National Tuberculosis Reference Laboratory Research Articles

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

IntroductionIn 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.ObjectiveTo 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.MethodsClinical 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).ResultsOf 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.ConclusionMost 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.

Detection of Second Line Drug Resistance among Drug Resistant Mycobacterium Tuberculosis Isolates in Botswana.

The emergence and transmission of multidrug resistant (MDR) and extensively drug resistant (XDR) Mycobacterium tuberculosis (M.tb) strains is a threat to global tuberculosis (TB) control. The early detection of drug resistance is critical for patient management. The aim of this study was to determine the proportion of isolates with additional second-line resistance among rifampicin and isoniazid resistant and MDR-TB isolates. A total of 66 M.tb isolates received at the National Tuberculosis Reference Laboratory between March 2012 and October 2013 with resistance to isoniazid, rifampicin or both were analyzed in this study. The genotypes of the M.tb isolates were determined by spoligotyping and second-line drug susceptibility testing was done using the Hain Genotype MTBDRsl line probe assay version 2.0. The treatment outcomes were defined according to the Botswana national and World Health Organization (WHO) guidelines. Of the 57 isolates analyzed, 33 (58%) were MDR-TB, 4 (7%) were additionally resistant to flouroquinolones and 3 (5%) were resistant to both fluoroquinolones and second-line injectable drugs. The most common fluoroquinolone resistance-conferring mutation detected was gyrA A90V. All XDR-TB cases remained smear or culture positive throughout the treatment. Our study findings indicate the importance of monitoring drug resistant TB cases to ensure rapid detection of second-line drug resistance.

Introduction of quality management in a National Reference Laboratory in Germany

BackgroundHigh quality diagnostic services are crucial for tuberculosis (TB) diagnosis, treatment and control. A strong laboratory quality management system (QMS) is critical to ensuring the quality of testing and results. Recent initiatives to improve TB laboratory quality have focused on low and middle-income countries, but similar issues also apply to high-income countries.Methods and findingsUsing a multipronged approach reviews of facilities, equipment, processes (purchasing, pre-analytic, analytic and post-analytic), staff, health and safety, documentation, information management and organization based on the ISO 15189 and the twelve quality system essentials were conducted between October 2015 and January 2016 at the National TB Reference Laboratory in Germany. Outcome assessment included proportion of smear positive slides, proportion of contaminated liquid cultures and DNA contamination rates before and after implementation of QMS. The odds ratio for these outcomes was calculated using a before/after comparison. Reviews highlighted deficiencies across all twelve quality system essentials and were addressed in order of priority and urgency. Actions aimed at improving analytical quality, health and safety and information management were prioritised for initial implementation in parallel with each other. The odds ratio for a sample to be tested as microscopically positive increased by 2.08 (95%CI 1.41–3.06) comparing the time before with the time after implementation of quality managed fluorescence microscopy. Liquid culture contamination rates decreased from 23.6- 7.6% in April-July 2016 to <10% in November 2017-March 2018. The proportion of negative controls showing evidence of DNA contamination decreased from 38.2% in 2013 to 8.1% in 2017, the corresponding odds ratio was 0.14 (95%CI 0.07–0.29).ConclusionThis study showed marked improvement on quality indicators after implementation of a QMS in a National TB Reference Laboratory. The challenges and lessons learned in this study are valuable not just for high-income settings, but are equally generalizable to other laboratories.

