The Magnitude of MTB and Rifampicin Resistance MTB Using Xpert-MTB/RIF Assay Among Tuberculosis Suspected Patients in Gedeo Zone, Southern Ethiopia

Trends of Mycobacterium tuberculosis and Rifampicin resistance in Northwest Ethiopia: Xpert® MTB/RIF assay results from 2015 to 2021

BACKGROUND

Tuberculosis (TB) remains one of the leading causes of morbidity and mortality worldwide, particularly in countries with limited resources. The emergence of drug resistance in mycobacterium tuberculosis (MTB), particularly rifampicin (RIF) resistance, hindered TB control efforts. Continuous surveillance and regular monitoring of drug-resistant TB, including rifampicin resistance (RR), are required for effective TB intervention strategies and prevention and control measures.

OBJECTIVE

Determine the trend of TB and RR-TB among presumptive TB patients in Northwest Ethiopia.

METHOD

A retrospective study was conducted at the University of Gondar Comprehensive Specialized Hospital (UoG-CSH). The study included TB registration logbook data from all patients who visited the hospital and were tested for MTB using the Xpert® MTB/RIF assay between 2015 and 2021. The SPSS version 26 software was used to enter, clean, and analyze the laboratory-based data.

RESULTS

A total of 18,787 patient results were included, with 93.8% (17,615/18787) of them being successful, meaning they were not invalid, error, or aborted. About 10.5% (1846/17615) of the 17,615 results were MTB-positive, with 7.42% (137/1846) RIF resistant. Age, anti-TB treatment history, and diagnosis year were associated with the presence of MTB and RR-MTB. Tuberculosis (TB) prevalence was higher in productive age groups, whereas RR-TB prevalence was higher in the elderly. Regarding diagnosis year, the prevalence of TB and RR-TB showed a declining trend as the year progressed. While MTB was detected in 12.8% (471/3669) of new and 22.2% (151/679) of re-treatment presumptive TB patients, RR-MTB was detected in 8.5% (40/471) of new and 18.5% (28/151) of re-treatment TB cases.

CONCLUSION

The prevalence of TB and RR-TB in the study area showed a declining trend over the years. While TB was more prevalent in productive age groups (15 to 45 years), RR-TB was more prevalent in older populations (over 45 years), than others. Moreover, patients with a history of anti-TB drug exposure were more likely to be positive for DR-TB, highlighting the need to strengthen DOT programs for proper management of TB treatment.

Evaluating the Sensitivity of Different Molecular Techniques for Detecting Mycobacterium tuberculosis Complex in Patients with Pulmonary Infection

This study aimed to evaluate the accuracy of detecting drug-resistant Mycobacterium tuberculosis complex (MTBC)-specific DNA in sputum specimens from 48 patients diagnosed with pulmonary tuberculosis. The presence of MTBC DNA in the specimens was validated using the GeneXpert MTB/RIF system and compared with a specific PCR assay targeting the IS6110 and the mtp40 gene sequence fragments. Additionally, the results obtained by multiplex PCR assays to detect the most frequently encountered rifampin, isoniazid, and ethambutol resistance-conferring mutations were matched with those obtained by GeneXpert and phenotypic culture-based drug susceptibility tests. Of the 48 sputum samples, 25 were positive for MTBC using the GeneXpert MTB/RIF test. Nevertheless, the IS6110 and mtp40 single-step PCR revealed the IS6110 in 27 of the 48 sputum samples, while the mtp40 gene fragment was found in only 17 of them. Furthermore, multiplex PCR assays detected drug-resistant conferring mutations in 21 (77.8%) of the 27 samples with confirmed MTBC DNA, 10 of which contained single drug-resistant conferring mutations towards ethambutol and two towards rifampin, and the remaining nine contained double-resistant mutations for ethambutol and rifampin. In contrast, only five sputum specimens (18.5%) contained drug-resistant MTBC isolates, and two contained mono-drug-resistant MTBC species toward ethambutol and rifampin, respectively, and the remaining three were designated as multi-drug resistant toward both drugs using GeneXpert and phenotypic culture-based drug susceptibility tests. Such discrepancies in the results emphasize the need to develop novel molecular tests that associate with phenotypic non-DNA-based assays to improve the detection of drug-resistant isolates in clinical specimens in future studies.

