient's registration that are diagnosed by Xpert MTB/RIF. We used binary logistic regression analysis to identify associated factors. Odds ratio with 95% CI was computed to assess the strength of the associations.ResultsOf the 209 participants interviewed, the majority 151 (72.2%) were nurses. More than a half of the respondents 114 (54.6%) had poor knowledge. Health professionals with age above 35 years (AOR = 6.253, 95% CI (1.1995, 19.604)) and those who read the Xpert guideline (AOR = 4.231, 95% CI (2.011, 8.900)) were more likely to have good knowledge on Xpert.Conclusion and recommendationThis study revealed that the overall magnitude of knowledge status was found to be low. Health workers above 35 years and those who read the guideline on Xpert had higher knowledge status on Xpert. Distribution of national guideline on Xpert and assigning experienced clinicians in TB DOTs clinics are recommended.