Comparison of GeneXpert and line probe assay for detection of Mycobacterium tuberculosis and rifampicin-mono resistance at the National Tuberculosis Reference Laboratory, Kenya

BackgroundThe dual challenge of low diagnostic sensitivity of microscopy test and technical challenge of performing a TB culture test poses a problem for case detection and initiation of Tuberculosis (TB) second-line treatment. There is thus need for a rapid, reliable and easily accessible assay. This comparative analysis was performed to assess diagnostic performance characteristics of GeneXpert MTB/RIF and Line Probe Assay (LPA).MethodsThree hundred twenty nine sputum samples of patients across the 47 counties in Kenya suspected to have drug resistant TB were picked and subjected to GeneXpert, LPA and Culture MGIT at the National TB Reference Laboratory. Sensitivity, specificity and predictive values were then determined to assess the performance characteristics of the various assays.ResultsAgainst culture MGIT as the gold standard for TB diagnosis, GeneXpert had a sensitivity, specificity, positive predictive value, and negative predictive value of 78.5, 64.9, 59.4 and 82.2% respectively while LPA had 98.4, 66.0, 65.4 and 98.4%. For diagnosis of rifampicin mono-resistance GeneXpert had a moderate agreement (Kappa 0.59, P < 0.01) (sensitivity 62.50%, specificity 96.50%) while LPA that had almost perfect agreement (Kappa = 0.89, p < 0.01) with a (sensitivity 90.0% and specificity 99.1%).ConclusionLPA has a better performance characteristic to GeneXpert and an alternative to culture with regards to detection of RIF’s mono-resistance.

Prevalence of tuberculosis, multidrug resistant tuberculosis and associated risk factors among smear negative presumptive pulmonary tuberculosis patients in Addis Ababa, Ethiopia

BackgroundThe 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.MethodsAnalytic 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.ResultsFrom 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.ConclusionIn 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.

Mind the gap: Improving the performance of the reference laboratory to end-tuberculosis in Armenia.

A one of the step towards achieving TB related targets is to ensure early and quality diagnosis of TB in national laboratories. WHO recommends that all national reference laboratories in TB burden countries strive to reach accreditation by 2025, based on ISO15189:2012 quality management system standard. To identify gaps, progress and evaluated the evolution in implementation QMS we performed a formal assessment of the national TB reference laboratory of Armenia, as well as estimates the specific quality indicators of NRL activity. This is retrospective study cross-sectional study using laboratory data from the National TB Reference Laboratory in Armenia. Quality Management System assessments was conducted twice a year, using TB SLMTA assessment checklist. The sputum rejection and culture rates for quality indicators are calculated and assessed monthly. Compared to the baseline in 2016, there was a quality improvement reflecting the progress from zero to a "one star" in 2018. Areas that reached half of the target score included document and records, management review and responsibilities, evaluation and audits. Sections as "client management and customer service" and "evaluation and audits" stagnated in terms of progress. In terms of NRL performace, all indicators improved except for culture positivity in smear negative tuberculosis. Although a quality management system was introduced in the NRL there is now an urgent need to develop and implement an adapted roadmap for Armenia. This will be vital to hasten the much-needed pace towards accreditation.

PO 8408 DETECTION OF EXTENSIVELY DRUG-RESISTANT TUBERCULOSIS AMONG MULTIDRUG-RESISTANTMYCOBACTERIUM TUBERCULOSISCLINICAL ISOLATES IN BOTSWANA

