Risk of developing tuberculosis disease among persons diagnosed with latent tuberculosis infection in the Netherlands.

Diagnosis and preventive treatment of latent tuberculosis infection (LTBI) among high-risk groups is recommended to achieve tuberculosis (TB) elimination in low-incidence countries.We studied TB incidence rates among those notified with LTBI in the Netherlands from 2005 to 2013 and analysed associated risk factors. We stratified analyses by target group for screening, and by initiation and completion of preventive treatment.The incidence for those completing, stopping and not receiving preventive treatment was 187, 436 and 355 per 100 000 person-years for contacts of TB patients, respectively, and 63, 96 and 110 per 100 000 person-years for other target groups. The rate ratio for TB development among contacts compared to other target groups was 3.1 (95% CI 2.0-4.9). In both groups, incidence was highest in the first year after diagnosis. Independent factors associated with progression to TB among contacts were age <5 years and stopping preventive treatment within 28 days compared to those not receiving preventive treatment. Among other target groups, being foreign born was the only risk factor associated with the risk of developing TB.We conclude that the epidemiological impact of preventive treatment is highest in contacts of TB patients and limited in other target groups for LTBI management in the Netherlands.

[Tuberculosis among asylum-seekers in the Netherlands: a descriptive study among the two largest groups of asylum-seekers]. / Tuberculose bij asielzoekers in Nederland: descriptief onderzoek onder de 2 grootste groepen asielzoekers.

OBJECTIVE: To investigate the prevalence and incidence of tuberculosis (TB) among the two largest groups of asylum-seekers in the Netherlands, i.e. Syrians and Eritreans/Ethiopians. DESIGN: Descriptive study. METHOD: We collected data from the screening of Syrian and Eritrean/Ethiopian asylum-seekers for the period January 2013 - September 2015 and linked these to notifications in the Netherlands Tuberculosis Register. RESULTS: Asylum-seekers from Syria and Eritrea/Ethiopia represented 65% and 72% of all asylum applications in 2014 and in the first nine months of 2015 respectively. Fourteen Syrian asylum-seekers applying during the study period were diagnosed with tuberculosis. The prevalence was 22 cases per 100,000 persons screened upon arrival (95% CI: 10-44), while the incidence within the first year after arrival was 19 per 100,000 persons (95% CI: 3-62). Tuberculosis was diagnosed in 133 Eritrean/Ethiopian asylum-seekers applying during the study period. The prevalence was 283 cases per 100,000 persons screened upon arrival (95% CI: 198-393) and the incidence in the first year after arrival was 1394 per 100,000 persons (95% CI: 1095-1751). CONCLUSION: In the last two years, most asylum-seekers have originated from Syria and among them tuberculosis is relatively uncommon. However, among Eritrean/Ethiopian asylum-seekers, prevalence and incidence in the first year in the Netherlands are high. This suggests that many of them have been recently infected, in their country of origin or during the journey. Other interventions are required, such as screening for latent infection, to prevent tuberculosis among high-risk asylum-seekers and further reduce the incidence of this disease in the Netherlands.

Monitoring latent tuberculosis infection diagnosis and management in the Netherlands.

Targeted diagnosis and treatment of latent tuberculosis (TB) infection (LTBI) among persons with a high risk of exposure to TB or of developing TB when infected has been performed and monitored routinely in the Netherlands since 1993. We describe trends in target groups, diagnostic methods and treatment regimens, and explore determinants for treatment initiation, treatment completion and adverse events.In total, 37 729 persons were registered with LTBI from 1993 to 2013, of whom 28 931 (77%) started preventive treatment; 82% of those completed preventive treatment and 8% stopped preventive treatment due to adverse events. Two-thirds of the notified cases were detected through contact investigation.Increasing numbers of persons with immunosuppressive disorders, elderly persons and foreign-born persons were notified in recent years, due to policy changes and the introduction of the interferon-γ release assay. Children (96%) and the immunosuppressed (95%) were more likely to start preventive treatment. Children (93%) were also more likely to complete preventive treatment, as were persons treated with rifampicin or rifampicin/isoniazid regimens (91% and 92%, respectively). The latter groups were also 40% less likely to stop preventive treatment due to adverse events.Under these operational conditions, the estimated risk reduction on incident TB in the target population for LTBI management is 40-60%.

The epidemiology of childhood tuberculosis in the Netherlands: still room for prevention.

