BackgroundMulti drug resistant tuberculosis (MDR-TB) poses formidable challenges to TB control due to its complex diagnostic and treatment challenges and often associated with a high rate of mortality. Accurate and rapid detection of MDR-TB is critical for timely initiation of treatment. Line Probe Assay (LPA) is a qualitative in vitro diagnostic test based on DNA-STRIP technology for the identification of the M. tuberculosis complex and its resistance to rifampicin (RMP) and/or isoniazid (INH). Hain Lifescience, GmbH, Germany has improved the sensitivity of Genotype MTBDRplus VER 2.0 LPA for the detection of MDR-TB; with the possibility of applying the tool in smear negative sputum samples.MethodA cross sectional study was conducted on 274 presumptive MDR-TB patients referred to the National TB Reference Laboratory (NTRL), Ethiopian Public Health Institute (EPHI) who submitted sputum samples for laboratory diagnosis of drug resistant-TB testing. Seventy-two smear and culture positive samples processed in smear positive direct LPA category and 197 smear negative sputum samples were processed for direct LPA. Among the smear negative samples 145 (73.6%) were culture negative and 26 (13.2%) were culture positive. All specimens were processed using NALC-NaOH method and ZN smear microscopy done from sediments. Genotype MTBDRplus VER 2.0 done from processed sputum sediments and the result was compared against the reference, BACTEC MGIT 960 culture and DST. Sensitivity, specificity, PPV and NPV of Genotype MTBDRplus VER 2.0 assay was determined and P-value <0.05 was considered as statistically significant.ResultsThe sensitivity, specificity, PPV and NPV of Genotype MTBDRplus VER 2.0 LPA were 96.4, 100, 100 and 96.9%, respectively for the detection of MDR-TB from direct smear positive sputum samples. The sensitivity, specificity, PPV and NPV of Genotype MTBDR plus VER 2.0 LPA were 77.8, 97.2, 82.4 and 97.2%, respectively, for the detection of M. tuberculosis from direct smear negative sputum samples. Fourteen (53.8%) samples had valid results with LPA among the 26 smear negative culture positive samples. The remaining 8 (30.8%) and 4 (15.4%) were invalid and negative with LPA, respectively. The sensitivity and specificity of Genotype MTBDRplus VER 2.0 LPA were 100% for the detection of MDR-TB among 14 direct smear negative and culture positive sputum samples.The most common mutations associated with RMP and INH resistance were S531L and S315TL, respectively. A single rare mutation (C15T/A16G) was detected for INH resistance.ConclusionThe diagnostic performance of Genotype MTBDRplus VER 2.0 LPA in direct smear positive sputum sample was highly sensitive and specific for early detection of MDR-TB. However, the diagnostic performance of this molecular assay in direct smear negative sputum sample was low and showed a high level of invalid results for detection of M. tuberculosis and its resistance to RMP and/or INH so it is unlikely to implement Genotype MTBDRplus VER 2.0 for the detection of MDR-TB in direct smear negative ...

Background In co-endemic areas, rate of intestinal parasites and tuberculosis (TB) co-infection thought to be high. However, there are limited studies on the epidemiology of this co-infection in Ethiopia. Therefore, the present study aimed to generate evidence on intestinal parasites co-infection rate and associated factors among pulmonary tuberculosis patients (PTB) and their household contacts in Addis Ababa, Ethiopia. Methods Unmatched case-control study was conducted. Data were collected from 91 PTB patients (cases) and 89 household contacts (controls). Socio-demographic characteristics and associated factors were collected using structured questionnaire. Sputum, stool and blood specimens were collected, processed and examined for PTB, intestinal parasites and Human Immunodeficiency virus anti-body test, respectively. Data were entered and analyzed by Statistical Packages for Social Sciences (SPSS) Version 20. Descriptive statistics, Fisher’s exact test, binary logistic regression, and odds ratio were used. P-value of < 0.05 was considered as statistically significant. Results The infection rate of intestinal parasites based on one stool samples in PTB patients and controls was 22 and 9%, respectively. The difference was statistically significant (COR = 2.85;95% CI = 1.18–6.87). The most prevalent intestinal parasite in PTB patients was Gardia lamblia (8.8%, 8), followed equally by Ascaris lumbricoides , Haymenolopsis nana and Entamoeba histolytica/dispar (4.4%, 4). Co-infection in PTB patients was associated with body mass index (BMI) < 18.5 (AOR = 6.71;95% CI = 1.65–27.25) and dirty material in finger nails (AOR = 8.99;95% CI = 2.46–32.78). There was no variable associated with parasitic infections in controls in our analysis, which might be due to the low prevalence of intestinal parasites’. Conclusions There was a statistical significant difference in the infection rate of intestinal parasites in PTB patients compared to healthy household contacts. The consequence of co-infection on developing an active disease, disease severity and treatment efficacy needs to be investigated in future.