BackgroundThe emergence and transmission of multidrug-resistant (MDR) and extensively drug-resistant (XDR)Mycobacterium tuberculosis(Mtb) strains is a serious threat to tuberculosis control in Botswana. Early detection of drug-resistant isolates is critical to ensure optimal treatment and thereby improve treatment outcomes. The objective of this study was to determine the extent of second-line drug resistance among drug-resistant Mtb-isolates from Botswana.MethodsA total of 60 drug-resistant Mtb isolates received at Botswana National Tuberculosis Reference Laboratory between 2012 and 2013 were analysed. DNA was extracted from BD Mycobacterial Growth Indicator Tubes (MGIT) using GenoLyse DNA isolation kit (Hain Lifescience). Spoligotyping was done using a commercially available spoligotyping kit (Isogen Life Science). The spoligotype patterns were compared with existing patterns in the SITVIT2 Web database. GenoType MTBDRs assay (Hain Lifescience) was used for second-line drug susceptibility testing. Fisher’s exact test was used to test for association between drug resistance patterns and HIV status, lineage and geographical location.ResultsSeventeen distinct spoligotype patterns were detected amongst the 60 drug-resistant isolates. The most predominant lineages were Euro-American (58.3%), East Asian (25%) and Indo-Oceanic (15%). Fifty (83.3%) were MDR, 7 (11.7%) were resistant to fluoroquinolones (Pre-XDR) whereas 3 (5%) were resistant to both fluoroquinolones and second-line injectable drugs (XDR). Drug resistance profiles were significantly associated with Mtb lineage (p&lt;0.001). There was no association between drug resistance profile and HIV status (p=0.057) and geographical location (p=0.372).ConclusionThis study highlights the importance of including second-line drug susceptibility testing in a testing algorithm in Botswana. The detection of XDR isolates among MDR-TB isolates highlights the ongoing evolution of resistance and the need for strengthened treatment regimens to improve treatment outcomes and to prevent the spread of these highly resistant strains. Second-line testing will be essential if the 9 month MDR regimen is used in Botswana.

Surveillance of Rifampicin Resistance With GeneXpert MTB/RIF in the National Reference Laboratory for Tuberculosis at the Institut Pasteur in Bangui, 2015-2017.

BackgroundThe Central African Republic (CAR) has one of the heaviest burdens of tuberculosis (TB) in the world, with an incidence of 423 cases per 100 000 population. Surveillance of resistance to rifampicin with GeneXpert MTB/RIF was instituted in the National TB Reference Laboratory in 2015. The aim of this study was to evaluate, after 3 years, resistance to rifampicin, the most effective firstline drug against TB.MethodsThe surveillance database on cases of rifampicin resistance was retrospectively analyzed. The populations targeted by the National TB Programme were failure, relapse, default, and contacts of multidrug-resistant TB (MDR-TB). Statistical analyses were performed with Stata software, version 14, using chi-square tests and odds ratios.ResultsSix hundred seventeen cases were registered; 63.7% were male, 36.3% were female, and the mean age was 35.5 years (range from 2 to 81). GeneXpert MTB/RIF tests were positive in 79.1% (488/617), and resistance to rifampicin was positive in 42.2% (206/488), with 49.1% (56/114) in 2015, 34.7% (57/164) in 2016, and 44.3% (93/210) in 2017. Failure cases had the highest rate of resistance (70.4%), with a significant difference (P < .0001; odds ratio, 9.5; 95% confidence interval, 4.4–20.5). Resistance was observed in 40% of contacts of MDR-TB, 28.2% of the relapses and 20% of the defaults without significant difference.ConclusionsResistance to rifampicin is still high in the CAR and is most strongly associated with treatment failure. The Ministry of Health must to deploy GeneXpert MTB/RIF tests in the provinces to evaluate resistance to TB drugs in the country.

Access to second-line drug susceptibility testing results among patients with Rifampicin resistant tuberculosis after introduction of the Hain® Line Probe Assay in Southern provinces, Zimbabwe

ObjectivesTo determine the proportion of rifampicin-resistant tuberculosis (RR-TB) patients who accessed second-line drug susceptibility testing (SL-DST) results following introduction of the Hain technology in southern provinces, Zimbabwe. DesignCohort study using secondary data. ResultsXpert MTB/RIF results were used to identify 133 RR-TB patients for this study. Their mean age (SD) was 37.9 (11.1) years, 83 (62%) were males and 106 (80%) were HIV-infected. There were 6 (5%) participants who had pre-treatment attrition. Of the 133 pulmonary TB (PTB) patients, 117 (80%) had additional sputum specimens collected; 96 (72%) specimens reached the National TB Reference Laboratory (NTBRL); 95 (71%) were processed; 68 (51%) had SL-DST results. Only 53 (40%) SL-DST results reached the peripheral facilities. Median time from specimen reception at the NTBRL to SL-DSTs was 40 days, interquartile range (IQR: 28–67). Median time from presumptive diagnosis of RR-TB by health care worker to SL-DST results was 50days (IQR: 39–80), and increased to 79days (IQR: 39–101) in facilities >250km from the NTBRL. The proportion with any fluoroquinolone resistance was 9 (13.2%). ConclusionAlthough RR-TB patients with PTB were initiated timely on treatment, access to SL-DSTs by facilities needs improvement. Health inequities exist as remote areas are less likely to get SL-DST results in time.

