GeneXpert Mycobacterium tuberculosis/rifampicin assay for molecular epidemiology of rifampicin-Resistant Mycobacterium tuberculosis in an Urban Setting of Banten province, Indonesia

Diagnosis of tuberculous pleural effusion in a tertiary care hospital of central India: The role of xpert Mycobacterium tuberculosis/rifampicin

Background

In India, 15%-20% of tuberculosis (TB) cases are categorized as extra-pulmonary TB, and tuberculous pleural effusion (TPE) is the second-most common type after tuberculous lymphadenitis. However, the paucibacillary nature of TPE makes its diagnosis challenging. As a result, relying on empirical anti-TB treatment (ATT) based on clinical diagnosis becomes necessary for achieving the best possible diagnostic outcome. The study aims to determine the diagnostic utility of Xpert Mycobacterium tuberculosis/rifampicin (MTB/RIF) for the detection of TB in TPE in high incidence setting of Central India.

Methods

The study enrolled 321 patients who had exudative pleural effusion detected through radiological testing and were suspected of having TB. The medical procedure of thoracentesis was conducted to collect the pleural fluid, which was then subjected to both the Ziehl-Neelsen staining and Xpert MTB/RIF test. The patients who showed improvement after receiving anti-tuberculosis treatment (ATT) were considered the composite reference standard.

Results

The sensitivity of smear microscopy was found to be 10.19%, while that of the Xpert MTB/RIF method was 25.93% when compared to the composite reference standard. The accuracy of clinical diagnosis was measured using receiver operating characteristics based on clinical symptoms, and it was found to be 0.858 (area under the curve).

Conclusions

The study shows that Xpert MTB/RIF has significant value in diagnosing TPE, despite its low sensitivity of 25.93%. Clinical diagnosis based on symptoms was relatively accurate, but relying on symptoms alone is not enough. Using multiple diagnostic tools, including Xpert MTB/RIF, is crucial for accurate diagnosis. Xpert MTB/RIF has excellent specificity and can detect RIF resistance. Its quick results make it useful in situations where a rapid diagnosis is necessary. While it should not be the only diagnostic tool, it has a valuable role in diagnosing TPE.

Study the prevalence of rifampicin resistance among pulmonary tuberculosis patients by genexpert assay from a tertiary care hospital of North India

Background

Rifampicin (RIF) resistance (RR) tuberculosis (TB) has posed a great challenge to TB control programs globally. Evidence of RIF-RR can help as a surrogate marker to find out multidrug-resistance cases. The study aimed to determine the prevalence of RIF-RR in pulmonary TB (PTB) patients over the 4 years at Dr. RPGMC, Tanda, from the year 2018 to 2021.

Methods

This was a retrospective study conducted at Dr. RPGMC, Tanda at Kangra, where we checked (from January 2018 to December 2021) clinically suspected PTB patients, whose samples were sent to the laboratory for GeneXpert assay to identify Mycobacterium TB/RIF (MTB/RIF) testing.

Results

Of the total 11,774 clinically suspected PTB specimens were collected, and identified by GeneXpert MTB/RIF assay, in which 2358 samples were MTB positive and 9416 were MTB negative. Among 2358 MTB-positive samples, 2240 (95%) samples were RIF sensitive, in which 1553 (65.9%) were males and 687 (29.1%) were females, 76 (3.2%) samples were RIF-RR, in which 51 (2.2%) were males and 25 (1%) were females, and 42 (1.8%) samples were RIF indeterminate, in which 25 (1%) were males and 17 (0.8%) were females.

Conclusion

The rate of RIF-RR was found 3.2% of total samples which was more in males. The overall positivity rate was 20%, and the rate of positivity decreased from 32% to 14% over the 4 years in sputum samples. Hence, the GeneXpert assay was found to be very important tool to detect RIF-RR among suspected PTB patients.

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.

Association between serum PGE2 levels and degree of acid-fast bacilli positivity in sputum of pulmonary tuberculosis patients

Background

Mycobacterium tuberculosis that infected apoptotic macrophages is triggered by PGE₂. Apoptosis suppresses the growth of Mycobacterium tuberculosis bacteria, which is shown in the results of acid-fast bacilli (AFB) in the sputum that becomes a marker of the number of bacteria.

Objective

Analyzing the association between serum PGE₂ levels and the positivity of AFB in the sputum of tuberculosis patients.

Methods

A cross-sectional study was carried out from August 2019–July 2020. Serum PGE₂ levels and AFB levels in sputum were collected from participants. Data analysis used the Chi-square test and Spearman's correlation with p < 0.05.

Results

The average participants’ serum PGE₂ levels were 446.37 ± 510.27 pg/ml, with a median value of 216.95 pg/ml. Most participants had normal serum PGE₂ levels (62.9%). Most participants had a high positivity of AFB in sputum (58.1%). Analysis of the association between serum PGE₂ levels and the degree of AFB positivity in sputum obtained r = −0.036 and p-value = 0.780.

