Unsuccessful Xpert® MTB/RIF results: the Nigerian experience

Analysis of unsuccessful tests and the effect of prolonged clinical sample preprocessing in the GeneXpert MTB/RIF assay

BACKGROUND

The GeneXpert MTB/RIF (Xpert) assay is a widely used technology for detecting Mycobacterium tuberculosis (MTB) in clinical samples. However, the study on the failure of the Xpert assay during routine implementation and its potential solutions is limited.

METHODS

We retrospectively analyzed the records of unsuccessful tests in the Xpert and the GeneXpert MTB/RIF Ultra (Ultra) assays between April 2017 and April 2021 at the Shanghai Public Health Clinical Center. To further investigate the effect of prolonged preprocessing on clinical sputum, an additional 120 sputum samples were collected for Xpert testing after 15 min, 3 h, and 6 h preprocessing. The analysis was performed by SPSS version 19.0 software.

RESULTS

A total of 11,314 test records were analyzed, of which 268 (2.37%) had unsuccessful test results. Among these, 221 (1.95%) were reported as "Error", 43 (0.38%) as "Invalid", and 4 (0.04%) as "No result". The most common clinical specimen for Xpert tests was sputum, accounting for 114 (2.17%) unsuccessful tests. The failure rate of urine specimens was lower than that of sputum (OR = 0.12, 95% CI: 0.02-0.88, χ2 = 6.22, p = 0.021). In contrast, the failure rate of stool specimens was approximately twice as high as that of sputum (OR = 1.93, 95% CI: 1.09-3.40, χ2 = 5.35, p = 0.014). In the prolonged preprocessing experiment, 102 cases (85%) yielded consistent results in Xpert tests. Furthermore, 7 cases (5.83%) detected an increase in MTB load, 8 cases (6.67%) detected a decrease in MTB load, and 3 cases (2.5%) yielded incongruent results in MTB and rifampicin resistance detection.

CONCLUSIONS

The primary cause of unsuccessful tests in the Xpert assay was reported as "Error". Despite varying failure rates depending on the samples, the Xpert assay can be applied to extrapulmonary samples. For paucibacillary specimens, retesting the remaining preprocessed mixture should be carefully considered.

Pooling sputum testing to diagnose tuberculosis using xpert MTB/RIF and xpert ultra: a cost-effectiveness analysis

BACKGROUND

The World Health Organization (WHO) recommends the diagnosis of tuberculosis (TB) using molecular tests, such as Xpert MTB/RIF (MTB/RIF) or Xpert Ultra (Ultra). These tests are expensive and resource-consuming, and cost-effective approaches are needed for greater coverage.

METHODS

We evaluated the cost-effectiveness of pooling sputum samples for TB testing by using a fixed amount of 1,000 MTB/RIF or Ultra cartridges. We used the number of people with TB detected as the indicator for cost-effectiveness. Cost-minimization analysis was conducted from the healthcare system perspective and included the costs to the healthcare system using pooled and individual testing.

RESULTS

There was no significant difference in the overall performance of the pooled testing using MTB/RIF or Ultra (sensitivity, 93.9% vs. 97.6%, specificity 98% vs. 97%, p-value > 0.1 for both). The mean unit cost across all studies to test one person was 34.10 international dollars for the individual testing and 21.95 international dollars for the pooled testing, resulting in a savings of 12.15 international dollars per test performed (35.6% decrease). The mean unit cost per bacteriologically confirmed TB case was 249.64 international dollars for the individual testing and 162.44 international dollars for the pooled testing (34.9% decrease). Cost-minimization analysis indicates savings are directly associated with the proportion of samples that are positive. If the TB prevalence is ≥ 30%, pooled testing is not cost-effective.

CONCLUSION

Pooled sputum testing can be a cost-effective strategy for diagnosis of TB, resulting in significant resource savings. This approach could increase testing capacity and affordability in resource-limited settings and support increased testing towards achievement of WHO End TB strategy.

