Enhanced Tuberculosis Surveillance System Research Articles

Estimating the effect of the 2005 change in BCG policy in England: a retrospective cohort study, 2000 to 2015.

BackgroundIn 2005 in England, universal Bacillus Calmette–Guérin (BCG) vaccination of school-age children was replaced by targeted BCG vaccination of high-risk neonates.AimEstimate the impact of the 2005 change in BCG policy on tuberculosis (TB) incidence rates in England.MethodsWe conducted an observational study by combining notifications from the Enhanced Tuberculosis Surveillance system, with demographic data from the Labour Force Survey to construct retrospective cohorts relevant to both the universal and targeted vaccination between 1 January 2000 and 31 December 2010. We then estimated incidence rates over a 5-year follow-up period and used regression modelling to estimate the impact of the change in policy on TB.ResultsIn the non-United Kingdom (UK) born, we found evidence for an association between a reduction in incidence rates and the change in BCG policy (school-age incidence rate ratio (IRR): 0.74; 95% credible interval (CrI): 0.61 to 0.88 and neonatal IRR: 0.62; 95%CrI: 0.44 to 0.88). We found some evidence that the change in policy was associated with an increase in incidence rates in the UK born school-age population (IRR: 1.08; 95%CrI: 0.97 to 1.19) and weaker evidence of an association with a reduction in incidence rates in UK born neonates (IRR: 0.96; 95%CrI: 0.82 to 1.14). Overall, we found that the change in policy was associated with directly preventing 385 (95%CrI: −105 to 881) cases.ConclusionsWithdrawing universal vaccination at school age and targeting vaccination towards high-risk neonates was associated with reduced incidence of TB. This was largely driven by reductions in the non-UK born with cases increasing in the UK born.

Effectiveness of pre-entry active tuberculosis and post-entry latent tuberculosis screening in new entrants to the UK: a retrospective, population-based cohort study

Evaluating interventions that might lead to a reduction in tuberculosis in high-income countries with a low incidence of the disease is key to accelerate progress towards its elimination. In such countries, migrants are known to contribute a large proportion of tuberculosis cases to the burden. We assessed the effectiveness of screening for active tuberculosis before entry to the UK and for latent tuberculosis infection (LTBI) post-entry for reduction of tuberculosis in new-entrant migrants to the UK. Additionally, we investigated the effect of access to primary care on tuberculosis incidence in this population. We did a retrospective, population-based cohort study of migrants from 66 countries who were negative for active tuberculosis at pre-entry screening between Jan 1, 2011, and Dec 31, 2014, and eligible for LTBI screening. We used record linkage to track their first contact with primary care, uptake of LTBI screening, and development of active tuberculosis in England, Wales, and Northern Ireland. To assess the effectiveness of the pre-entry screening programme, we identified a control group of migrants who were not screened for active tuberculosis using the specific code for new entrants to the UK registering in primary care within the National Health Service patient registration data system. Our primary outcome was development of active tuberculosis notified to the National Enhanced Tuberculosis Surveillance System. Our cohort comprised 224 234 migrants who were screened for active tuberculosis before entry to the UK and a control group of 118 738 migrants who were not. 103 990 (50%) migrants who were screened for active tuberculosis registered in primary care; all individuals in the control group were registered in primary care. 1828 tuberculosis cases were identified during the cohort time, of which 31 were prevalent. There were 26 incident active tuberculosis cases in migrants with no evidence of primary care registration, and 1771 cases in the entire cohort of migrants who registered in primary care (n=222 728), giving an incidence rate of 174 (95% CI 166-182) per 100 000 person-years. 672 (1%) of 103 990 migrants who were screened for active tuberculosis went on to develop tuberculosis compared with 1099 (1%) of 118 738 not screened for active tuberculosis (incidence rate ratio [IRR] 1·49, 95% CI 1·33-1·67; p<0·0001). 2451 (1%) of the 222 728 migrants registered in primary care were screened for LTBI, of whom 421 (17%) tested positive and 1961 (80%) tested negative; none developed active tuberculosis within the observed time period. Migrants settling in the least deprived areas had a decreased risk of developing tuberculosis (IRR 0·74, 95% CI 0·62-0·89; p=0·002), and time from UK arrival to primary care registration of 1 year or longer was associated with increased risk of active tuberculosis (2·96, 2·59-3·38; p<0·0001). Pre-entry tuberculosis screening, early primary care registration, and LTBI screening are strongly and independently associated with a lower tuberculosis incidence in new-entrant migrants. National Institute for Health Research (NIHR) Health Protection Research Unit in Respiratory Infections and NIHR Imperial Biomedical Research Centre.