Conclusion

There is a weak negative association between serum PGE₂ levels and the degree of AFB positivity in sputum but not statistically significant.

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Serum PGE₂ levels of tuberculosis patients tend to be normal even though acid-fast bacilli (AFB) values are high.

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Most of the new and recurrent cases of pulmonary tuberculosis patients had normal PGE₂ levels.

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Serum PGE₂ levels have a negative association with AFB value.

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

Background

Tuberculosis (TB) remains a major global health problem causing death among millions of people each year. The new barrier that challenges the control of tuberculosis is the emerging and the increasing number of drug-resistant TB that becomes a world concern. This study aimed to determine the magnitude of rifampicin-resistant Mycobacterium tuberculosis (RR-MTB) among presumptive TB patients attending Dilla University Referral Hospital, Gedeo Zone, Ethiopia.

Methods

A retrospective cross-sectional study was conducted at Dilla University Referral Hospital from January 2014 to December 2020. Sputum results were done using Xpert MTB/RIF assay and other necessary data were collected from the registration logbooks using a standardized data extraction format and analyzed using SPSS version 23 statistical software.

Results

A total of 17,745 presumptive TB patients were included, of which 62.2% were males. The overall prevalence of Mycobacterium tuberculosis (MTB) was 11.8%, of which 5.1% were confirmed to have RR-MTB. Extra-pulmonary TB was reported in 1.5% of the study participants. The highest prevalence of MTB and RR-MTB was recorded in 2017 with a prevalence of 20.1% and 8.5%, respectively. All age groups were significantly associated with a higher prevalence of MTB (p < 0.036). TB patients with a history of previous treatment and HIV positive were significantly associated with MTB (P < 0.021), while RR-MTB was only significantly associated with patients with a history of previous treatment (P < 0.018).

Conclusion

A high magnitude of MTB and RR-MTB was reported among TB patients with HIV and a history of previous treatment. Therefore, coordinated efforts should be applied to the improvement of treatment adherence of known TB cases, and appropriate control and prevention methods to reduce the emergence and increase of MTB and RR-MTB cases.

Correlation of inflammatory cytokines on corrected QT interval in rifampicin-resistant tuberculosis patients

Background

The cases of Rifampicin-Resistant Tuberculosis (RR-TB) in our country have increased every year and RR-TB deaths are thought to be caused by prolongation of the QTc interval due to side effects of anti-tuberculosis drugs. Thus, cytokines are needed to be used as early markers of prolongation of the QTc interval in RR-TB patients.

Objective

This study aims to analyze the correlation of inflammatory cytokines on QTc interval in RR-TB patients who received shorter regimens.

Methods

This study uses a case-control study with a time series conducted in the period September 2019 to February 2020 in one of the referral hospitals for Tuberculosis in Indonesia. Cytokines levels from blood samples were measured using the ELISA method, while QTc intervals were automatically recorded using an electrocardiography machine. The statistical analysis used was the Chi-square test, Man Whitney test, Independence t-test, and Spearman-rank test with p < 0.05.

Results

There was no significant correlation between inflammatory cytokines and QTc prolongation in intensive phase which TNF-α value (6.8 pg/ml; r = 0.207; p = 0.281), IL-1β (20.13 pg/ml; r = 0.128; p = 0.509), and IL-6 (43.17 pg/ml; r = -0.028; p = 0.886). Meanwhile, in the continuation phase, the values for TNF-α (4.79 pg/ml; r = 0.046; p = 0.865), IL-1β (7.42 pg/ml; r = -0.223; p = 0.406), and IL- 6 (40.61 pg/ml; r = -0.147; p = 0.586).

Conclusion

inflammatory cytokines (TNF-α, IL-1β, and IL-6) cannot be used to identify QTc interval prolongation in RR-TB patients who received shorter regimens.

Diagnostic challenges and Gene-Xpert utility in detecting Mycobacterium tuberculosis among suspected cases of Pulmonary tuberculosis

The incidence of pulmonary tuberculosis (PTB) can be reduced by preventing transmission with rapid and precise case detection and early treatment. The Gene-Xpert MTB/RIF assay is a useful tool for detecting Mycobacterium tuberculosis (MTB) with rifampicin resistance within approximately two hours by using a nucleic acid amplification technique. This study was designed to reduce the underdiagnosis of smear-negative pulmonary TB and to assess the clinical and radiological characteristics of PTB patients. This cross-sectional study included 235 participants who went to the Luyang primary health care clinic from September 2016 to June 2017. The demographic data were analyzed to investigate the association of patient gender, age group, and ethnicity by chi-square test. To assess the efficacy of the diagnostic test, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. The area under the curve for sputum for both AFB and gene-Xpert was analyzed to compare their accuracy in diagnosing TB. In this study, TB was more common in males than in females. The majority (50.71%) of the cases belonged to the 25-44-year-old age group and the Bajau ethnicity (57.74%). Out of 50 pulmonary TB cases (smear-positive with AFB staining), 49 samples were positive according to the Gene-Xpert MTB/RIF assay and was confirmed by MTB culture. However, out of 185 smear-negative presumptive cases, 21 cases were positive by Gene-Xpert MTB/RIF assay in that a sample showed drug resistance, and these results were confirmed by MTB culture, showing resistance to isoniazid. In comparison to sputum for AFB, Gene-Xpert showed more sensitivity and specificity with almost complete accuracy. The additional 21 PTB cases detection from the presumptive cases by GeneXpert had significant impact compared to initial observation by the routine tests which overcame the diagnostic challenges and ambiguities.