Challenges with the use of Xpert HPV as a screening tool for oral HPV among people living with HIV (PLHIV): experiences from Pune, India

BACKGROUND

People living with HIV (PLHIV) are at higher risk for human papillomavirus (HPV)-related oropharyngeal cancers compared to the general population. Xpert HPV test is a polymerase chain reaction (PCR) assay capable of rapid HPV detection. Performing the assay requires minimal intervention by laboratory personnel. Its use could improve oropharyngeal cancer screening among PLHIV living in low-and middle-income countries (LMICs) with limited diagnostic capacities. However, Xpert HPV performance for oral samples has not been evaluated. Here, we describe our experience with Xpert HPV and compare its results with traditional PCR, for oral samples.

METHODS

Oral samples from 429 PLHIV receiving care at a tertiary care hospital affiliated antiretroviral therapy center in Pune, India were used. Samples were collected either after a 30s oral rinse and gargle (n = 335) or in combination with cytobrush scraping of the oral mucosa (n = 91). Unsuccessful tests were those that generated an invalid or error result on Xpert HPV. Successful tests were those that generated a positive or negative result. Kappa statistic was used to compare concordance between Xpert HPV and traditional real-time PCR results.

RESULTS

There were 29.8% (n = 127) unsuccessful tests, of which 78.7% (n = 100) were invalid and 21.3% (n = 27) were error results. Adding cytobrush scraping to oral rinse as a collection procedure did not significantly reduce the proportion of unsuccessful tests (p = 0.9). For successful tests, HPV positivity on Xpert was 0.3% (n = 1/299). Kappa statistic was 0.11, indicating poor agreement between Xpert HPV and traditional PCR results.

CONCLUSIONS

Presently, Xpert HPV appears to have limited use for oral HPV detection among PLHIV using oral samples. More research to improve the diagnostic capabilities of Xpert HPV for oral samples among PLHIV is needed.

Trends in pediatric tuberculosis diagnosis utilizing xpert Mycobacterium tuberculosis/Rifampicin in a poor-resource, high-burden region: A retrospective, multicenter study

Background

The burden of tuberculosis (TB) in Nigeria remains high, and diagnosis in children, a challenge. We aimed to document yield from Xpert Mycobacterium tuberculosis/rifampicin (MTB/RIF) as a mode of diagnosis for children and the variables associated with a positive result.

Methods

This was a retrospective review of TB treatment cards of children aged 0-15 years managed from January 2017 to December 2021 across six public tertiary institutions in Nigeria. The data obtained were analyzed using the descriptive and inferential statistics. Statistical significance was set at P < 0.05.

Results

Of 1489 children commenced on TB treatment, 1463 (97.9%) had sufficient data for analysis the median age of study participants was 60 months (interquartile range [IQR]: 24, 120), and 814 (55.6%) were males. Xpert MTB/RIF test was performed in 862 (59%) participants and MTB was detected in 171 (19.8%) participants, of which 6.4% (11/171) had RIF resistance reported. The use of Xpert MTB/RIF rose from 56.5% in 2017 to 64% in 2020 but fell to 60.9% in 2021. We found that older age (> 10 years), the presence of pulmonary TB (PTB), and a negative human immunodeficiency virus (HIV) status were associated with positive Xpert MTB/RIF tests (P = 0.002, 0.001, and 0.012, respectively).

Conclusion

The utilization of Xpert MTB/RIF in children increased in the years before the COVID-19 pandemic. Factors associated with MTB detection by Xpert MTB/RIF include older age, the presence of PTB, and a negative HIV status. Clinical and radiological evaluation continues to play vital roles in the diagnosis of childhood TB in Nigeria.

Pretreatment attrition and treatment initiation delay among rifampicin-resistant tuberculosis patients in Lagos, Nigeria: a retrospective cohort study

BACKGROUND

Assessing associated factors of pretreatment attrition and treatment delays among rifampicin-resistant tuberculosis (RR-TB) patients could serve as a valuable tool to control and prevent its community spread. We assessed the factors associated with pretreatment attrition and treatment initiation delays among RR-TB patients in Lagos, Nigeria.

METHODS

A retrospective cohort study was conducted involving secondary program data of RR-TB patients diagnosed using the Xpert MTB/RIF assay and initiated on treatment between 1 January 2015 and 31 December 2017 in Lagos. Factors associated with pretreatment attrition and treatment initiation delay were determined using logistic regression.

