Identification of Childhood-Onset Inflammatory Bowel Disease in Swedish Healthcare Registers: A Validation Study.

Purpose: The Swedish National Patient Register (NPR) is often used in observational studies of childhood-onset inflammatory bowel disease (IBD) (<18 years of age) and its subtypes, but the validity of previously used register-based algorithms for capturing childhood-onset IBD has never been examined. Methods: We identified a random sample of 233 individuals with at least two first ever diagnostic listings of IBD in the NPR between 2002 and 2014. We calculated the test characteristics for different register-based definitions of IBD and its subtypes using the Copenhagen criteria and the revised Porto criteria as gold standard, both based on medical chart review. We made assumptions of the occurrence of undiagnosed IBD in the general child population based on available literature. Results: Out of 233 individuals with at least two diagnostic listings of IBD, 216 had true IBD, resulting in a positive predictive value (PPV) = 93% (95% confidence interval (CI) 89-96), sensitivity = 88% (95% CI 83-92), specificity = 100% (95% CI 100-100), and negative predictive value (NPV) = 100% (95% CI 100-100). The PPV for the NPR-based definitions of IBD subtypes at time of first IBD diagnosis and at end of follow-up were 78% (95% CI 69-86) and 88% (95% CI 80-94), respectively, for Crohn's disease and 74% (95% CI 63-83) and 71% (95% CI 60-80), respectively, for ulcerative colitis. Conclusion: The validity of register-based definitions of childhood-onset IBD in the Swedish NPR is high and can be used to identify patients in observational research.

Prevalence of Latent TB and Effectiveness of BCG Vaccination Against Latent Tuberculosis: An Observational Study.

OBJECTIVES: This study aimed to determine the prevalence of latent tuberculosis infection (LTBI) in immigrant children and adolescents (aged 0-17 years) living or recently arriving in Sweden. It also aimed to estimate the effectiveness of Bacillus Calmette-Guérin (BCG) against LTBI in immigrant children coming to Sweden from high-incidence countries, most of them being asylum seekers. LTBI was defined as a positive Quantiferon or a tuberculin skin test (TST) of ≥ 10 mm in small children from whom it was difficult to obtain 3 mL of blood. DESIGN: A typical BCG scar was used as a substitute for written documentation of BCG vaccination. The study comprised 1,404 immigrants aged 0-17 years. The arms and legs of all of them were inspected for a BCG scar, and Quantiferon or TST was performed. The study was a retrospective, observational, comparative cohort study. RESULTS: LTBI was found in 123 of 1,011 (12%) children with a BCG scar and in 116 of 393 (29.5%) without a BCG scar, giving an estimated vaccine effectiveness of 59%. CONCLUSIONS: LTBI was common among the immigrant children (17%). LTBI can progress to active TB and then spread in the immigrant population and to the general population if all immigrant arrivals are not tested and given prophylactic treatment if they have LTBI. The BCG vaccine was found to have a significant effect on LTBI (59%).

Neuroborreliosis in Swedish Children: A Population-based Study on Incidence and Clinical Characteristics.

BACKGROUND: Borrelia burgdorferi is a common cause of bacterial meningitis, but there are very few studies on incidence in Europe. The aim of this study was to report the incidence and symptoms of neuroborreliosis in Swedish children. METHODS: Medical records of children (< 15 years) treated for neuroborreliosis 2002-2014 were studied retrospectively. The patients were identified in the computerized registers of discharge diagnoses at the Departments of Pediatrics and Infectious Diseases in Gothenburg, Borås, Trollhättan and Halmstad using International Classification of Diseases 10 diagnosis codes G51.0, G01.9 and/or A69.1. Of those, patients with symptoms compatible with neuroborreliosis and a white blood cell count in cerebrospinal fluid ≥ 7 cells/mm with ≥ 80% mononuclear cells were included. Only children living in the city of Gothenburg and 10 surrounding municipalities were included. RESULTS: Five hundred forty-eight children were included. The median age was 7 (1-14) years. The total incidence for the 13-year-period was 2.8/10,000 and remained unchanged during the period. The incidence was significantly higher in rural (4.0/10,000) than in urban municipalities (2.1/10,000). The most common presenting symptoms were headache (n = 335), fatigue (n = 330) and cranial nerve palsies (n = 329). The median duration of symptoms before admittance was 4.0 days for facial palsy and 14.0 days for other symptoms (P < 0.001). The median white blood cell count in cerebrospinal fluid was 129 (7-1069) cells/mm. CONCLUSIONS: This study is the largest so far in a pediatric population. The incidence of neuroborreliosis was higher than in previous European reports. This might be explained by increased Borrelia awareness, the distribution of tick population in Sweden, and the possibility that Swedish children more frequently play outdoors.