Exploring the effects of BCG vaccination in patients diagnosed with tuberculosis: Observational study using the Enhanced Tuberculosis Surveillance system

BackgroundBacillus Calmette–Guérin (BCG) is one of the most widely-used vaccines worldwide. BCG primarily reduces the progression from infection to disease, however there is evidence that BCG may provide additional benefits. We aimed to investigate whether there is evidence in routinely-collected surveillance data that BCG vaccination impacts outcomes for tuberculosis (TB) cases in England. MethodsWe obtained all TB notifications for 2009–2015 in England from the Enhanced Tuberculosis surveillance system. We considered five outcomes: All-cause mortality, death due to TB (in those who died), recurrent TB, pulmonary disease, and sputum smear status. We used logistic regression, with complete case analysis, to investigate each outcome with BCG vaccination, years since vaccination and age at vaccination, adjusting for potential confounders. All analyses were repeated using multiply imputed data. ResultsWe found evidence of an association between BCG vaccination and reduced all-cause mortality (aOR:0.76 (95%CI 0.64–0.89), P:0.001) and weak evidence of an association with reduced recurrent TB (aOR:0.90 (95%CI 0.81–1.00), P:0.056). Analyses using multiple imputation suggested that the benefits of vaccination for all-cause mortality were reduced after 10 years. ConclusionsWe found that BCG vaccination was associated with reduced all-cause mortality in people with TB although this benefit was less pronounced more than 10 years after vaccination. There was weak evidence of an association with reduced recurrent TB.

A Quantitative Evaluation of MIRU-VNTR Typing Against Whole-Genome Sequencing for Identifying Mycobacterium tuberculosis Transmission: A Prospective Observational Cohort Study.

BackgroundMycobacterial Interspersed Repetitive Unit-Variable Number Tandem Repeat (MIRU-VNTR) typing is widely used in high-income countries to determine Mycobacterium tuberculosis relatedness. Whole-genome sequencing (WGS) is known to deliver greater specificity, but no quantitative prospective comparison has yet been undertaken.MethodsWe studied isolates from the English Midlands, sampled consecutively between 1 January 2012 and 31 December 2015. In addition to routinely performed MIRU-VNTR typing, DNA was extracted from liquid cultures and sequenced using Illumina technology. Demographic and epidemiological data for the relevant patients were extracted from the Enhanced Tuberculosis Surveillance system run by Public Health England. Closely related samples, defined using a threshold of five single nucleotide variants (SNVs), were compared to samples with identical MIRU-VNTR profiles, to samples from individuals with shared epidemiological risk factors, and to those with both characteristics.Findings1999 patients were identified for whom at least one M. tuberculosis isolate had been MIRU-VNTR typed and sequenced. Comparing epidemiological risk factors with close genetic relatedness, only co-residence had a positive predictive value of over 5%. Excluding co-resident individuals, 18.6% of patients with identical MIRU-VNTR profiles were within 5 SNVs. Where patients also shared social risk factors and ethnic group, this rose to 48%. Only 8% of MIRU-VNTR linked pairs in lineage 1 were within 5 SNV, compared to 31% in lineage 4.InterpretationIn the setting studied, this molecular epidemiological study shows MIRU-VNTR typing and epidemiological risk factors are poorly predictive of close genomic relatedness, assessed by SNV. MIRU-VNTR performance varies markedly by lineage.FundingPublic Health England, Health Innovation Challenge Fund, NIHR Health Protection Research Unit Oxford, NIHR Oxford Biomedical Research Centre.

The challenge of estimating tuberculosis mortality accurately in England and Wales.

