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.

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.

A comparative examination of tuberculosis immigration medical screening programs from selected countries with high immigration and low tuberculosis incidence rates.

BACKGROUND: Tuberculosis (TB) in migrants is an ongoing challenge in several low TB incidence countries since a large proportion of TB in these countries occurs in migrants from high incidence countries. To meet these challenges, several countries utilize TB screening programs. The programs attempt to identify and treat those with active and/or infectious stages of the disease. In addition, screening is used to identify and manage those with latent or inactive disease after arrival. Between nations, considerable variation exists in the methods used in migration-associated TB screening. The present study aimed to compare the TB immigration medical examination requirements in selected countries of high immigration and low TB incidence rates. METHODS: Descriptive study of immigration TB screening programs. RESULTS: 16 out of 18 eligible countries responded to the written standardized survey and phone interview. Comparisons in specific areas of TB immigration screening programs included authorities responsible for TB screening, the primary objectives of the TB screening program, the yield of detection of active TB disease, screening details and aspects of follow up for inactive pulmonary TB. No two countries had the same approach to TB screening among migrants. Important differences, common practices, common problems, evidence or lack of evidence for program specifics were noted. CONCLUSIONS: In spite of common goals, there is great diversity in the processes and practices designed to mitigate the impact of migration-associated TB among nations that screen migrants for the disease. The long-term goal in decreasing migration-related introduction of TB from high to low incidence countries remains diminishing the prevalence of the disease in those high incidence locations. In the meantime, existing or planned migration screening programs for TB can be made more efficient and evidenced based. Cooperation among countries doing research in the areas outlined in this study should facilitate the development of improved screening programs.