RESULTS

Of the 606 RR-TB patients diagnosed during the review period, 135 (22.3%) had pretreatment attrition. Previously treated TB patients had a 2.4-fold greater chance of having pretreatment attrition than new RR-TB patients (adjusted odds ratio 2.4 [95% confidence interval 1.2-5.0]). The median time to treatment initiation was 29 d (interquartile range [IQR] 18-49). It was longer for new RR-TB patients (49 d [IQR 36-59]) than previously treated TB patients (28 d [IQR 17-44]). A total of 47% had long treatment delays. Being newly diagnosed with RR-TB was associated with long treatment delays.

CONCLUSIONS

The pretreatment attrition rate and proportion of RR-TB patients with treatment delays were high. Pragmatic approaches to address the high pretreatment attrition and treatment delays in Lagos, Nigeria, are urgently needed.

Effect of sputum quality and role of Xpert® MTB/ RIF assay for detection of smear-negative pulmonary tuberculosis in same-day diagnosis strategy in Addis Ababa, Ethiopia

Background

There is limited information on the performance of the Xpert® MTB/RIF test for diagnosis of smear-negative pulmonary tuberculosis (SNPT) and rifampicin resistance (RR) in the same-day diagnosis approach. The effects of sputum quality and other factors affecting the Xpert performance are also under-investigated.

Objective

This study aimed to determine the performance of the Xpert® MTB/RIF test for detection of SNPT and RR in the same-day diagnosis strategy and the effect of sputum quality and other factors on its performance.

Methods

A cross-sectional study was conducted from August 2017 to January 2018 across 16 health facilities in Addis Ababa, Ethiopia. Two spot sputum samples were collected from 418 presumptive SNPT patients, tested with Xpert® MTB/RIF, then compared to tuberculosis culture. Additionally, culture isolates were tested for RR by BACTEC MGIT™ 960 drug susceptibility testing (DST) and MTBDRplus version 2.

Results

The Xpert® MTB/RIF test detected 24 (5.7%) SNPT cases, with a sensitivity of 92.3% (75.9% - 97.9%) and specificity of 99.2% (97.8% - 99.7%) compared with tuberculosis culture. Xpert® MTB/RIF also detected three (11.58%) RR strains with 100.0% concordance with BACTEC MGIT™ 960 DST and MTBDRplus results. Three blood-stained SNPT samples were positive by Xpert (30.0%), which was 6.9 times higher compared to salivary sputum (odds ratio: 6.9, 95% confidence interval: 1.36-34.96, p = 0.020).

Conclusion

The performance of the Xpert® MTB/RIF to detect SNPT and RR in same-day diagnosis is high. However, SNPT positivity varies among sputum qualities, and good sample collection is necessary for better test performance.

Evaluating the efficacy of stool sample on Xpert MTB/RIF Ultra and its comparison with other sample types by meta-analysis for TB diagnostics

Precise and timely detection of tuberculosis (TB) is crucial to reduce transmission. This study aims to assess the accuracy of Xpert MTB/RIF Ultra on stool samples and systematically review the performance of Xpert MTB/RIF Ultra with different sample types by meta-analysis. Stool samples of smear-negative pulmonary TB (PTB), cervical lymph node TB, and abdominal TB patients were tested on the Xpert MTB/RIF Ultra system. Meta-analysis was performed on a set of 44 studies. Data were grouped by sample type, and the pooled sensitivity and specificity of Xpert MTB/RIF Ultra were calculated. The sensitivity of Xpert MTB/RIF Ultra with stool samples was 100% for smear-negative PTB, 27.27% for cervical lymph node TB, and 50% for abdominal TB patients, with 100% specificity for all included TB groups. The summary estimate for all PTB samples showed 84.2% sensitivity and 94.5% specificity, and EPTB samples showed 88.6% sensitivity and 96.4% specificity. Among all sample types included in our meta-analysis, urine showed the best performance for EPTB diagnosis. This pilot study supports the use of stool as an alternative non-invasive sample on Xpert MTB/RIF Ultra for rapid testing, suitable for both PTB and EPTB diagnosis.

Implementation of GeneXpert for TB Testing in Low- and Middle-Income Countries: A Systematic Review

This review highlights a commonality of implementation barriers across geographically dispersed GeneXpert interventions for TB testing. This indicates the importance of using implementation frameworks to report findings that can improve public health outcomes across low- and middle-income countries.

