Population structure and spatial distribution of Mycobacterium tuberculosis in Ethiopia.

Ethiopia is one of the countries with a high tuberculosis (TB) burden, yet little is known about the spatial distribution of Mycobacterium tuberculosis (Mtb) lineages. This study identifies the spoligotyping of 1735 archived Mtb isolates from the National Drug Resistance Survey, collected between November 2011 and June 2013, to investigate Mtb population structure and spatial distribution. Spoligotype International Types (SITs) and lineages were retrieved from online databases. The distribution of lineages was evaluated using Fisher's exact test and logistic regression models. The Global Moran's Index and Getis-Ord Gi statistic were utilized to identify hotspot areas. Our results showed that spoligotypes could be interpreted and led to 4 lineages and 283 spoligotype patterns in 91% of the isolates, including 4% of those with multidrug/rifampicin resistance (MDR/RR) TB. The identified Mtb lineages were lineage 1 (1.8%), lineage 3 (25.9%), lineage 4 (70.6%) and lineage 7 (1.6%). The proportion of lineages 3 and 4 varied by regions, with lineage 3 being significantly greater than lineage 4 in reports from Gambella (AOR = 4.37, P < 0.001) and Tigray (AOR = 3.44, P = 0.001) and lineage 4 being significantly higher in Southern Nations Nationalities and Peoples Region (AOR = 1.97, P = 0.026) than lineage 3. Hotspots for lineage 1 were located in eastern Ethiopia, while a lineage 7 hotspot was identified in northern and western Ethiopia. The five prevalent spoligotypes, which were SIT149, SIT53, SIT25, SIT37 and SIT26 account for 42.8% of all isolates under investigation, while SIT149, SIT53 and SIT21 account for 52-57.8% of drug-resistant TB cases. TB and drug resistant TB are mainly caused by lineages 3 and 4, and significant proportions of the prevalent spoligotypes also influence drug-resistant TB and the total TB burden. Regional variations in lineages may result from both local and cross-border spread.

A smooth tubercle bacillus from Ethiopia phylogenetically close to the Mycobacterium tuberculosis complex.

The Mycobacterium tuberculosis complex (MTBC) includes several human- and animal-adapted pathogens. It is thought to have originated in East Africa from a recombinogenic Mycobacterium canettii-like ancestral pool. Here, we describe the discovery of a clinical tuberculosis strain isolated in Ethiopia that shares archetypal phenotypic and genomic features of M. canettii strains, but represents a phylogenetic branch much closer to the MTBC clade than to the M. canettii strains. Analysis of genomic traces of horizontal gene transfer in this isolate and previously identified M. canettii strains indicates a persistent albeit decreased recombinogenic lifestyle near the emergence of the MTBC. Our findings support that the MTBC emergence from its putative free-living M. canettii-like progenitor is evolutionarily very recent, and suggest the existence of a continuum of further extant derivatives from ancestral stages, close to the root of the MTBC, along the Great Rift Valley.

Genetic diversity and drug sensitivity profile of Mycobacterium tuberculosis among children in Ethiopia.

BACKGROUND: Worldwide, tuberculosis (TB) affects about one million children every year. The burden of the disease is higher in developing countries. However, there is limited information on the lineages and drug sensitivity patterns of Mycobacterium tuberculosis (M. tuberculosis) infecting children in these countries, including Ethiopia. Thus, this study aimed to characterize the different lineages of the M. tuberculosis complex causing childhood pulmonary tuberculosis and evaluate the drug-sensitivity patterns to the first-line anti-TB drugs. METHOD: A total of 54 stored cultures were used in this study. The region of difference 9 (RD9) based polymerase chain reaction (PCR) and spoligotyping were employed for the identification of the isolates at the species and lineages level respectively. Lineage identification was done by using the pre-existing database. Identification of clustering of the spoligotype patterns was by using the SPOLIDB3-based model. The result was retrieved by the most probable family format. Furthermore, the phenotypic, and genotypic drug-sensitivity test (DST) was performed using Mycobacterium Growth Indicator Tube (MGIT™ 960) and GenoTypeMTBDRplus assay respectively. Data analysis was done using SPSS version 27 software. RESULT: Spoligotyping produced 39 interpretable results for M. tuberculosis. The majority (74.4%) of them were clustered into 7 groups, while the rest (25.6%) were single. The Euro-American (EA) lineage was the predominant lineage (64.1%) followed by the East-African Indian (EAI) (30.8%) and M. Africanum (5.1%) lineages. The most predominant subtypes were SIT37 (15.4%), SIT149 (12.8%), SIT25 (7.7%), and SIT53 (7.7%). Furthermore, of the identified SITs, T1 and CAS families consisted of 38.5% and 28.2% of the lineages respectively. Drug susceptibility was 91.9% by phenotypic method and 97.4% by molecular assay. The overall prevalence of any resistance was 7.8% and there was a single MDR-TB. CONCLUSION: Many of the isolates belong to the modern lineages (Euro American) representing the most common circulating strains in the country. More importantly, despites the tiny isolates tested, drug resistance is low. To fully describe the molecular epidemiology of MTBC lineages in children, we recommend a prospective large-scale study.

