Alarming levels of multidrug-resistant tuberculosis in Ukraine: results from the first national survey.

SETTING: The true prevalence of multidrug-resistant tuberculosis (MDR-TB) in Ukraine is not known. Available data are a decade old and limited to only one province. OBJECTIVE: To determine the prevalence of MDR-TB among new and previously treated TB cases in Ukraine and explore the risk factors associated with drug resistance. METHODS: A total of 1550 sputum smear-positive pulmonary TB patients were recruited from 40 clusters throughout Ukraine. Sputum specimens were examined using culture, drug susceptibility testing and pncA gene sequencing. RESULTS: The proportion of MDR-TB among new and previously treated TB cases was respectively 24.1% (95%CI 20.7-27.6) and 58.1% (95%CI 52.1-64.1). More than one third (38.0%) of MDR-TB or rifampicin (RMP) resistant cases showed resistance to either a fluoroquinolone (FQ) or a second-line injectable agent or both. Resistance to pyrazinamide and FQs was low in patients with RMP-susceptible TB. Among new TB cases, the odds of MDR-TB were higher among patients who were younger, female and living in south-eastern provinces, as well as among human immunodeficiency virus-positive patients who belonged to a low socio-economic group. CONCLUSIONS: Our study showed that the burden of MDR-TB in Ukraine was much greater than previously assumed. Urgent actions are needed to prevent further spread of drug-resistant TB in Ukraine.

Laboratory diagnosis of paediatric tuberculosis in the European Union/European Economic Area: analysis of routine laboratory data, 2007 to 2011.

Laboratory confirmation of paediatric tuberculosis (TB) is frequently lacking. We reviewed the range of routine laboratory tests and their performance in different biological samples used to diagnose active TB in children. A questionnaire-based survey was conducted among the European Reference Laboratory Network for TB followed by collection of routine laboratory data on 10,549 paediatric samples tested in 2007 to 2011 at six reference laboratories (in Croatia, Germany, Italy, Latvia, Lithuania and the United Kingdom (UK)). The questionnaire showed that all laboratories used rapid assays. Non-respiratory samples were collected more often in Germany (135/275, 49.1%) and the UK (490/2,140, 22.9%) compared with Croatia (138/2,792, 4.9%), Latvia (222/2,401, 9.2%) and Lithuania (76/1,549, 4.9%). Overall laboratory positivity rates (isolation of Mycobacterium tuberculosis complex and/or identification of its nucleic acids in a sample) were higher in lymph node and gastric aspirate samples (14/203 (6.9%) and 43/1,231 (3.5%)) than in sputum samples (89/4,684 (1.9%)). Pooled sensitivity, specificity, positive and negative predictive values and accuracy of molecular assays assessed against solid or liquid culture were 79.2%, 93.6%, 67.1%, 96.5% and 91.6%, respectively. A more intensive approach in obtaining gastric aspirate and non-respiratory samples may increase laboratory confirmation of paediatric TB. Major effort is needed in optimisation and validation of molecular tests in these samples.

Multi- and extensively drug-resistant tuberculosis in Latvia: trends, characteristics and treatment outcomes.

SETTING: Drug-resistant tuberculosis (TB) is an important public health problem in Latvia. OBJECTIVE: To document trends, characteristics and treatment outcomes of registered patients with multi-drug-resistant (MDR-) and extensively drug-resistant (XDR-) TB in Latvia from 2000 to 2010. DESIGN: A retrospective national cohort study. RESULTS: Of 1779 patients, 1646 (92%) had MDR- and 133 (8%) XDR-TB. Over 11 years, the proportion of XDR-TB among MDR-TB patients increased from 2% to 18%. Compared to MDR-TB patients, those with XDR-TB were significantly more likely to have failed MDR-TB treatment (OR 8.4, 95%CI 4.3-16.2), have human immunodeficiency virus infection (OR 3.2, 95%CI 1.8-5.7), be illegal drug users (OR 5.7, 95%CI 2.6-11.6) or have had contact with MDR-TB patients (OR 1.9, 95%CI 1.3-2.8). Cure rates for XDR-TB were 50%. Compared with MDR-TB patients, those with XDR-TB had a higher risk of treatment failure (29% vs. 8%, respectively, P < 0.001). Unfavourable treatment outcomes were significantly associated with being male; having smear-positive disease; pulmonary cavities; failure, default or relapse after previous MDR-TB treatment; and a history of incarceration. CONCLUSION: More MDR-TB in Latvia is now also XDR-TB. This study identified several risk factors for XDR-TB and, for unfavourable treatment outcomes, highlighting the importance of early diagnosis and appropriate management of MDR-/XDR-TB.