Socio-Demographic Characteristics and Risk Factors Contributing Pulmonary Tuberculosis Infection and Recent Transmission

Host factors, environmental factors, genetic diversity and distinct phylogeographic distribution of Mycobacterium tuberculosis (MTB) contribute to regional differences in drug resistance. Bangladesh remains among the top 20 high Multi drug resistant tuberculosis (MDR-TB) burden countries of the world. This cross sectional study was conducted to identify the socio demographic characteristics and the risk factors contributing Pulmonary tuberculosis (PTB) infection. These characteristics and risk factors were further investigated among the clustered isolates. Total 60 culture isolates consist of 40 RR and 20 rifampicin sensitive (RS) isolates were enrolled in this study. Laboratory works were done in National Tuberculosis Reference Laboratory (NTRL) and Department of Microbiology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. All 60 samples were confirmed as MTB by MPT 64 antigen detection. Two samples were excluded for possible cross contamination and two for failing to give PCR product for most of the locus. So, finally 56 samples were further analyzed for results. Four isolates were distributed within two clusters which were belonged to Beijing lineage. Socio demographic data and risk factors analysis of this study found significant male predominance (p = 0.04) with history of smoking (p = 0.01) and previous anti-TB treatment (p = 0.012) as the significant risk factors for RR TB.

Identification of rpoB, gyrA and embB Gene Mutations in Mycobacterium Tuberculosis Isolates from Retreatment Tuberculosis Patients in Nepal

Introduction: Tuberculosis remains one of the major public health problems in Nepal and increasing trend of multi drug resistant and extensively drug resistant tuberculosis (MDR /XDR TB) is a big challenge. Rapid diagnosis and appropriate treatment of MDR/XDR TB is crucial. Identification and comparison of MDR TB using rapid molecular techniques (for rpob, gyrA, rrs and embB gene mutations) with reference to drug susceptibility test (DST) were the main objectives of this study.Methodology: A cross sectional study was carried out in National TB Centre (NTC). Gene Xpert, proportion method and Line Probe Assay (LPA) were used for first and second line drugs susceptibility testing (FLD-DST and SLD-DST). A total of 29 mucopurulent sputum samples were freshly collected from retreatment TB patients (Female 41.4%, Male 58.6%) with median age of 40 years attending to the four MDR TB treatment centres of eastern and central Nepal (via private courier and directly to National TB Reference Laboratory (NRL) at NTC from April 2013 to October 2017.Results: Among 29 sputum samples (Female 41.4%; all smear+ve, Male 58.6%; 16 smear+ve and 1 smear-ve), Gene Xpert MTB/RIF assay detected 100% M. tuberculosis and rifampicin resistance (rpoB gene resistant) of which, 100% were culture positive by conventional Lowenstein–Jensen (LJ) method. FLDDST was performed on all culture positives of which, 96.6% showed MDR TB and 3.4% showed mono resistance to isonizid only. SLD-DST on 29 MDRTB strains by LPA showed 100%, 58.6%, 44.8% wild type for rrs, gyrA and emb B genes respectively. Mutation for gyrA and emb B genes was 41.4% and 51.2% respectively, rrs genes none. Twelve (Female 6, Male 6) MDR TB strains were identified as pre-XDR-TB. Chi square (χ2) for trend was used to analyze Gene Xpert, smear, FLD-DST and LPA results.Conclusion: From this study, 29(100%) MDRTB were detected from retreatment TB cases by Gene Xpert and FLDDST. Almost 41.4% MDR TB strains were detected as pre-XDR TB by LPA, which were found to be higher in 15-60 years group of females and males. Samples from retreatment TB patients need to be tested by rapid molecular techniques with reference to culture and DST.SAARC Journal of Tuberculosis, Lung Diseases and HIV/AIDS, Vol. 14, No. 2, 2017, Page: 39-50