Introduction:

Current evidence indicates that the impact of GeneXpert for diagnosing TB in low- and middle-income countries (LMICs) has not demonstrated equivalent outcomes when compared to Xpert evaluations in upper-middle-income countries. Challenges associated with implementation are possible contributing factors preventing this innovative diagnostic technology from achieving more significant public health outcomes. This review aimed to assess the use of implementation science frameworks when reporting the enablers and barriers for the implementation of GeneXpert for diagnosing TB in LMICs.

Methods:

We conducted a qualitative systematic review of the peer-reviewed literature using PubMed, Medline, and Scopus. Eligible articles were those published between January 2010 and March 2020 that identified enablers and barriers to GeneXpert implementation, as well as the implementation approach delivered in an LMIC.

Results:

Eleven studies were included in the review. Implementation barriers were found to be relatively consistent across studies and included patient-level factors, human resources, material resources, service implementation, service coordination, and technical operations. Few studies (n=5) identified enabling factors in the implementation of Xpert for TB testing. Identified enablers included strategies such as active case finding, expanding diagnostic algorithms, and daily transport of samples. The public health impact of Xpert TB testing interventions was commonly influenced by implementation barriers (n=4). Of the 11 studies, only 3 reported against an implementation framework.

Conclusion:

This review identified a commonality in implementation barriers and enablers that influenced the overall public health impact of GeneXpert. With greater transparency of these barriers and enablers, program planners can promote a more collaborative approach and adapt interventions. It is recommended that program planners use implementation science frameworks when conducting research and publishing. This will build an evidence base focused on implementation and thereby support programs to address implementation barriers and include enabling factors in program design.

The Simple One-Step (SOS) Stool Processing Method for Use with the Xpert MTB/RIF Assay for a Child-Friendly Diagnosis of Tuberculosis Closer to the Point of Care

Young children cannot easily produce sputum for diagnosis of pulmonary tuberculosis (TB). Alternatively, Mycobacterium tuberculosis complex bacilli can be detected in stool by using the Xpert MTB/RIF (Ultra) assay (Xpert). Published stool processing methods contain somewhat complex procedures and require 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 Xpert testing of sputum samples, for the detection of M. tuberculosis in stool samples. We first assessed whether the SOS stool method could provide valid Xpert results without the need for bead-beating, dilution, and filtration steps. We concluded that this was the case, and we then validated the SOS stool method by testing spiked stool samples. By using the SOS stool method, 27 of the 29 spiked samples gave valid Xpert results, and M. tuberculosis was recovered from all 27 samples. The proof of principle of the SOS stool method was demonstrated in routine settings in Addis Ababa, Ethiopia. Nine of 123 children with presumptive TB had M. tuberculosis-positive results for nasogastric aspiration (NGA) samples, and 7 (77.8%) of those children also had M. tuberculosis-positive Xpert results for stool samples. Additionally, M. tuberculosis was detected in the stool samples but not the NGA samples from 2 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.

Epidemiology of molecular probes in Xpert MTB/RIF assay in Khyber Pakhtunkhwa, Pakistan

Regardless of a plethora of advanced diagnostics, TB and drug resistance remains a principal killer. We proposed gold nanoparticles (AuNPs) attached with probes to enhance the efficiency of GeneXpert MTB/RIF assay instead of conventional dye probes for molecular detection. A total of 15,000 samples were collected from TB suspects and subjected to Xpert MTB/RIF assay, where 6800 (45.3%) were detected as MTB positive, 280 (4.3%) were detected to harbor mutations in the RRDR, while invalid /errors were found in 690 (4.6%) cases. The mutations were detected by probe E, 199 (71.1%), while probes B and D, 30 and 26 (10% and 9%), respectively. In the Xpert MTB/RIF Assay were found mutations picked by probes E and B codons 529-533 (71%) and 512-518 (10%), respectively. The fast-rising works of TB nano-diagnostics, of Xpert probes, may improve by the applications of gold nanoparticle probes.

Driving the usage of tuberculosis diagnostic data through capacity building in low- and middle-income countries

BACKGROUND

Connectivity platforms collect a wealth of data from connected GeneXpert instruments, with the potential to provide valuable insights into the burden of disease and effectiveness of tuberculosis programmes. The challenge faced by many countries is a lack of training, analytical skills, and resources required to understand and translate this data into patient management and programme improvement.