Performance of the GenoType® MTBDRPlus assay in routine settings: a multicenter study.

Former Soviet Union countries including the Baltic States (Latvia, Lithuania, and Estonia) are hot spots for an emerging epidemic of drug resistant tuberculosis (TB). As a part of the development of a co-ordinated network of centers for diagnostic trials across Eastern Europe we conducted a retrospective multicenter analysis of the performance of the GenoType® MTBDRPlus assay for TB identification and susceptibility to isoniazid (INH) and rifampicin (RIF) in routine settings. A total of 1,045 primary samples, 1045 TB cultures derived from these specimens and 306 separate M. tuberculosis isolates tested in 2007-2010 at four participating sites (Tartu, Estonia; Riga, Latvia; Vilnius, Lithuania; and Samara, Russian Federation) were included in the analysis. The pooled sensitivity and specificity values for RIF and INH were 95.3% and 95.5%, 89.9 and 87.1%, respectively; there were no statistically significant variations in performance across sites. The proportion of multidrug resistant (MDR) strains in the collections ranged from 21.8% (in Estonia) to 55.9% (in Russia). In a routine non-trial context, the assay reliably detected both rifampicin and isoniazid resistance. The absence of statistically significant differences between sites suggested that the comparable performance obtained using these assays has helped demonstrate the formation of a successful diagnostic trial network.

Implementation of the INNO-LiPA Rif. TB® line-probe assay in rapid detection of multidrug-resistant tuberculosis in Latvia.

SETTING: In Latvia, 11% of tuberculosis (TB) patients have multidrug-resistant TB (MDR-TB). The INNO-LiPA Rif.TB ® line-probe assay (LPA) detects rifampin (RMP) resistance and may accelerate the time to effective MDRTB treatment. OBJECTIVE: To determine the impact of LPA on time to diagnosis, initiation of treatment, sputum culture conversion and treatment outcome. DESIGN: From October 2004 to September 2006, we performed LPA and drug susceptibility testing (DST) using BACTEC and Löwenstein-Jensen (LJ) media among all individuals at risk for MDR-TB compared to a 2003 cohort of 48 MDR-TB patients detected by BACTEC. RESULTS: In a total of 107 sputum smear-positive individuals at risk for MDR-TB, Mycobacterium tuberculosis was isolated from 85; 23 were RMP-resistant on LJ compared to 22 on LPA (96% sensitivity). There was a significant difference in the mean time between specimen collection and LPA result (10.0 days) and BACTEC DST result (17.0 days, P = 0.0005) in the LPA cohort. The LPA cohort achieved culture conversion a median of 105 days after treatment initiation vs. a median of 88.5 days (P = 0.54) in the BACTEC cohort. There was no difference in the proportion achieving culture conversion (P = 0.54) or in treatment outcome ( P = 0.65). CONCLUSION: LPA accelerated empiric treatment, but did not reduce the time to culture conversion or improve the rate of culture conversion or treatment outcome.

Recent nosocomial transmission and genotypes of multidrug-resistant Mycobacterium tuberculosis.