BACKGROUND: The occurrence of tuberculosis (TB) among children has long been neglected as a public health concern. However, any child with TB is a sentinel event indicating recent transmission. Vaccination, early case finding and treatment of those latently infected with TB can prevent cases, severe morbidity and unnecessary death. METHOD: The objective of the study was to describe the occurrence of TB events among children in the Netherlands which may be avoided through preventive measures. For this purpose we performed a trend analysis of routine Dutch TB and LTBI (surveillance data in 1993-2012 and a descriptive analysis of children with TB and with LTBI diagnosed in 2005-2012). RESULTS: Overall childhood TB incidence has declined over the last two decades from 3.6 in 1993 to 1.9 per 100,000 children in 2012. The decline was stronger among Dutch-born children compared to foreign-born children. In 2005-2012 64% of childhood TB cases were detected through active case finding. Foreign-born children with TB were less likely to be detected through active case finding, when not detected through post-entry TB screening. Childhood TB diagnosis was culture confirmed in 68% of passively detected cases and 12% of actively detected cases. Of 1,049 children with LTBI started on preventive treatment in 2005-2012, 90% completed treatment. In 37% of all childhood TB cases there was at least one 'missed opportunity' for prevention. Thirty nine percent of child TB patients eligible for BCG were not vaccinated. CONCLUSION: Children with TB in the Netherlands are generally detected at an early stage and treatment completion rates are high. However, more TB cases among children can be prevented through enhancing TB case finding and screening and preventive treatment of latent TB infection among migrant children, and improving the coverage of BCG vaccination among eligible risk groups.

Tuberculosis treatment outcome monitoring in European Union countries: systematic review.

Treatment success measured by treatment outcome monitoring (TOM) is a key programmatic output of tuberculosis (TB) control programmes. We performed a systematic literature review on national-level TOM in the 30 European Union (EU)/European Economic Areas (EEA) countries to summarise methods used to collect and report data on TOM. Online reference bibliographic databases PubMed/MEDLINE and EMBASE were searched to identify relevant indexed and non-indexed literature published between January 2000 and August 2010. The search strategy resulted in 615 potentially relevant indexed citations, of which 27 full-text national studies (79 data sets) were included for final analysis. The selected studies were performed in 10 EU/EEA countries and gave a fragmented impression of TOM in the EU/EEA. Publication year, study period, sample size, databases, definitions, variables, patient and outcome categories, and population subgroups varied widely, portraying a very heterogeneous picture. This review confirmed previous reports of considerable heterogeneity in publications of TOM results across EU/EEA countries. PubMed/MEDLINE and EMBASE indexed studies are not a suitable instrument to measure representative TOM results for the 30 EU/EEA countries. Uniform and complete reporting to the centralised European Surveillance System will produce the most timely and reliable results of TB treatment outcomes in the EU/EEA.

Missed opportunities in tuberculosis control in The Netherlands due to prioritization of contact investigations.

BACKGROUND: The Dutch contact investigation guidelines stipulate that Public Health Services should examine contacts around all pulmonary tuberculosis (TB) patients to prevent disease and further transmission. Our objective was to assess to what extent these guidelines were applied and whether patient characteristics were associated with having contacts investigated. METHODS: We extracted the records of all reported pulmonary TB patients from the nationwide surveillance register covering 2006-07. Patient characteristics associated with having contacts investigated were assessed by multivariable logistic regression analysis. RESULTS: Out of the 1236 pulmonary TB patients reported, 909 (74%) patients were eligible for analysis, since 133 (11%) patients had incomplete records and 194 (16%) patients were registered by Public Health Services who did not report contact investigation results. For 710 (78%) out of the 909 patients contacts were investigated. Compared with Dutch patients, contacts were significantly less often investigated around immigrant patients (84 vs. 75%, OR: 0.60; 95% CI: 0.40-0.92). Contacts were significantly more often investigated for smear positive patients (OR: 3.52; 95% CI: 2.23-5.55) and culture positive patients (OR: 2.71; 95% CI: 1.76-4.16), compared with smear negative and culture negative patients, respectively. CONCLUSION: Initiating contact investigations appear to be prioritized based on the infectiousness, but also on the ethnicity of pulmonary TB patients. By not investigating the contacts of 25% of the immigrant patients, there is a risk of missing a significant number of infected and diseased contacts, since the incidence in this group is markedly higher than in the Dutch population.

Projection of the number of patients with tuberculosis in the Netherlands in 2030.

BACKGROUND: The incidence of tuberculosis (TB) in The Netherlands has been declining for many years. For the purpose of planning future TB-control activities we estimated the number of TB patients in The Netherlands up to 2030. METHODS: Statistical modelling for 5-year age groups up to 2030 distinguishing among Dutch TB patients infected by a Dutch source (survival model), non-Dutch patients (projection of the proportion of culture-positive patients among first generation immigrants) and Dutch patients infected by a non-Dutch source (fixed relation with the number of non-Dutch patients). RESULTS: The number of TB patients is expected to decline to 877 in 2030. After 2010 declines may slow due to an increase in non-Dutch TB patients. This increase cancels out the decrease of Dutch TB patients infected by a Dutch source. In 2030, 85% of all TB patients are expected to be non-Dutch. In the four largest counties and the rest of The Netherlands, this will be 89 and 76%, respectively. CONCLUSION: The decrease in TB incidence observed over many years may stall from 2010 onwards because of an estimated increase in non-Dutch TB patients. Given their disproportionate burden, future TB-control activities should prioritize the health of first-generation immigrants. Enhanced TB control in the countries of origin and new diagnostic tests to identify those at high risk of developing active TB could help in reducing further the TB incidence in the Netherlands. Future TB-control efforts must be organized in a flexible way to be able to incorporate changing epidemiological situations.