Impacts of a comprehensive tuberculosis control model on the quality of clinical services and the financial burden of treatment for patients with drug-resistant tuberculosis in China: a mixed-methods evaluation

Background

The China National Health Commission-Gates TB Project Phase III implemented a comprehensive TB control model including multiple interventions to address the burden of drug-resistant TB (DRTB). This study aims to evaluate the quality of DRTB clinical services and assess the financial burden of DRTB patients during the intervention period.

Methods

A mixed-methods approach was used to evaluate the effectiveness of interventions in the three project provinces: Zhejiang, Jilin and Ningxia Hui Autonomous Region. The quantitative data included de-identified DRTB registry data during 2015–2018 in project provinces from China CDC, medical records of DRTB patients registered in 2018 (n = 106) from designated hospitals, and a structured DRTB patient survey in six sample prefectures in 2019. The quality of clinical services was evaluated using seven indicators across patient screening, diagnosis and treatment. Logistic regression was conducted to explore factors associated with the extremely high financial burden. Semi-structured in-depth interviews with policymakers and focus group discussions with physicians and DRTB patients were conducted to understand the interventions implemented and their impacts.

Results

The percentage of bacterially confirmed patients taking a drug susceptibility test (DST) increased significantly between 2015 and 2018: from 57.4 to 93.6% in Zhejiang, 12.5 to 86.5% in Jilin, and 29.7 to 91.4% in Ningxia. The treatment enrollment rate among diagnosed DRTB patients also increased significantly and varied from 73 to 82% in the three provinces in 2018. Over 90% of patients in Zhejiang and Jilin and 75% in Ningxia remained in treatment by the end of the first six months’ treatment. Among all survey respondents 77.5% incurred extremely high financial burden of treatment. Qualitative results showed that interventions on promoting rapid DST technologies and patient referral were successfully implemented, but the new financing policies for reducing patients’ financial burden were not implemented as planned.

Conclusions

The quality of DRTB related clinical services has been significantly improved following the comprehensive interventions, while the financial burden of DRTB patients remains high due to the delay in implementing financing policies. Stronger political commitment and leadership are required for multi-channel financing to provide additional financial support to DRTB patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40249-021-00832-5.

Policy changes and the screening, diagnosis and treatment of drug-resistant tuberculosis patients from 2015 to 2018 in Zhejiang Province, China: a retrospective cohort study

OBJECTIVES

To examine changes in the screening, diagnosis, treatment and management of drug-resistant tuberculosis (DRTB) patients, and investigate the impacts of DRTB-related policies on patients of different demographic and socioeconomic characteristics.

DESIGN

A retrospective cohort study using registry data, plus a survey on DRTB-related policies.

SETTING

All prefecture-level Centres for Disease Control in Zhejiang Province, China.

MAIN OUTCOME MEASURES

Alongside the care cascade, we examined: (1) reported number of presumptive DRTB patients; (2) percentage of presumptive patients with drug susceptibility testing (DST) records; (3) percentage of DRTB/rifampicin-resistant (RR) patients registered; (4) percentage of RR/multidrug-resistant TB (MDRTB) patients that received anti-DRTB treatment; and (5) percentage of RR/MDRTB patients cured/completed treatment among those treated. Multivariate logistic regressions were conducted to explore the impacts of DRTB policies after adjusting for other factors.

RESULTS

The number of reported presumptive DRTB patients and the percentage with DST records largely increased during 2015-2018, and the percentage of registered patients who received anti-DRTB treatment also increased from 59.0% to 86.5%. Patients under the policies of equipping GeneXpert plus expanded criteria for DST had a higher likelihood of being registered compared with no GeneXpert (adjusted OR (aOR)=2.57, 95% CI: 1.20 to 5.51), while for treatment initiation the association was only significant when further expanding the registration criteria (aOR=2.38, 95% CI: 1.19 to 4.79). Patients with registered residence inside Zhejiang were more likely to be registered (aOR=1.96, 95% CI: 1.52 to 2.52), treated (aOR=3.83, 95% CI: 2.78 to 5.28) and complete treatment (aOR=1.92, 95% CI: 1.03 to 3.59) compared with those outside.

CONCLUSION

The policy changes on DST and registration have effectively improved DRTB case finding and care. Nevertheless, challenges remain in servicing vulnerable groups such as migrants and improving equity in the access to TB care. Future policies should provide comprehensive support for migrants to complete treatment at their current place of residence.