Accurate estimates of tuberculosis (TB) mortality are required to monitor progress towards the World Health Organization End TB goal of reducing TB deaths by 95% by 2035. We compared TB death data for England and Wales from the national surveillance system (Enhanced Tuberculosis Surveillance System [ETS]) and the vital registration system from the Office for National Statistics (ONS). TB cases notified in ETS were matched to deaths in ONS (dONS) with International Classification of Diseases, Tenth Revision (ICD-10) codes indicating that TB caused/contributed to the death (A15-A19). Deaths captured in one but not both systems were assessed to identify if ONS captured all TB deaths and if there was under-notification of TB in ETS. We stratified deaths into active TB, TB sequelae, incidental deaths and not TB. Between 2005 and 2015, there were fewer deaths in ETS (dETS) than dONS with ICD-10 codes A15-A19 (n = 4207 vs. n = 6560); 57% of dETS were recorded as dONS and 53% of dONS were notified to ETS. A total of 9289 deaths were identified from dETS and dONS: 64% were due to active TB, 23% were TB sequelae, 6% were incidental and 7% were not TB. TB deaths in ETS and ONS differ substantially. Almost one third of TB deaths recorded by ONS are not due to active TB; this can be amended through coding changes.

Observational study to estimate the changes in the effectiveness of bacillus Calmette-Guérin (BCG) vaccination with time since vaccination for preventing tuberculosis in the UK.

Until recently, evidence that protection from the bacillus Calmette-Guérin (BCG) vaccination lasted beyond 10 years was limited. In the past few years, studies in Brazil and the USA (in Native Americans) have suggested that protection from BCG vaccination against tuberculosis (TB) in childhood can last for several decades. The UK's universal school-age BCG vaccination programme was stopped in 2005 and the programme of selective vaccination of high-risk (usually ethnic minority) infants was enhanced. To assess the duration of protection of infant and school-age BCG vaccination against TB in the UK. Two case-control studies of the duration of protection of BCG vaccination were conducted, the first on minority ethnic groups who were eligible for infant BCG vaccination 0-19 years earlier and the second on white subjects eligible for school-age BCG vaccination 10-29 years earlier. TB cases were selected from notifications to the UK national Enhanced Tuberculosis Surveillance system from 2003 to 2012. Population-based control subjects, frequency matched for age, were recruited. BCG vaccination status was established from BCG records, scar reading and BCG history. Information on potential confounders was collected using computer-assisted interviews. Vaccine effectiveness was estimated as a function of time since vaccination, using a case-cohort analysis based on Cox regression. In the infant BCG study, vaccination status was determined using vaccination records as recall was poor and concordance between records and scar reading was limited. A protective effect was seen up to 10 years following infant vaccination [< 5 years since vaccination: vaccine effectiveness (VE) 66%, 95% confidence interval (CI) 17% to 86%; 5-10 years since vaccination: VE 75%, 95% CI 43% to 89%], but there was weak evidence of an effect 10-15 years after vaccination (VE 36%, 95% CI negative to 77%; p = 0.396). The analyses of the protective effect of infant BCG vaccination were adjusted for confounders, including birth cohort and ethnicity. For school-aged BCG vaccination, VE was 51% (95% CI 21% to 69%) 10-15 years after vaccination and 57% (95% CI 33% to 72%) 15-20 years after vaccination, beyond which time protection appeared to wane. Ascertainment of vaccination status was based on self-reported history and scar reading. The difficulty in examining vaccination sites in older women in the high-risk minority ethnic study population and the sparsity of vaccine record data in the later time periods precluded robust assessment of protection from infant BCG vaccination > 10 years after vaccination. Infant BCG vaccination in a population at high risk for TB was shown to provide protection for at least 10 years, whereas in the white population school-age vaccination was shown to provide protection for at least 20 years. This evidence may inform TB vaccination programmes (e.g. the timing of administration of improved TB vaccines, if they become available) and cost-effectiveness studies. Methods to deal with missing record data in the infant study could be explored, including the use of scar reading. The National Institute for Health Research Health Technology Assessment programme. During the conduct of the study, Jonathan Sterne, Ibrahim Abubakar and Laura C Rodrigues received other funding from NIHR; Ibrahim Abubakar and Laura C Rodrigues have also received funding from the Medical Research Council. Punam Mangtani received funding from the Biotechnology and Biological Sciences Research Council.