The contamination rate in the liquid and solid culture using sputum sample at the national TB reference laboratory, 2016

Introduction: culture is the gold-standard procedure for tuberculosis (TB) diagnostic and treatment monitoring because of its high sensitivity allowing the mycobacteria isolation for identification and tests of drug sensitivity. However, the culture is prone to contamination allowing growth of other microorganisms than TB, which causes delays and invalid results for patients. The objective of the study was to determine the contamination rate (CR) in the solid and liquid culture of the sputum samples received at the National TB Reference Laboratory (NTRL) in 2016.

Geographic characterization of the tuberculosis epidemiology in iran using a geographical information system

Background: Medical geographic information systems (Medical GIS) has a pronounced capacity to help us understand infectious disease epidemiology, and the transmission of pathogens in a defined geographical area over time. This could not only help us increase the understanding of public health, but also be a most useful base for medical intervention as improved infection control where it is most needed. In this study, we applied GIS to characterize Tuberculosis (TB) epidemiology in Iran. TB, caused by Mycobacterium tuberculosis, is a severe bacterial infection that can be transmitted among humans and more than 10 million people develop active TB every year and with a mortality of 1.4 million. Methods: In this cross-sectional study carried out on 3710 tuberculosis patients who had been diagnosed in 2013 to 2017 at the National Tuberculosis Reference Laboratory, we aimed to explore the geographic and gender patterns of tuberculosis in Iran using GIS. Results: Results showed that the number of patients with tuberculosis was highest in Tehran city, despite the fact that it is the richest and most developed city of Iran and that the tuberculosis dispersion reflected by GIS revealed a significant geographical heterogeneity. Conclusion: These results could be useful to establish and implement new guidelines for effective control strategies in geographic areas with the highest prevalence of tuberculosis.

Analysis of isoniazid and rifampicin resistance in Mycobacterium tuberculosis isolates in Morocco using GenoType® MTBDRplus assay.

The number of multidrug-resistant tuberculosis (MDR-TB) cases is rising worldwide. The present investigation aimed to evaluate, using the GenoType® MTBDRplus assay, the most common mutations associated with rifampicin (RIF) and isoniazid (INH) resistance among resistant strains in Morocco. A total of 319 Mycobacterium tuberculosis isolates sent to the National Tuberculosis Reference Laboratory between 2013 and 2015 were subjected to GenoType® MTBDRplus for detecting M. tuberculosis and determination of drug susceptibility. Correlation of the minimum inhibitory concentrations (MICs) of INH with genotypic assay results was carried out for 97 MDR-TB strains. Various concentrations of INH were tested. The most frequent mutations observed were rpoBS531L (67.2%) and katGS315T1/2 (66.5%). Isolates with inhA gene mutation, katG gene mutation, and dual mutations in katG and inhA had MICs ranging from 0.5-1μg/mL, 2-10μg/mL and ≥12μg/mL, respectively. In Morocco, 66.5% and 76.7% of M. tuberculosis strains carried mutations causing high-level resistance to INH and RIF, respectively.

Outcomes of multidrug-resistant tuberculosis in Zambia: a cohort analysis.