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.

Young children cannot easily produce sputum for diagnosis of pulmonary tuberculosis. Alternatively, Mycobacterium tuberculosis complex (MTB) bacilli can be detected in stool by using the Xpert MTB/RIF (Ultra) assay (Xpert). Published stool processing methods contain somewhat complex procedures and additional supplies. The aim of this study was to develop a simple one step (SOS) stool processing method, based on gravity sedimentation only, similar to sputum Xpert testing for the detection of MTB in stool. We first assessed if the SOS stool method could provide valid Xpert results without the need of bead-beating, dilution and filtration steps. We concluded that this was the case and, subsequently, validated the SOS stool method by testing spiked stool samples. By using the SOS stool method, of the 29 spiked samples, 27 gave valid Xpert results and MTB was recovered from all 27. The proof of principle of the SOS stool method was demonstrated in a routine setting in Addis Ababa, Ethiopia. Nine of 123 children with presumptive TB were MTB positive on nasogastric aspirate (NGA), and seven (77.8%) of these also had an MTB positive Xpert result on stool. Additionally, MTB was detected in the stool but not on the NGA of two children. The SOS stool processing method makes use of the standard Xpert assay kit, without the need for additional supplies or equipment. The method can potentially be rolled out to any Xpert site, bringing a bacteriologically confirmed diagnosis of TB in children closer to the point of care.

Background Both passive and active surveillance of drug resistance have an important role in tuberculosis (TB) control program. Surveillance data are important to estimate the magnitude of drug resistance TB, to know the trend of the disease, assess the performance of the program, and to forecast diagnosis and treatment supplies. Therefore, this study aimed to determine the prevalence and the proportion of drug resistant tuberculosis in Ethiopia based on passively collected data. Methods A cross-sectional study was conducted at the National Tuberculosis Reference Laboratory and seven Regional TB laboratories in Ethiopia on a retrospective data collected from July 2017 to June, 2018. Data were collected by standardized checklist from TB culture laboratory registration book. Percentage of recovery rate, contamination rate, and prevalence of drug resistance TB were determined by Statistical Package for Social Science (SPSS) version 23. Result Of 10 134 TB suspected individuals included into this analysis, 1183 (11.7%) were culture positive. The overall contamination proportion was 5.3% and nontuberculous mycobacteria proportion was 0.98%. First-line drug susceptibility test was performed for 329 Mycobacterium tuberculosis complex isolates, and the proportion of resistance was 5.7 and 6.3% for isoniazid and rifampicin respectively. The proportion of multidrug-resistant tuberculosis (MDR-TB) was 4.3% in new patients, while 6.7% in previously treated patients. However, there was no category for 0.6% patients, and the overall proportion of MDR-TB was 11.6%. Conclusions The result of this study indicated that MDR-TB is a serious public health problem in Ethiopia. Thus, strengthen prevention and control program is vital to halt the burden of drug resistant TB in the country. Electronic supplementary material The online version of this article (10.1186/s40249-019-0554-4) contains supplementary material, which is available to authorized users.