OBJECTIVE

We describe a novel training programme, the tuberculosis Data Fellowship, designed to build capacity in low- and middle- income countries for tuberculosis data analytics.

METHODS

The programme consisted of classroom and remote training plus mentorship over a 12-month period. The focus was on skills development in Tableau software, followed by training in exploration, analysis, and interpretation of GeneXpert tuberculosis data across five key programme areas: patient services, programme monitoring, quality of testing, inventory management, and disease burden.

RESULTS

The programme was piloted in six countries (Bangladesh, Ethiopia, Ghana, Malawi, Mozambique) in July 2018 and Nigeria in September 2018; 20 participants completed the training. A number of key outputs have been achieved, such as improved instrument utilisation rates, decreased error rates, and improved instrument management.

CONCLUSION

The training programme empowers local tuberculosis programme staff to discover and fix critical inefficiencies, provides high-level technical and operational support to the tuberculosis programme, and provides a platform for continued sharing of insights and best practices between countries. It supports the notion that connectivity can increase efficiencies and clinical benefits with better data for decision making, if coupled with commensurate capacity building in data analysis and interpretation.

Perspectives and practices of health workers around diagnosis of paediatric tuberculosis in hospitals in a resource-poor setting - modern diagnostics meet age-old challenges

BACKGROUND

Detection of tuberculosis (TB) in children in Kenya is sub-optimal. Xpert MTB/RIF® assay (Xpert®) has the potential to improve speed of TB diagnosis due to its sensitivity and fast turnaround for results. Significant effort and resources have been put into making the machines widely available in Kenya, but use remains low, especially in children. We set out to explore the reasons for the under-detection of TB and underuse of Xpert® in children, identifying challenges that may be relevant to other newer diagnostics in similar settings.

METHODS

This was an exploratory qualitative study with an embedded case study approach. Data collection involved semi-structured interviews; small-group discussions; key informant interviews; observations of TB trainings, sensitisation meetings, policy meetings, hospital practices; desk review of guidelines, job aides and policy documents. The Capability, Opportunity and Motivation (COM-B) framework was used to interpret emerging themes.

RESULTS

At individual level, knowledge, skill, competence and experience, as well as beliefs and fears impacted on capability (physical & psychological) as well as motivation (reflective) to diagnose TB in children and use diagnostic tests. Hospital level influencers included hospital norms, processes, patient flows and resources which affected how individual health workers attempted to diagnose TB in children by impacting on their capability (physical & psychological), motivation (reflective & automatic) and opportunity (physical & social). At the wider system level, community practices and beliefs, and implementation of TB programme directives impacted some of the decisions that health workers made through capability (psychological), motivation (reflective & automatic) and opportunity (physical).

CONCLUSION

We used comprehensive approaches to identify influencers of TB case detection and use of TB diagnostic tests in children in Kenya. These results are being used to design a contextually-appropriate intervention to improve TB diagnosis, which may be relevant to similar low-resource, high TB burden countries and can be feasibly implemented by the National TB programme.

Evaluation of Xpert MTB/RIF for the Diagnosis of Lymphatic Tuberculosis

Background

The World Health Organization approved the use of Xpert MTB/RIF for the detection of Mycobacterium tuberculosis DNA, which has significantly improved the diagnosis of tuberculosis. In this study, our main objective was to evaluate the diagnostic efficacy of Xpert MTB/RIF for lymphoid tuberculosis to determine whether Xpert MTB/RIF could be used as a routine detection method.

Materials and Methods

We searched four databases for the relevant literature published from May 2007 to December 2019. The quality of the literature was evaluated with reference to the evaluation criteria. Data that were extracted from the literature on Xpert MTB/RIF diagnosis of lymphatic tuberculosis were used to plot the summary receiver operating characteristic (SROC) curve, after which the software was used to combine and analyze the accuracy of these data.

Results

A total of 27 studies were included. The sensitivity of Xpert MTB/RIF for detecting lymphatic tuberculosis was 0.79 (95% CI (0.77, 0.81)), the specificity was 0.88 (95% CI (0.87, 0.90)), and the positive likelihood ratio (PLR) was 7.21 (95% CI (4.93, 10.55)). In addition, the negative likelihood ratio (NLR) was 0.25 (95% CI (0.19, 0.32)) and the diagnostic odds ratio (DOR) was 40.23 (95% CI (24.53, 65.98)). At the same time, we used the extracted data to make the SROC curve, obtaining the following parameters: area under the curve (AUC) = 0.9144, Q = 0.8470 (SE = 0.0163).