Tuberculosis in migrants moving from high-incidence to low-incidence countries: a population-based cohort study of 519 955 migrants screened before entry to England, Wales, and Northern Ireland

SummaryBackgroundTuberculosis elimination in countries with a low incidence of the disease necessitates multiple interventions, including innovations in migrant screening. We examined a cohort of migrants screened for tuberculosis before entry to England, Wales, and Northern Ireland and tracked the development of disease in this group after arrival.MethodsAs part of a pilot pre-entry screening programme for tuberculosis in 15 countries with a high incidence of the disease, the International Organization for Migration screened all applicants for UK visas aged 11 years or older who intended to stay for more than 6 months. Applicants underwent a chest radiograph, and any with results suggestive of tuberculosis underwent sputum testing and culture testing (when available). We tracked the development of tuberculosis in those who tested negative for the disease and subsequently migrated to England, Wales, and Northern Ireland with the Enhanced Tuberculosis Surveillance system. Primary outcomes were cases of all forms of tuberculosis (including clinically diagnosed cases), and bacteriologically confirmed pulmonary tuberculosis.FindingsOur study cohort was 519 955 migrants who were screened for tuberculosis before entry to the UK between Jan 1, 2006, and Dec 31, 2012. Cases notified on the Enhanced Tuberculosis Surveillance system between Jan 1, 2006, and Dec 31, 2013, were included. 1873 incident cases of all forms of tuberculosis were identified, and, on the basis of data for England, Wales, and Northern Ireland, the estimated incidence of all forms of tuberculosis in migrants screened before entry was 147 per 100 000 person-years (95% CI 140–154). The estimated incidence of bacteriologically confirmed pulmonary tuberculosis in migrants screened before entry was 49 per 100 000 person-years (95% CI 45–53). Migrants whose chest radiographs were compatible with active tuberculosis but with negative pre-entry microbiological results were at increased risk of tuberculosis compared with those with no radiographic abnormalities (incidence rate ratio 3·2, 95% CI 2·8–3·7; p<0·0001). Incidence of tuberculosis after migration increased significantly with increasing WHO-estimated prevalence of tuberculosis in migrants' countries of origin. 35 of 318 983 pre-entry screened migrants included in a secondary analysis with typing data were assumed index cases. Estimates of the rate of assumed reactivation tuberculosis ranged from 46 (95% CI 42–52) to 91 (82–102) per 100 000 population.InterpretationMigrants from countries with a high incidence of tuberculosis screened before being granted entry to low-incidence countries pose a negligible risk of onward transmission but are at increased risk of tuberculosis, which could potentially be prevented through identification and treatment of latent infection in close collaboration with a pre-entry screening programme.FundingWellcome Trust, UK National Institute for Health Research, UK Medical Research Council, Public Health England, and Department of Health Policy Research Programme.

Towards better guidance on caseload thresholds to promote positive tuberculosis treatment outcomes: a cohort study.

BackgroundIn low-incidence countries, clinical experience of tuberculosis is becoming more limited, with potential consequences for patient outcomes. In 2007, the Department of Health released a guidance ‘toolkit’ recommending that tuberculosis patients in England should not be solely managed by clinicians who see fewer than 10 cases per year. This caseload threshold was established to try to improve treatment outcomes and reduce transmission, but was not evidence based. We aimed to assess the association between clinician or hospital caseload and treatment outcomes, as well as the relative suitability of making recommendations using each caseload parameter.MethodsDemographic and clinical data for tuberculosis cases in England notified to Public Health England’s Enhanced Tuberculosis Surveillance system between 2003 and 2012 were extracted. Mean clinician and hospital caseload over the past 3 years were calculated and treatment outcomes grouped into good/neutral and unfavourable. Caseloads over time and their relationship with outcomes were described and analysed using random effects logistic regression, adjusted for clustering.ResultsIn a fully adjusted multivariable model (34,707 cases)there was very strong evidence that management of tuberculosis by clinicians with fewer than 10 cases per year was associated with greater odds of an unfavourable outcome compared to clinicians who managed greater numbers of cases (cluster-specific odds ratio, 1.14; 95 % confidence interval, 1.05–1.25; P = 0.002). The relationship between hospital caseload and treatment outcomes was more complex and modified by a patient’s place of birth and ethnicity. The clinician caseload association held after adjustment for hospital caseload and when the clinician caseload threshold was reduced down to one.ConclusionsDespite the relative ease of making recommendations at the hospital level and the greater reliability of recorded hospital versus named clinician, our results suggest that clinician caseload thresholds are more suitable for clinical guidance. The current recommended clinician caseload threshold is functional. Sensitivity analyses reducing the threshold indicated that clinical experience is pertinent even at very low average caseloads, which is encouraging for low burden settings.Electronic supplementary materialThe online version of this article (doi:10.1186/s12916-016-0592-8) contains supplementary material, which is available to authorized users.