The purpose of this study was to establish a baseline for measuring the impact of the programmatic management of drug-resistant TB program by following up on outcomes of all patients diagnosed with multidrug-resistant tuberculosis in Zambia between 2012 and 2014. A cohort study of all the MDR-TB patients diagnosed at the national TB reference laboratory from across Zambia. MDR-TB was diagnosed by culture and DST, whereas outcome data were collected in 2015 by patient record checks and home visits. The total number of patients diagnosed was 258. Of those, 110 (42.6%) patients were traceable for this study. There were 67 survivor participants (60.9%); 43 (39.1%) were deceased. Out of the 110 patients who were traced, only 71 (64.5%) were started on second-line treatment. Twenty-nine (40.8%) patients were declared cured and 16.9% were still on treatment; 8.4% had failed treatment. The survival rate was 20.2 per 100 person-years of follow-up. Taking ARVs was associated with a decreased risk of dying (hazard ratio 0.12, p=0.002). Sex, age, marital status and treatment category were not important predictors of survival in MDR-TB patients. More than half of the patients diagnosed with MDR-TB were lost to follow-up before second-line treatment was initiated.

Extensively drug-resistant tuberculosis (XDR-TB) in Morocco.

Extensively drug-resistant tuberculosis (XDR-TB) has recently been identified as a major global health threat. The aim of this study was to evaluate the presence of XDR-TB among Mycobacterium tuberculosis isolates in Morocco and its association with demographic, clinical and epidemiological features. A total of 524 patients from the Moroccan National Tuberculosis Reference Laboratory, representative of all of the geographic regions, were subject to first-line drug susceptibility testing (DST). Subsequently, 155 isolates found to be multidrug-resistant tuberculosis (MDR-TB) underwent second-line DST. Moreover, to enhance our understanding of the genetic basis of these drug-resistant strains, drug resistance-associated mutations were investigated in isolates either identified as pre-XDR- and XDR-TB or suspected resistant using the GenoType® MTBDRsl V1.0 assay. In this study, 4 (2.6%) XDR-TB and 18 (11.6%) pre-XDR-TB isolates were identified. Agreement between the MTBDRsl assay results and phenotypic DST was 95.2% for ofloxacin, 81.0% for kanamycin and 95.2% for amikacin. To the best of our knowledge, this is the first study to evaluate the frequency of XDR-TB in Morocco. These results highlight the need to reinforce the TB management policy in Morocco with regard to control and detection strategies in order to prevent further spread of XDR-TB isolates.

Implementation of the Xpert MTB/RIF assay for tuberculosis in Mongolia: a qualitative exploration of barriers and enablers.

ObjectiveThe aim of our study was to identify barriers and enablers to implementation of the Xpert MTB/RIF test within Mongolia’s National Tuberculosis Program.MethodsTwenty-foursemi-structured interviews were conducted between June and September 2015 with laboratory staff and tuberculosis physicians in Mongolia’s capital Ulaanbaatar and regional towns where Xpert MTB/RIF testing had been implemented. Interviews were recorded, transcribed, translated and analysed thematically using NVIVO qualitative analysis software.ResultsEight laboratory staff (five from the National Tuberculosis Reference Laboratory in Ulaanbaatar and three from provincial laboratories) and sixteen tuberculosis physicians (five from the Mongolian National Center for Communicable Diseases in Ulaanbaatar, four from district tuberculosis clinics in Ulaanbaatar and seven from provincial tuberculosis clinics) were interviewed. Major barriers to Xpert MTB/RIF implementation identified were: lack of awareness of program guidelines; inadequate staffing arrangements; problems with cartridge supply management; lack of local repair options for the Xpert machines; lack of regular formal training; paper based system; delayed treatment initiation due to consensus meeting and poor sample quality. Enablers to Xpert MTB/RIF implementation included availability of guidelines in the local language; provision of extra laboratory staff, shift working arrangements and additional modules; capacity for troubleshooting internally; access to experts; opportunities for peer learning; common understanding of diagnostic algorithms and decentralised testing.ConclusionOur study identified a number of barriers and enablers to implementation of Xpert MTB/RIF in the Mongolian National Tuberculosis Program. Lessons learned from this study can help to facilitate implementation of Xpert MTB/RIF in other Mongolian locations as well as other low-and middle-income countries.