Prevalence of rifampicin resistant pulmonary tuberculosis using geneXpert assay in Ethiopia, a systematic review and meta-analysis

Background

Drug-resistant tuberculosis continues to be a global public health threat. Ethiopia is one of the high-burden countries for tuberculosis and multi-drug resistant tuberculosis. The estimated annual incidents of tuberculosis were 119 per 100,000 populations in 2021 and the prevalence of multi-drug resistance tuberculosis is about 0.7% among newly diagnosed cases in Ethiopia. On time detection of rifampicin resistance is essential for the management of the disease and earlier treatment initiation. Among the different diagnostic tests; Xpert is widely used for the rapid detection of Mycobacterium tuberculosis and rifampicin resistant in the country. The prevalence of rifampicin resistance-pulmonary tuberculosis varied from locality to locality and the estimated national prevalence of rifampicin resistance pulmonary tuberculosis is not available in the country. Therefore, the aim of this meta-analysis was to summarize the results of available studies and generate pooled prevalence estimate of rifampicin resistance pulmonary tuberculosis in Ethiopia.

Methods

Literature search was carried out using PubMed and Scopus public databases. Original articles conducted in Ethiopia and those containing a prevalence report of rifampicin resistance pulmonary tuberculosis diagnosed by Xpert Mycobacterium tuberculosis/rifampicin resistance assay were included in the meta-analysis. All retrospective and prospective studies published until May 2022 were screened in the study. The methodological qualities of included article were assessed using Joanna Briggs Institute quality assessment tool for cross-sectional studies. Random effect model was used to determine the pooled prevalence of rifampicin resistance pulmonary tuberculosis. Subgroup analysis and regression were carried out across regional states and study designs. Heterogeneity across studies was assessed using I2 test. The data were analyzed using STATA version 14.

Result

A total of 1570 titles were identified and 34 studies met the inclusion criteria. Of the total 17,292 pulmonary tuberculosis patients who were identified from the included articles, 1669 were rifampicin resistance pulmonary tuberculosis. The pooled prevalence of rifampicin resistant among pulmonary tuberculosis patients diagnosed with Xpert Mycobacterium tuberculosis/rifampicin resistance assay was 9.67% (95% CI: 8.11-11.24). The highest pooled prevalence was from Oromia11.84% (95% CI: 4.49-19.2%) and the lowest rifampicin resistance was identified in Amhara Regional State, 8.51% (95% CI: 5.96-11.06%). The pooled prevalence rates of rifampicin resistant among pulmonary tuberculosis patients were 10.18% (95% CI: 6.85-13.51) and 9.57% (95% CI: 7.68-11.47) in prospective and retrospective types of cross-sectional studies.

Conclusion

Our study showed that the pooled prevalence of rifampicin resistance among pulmonary tuberculosis patients was 9.67%. This showed that the occurrence of rifampicin resistance pulmonary tuberculosis among Mycobacterium tuberculosis patients remains high in Ethiopia. Regional state wise, rifampicin resistance variation was small. Further meta-analysis of factors associated with rifampicin resistance among pulmonary tuberculosis patients as well as among extrapulmonary Mycobacterium tuberculosis cases should be carried out.

Trends in Rifampicin Resistance Among Children With Presumptive TB in the Pre-COVID and COVID-Era

Publications on COVID-19's impact on the global tuberculosis burden are from adult cohorts, pediatric data are lacking for inform decision. We compared the TB trends in southern Nigerian children in the pre-COVID-19 and COVID-19 era. This was a retrospective, cross-sectional study of early morning sputum/gastric washing or stool samples from children with presumptive TB evaluated using GeneXpert in a tertiary hospital from January 2016 to May 2022. Of the 20 589 persons screened for presumed TB in the pre-COVID-19 and the COVID-19 era, only 1104 (88.7%) of 1245 children had complete data for analysis. In the COVID era, a significantly higher number of children were presumed to have TB 755 (68.4%), P < .001. The overall incidence of MTB detected by Xpert MTB/RIF during the study period was 6.4% (71/1104). The incidence of MTB in the pre-COVID-19 era was 24/349 (6.9%), which was slightly higher than the COVID-19 era (47/755; 6.2%), P > .05). The annual trends of MTB detected peaked in 2019 [18/115; 15.7%] in the pre-COVID-19 era, then plummeted to 12/228 (5.3%) in 2020 in the COVID-19 era, and reached its all-time low of 6/160 (3.8%) in the first half of 2022, (P < .001). The overall incidence of Rifampicin-resistant TB (RR-TB) was 2.8% among the MTB detected cases and all occurred in the COVID-19 era. This study found a significant decline in MTB diagnosis and in the emergence of RR-TB in the COVID-19 era. This necessitates re-prioritizing worldwide efforts to manage childhood tuberculosis, including increased testing, if the aim of eliminating tuberculosis by 2035 is to be met.