Development of an open source tool for mapping disease clusters

BackgroundMapping is an important step in investigations of infectious disease outbreaks. Despite advances in molecular characterisation of pathogens that allow delineation of outbreaks with greater precision, geospatial methods that complement these analyses are rarely used in real time. Barriers include lack of flexibility, expense of specialised software, and the need for trained personnel. This study aimed to develop a tool with free, open source software that could be used by public health professionals to display clusters of disease on a map, and to demonstrate its utility through the exemplar of molecular clusters of tuberculosis in London. MethodsWe developed a bespoke interactive mapping tool using Shiny, a web application framework for the statistical software package, R. Mapping was enabled using Leaflet, a JavaScript library for interactive mapping, through the R package leaflet. Data were extracted from the Enhanced Tuberculosis Surveillance System for cases of tuberculosis with a residential postcode in London, who were part of a molecular cluster, and were notified between Jan 1, 2010, and Dec 31, 2013. FindingsData subsets can be interactively displayed on the basis of cluster name, notification date, demographics, and reported risk factors. In addition to mapping, epidemic curves and summary tables are automatically produced. The tool was used to explore 3194 cases of tuberculosis in 767 clusters in London, and allowed rapid overview of the geographical, temporal, and epidemiological features to support cluster investigation. InterpretationGeographical displays of molecular data can enhance understanding of disease transmission. Advantages of the tool developed in this study include: flexibility, allowing user-defined subsets of data in any geographical location to be displayed; potential adaptability to other geocoded health or other contextual data; and a web interface, which is user-friendly, needs minimal training to operate, and does not require upload of identifiable information to the internet. A potential limitation is maintenance of code, although the use of open source software also benefits from support and improvement from the wider developer community. Future work will involve testing of the tool with potential users to assess its utility in practice. FundingCMS is funded by the Farr Institute of Health Informatics Research.

S78 Do Tuberculosis Cases Managed By Clinicians With Average Annual Caseloads Below 10 Have Poorer Treatment Outcomes?

Introduction and objectives The 2007 Department of Health Tuberculosis Toolkit advises that clinicians should not be solely managing tuberculosis (TB) cases if their average caseload is less than 10 per year. A systematic evaluation of whether these guidelines are being followed, and how effective such a threshold is, has not been undertaken in the UK. Methods All UK TB cases notified 2003–2011 were extracted from Public Health England’s Enhanced Tuberculosis Surveillance system. Mean caseload for each clinician was calculated over the preceding year and three years by using case notification date. 12 month TB treatment outcomes were categorised as unfavourable or good/neutral.1,2 Cases without clinician information and resistant to rifampicin were excluded, the latter due to UK recommendations on the length of treatment. The proportion of cases managed by clinicians with a caseload under 10 was analysed, then random effects logistic regression utilised to determine the relationship between caseload and treatment outcomes, adjusting for clustering by clinician and confounding. Results 74,550 TB cases were notified 2003–11. The proportion of TB cases seen by a clinician who had a low caseload (less than 10) in the preceding year declined gradually 2004–11 (42 to 28%), with no apparent acceleration post-Toolkit. Univariate modelling demonstrated very strong evidence of increased odds of an unfavourable treatment outcome among cases seen by a clinician who had a low caseload over the preceding three years (cluster-specific odds ratio 1.23 (95% confidence interval 1.14–1.33), p-value Conclusions Our analysis indicates that TB cases managed by clinicians with a mean caseload of under 10 over the preceding three years have increased odds of an unfavourable treatment outcome. However other factors, such as the number of clinicians managing TB cases in the hospital overall, should potentially be taken into account for policy recommendations. References Ditah, Thorax 2008;63:440–446 Anderson, Euro Surveill. 2013;18(40):pii=20601

S56 Does time since arrival affect site of TB disease in UK migrants?

BackgroundIn contrast to global tuberculosis (TB) epidemiology, the UK and many low incidence countries have a high proportion of cases with extra-pulmonary tuberculosis (ETB). Almost 70% of reported cases in...

What really happens to tuberculosis patients classified as lost to follow-up in West Yorkshire?