Epidemiology of extensively drug-resistant tuberculosis among patients with multidrug-resistant tuberculosis: A systematic review and meta-analysis.

OBJECTIVES: To estimate the pooled proportion of extensively drug-resistant tuberculosis (XDR-TB) and pre-extensively drug-resistant tuberculosis (pre-XDR-TB) in patients with multidrug-resistant TB (MDR-TB). METHODS: We systematically searched articles from electronic databases: MEDLINE (PubMed), ScienceDirect, and Google Scholar. We also searched gray literature from the different literature sources main outcome of the review was either XDR-TB or pre-XDR-TB in patients with MDR-TB. We used the random-effects model, considering the substantial heterogeneity among studies. Heterogeneity was assessed by subgroup analyses. STATA version 14 was used for analysis. RESULTS: A total of 64 studies that reported on 12,711 patients with MDR-TB from 22 countries were retrieved. The pooled proportion of pre-XDR-TB was 26% (95% confidence interval [CI]: 22-31%), whereas XDR-TB in MDR-TB cases was 9% (95% CI: 7-11%) in patients treated for MDR-TB. The pooled proportion of resistance to fluoroquinolones was 27% (95% CI: 22-33%) and second-line injectable drugs was 11% (95% CI: 9-13%). Whereas the pooled resistance proportions to bedaquiline, clofazimine, delamanid, and linezolid were 5% (95% CI: 1-8%), 4% (95% CI: 0-10%), 5% (95% CI; 2-8%), and 4% (95% CI: 2-10%), respectively. CONCLUSION: The burden of pre-XDR-TB and XDR-TB in MDR-TB were considerable. The high burdens of pre-XDR-TB and XDR-TB in patients treated for MDR-TB suggests the need to strengthen TB programs and drug resistance surveillance.

Detection of Mycobacterium tuberculosis and rifampicin resistance by Xpert® MTB/RIF assay among presumptive tuberculosis patients in Addis Ababa, Ethiopia from 2014 to 2021.

Objective: This study aimed to determine the frequencies and trends of Mycobacterium tuberculosis and rifampicin resistance among presumptive tuberculosis patients in Ethiopia, who were tested using the Xpert MTB/RIF assay between 2014 and 2021. Methods: Data were collected retrospectively from patient registries. Laboratory-based data were extracted from the national tuberculosis (TB) referral laboratory database. All patients referred to the National Tuberculosis Reference Laboratory (NTRL) for TB diagnosis from all over the country between March 1, 2014 and September 30, 2021, and tested using the Xpert MTB/RIF assay, were included. The extracted data were entered into a Microsoft Excel sheet and analyzed by Statistical Package for Social Sciences (SPSS) version 23. Results: Among a total of 13 772 individuals tested using the Xpert MTB/RIF assay, the majority (8223; 59.7%) were males, and 48.5% (6678) of the individuals were aged between 15 and 39 years. Mycobacterium tuberculosis (MTB) was detected in 17.0% (2347) of the examined individuals. Of the detected MTB cases, nearly 9.9% (233) were rifampicin resistant (RR-TB), while 24 (1.0%) were RR-intermediate. Among all RR-TB cases, more than half (125; 53.6%) were detected in males, and 105 were new TB cases. Extrapulmonary (EPTB) patients had a greater rate of rifampicin resistance (11.0%) than pulmonary (PTB) patients (9.6%). Conclusion: The frequency of TB and RR-TB remains high in the study setting. RR-TB was found to have a statistically significant association with previous anti-TB medication treatment. As a result, improving treatment adherence in recognized instances could assist in preventing MTB and RR-TB cases.

Pre-extensively drug-resistant tuberculosis among multidrug-resistant tuberculosis patients in Ethiopia: a laboratory-based surveillance study.

Background: The rise of drug-resistant tuberculosis (DR-TB) has presented a substantial challenge to the national tuberculosis (TB) control program. Understanding the epidemiology of pre-extensively drug-resistant tuberculosis (pre-XDR-TB) could help clinicians to adapt MDR-TB treatment regimens at an earlier stage. This study aimed to assess second-line anti-TB drug resistance among MDR-TB patients in Ethiopia using routine laboratory-based data. Methods: Laboratory-based cross-sectional data were collected from the national TB reference laboratory and seven regional tuberculosis culture laboratories in Ethiopia from July 2019 to March 2022. The required data, such as drug-susceptibility testing (DST) results and sociodemographics, were collected on a structured checklist from laboratory registration books and electronic databases. Data were entered into a Microsoft Excel spreadsheet and analyzed using SPSS version 23. Descriptive statistics were performed to show the distribution and magnitude of drug resistance. Results: Second-line drugs (SLDs) susceptibility testing was performed for 644 MDR isolates, of which 19 (3%) were found to be pre-XDR-TB cases. Of the total MDR-TB isolates, 19 (3%) were resistant to at least one fluoroquinolone drug, while 11 (1.7%) were resistant to at least one injectable second-line drug. Of the 644 MDR-TB isolates, 1.9% (5/261) pre-XDR were from new MDR-TB cases, while 3.7% (14/383) were from previously treated MDR-TB patients. The most frequently identified mutations, based on MTBDRsl results, were in codon A90V of the gyrA gene (77.3%) and A1401G of the rrs gene (45.5%). Conclusion: The overall prevalence of pre-XDR-TB in Ethiopia is considerable. The majority of SLD resistance mutations were in the gyrA gene at position A90V. Modern, rapid DST is necessary to enable identification of pre-XDR-TB and XDR-TB in supporting proper regimen administration for patients.