Conclusion

Xpert MTB/RIF has high accuracy in detecting lymphatic tuberculosis, and it can be used to quickly and easily diagnose lymphatic tuberculosis at an early stage as a general method.

Improving the design of studies evaluating the impact of diagnostic tests for tuberculosis on health outcomes: a qualitative study of perspectives of diverse stakeholders

Background: Studies evaluating the impact of Xpert MTB/RIF testing for tuberculosis (TB) have demonstrated varied effects on health outcomes with many studies showing inconclusive results. We explored perceptions among diverse stakeholders about studies evaluating the impact of TB diagnostic tests, and identified suggestions for improving these studies. Methods: We used purposive sampling with consideration for differing expertise and geographical balance and conducted in depth semi-structured interviews. We interviewed English-speaking participants, including TB patients, and others involved in research, care or decision-making about TB diagnostics. We used the thematic approach to code and analyse the interview transcripts. Results: We interviewed 31 participants. Our study showed that stakeholders had different expectations with regard to test impact and how it is measured. TB test impact studies were perceived to be important for supporting implementation of tests but there were concerns about the unrealistic expectations placed on tests to improve outcomes in health systems with many influencing factors. To improve TB test impact studies, respondents suggested conducting health system assessments prior to the study; developing clear guidance on the study methodology and interpretation; improving study design by describing questions and interventions that consider the influences of the health-care ecosystem on the diagnostic test; selecting the target population at the health-care level most likely to benefit from the test; setting realistic targets for effect sizes in the sample size calculations; and interpreting study results carefully and avoiding categorisation and interpretation of results based on statistical significance alone. Researchers should involve multiple stakeholders in the design of studies. Advocating for more funding to support robust studies is essential. Conclusion: TB test impact studies were perceived to be important to support implementation of tests but there were concerns about their complexity. Process evaluations of their health system context and guidance for their design and interpretation are recommended.

Monitoring quality indicators for the Xpert MTB/RIF molecular assay in Ethiopia

INTRODUCTION

In Ethiopia, >300 GeneXpert instruments have been deployed for tuberculosis (TB) testing using the Xpert MTB/RIF cartridge. Implementing quality indicators is necessary for monitoring and evaluating the quality of Xpert MTB/RIF diagnostic services.

OBJECTIVE

To assess the use of quality indicators for the Xpert MTB/RIF molecular assay in Ethiopia and to compare the findings with the predefined targets described in the literature.

METHODS

Clinical specimens collected from patients with suspected TB were subjected to Xpert MTB/RIF testing at the National TB Reference Laboratory (NTRL) between January and December 2018. Data were collected from GeneXpert software and Laboratory Information System (LIS) databases. Quality indicators were calculated and analyzed. Bivariate and multivariate analyses were performed using SPSS software version 20 (SPSS Inc., Chicago, Illinois, USA).

RESULTS

Of the 2515 specimens tested, 2274 (90.4%) had successful test results; 18.2% were positive for Mycobacterium tuberculosis (MTB). Among MTB positives (n = 413), 4.8% and 1.0% were rifampicin (RIF)-resistant and RIF-indeterminate cases, respectively. Unsuccessful results were 241 (9.6%); 8.9% of the total number of tests were errors, 0.04% had invalid results and 0.6% 'no result'. The most frequent error was probe check failure (error 5007). Instrument module A4, B2, B3, C3, and D3 (p<0.05) and tester experience (p<0.05) had a statistically significant association with errors in multivariate analysis. Additional 42 MTB cases (9.2% of the total cases) were detected among unsuccessful results by follow-up tests. Sixty-four percent of the initial test results were released within the turnaround time (TAT) ≤24 hours.

CONCLUSION

Most of the quality indicators for the Xpert MTB/RIF molecular assay were maintained within the targets. However, the error rate and TAT were out of the targets. Defective modules and lacking experience were the factors affecting successful test outcomes.