Tuberculosis (TB) patients who do not complete treatment pose a potential public health risk. In West Yorkshire, local clinicians suspected that this risk was overestimated by the national Enhanced Tuberculosis Surveillance system. We audited patients who failed to complete treatment and were categorised as lost-to-follow-up (LTFU) between 2004 and 2008, using a combination of hand searching existing records and obtaining additional information from clinicians. In the study period 2,031 TB cases with reported outcome were notified in West Yorkshire, 23% (n=474) did not complete treatment, and 199 (42%) of those were categorised as LTFU 12 months after notification. Of these 199, 49% (n=98) remained LTFU after the audit, 51% (n=101) were re-classified to the following categories: 24% (n=47) transferred abroad, 16% (n=31) recommenced and completed treatment, 6% (n=13) transferred to another clinic in the United Kingdom (UK), and 5% (n=10) died. These patients therefore no-longer posed a public health risk. Further training for clinicians to improve accuracy of outcome reporting has been initiated. Nationally, the collection of treatment outcome data needs to be strengthened and extending the follow-up for treatment outcome monitoring should be considered.

P52 Rising paediatric tuberculosis in Greater Manchester: epidemiology and BCG vaccination status of cases

BackgroundTuberculosis cases in Greater Manchester (GM) have increased annually since 2004. The Paediatric TB clinic at Royal Manchester Children's Hospital has grown since its inception in 2004, but it is...

Effects of distance to treatment centre and case load upon tuberculosis treatment completion

To the Editors: The prompt identification and adequate treatment of tuberculosis (TB) cases are key components of the global control effort [1]. In many high-income countries, TB is relatively uncommon, implying that many clinicians do not have regular and continuing experience of managing TB. To address this, a policy response is a trend towards small numbers of centralised treatment facilities where individuals may receive better and more complete treatment [2, 3]. This centralising trend is the opposite to many low-income countries, where there is a move towards larger numbers of more decentralised TB services to facilitate patient access [4]. The difference is that such countries have sufficient cases to allow clinical staff to maintain their expertise, even in rural areas. If TB services become more centralised, then patients may experience greater difficulty in accessing TB services due to increasing the distance between the home and treatment centre. There is little research on how distance affects TB completion, but rural residence is a known risk factor associated with a delay in the diagnosis and treatment of TB [5] and may therefore affect treatment completion. However, most of this evidence comes from low-income countries. In contrast, in high-income countries, good transport links and reasonable social security systems imply that such barriers may not exist. This epidemiological study examined whether treatment centre case load (annual number of TB patients seen) and healthcare accessibility (proximity of patient residence to TB treatment centre) have an influence upon the completion of TB treatment in England and Wales, UK. The study was based upon a sample of 21,954 patients reported to the national enhanced TB surveillance system (ETS) from 2001 to 2006 in England and Wales. These TB patients all had …

Dedicated outreach service for hard to reach patients with tuberculosis in London: observational study and economic evaluation

Objective To assess the cost effectiveness of the Find and Treat service for diagnosing and managing hard to reach individuals with active tuberculosis. Design Economic evaluation using a discrete, multiple...

The influence of socio-economic deprivation on tuberculosis treatment delays in England, 2000–2005

This study investigates the association between socio-economic deprivation and tuberculosis (TB) treatment delays in England, 2000-2005. Patients reported to the Enhanced TB Surveillance system were assigned a deprivation score based on residential postcode, and categorized into deprivation quartiles. Data were analysed using Cox regression. The median interval from symptom onset to treatment initiation was 67 days (inter-quartile range 30-131). The effect of deprivation on this interval was modified by ethnic group and place of birth/time since entry into the United Kingdom. Longer intervals were experienced by the most deprived black Africans, Indians/Pakistanis/Bangladeshis and recent entrants to the United Kingdom, compared to the least deprived. In contrast, among white and UK-born patients, longer intervals were experienced by the least deprived. In conclusion, the effect of deprivation on TB treatment delays varies in different population groups. Efforts are needed to reduce delays including improving awareness of TB and increasing the index of clinical suspicion.

Increasing antituberculosis drug resistance in the United Kingdom: analysis of national surveillance data

Objective To identify recent trends in, and factors associated with, resistance to antituberculosis drugs in England, Wales, and Northern Ireland.Design Cohort of tuberculosis cases reported to the enhanced tuberculosis surveillance...

Monitoring tuberculosis treatment outcome: analysis of national surveillance data from a clinical perspective

Background:In 1998, the World Health Organization (WHO) and the International Union Against Tuberculosis and Lung Disease (IUATLD) published recommendations standardising the evaluation of tuberculosis treatment outcome in Europe. These guidelines...