First insights into the molecular epidemiology of tuberculosis in Croatia during a three-year period, 2009 to 2011

Žmak, Ljiljana; Obrovac, Mihaela; Jankovic, Vera Katalinic

doi:10.3109/00365548.2013.855322

Cited by 6 publications

(3 citation statements)

References 30 publications

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“…We found that in the setting of our hospital, which is located in a low-prevalence country, the sensitivity and specificity of the Xpert MTB/RIF were higher than the sensitivity and specificity of smear microscopy. These results are in line with all the studies conducted so far that have evaluated the performance of the Xpert MTB/RIF [2,21,22]. We next compared the semiquantitative result of the Xpert MTB/RIF with those of conventional microscopy using the international smear grading system [19] and found that the results of the Xpert MTB/RIF could be used as a predictor of smear result.…”

Section: Discussionsupporting

confidence: 82%

Added value of molecular assay Xpert MTB/RIF compared to sputum smear microscopy to assess the risk of tuberculosis transmission in a low-prevalence country

Opota

Senn

Prod’hom

et al. 2016

Clinical Microbiology and Infection

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Airborne precautions are required at hospital admission for patients with suspected pulmonary tuberculosis. The isolation is maintained until 3 serially collected sputum smears are acid-fast bacilli negative, a time- and labor-intensive method with limited sensitivity and specificity, which has a great impact on patient flow management. We evaluated the possibility of replacing the result of microscopy by the semiquantitative result of the molecular point-of-care test Xpert MTB/RIF to assess patients' transmission risk to quickly guide airborne isolation decisions in low-endemic countries. The performance of the Xpert MTB/RIF, used as a first-line test, was compared to the results of microscopy for specimens (n=242) collected from May 2010 to December 2014 in Lausanne, Switzerland. The sensitivity and specificity of Xpert MTB/RIF were 91.5% (65/71) and 99.6% (170/171), respectively, vs. 64.8% (46/71) and 94.2% (161/171) for microscopy. Samples with negative Xpert MTB/RIF were all smear negative for Mycobacterium tuberculosis (negative predictive value, 100%). The semiquantitative results of Xpert MTB/RIF-high, medium, low or very low-were found to correlate with acid-fast bacilli detection: positive predictive value of 100% (6/6), 96.5% (27/28), 52.2% (12/23) and 11.1% (1/9) respectively. Finally, when including clinical criteria, we identified 11 smear-negative but Xpert MTB/RIF-positive patients with a significant transmission potential. In conclusion, our data support the introduction of an Xpert MTB/RIF-based strategy as a replacement of smear microscopy for a faster and more accurate management of tuberculosis patients' transmission risk in a low-prevalence country.

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Section: Discussionsupporting

confidence: 82%

Added value of molecular assay Xpert MTB/RIF compared to sputum smear microscopy to assess the risk of tuberculosis transmission in a low-prevalence country

Opota

Senn

Prod’hom

et al. 2016

Clinical Microbiology and Infection

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“…Studies were published between 2007 and 2014 and the clustering reported varied from 0% 37 to 62.8%. 38 In all studies, clustered isolates were defined as having identical strain types based on the MIRU-VNTR loci typed, with or without Spoligotyping. Seventeen studies included isolates from newly diagnosed TB cases, three studies reported including isolates from new and chronic cases of TB, and seven did not report this information.…”

Section: Resultsmentioning

confidence: 99%

“…Sensitivity analyses to examine the effect of excluding studies reporting 0% clustering, 37 only M. bovis cases, 39 studies using the ‘old 12’ MIRU loci, 39–44 and studies assessed as having a high risk of bias, 37 38 45–47 did not generally change the results. The proportion of culture-positive TB in the population remained insignificant but explained 2.6% of the between study variation when excluding 0% clustering (p=0.278 and adjusted R 2 =2.62).…”

Section: Resultsmentioning

confidence: 99%

Effect of study design and setting on tuberculosis clustering estimates using Mycobacterial Interspersed Repetitive Units-Variable Number Tandem Repeats (MIRU-VNTR): a systematic review

et al. 2015

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ObjectivesTo systematically review the evidence for the impact of study design and setting on the interpretation of tuberculosis (TB) transmission using clustering derived from Mycobacterial Interspersed Repetitive Units-Variable Number Tandem Repeats (MIRU-VNTR) strain typing.Data sourcesMEDLINE, EMBASE, CINHAL, Web of Science and Scopus were searched for articles published before 21st October 2014.Review methodsStudies in humans that reported the proportion of clustering of TB isolates by MIRU-VNTR were included in the analysis. Univariable meta-regression analyses were conducted to assess the influence of study design and setting on the proportion of clustering.ResultsThe search identified 27 eligible articles reporting clustering between 0% and 63%. The number of MIRU-VNTR loci typed, requiring consent to type patient isolates (as a proxy for sampling fraction), the TB incidence and the maximum cluster size explained 14%, 14%, 27% and 48% of between-study variation, respectively, and had a significant association with the proportion of clustering.ConclusionsAlthough MIRU-VNTR typing is being adopted worldwide there is a paucity of data on how study design and setting may influence estimates of clustering. We have highlighted study design variables for consideration in the design and interpretation of future studies.

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A Snapshot of Drug-Resistant M. tuberculosis Strains in Croatia

Žmak¹,

Obrovac²,

Katalinić-Janković³

2015

Advances in Experimental Medicine and Biology

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Tuberculosis caused by resistant M. tuberculosis strains poses a serious threat as it requires prolonged and costly treatment and has high mortality rate. In order to investigate resistance to antituberculous drugs in Croatia, we analysed all resistant M. tuberculosis strains isolated from patients' samples in period 2010-2014 (1 strain per patient). Out of 2384 M. tuberculosis strains, we identified 88 (3.69 %) resistant strains. The analysis included resistance patterns, resistance conferring mutations and, according to MIRU-VNTR analysis, clustering and global lineages distribution. Relatively high number of strains was monoresistant, especially to isoniazid, while there were only six multiresistant strains. Among 59 strains with any pattern that includes resistance to isoniazid, a total of 22 (37.29 %) had resistance conferring mutation in katG gene (S315T), 23 (38.98 %) in inhA promoter region (C-15T) and 14 (23.73 %) had none of these mutations. The observed clustering rate of resistant strains was 28.41 %, and the most common global lineage was Euro-American (75 %).

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First insights into the molecular epidemiology of tuberculosis in Croatia during a three-year period, 2009 to 2011

Cited by 6 publications

References 30 publications

Added value of molecular assay Xpert MTB/RIF compared to sputum smear microscopy to assess the risk of tuberculosis transmission in a low-prevalence country

Added value of molecular assay Xpert MTB/RIF compared to sputum smear microscopy to assess the risk of tuberculosis transmission in a low-prevalence country

Effect of study design and setting on tuberculosis clustering estimates using Mycobacterial Interspersed Repetitive Units-Variable Number Tandem Repeats (MIRU-VNTR): a systematic review

A Snapshot of Drug-Resistant M. tuberculosis Strains in Croatia

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