Evaluation of genotype MTBDRplus VER 2.0 line probe assay for the detection of MDR-TB in smear positive and negative sputum samples

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 sample in our routine settings. The sensitivity of the assay should be improved for detection of MDR-TB in direct smear negative sputum specimens.

Mozambique's journey toward accreditation of the National Tuberculosis Reference Laboratory.

BackgroundInternationally-accredited laboratories are recognised for their superior test reliability, operational performance, quality management and competence. In a bid to meet international quality standards, the Mozambique National Institute of Health enrolled the National Tuberculosis Reference Laboratory (NTRL) in a continuous quality improvement process towards ISO 15189 accreditation. Here, we describe the road map taken by the NTRL to achieve international accreditation.MethodsThe NTRL adopted the Strengthening Laboratory Management Toward Accreditation (SLMTA) programme as a strategy to implement a quality management system. After SLMTA, the Mozambique National Institute of Health committed to accelerate the NTRL’s process toward accreditation. An action plan was designed to streamline the process. Quality indicators were defined to benchmark progress. Staff were trained to improve performance. Mentorship from an experienced assessor was provided. Fulfilment of accreditation standards was assessed by the Portuguese Accreditation Board.ResultsOf the eight laboratories participating in SLMTA, the NTRL was the best-performing laboratory, achieving a 53.6% improvement over the SLMTA baseline conducted in February 2011 to the Stepwise Laboratory Quality Improvement Process Towards Accreditation (SLIPTA) assessment in June 2013. During the accreditation assessment in September 2014, 25 minor nonconformities were identified and addressed. In March 2015, the NTRL received Portuguese Accreditation Board recognition of technical competency for fluorescence smear microscopy, and solid and liquid culture. The NTRL is the first laboratory in Mozambique to achieve ISO 15189 accreditation.ConclusionsFrom our experience, accreditation was made possible by institutional commitment, strong laboratory leadership, staff motivation, adequate infrastructure and a comprehensive action plan.

Performance evaluation of tuberculosis smear microscopists working at rechecking laboratories in Ethiopia.

BackgroundTuberculosis is an infectious disease caused by the bacillus Mycobacterium tuberculosis. According to the Ethiopian Federal Ministry of Health’s 2013–2014 report, the tuberculosis case detection rate was 53.7%, which was below the target of 81% set for that year.ObjectiveThis study assessed the performance of tuberculosis smear microscopists at external quality assessment rechecking laboratories in Ethiopia.MethodsA cross-sectional study was conducted at 81 laboratories from April to July 2015. Panel slides were prepared and validated at the National Tuberculosis Reference Laboratory. The validated panel slides were used to evaluate the performance of microscopists at these laboratories compared with readers from the reference laboratory.ResultsA total of 389 external quality assessment rechecking laboratory microscopists participated in the study, of which 268 (68.9%) worked at hospitals, 241 (62%) had more than five years of work experience, 201 (51.7%) held Bachelors degrees, and 319 (82%) reported tuberculosis smear microscopy training. Overall, 324 (83.3%) participants scored ≥ 80%. Sensitivity for detecting tuberculosis bacilli was 84.5% and specificity was 93.1%. The overall percent agreement between participants and reference readers was 87.1 (kappa=0.72). All 10 slides were correctly read (i.e., scored 100%) by 80 (20.6%) participants, 156 (40.1%) scored 90% – 95%, 88 (22.6%) scored 80% – 85% and 65 (16.7%) scored below 80%. There were 806 (20.7%) total errors, with 143 (3.7%) major and 663 (17%) minor errors.ConclusionThe overall performance of participants in reading the slides showed good agreement with the reference readers. Most errors were minor, and the ability to detect tuberculosis bacilli can be improved through building the capacity of professionals.