SETTING: Multidrug-resistant tuberculosis (MDR-TB) is a serious health problem in Eastern European countries, including Latvia. OBJECTIVE: To investigate the proportion of tuberculosis, including MDR-TB cases, attributable to recent transmission and risk factors associated with clustering. DESIGN: Retrospective nested case-control study. The data set incorporated a wide spectrum of social features, as well as genotypes of Mycobacterium tuberculosis isolates determined by insertion sequence 6110 restriction fragment length polymorphism analysis of PvuII cleaved genomic DNA and spoligotyping. RESULTS: In comparison with non-clustered M. tuberculosis, the Beijing genotype (OR 12.15) and multidrug resistance (OR 5.61, P < 0.01) were associated with clustering. In comparison with clustered drug-susceptible M. tuberculosis, clustering of MDR M. tuberculosis was associated with Beijing genotype (OR 41.67), previous hospitalisation (OR 18.33) and previous TB treatment (OR 17.68, P < 0.05). Direct epidemiological links in hospitals were found for almost one third (32%) of MDR Beijing cases. CONCLUSIONS: MDR cases were more likely to be found in clusters than drug-susceptible cases (74.0% vs. 33.6%). Recent nosocomial transmission of MDR-TB is an important risk factor for the spread of multiresistance, and is associated with the Beijing genotype. Special attention should be paid to infection control measures in hospitals and ambulatory treatment should be enforced.

Treatment outcome of multidrug/extensively drug-resistant tuberculosis in Latvia, 2000-2004.

In the present study, we characterised drug-resistance patterns, compared treatment outcome between extensively and nonextensively drug-resistant tuberculosis (non-XDR-TB) cases, and assessed risk factors for poor outcome in a high-prevalence country that screens all TB patients for first-line anti-TB drug resistance. We reviewed drug susceptibility test results among all pulmonary TB cases in Latvia diagnosed from 2000-2004, as well as demographic and clinical characteristics, drug-resistance patterns, and treatment outcomes. During the 5-yr period, 1,027 multidrug-resistant tuberculosis (MDR-TB) cases initiated treatment. Among all cases, the proportion that experienced an outcome of cure or completion increased from 66.2 to 70.2% (p = 0.06 for linear trend). Among the 48 (4.7%) XDR-TB cases, 18 (38%) were cured, four (8%) died, three (6%) defaulted, and treatment failed in 23 (48%). In proportional-hazards analysis, characteristics significantly associated with poor outcome included XDR-TB, being retired, presence of bilateral cavitation, and previous MDR-TB treatment history for those aged ≥55 yrs. Overall, treatment success among all MDR-TB cases increased over time. Strategies to prevent transmission of XDR-TB and to further improve treatment outcome are crucial for the future of TB control in Latvia.

Recommended standards for modern tuberculosis laboratory services in Europe.

The principles underpinning these standards are that any tuberculosis laboratory-based diagnostic procedure should be performed by appropriately trained staff, working to standardised operating procedures in appropriately equipped and safe laboratories, against clear national and international proficiency and quality standards. Quality should be the pre-eminent criteria, not cost. The standards are technologically feasible, but initially may not be within the financial capacity of all laboratories. There is a requirement for government and international donors to adequately fund an appropriate safe infrastructure to enable staff to deliver accurate and timely results at whatever level of activity they are performing. There is a need for national reference laboratories to train a new cadre of mycobacterial laboratory experts. This will require the funding of appropriate individuals at these centres to train and assist in the implementation of good laboratory practice and evaluation to build sustainable capacity. Further operational research is needed to establish the optimal configuration of new technologies to determine isoniazid, rifampicin and second-line drug susceptibility in mycobacterial cultures and also, increasingly, directly on specimens. Improved integration of laboratory medicine as a core part of all tuberculosis programmes is needed to achieve and maximise the potential of new developments.

Drug susceptibility testing of Mycobacterium tuberculosis to fluoroquinolones: first experience with a quality control panel in the Nordic-Baltic collaboration.

In the first attempt to establish a quality assurance programme for susceptibility testing of Mycobacterium tuberculosis to fluoroquinolones, 20 strains with different fluoroquinolone susceptibility patterns were distributed by the Supranational Reference Laboratory in Stockholm to the other mycobacterial reference laboratories of the Nordic and Baltic countries. Susceptibility testing to fluoroquinolones was performed according to routine procedures in each laboratory. Results were compared to sequence analysis of the gyrA gene and minimal inhibitory concentration determination. Most laboratories found identical susceptibility patterns. The two resistant strains were correctly identified by all laboratories, but three laboratories each falsely reported one susceptible strain as resistant. These results indicate that the participating laboratories yield reliable results in detection of fluoroquinolone-resistant strains, although the need for a standardised quality assurance programme for drug susceptibility testing for fluoroquinolones is stressed by the strains falsely reported as resistant.