High proportion of RR-TB and mutations conferring RR outside of the RRDR of the rpoB gene detected in GeneXpert MTB/RIF assay positive pulmonary tuberculosis cases, in Addis Ababa, Ethiopia

BACKGROUND

Globally, TB is the leading cause of infectious disease morbidity and mortality with many diagnostic uncertainties. Access to affordable and rapid diagnostics remained a major challenge for many developing countries which bear the greatest burden of TB delaying the initiation time to treatment.

OBJECTIVE

This study aimed to assess the GeneXpert MTBRIF assay probe utility for the detection of pulmonary TB and Rifampicin-resistant TB cases in Addis Ababa, Ethiopia.

MATERIALS AND METHODS

A cross-sectional study was performed from October 2019 to July 2020 in Saint Peter TB Specialized Hospital in Addis Ababa metropolitan area, Ethiopia. This study enrolled 216 clinically suspected new presumptive pulmonary TB cases confirmed by GeneXpert MTB/RIF Assay. Sociodemographic and clinical characteristics were captured using a structured tool. Data were entered in Microsoft Excel 2019, checked for inconsistency, cleaned promptly, and exported to IBM SPSS Statistics for Windows, Version 26.0. Armonk, N.Y: IBM Corp, the USA for analysis. Descriptive analysis and binary and multivariate logistics regression were performed and all statistical significance was determined at a 95% confidence level.

RESULTS

The majority of the study participants, 55.1% [119/216] were males aged 6-80 years. The prevalence of RR MTB was 11.11% [24/216]. A higher proportion of RR TB was found in female patients [54.2%, 13/24], in patients in the age group of 30-50 years [45.8%, 11/24], in married individuals [62.5%, 15/24], in persons whose residence is urban [79.2%, 19/24], in persons who had a previous history of TB symptoms [100%, 24/24], in persons who had a history of contact with active and LTBI [33.3%, 8/24], and in persons who had a history of HIV and IDUs [41.7%, 10/24]. Occupation (AOR 22.868, 95% CI 1.655-316.022, p = 0.019), history of previous PTB+ (AOR 4.222, 95% CI 1.020-17.47, p = 0.047), and history of HIV and IDUs (AOR 4.733, 95% CI 1.416-15.819, p = 0.012) were independent predictors associated with RR-TB emergence. The commonest mutation 62.5% [15/24] was found in probe E (codons 529-533) region. There was no mutation associated with probe A (codons 507-511), probe B (codons 511-518), and probe C (codons 518-523) regions, as well as no combination of missed probes, was revealed. However, 12.5% [3/24] of RR TB patients were found without unidentified missed probe types detected outside of the RRDR. The delta Ct max was >4.0 and the highest proportion of 35.6% [77/216] RR TB was detected in samples of medium DNA load.

CONCLUSION

The proportion of RR-TB we observed in this study was high. Similarly, a higher proportion of RR TB was detected outside of the RRDR. Moreover, a significant number of the GeneXpert MTB/RIF Assay probes were identified as unhybridized and this critical observation would mean that most of the probes had no or minimal utility in this geographical region. This calls for further studies to uncover mutation in the rpoB gene conferring RR and reshape TB triage and definite diagnostic algorithm in Ethiopia.