Clinical Features and Treatment Outcome of Coronavirus and Tuberculosis Co-Infected Patients: A Systematic Review of Case Reports.

Background: Coronavirus disease 19 (COVID-19) and Mycobacterium tuberculosis (MTB) are among the top ongoing health crises globally. Both cause respiratory diseases, and the clinical presentations are similar. There is no summarized information about cases of COVID-19 patients with concomitant TB infection from different settings. Therefore this review aimed to summerize the clinical features and treatment outcomes of coronavirus and tuberculosis co-infected patients. Methods: An electronic search of case reports published between 2020 and 2021 was conducted using Google Scholar, PubMed, Scopus, and ScienceDirect. From eligible reports, data were collected for the selected variables. We analyzed the collected information using SPSS version 27 software. Descriptive statistics were computed for the selected variables. Results: A total of 83 patient histories were collected from 47 case reports. The majority (80%) of the cases were reported for male patients. The mean age was 42.6 years (3 months to 84 years, SD=17.3). Fever was reported in 80% of cases, followed by cough (73.3%) and hypotension (37.1%). Blood cell parameters revealed lymphopenia (52%), lower hemoglobin (30%), elevated CRP (70%), elevated ferritin (28%), and increased D-dimer (23.4%). Treatment outcome is significantly associated with blood cell count results (p-0.044) and a rise in blood inflammatory cytokines(p-0.041). The mean days for viral clearance or negative PCR was 23 days (Range 5-82 days) and the overall mean duration of hospitalization was 27 days. The total death rate was 22.4%. Recovery was reported for 76.6% of cases. Survival status (p-0.613) and disease severity (p-0.68) are not significantly associated with the gender of the participants. Conclusion: An alteration in blood cell parameters is associated with an unfavorable treatment outcome. There is a higher death rate in COVID-19/TB co-infection. The death is associated with older age, smoking or smoking history, drug abuse, and co-morbidity of non-communicable diseases. Conversely, there is a lower death rate in HIV patients.

Diagnostic accuracy of Truenat Tuberculosis and Rifampicin-Resistance assays in Addis Ababa, Ethiopia.

BACKGROUND: Rapid and sensitive Tuberculosis (TB) diagnosis closer to patients is a key global TB control priority. Truenat assays (MTB, MTB Plus, and MTB-RIF Dx) are new TB molecular diagnostic tools for the detection of TB and Rifampicin (RIF)-resistance from sputum samples. The diagnostic accuracy of the assays is needed prior to implementation in clinical use in Ethiopia. This study aimed to determine the sensitivity and specificity of Truenat assays; and aimed to compare the assays to the Xpert MTB/RIF assay. METHODS: A prospective evaluation study was conducted among 200 presumptive TB patients in microscopy centers in Addis Ababa, Ethiopia from May 2019 to December 2020. Culture (Solid and Liquid methods) and phenotypic (liquid method) drug susceptibility testing (DST) were used as a reference standard. RESULTS: Of 200 adult participants, culture confirmed TB cases were 25 (12.5%), and only one isolate was resistant to RIF by phenotypic DST. The sensitivity of Truenat MTB was 88.0% [95% CI 70.1, 95.8], while 91.7 [95% CI 74.2, 97.7] for Truenat MTB Plus at the microscopy centers. The specificity of Truenat MTB was 97.2% [95% CI 93.1, 98.9], while for Truenat MTB Plus was 97.2% [95% CI 93.0, 99.0]. The sensitivity of Truenat MTB was 90.5% while for MTB Plus, 100% compared to the Xpert MTB/RIF assay. CONCLUSION: Truenat assays were found to have high diagnostic accuracy. The assays have the potential to be used as a point of care (POC) TB diagnostic tests.

Low Prevalence of Mycobacterium bovis in Tuberculosis Patients, Ethiopia.

An estimated 17% of all tuberculosis cases in Ethiopia are caused by Mycobacterium bovis. We used M. tuberculosis complex isolates to identify the prevalence of M. bovis as the cause of pulmonary tuberculosis. Our findings indicate that the proportion of pulmonary tuberculosis due to M. bovis is small (0.12%).