Rates and timeliness of treatment initiation among drug-resistant tuberculosis patients in Nigeria- A retrospective cohort study

Background

There were an estimated 580,000 new cases of multidrug/rifampicin resistant TB (DR-TB) in 2015, and only 20% were initiated on treatment. This study explored health system and patient factors associated with initiation and timeliness of treatment among DR-TB patients in Nigeria, ranked 4^th globally for estimated TB cases in 2015.

Methods

A retrospective cohort study using 2015 diagnosis and treatment data from the Nigerian TB program electronic records examined “treatment ever received” (yes/no) and “treatment within 30 days” (yes/no). We compared health system and patient characteristics using binomial logistic regression, while controlling for confounders.

Results

Of 996 patients diagnosed nationwide in 2015 (aged 0–87 years, median 34), 47.8% were never treated. Of those treated (n = 520), 51.2% were treated within the 30 days prescribed in the National treatment guideline. Healthcare facility locations were significantly associated with ever receiving treatment and timely treatment. Predictors of timely treatment at the national level also included level of care and patient treatment history. The South-West zone, where DR-TB programs started, showed overall better access to DR-TB healthcare.

Conclusions

Healthcare facility geographic locations were significantly associated with treatment initiation and timeliness. Significant regional differences in access to DR-TB care in Nigeria persist, reflecting uneven contexts for national DR-TB treatment rollout.

Xpert negative means no TB: A mixed-methods study into early implementation of Xpert in Puducherry, India

INTRODUCTION

Xpert MTB/RIF was implemented in 2016 as the initial diagnostic test for extrapulmonary, pediatric, and human immunodeficiency virus-associated tuberculosis (TB) and as an add-on test for sputum microscopy-negative patients under Revised National TB Control Programme, Puducherry, India. We intended to study the change in TB case notification rates (CNRs) after 2015 and explore the enablers and barriers for implementation of Xpert.

MATERIALS AND METHODS

Sequential mixed-methods study, quantitative phase followed by a descriptive qualitative phase (key informant interviews with healthcare providers in the program).

RESULTS

The TB (all forms) CNR increased in 2016 followed by a drop to 2015 levels in 2017. There was a reduction in patients notified as sputum-negative pulmonary TB and pediatric TB during 2016-2017. Healthcare providers used a negative Xpert result in ruling out TB among patients who would previously get diagnosed clinically. Perceived benefits of Xpert were efficiency, rapid results, and detecting resistance. Barriers included poor awareness among medical colleges and the private sector, difficulty in motivating sputum microscopy-negative patients for Xpert, and incompletely filled referral forms.

CONCLUSION

Xpert-negative results should be interpreted cautiously after clinical assessment. Identified barriers should be addressed to ensure that all eligible undergo testing.

Assessment of GeneXpert MTB/RIF Performance by Type and Level of Health-Care Facilities in Nigeria

Setting:

Nigeria adopted GeneXpert MTB Rif as a primary diagnostic tool were available and accessible since 2016. The current geographical coverage of GeneXpert machines by LGAs stands at 48%, with a varied access and utilization.

Objectives:

To assess the association between the type and level of health facilities implementing GeneXpert MTB/Rif and performance outcome of the machines in Nigeria.

Study Design:

Retrospective secondary data analysis of GeneXpert performance for 2017 from GXAlert database. The independent variables were type and levels of health care facilities, and dependent variables were GeneXpert performance (utilization, successful test, error rates, MTB detected, and Rifampicin resistance detected).

Results:

Only 366 health care facilities are currently implementing and reporting GeneXpert performance, the distribution is 86.9% and 13.1% public and private health care facilities respectively, and only 6.3% of the facilities are primary health care. Of 354,321 test conducted in 2017, 91.5% were successful, and among unsuccessful test 6.8% were errors. The yield was 16.8% MTB detected (54,713) among which 6.8% had Rif resistance. The GeneXpert utilization rate was higher among private health care facilities (55.8%) compared to 33.3% among public health care facilities. There was a statistically significant difference in the number of successful test between public and private health facility-based machines as determined by one-way ANOVA (F(1,2) = 21.81, P = 0.02) and between primary, secondary and tertiary level health facility-based machines (F(1,2) = 41.24, P < 0.01).

Conclusion:

Nigeria with very low TB coverage should rapidly scale-up and decentralize GeneXpert services to the private sector.