Detection of Mycobacterium tuberculosis using Gene Xpert-MTB/RIF assay among tuberculosis suspected patients at Mizan-Tepi university teaching hospital, southwest Ethiopia: An institution based cross-sectional study

BACKGROUND

Consistently deciding its current extent and chance elements of tuberculosis (TB) in all levels of clinical settings contributes to the anticipation and control exertion of the disease. In Ethiopia, updated information is still needed at every healthcare level and in different risk groups to monitor the national program's performance, which aims to attain the 2035 goal. Hence, this study aimed to generate additional evidence data on the magnitude of Mycobacterium tuberculosis using the Gene Xpert assay among TB-suspected patients at Mizan-Tepi university teaching hospital, southwest Ethiopia.

METHODS

A cross-sectional descriptive study was conducted from June to September 30, 2021. The required socio-demographic and other risk factor data were collected from a total of 422 suspected TB patients using a structured questionnaire. Approximately 392 pulmonary and 30 extra-pulmonary samples were collected and examined using the Gene Xpert-MTB/RIF assay. The statistical package for social sciences (SPSS) version 25 software was used to analyze the data.

RESULTS

In this study, Mycobacterium tuberculosis was detected in 12.5% (49/392) of pulmonary samples and 13.3% (4/30) of extra-pulmonary samples, giving an overall TB positivity of 12.6% (53/422). Rifampicin-resistant M. tuberculosis was detected in 3/53 (5.7%). Male sex (AOR: 2.54; 95% CI: 1.210, 5.354), previous contact (AOR: 4.25; 95% CI: 1.790, 10.092), smoking cigarette (AOR: 4.708; 95% CI: 1.004, 22.081), being HIV-positive (AOR: 4.27; 95% CI: 1.606, 11.344), and malnutrition (AOR: 3.55; 95% CI: 1.175, 10.747) were all significantly associated with M. tuberculosis detection using the GeneXpert MTB/RIF assay.

CONCLUSION

The overall frequency of M. tuberculosis in this study was still significant in different risk groups, despite the proposed strategies, which aimed to reduce TB prevalence to as low as 10 per 100,000 populations by 2035. Early case detection with better diagnostic tools and public health measures are important prevention and control strategies to meet the proposed target and reduce the burden of TB in the country.

Associated risk factor of tuberculosis infection among adult patients in Gedeo Zone, Southern Ethiopia

Background:

Tuberculosis remains a major global health problem causing death among millions of people each year. Even though many of the World Health Organization recommended tuberculosis control strategies were implemented, there is still a major gap in tuberculosis case detection and treatment which resulted in rapid transmission of the cases in high burden countries. This study aimed to provide updated information on the contributing factors for the development of tuberculosis.

Methods:

A case–control study was carried out in Gedeo Zone from February to July 2021 to assess the risk factors of tuberculosis. Cases were confirmed pulmonary tuberculosis patients with age ⩾18 years, while controls were participants who were confirmed to be pulmonary tuberculosis negative with the same age. Multivariate logistic regression models were used to assess the associated risk factor.

Results:

A total of 368 individuals (173 cases and 173 controls) were included in this study. Based on the multivariable logistic regression analysis, we identified six variables as independent risk factors for the development of tuberculosis after controlling possible confounders. Those were patients with income <1500 Ethiopian birr per month (adjusted odds ratio = 2.35; 95% confidence interval: 1.22–3.97), patients with no educational background (illiterate) (adjusted odds ratio = 2.10; 95% confidence interval: 1.17–2.51), patients smoking cigarette (adjusted odds ratio = 2.89; 95% confidence interval: 2.10–3.82), patients chewing khat (adjusted odds ratio = 2.86; 95% confidence interval: 1.28–3.79), patients in close contact with known tuberculosis cases (adjusted odds ratio = 3.63; 95% confidence interval: 2.24–4.46), and patients being positive for HIV (adjusted odds ratio = 3.01; 95% confidence interval: 1.07–3.52) who were found to be significantly associated with tuberculosis development, while Bacille Calmette-Guérin vaccination had a protective effect against the development of tuberculosis (adjusted odds ratio = 0.52; 95% confidence interval: 0.21–0.88).

Conclusion:

The priority should be given to the identified contributing factors through application of coordinated efforts on screening of patients suspected for pulmonary tuberculosis and all contacts of pulmonary tuberculosis patients and treatment of known tuberculosis cases, and appropriate control methods to reduce Mycobacterium tuberculosis cases.