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.

Analysing Tuberculosis Cases Among Healthcare Workers to Inform Infection Control Policy and Practices.

OBJECTIVE To determine the number and proportion of healthcare worker (HCW) tuberculosis (TB) cases infected while working in healthcare institutions in the Netherlands and to learn from circumstances that led to these infections. DESIGN Cohort analysis. METHODS We included all HCW TB patients reported to the Netherlands TB Register from 2000 to 2015. Using data from this register, including DNA fingerprints of the bacteria profile and additional information from public health clinics, HCW TB cases were classified into 4 categories: (1) infected during work in the Netherlands, (2) infected in the community, (3) infected outside the Netherlands, or (4) outside these 3 categories. An in-depth analysis of category 1 cases was performed to identify factors contributing to patient-to-HCW transmission. RESULTS In total, 131 HCW TB cases were identified: 32 cases (24%) in category 1; 13 cases (10%) in category 2; 42 cases (32%) in category 3; and 44 cases (34%) in category 4. The annual number of HCW TB cases (P<.05), the proportion among reported cases (P<.01), and the number of category 1 HCW TB cases (P=.12) all declined over the study period. Delayed diagnosis in a TB patient was the predominant underlying factor of nosocomial transmission in 47% of category 1 HCW TB patients, most of whom were subsequently identified in a contact investigation. Performing high-risk procedures was the main contributing factor in the other 53% of cases. CONCLUSION In low-incidence countries, every HCW TB case should warrant timely and thorough investigation to help further define and fine-tune the HCW screening policy and to monitor its proper implementation. Infect Control Hosp Epidemiol 2017;38:976-982.

Biomarkers Can Identify Pulmonary Tuberculosis in HIV-infected Drug Users Months Prior to Clinical Diagnosis.

BACKGROUND: Current diagnostic tests cannot identify which infected individuals are at risk for progression to tuberculosis (TB). Our aim was to identify biomarkers which can predict the development of TB prior to clinical diagnosis. METHOD: In a retrospective case-control study, RNA of 14 HIV-infected drug users obtained before TB diagnosis (cases) and of 15 who did not develop TB (controls) was analyzed for the expression of 141 genes by dcRT-MLPA followed by Lasso regression analysis. FINDINGS: A combined analysis of IL13 and AIRE had the highest discriminatory power to identify cases up to 8 months prior to clinical diagnosis. Cases expressing IL13 had a gene expression pattern strongly enriched for type I IFN related signaling genes, suggesting that these genes represent processes that contribute to TB pathogenesis. INTERPRETATION: We here demonstrated that biomarkers, such as IL13-AIRE, can identify individuals that progress to TB within a high risk population, months prior to clinical diagnosis.