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The Hague, Netherlands

Van Der Werf M.J.,KNCV Tuberculosis Foundation | Van Der Werf M.J.,University of Amsterdam | Van Der Werf M.J.,U.S. Center for Disease Control and Prevention | Langendam M.W.,University of Amsterdam | And 2 more authors.
European Respiratory Journal

Treating tuberculosis (TB) patients with inappropriate treatment regimens can lead to treatment failure and, thus, patients who have not been cured and/or to the development of (multi)-drug resistance. A systematic review was performed to assess the knowledge of appropriate TB drug regimens among all categories of healthcare workers (HCWs). In January 2011, MEDLINE, EMBASE and other databases were searched for relevant articles. Observational studies published as of the year 2000 that assessed HCW knowledge of TB treatment were selected. A treatment regimen, drug dosage or treatment duration was considered inappropriate if it was not recommended by national guidelines or by the World Health Organization (WHO). Of 1,896 studies, 31 were included from 14 different countries. No study was performed in Europe. In all studies, HCWs with inappropriate knowledge of treatment regimens (8-100%) or treatment duration (5-99%) were observed. The few studies providing detailed data showed that HCWs mainly reported giving treatment regimens with too many drugs and for too long. Knowledge of appropriate doses was also insufficient in most studies. The available studies show that there is a lack of knowledge of national or international TB treatment guidelines and recommendations. Generalisation of the findings to other settings and countries should be done with caution. Copyright©ERS 2012. Source

Borgdorff M.W.,University of Amsterdam | Van Den Hof S.,University of Amsterdam | Kalisvaart N.,KNCV Tuberculosis Foundation | Kremer K.,National Institute for Public Health and the Environment | Van Soolingen D.,National Institute for Public Health and the Environment
American Journal of Epidemiology

Molecular epidemiologic studies may use genotypic clustering of isolates as an indicator of recent transmission. It has been shown that missing cases lead to underestimating clustering, and modelling studies suggested that they may also lead to underestimating odds ratios for clustering. Using a national, comprehensive database from the Netherlands covering 15 years between 1993 and 2007 and including over 12,000 patients and their isolates, the authors determined the effects of sampling at random, in time, and by geographic area. As expected, sampling reduced the observed clustering percentages. However, sampling did not reduce the observed odds ratios for clustering. The main explanations for this discrepancy with model outcomes were that a substantial proportion of clustered cases were found in large clusters and that risk factors for clustering tended to be-among clustered cases-also risk factors for large clusters. The authors conclude that, in settings where risk factors for clustering may be interpreted as risk factors for recent transmission, these risk factors are also associated with larger cluster sizes. As a result, odds ratios would show limited sampling bias. © 2011 The Author. Source

Hoa N.B.,National Tuberculosis Programme Viet Nam | Sy D.N.,National Tuberculosis Programme Viet Nam | Nhung N.V.,National Tuberculosis Programme Viet Nam | Tiemersma E.W.,KNCV Tuberculosis Foundation | And 2 more authors.
Bulletin of the World Health Organization

Objective To estimate the prevalence of tuberculosis in Viet Nam with data from a population-based survey, compare it with the prevalence estimated by the World Health Organization, and identify major demographic determinants of tuberculosis prevalence. Methods A cross-sectional survey with multistage cluster sampling, stratified by urban, rural and remote areas, was done in 2006-2007 in 70 communes. All inhabitants aged ≥ 15 years were invited for cough and chest X-ray examination. Participants with findings suggestive of tuberculosis provided sputum specimens for smear examination and culture. Point prevalence estimates, 95% confidence intervals and design effects were calculated. Confidence intervals and P-values were adjusted for the cluster design. Findings Of 114 389 adult inhabitants, 94 179 (82.3%) were screened. Of 87 314 (92.7%) screened by both questionnaire and chest X-ray, 3522 (4.0%) had productive cough, 518 (0.6%) had a recent history of tuberculosis and 2972 (3.4%) had chest X-ray abnormalities suggestive of tuberculosis. Sputum tests were done for 7648 participants. Sputum test, bacterial culture or both confirmed 269 tuberculosis cases, 174 of which were smear-positive. The prevalence rate of smear-positive tuberculosis was 145 per 100 000 (95% confidence interval: 110-180) assuming no tuberculosis in persons aged < 15 years. Prevalence was 5.1 times as high in men as in women, increased with age, was higher in rural than in urban or remote areas and showed a north-to-south gradient. Conclusion In Viet Nam, the tuberculosis prevalence rate based on positive sputum smear tests was 1.6 times as high as previously estimated. Age and sex patterns were consistent with notification data. Tuberculosis control should remain a high priority in Viet Nam. Source

Van Der Werf M.J.,KNCV Tuberculosis Foundation | Van Der Werf M.J.,University of Amsterdam | Van Der Werf M.J.,U.S. Center for Disease Control and Prevention | Langendam M.W.,University of Amsterdam | And 2 more authors.
European Respiratory Journal

We conducted a systematic review and meta-analysis to assess the evidence for the postulation that inappropriate tuberculosis (TB) regimens are a risk for development of multidrug-resistant (MDR)-TB. MEDLINE, EMBASE and other databases were searched for relevant articles in January 2011. Cohort studies including TB patients who received treatment were selected and data on treatment regimen, drug susceptibility testing results and genotyping results before treatment and at failure or relapse were abstracted from the articles. Four studies were included in the systematic review and two were included in the meta-analysis. In these two studies the risk of developing MDR-TB in patients who failed treatment and used an inappropriate treatment regimen was increased 27-fold (RR 26.7, 95% CI 5.0-141.7) when compared with individuals who received an appropriate treatment regimen. This review provides evidence that supports the general opinion that the development of MDR-TB can be caused by inadequate treatment, given the drug susceptibility pattern of the Mycobacterium tuberculosis bacilli. It should be noted that only two studies provided data for the meta-analysis. The information can be used to advocate for adequate treatment for patients based on drug resistance profiles. Copyright©ERS 2012. Source

McNerney R.,London School of Hygiene and Tropical Medicine | Cunningham J.,University of Sheffield | Hepple P.,KNCV Tuberculosis Foundation | Zumla A.,University College London
International Journal of Infectious Diseases

Early detection and effective treatment are crucial for tuberculosis control, but global case detection rates remain low. The diagnosis of paediatric and extrapulmonary disease is problematic and there are, as yet, no rapid screening tests to assist active case finding in the community. Progress has been made in clinic-based detection tools with the introduction of Xpert MTB/RIF, a nucleic acid amplification test that combines sample processing and analysis in a single instrument to provide a diagnostic result and detection of resistance to rifampicin in under 2. h. Enthusiasm for Xpert MTB/RIF has been high and global rollout has been facilitated by donor agencies. However, concerns remain about access and sustainability due to the high cost and infrastructure requirements. Although more sensitive than smear microscopy, early studies suggest the impact of the new test on case detection rates and patient survival has been limited. Alternative technologies are being developed, including non-sputum-based tests to assist the detection of extrapulmonary disease. Evaluation studies are needed to provide evidence of the impact of the new technologies on patient outcomes. This will enable appropriate placement of new diagnostic products in the healthcare system to support the control and eventual eradication of tuberculosis disease. © 2015 The Authors. Source

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