Tuberculosis (TB) is one of the leading causes of morbidity and mortality in different zones of Ethiopia. This study was undertaken to identify the strains of Mycobacterium tuberculosis and evaluate their drug sensitivity profiles in the Arsi Zone. A total of 111 isolates of M. tuberculosis from individuals with pulmonary TB were included and speciation and strain identification were performed using Region of difference 9 and spoligotyping, respectively. The drug sensitivity patterns were assessed using Bactec MGIT 960 SIRE and GenoType MTBDRplus line probe assays. Of 111 isolates, 83% were interpretable and 56 different spoligotype patterns were identified. From these, 22 patterns were shared types while the remaining 34 were orphans. The predominant shared types were spoligotype international type (SIT) 149 and SIT53, comprising 12 and 11 isolates, respectively. Euro-American lineage was the dominant lineage followed by East-African-Indian. Phenotypically, 17.2% of tested isolates were resistant to any first-line drugs and 3.1% were multidrug-resistant. Higher (6.2%) mono-resistance was observed to streptomycin, and no resistance was observed to rifampicin or ethambutol. Genotypically, five (5.4%) isolates were resistant to isoniazid and mutated at codon S315T1 of katG. In contrast, only 1.1% of the isolates were resistant to rifampicin and were mutated at codon S531L of rpoB gene. In this study, a high proportion of orphan strains were isolated, which could suggest the presence of new strains and a high percentage of mono-resistance, warranting the need to strengthen control efforts.

Background: Xpert® MTB/RIF assay is currently used in Ethiopia for the rapid diagnosis of Mycobacterium tuberculosis (MTB) and mutations that confer Rifampicin resistance. Rifampicin resistance is determined based on any mutation in the 81 bp of rpoB gene using five overlapping probes represented as Probe A (codons 507-511), Probe B (codons 512-518), Probe C (codons 518-523), Probe D (codons 523-529) and Probe E (codons 529-533). In this review, we assessed the frequency of missed probe types for Rifampicin Resistance results. Methods: Data were reviewed from specimens received and tested using Xpert® MTB/RIF assay at Ethiopian National Tuberculosis Reference Laboratory, in Addis Ababa from 15 July 2016 to 31 December 2018 retrospectively. All archived data were reviewed carefully to describe missed probe types and the quantity of DNA in the sample. Results: A total of 100 specimens were reported as MTB Detected Rifampicin Resistance Detected by Xpert® MTB/RIF assay. More than half (55%) of these results were reported from male patients. The median age was 28.0 years (5 months to 88 years). Majorities (62%) of the cases were detected from sputum. Among the total of 38 extrapulmonary samples, lymph node aspirates were accounted for 50% (19/38). The most common mutations (81.0%) were found in the Probe E region followed by Probe D (10.0%), and Probe B (3.0%). Mutations in Probe A and Probe C regions were not observed. However, six (6.0%) Rifampicin resistance cases were found without any missed probe type. The delta Ct max is ≥4.3. No specimen yielded Rifampicin resistance associated with more than one probe failure or mutation combinations. Conclusion: Mutations associated with Probe E (codons 529-533) region were identified as the commonest rpoB gene mutations. The Rifampicin resistance results found without any identified missing probe needs further study. The lower DNA amount was observed in extrapulmonary specimens compared with sputum.

ObjectiveMultidrug-resistant tuberculosis (MDR-TB) case finding progressively increased in Ethiopia mainly as a result of the utilization of World Health Organization (WHO)-endorsed rapid technologies including MTBDRplus assay. However, there is inadequate data on routine testing performance of the MTBDRplus assay. Consequently, the aim of the study was to assess the routine performance of the MTBDRplus assay in detecting MDR-TB at St. Peter’s TB Specialized Hospital.ResultsThe sensitivity and specificity of MTBDRplus in detecting isoniazid (INH) resistance were 96.3 and 100%, respectively. While for rifampicin (RIF) 100% was recorded for both. Similarly, a sensitivity of 97.96% and a specificity of 100% was measured for detecting MDR-TB. Among 49 MTBDRplus RIF resistant isolates, 46 (93.9%) strains had rpoB mutation. S531L was the most common rpoB mutant (81.6% of RIF resistant cases). All MTBDRplus INH resistant isolates (n = 52) had S315T1 katG mutation.