Pre-admission virus detection during the COVID-19 pandemic in children with and without symptoms of infection.

AIM: Pre-admission viral screening is used only in exceptional situations such as pandemics. We therefore evaluated pre-admission screening for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), respiratory syncytial virus (RSV) and influenza during the COVID-19 pandemic, comparing epidemiology and clinical features of admitted children. METHODS: Children were screened at a paediatric emergency department from 1 March 2020 to 30 June 2022 by nasopharyngeal sampling and polymerase chain reaction kit. We retrospectively retrieved positive results from the laboratory and scrutinised charts of admitted children. RESULTS: Out of 15 927 screened children, 522, 127 and 572 were positive and admitted with RSV, influenza A or SARS-CoV-2, respectively. Of these, 29 (5.6%), 26 (24.1%) and 245 (44.8%) were incidental findings, lacking symptoms of infection. RSV and influenza A were initially absent but re-emerged in the autumn of 2021. The rate of COVID-19 rose when the Omicron variant emerged in December 2021. The median age of children with RSV was 0.3 years, of those with influenza A 6.7 years and of those with COVID-19 1.6 years. Major complications were rare. CONCLUSION: Frequent incidental detections of SARS-CoV-2 likely reflected widespread presence of a mild infection. Clinically, COVID-19 was like other viral respiratory infections in children.

The pneumococcal conjugate vaccine had a sustained effect on Swedish children 8 years after its introduction.

AIM: The pneumococcal conjugate vaccine, which covered seven serotypes of Streptococcus pneumoniae (PCV7), was introduced in Stockholm, Sweden, in 2007. It was replaced by a 13-valent vaccine (PCV13) in 2011. We previously reported a decreased incidence of pneumonia and sinusitis among young children 4 years after the introduction of the PCV7. This study followed the incidence of pneumonia, sinusitis, mastoiditis and meningitis for four more years. METHODS: We studied validated hospital registry data covering children up to 17 years of age, who were hospitalised in the Stockholm region from 2003 to 2016, when the child population peaked at 485 687. All 11 115 cases diagnosed with pneumonia, coded as bacterial pneumonia, sinusitis, mastoiditis, bacterial meningitis or empyema, were identified. The controls had viral pneumonia or pyelonephritis. RESULTS: The incidence rates for children under 2 years of age hospitalised for sinusitis, mastoiditis and meningitis decreased significantly by 61%-79% during the eight-year post-vaccination period. Hospitalisations for bacterial pneumonia decreased by 19%-25% in the same age group. These changes were probably due to both the vaccines and changes in diagnosis routines. CONCLUSION: The effect of vaccination on children under 2 years of age was sustained 8 years after the introduction of the pneumococcal conjugate vaccines.

Seizures in hospitalised paediatric patients with SARS-CoV-2 and comparison of severity with seizures in hospitalised paediatric patients with other respiratory viruses during the COVID-19 pandemic: a population-based cohort study.

OBJECTIVE: To study seizures in patients hospitalised due to SARS-CoV-2 infection, and compare their severity with seizures in patients hospitalised due to other viral respiratory tract infections (RTIs). DESIGN: Observational population-based cohort study. SETTING: Northern Stockholm. PATIENTS: Patients aged 1 month-18 years hospitalised due to SARS-CoV-2 with and without seizures, and patients of the same age hospitalised due to other viral RTIs with seizures, between 1 March 2020 and 30 June 2022. MAIN OUTCOME MEASURES: The prevalence of seizures in hospitalised patients due to SARS-CoV-2, the evaluation of assumed predictors of seizures and the comparison of severity markers in patients with SARS-CoV-2 versus other RTIs. RESULTS: 32 of 239 included patients (13.4%) admitted due to SARS-CoV-2 infection had seizures. Central nervous system (CNS) disease and the omicron period had significantly increased OR for seizures (OR: 5.12; CI: 2.06 to 12.72 and OR: 3.01; CI: 1.15 to 7.88, respectively). Seizures in patients with SARS-CoV-2 were more common in children older than 5 years (p=0.001), even in the absence of fever (p=0.007), as compared with other viral RTIs. The duration of hospitalisation was longer in patients with seizures due to other viral RTIs (p=0.023). There was no significant difference regarding severity markers of seizures between the two groups. CONCLUSIONS: CNS disease and the omicron period were risk factors for seizures in patients with SARS-CoV-2, who were older than patients with other RTIs. The severity of seizures was comparable between the two groups; hospitalisation was however longer in patients with other RTIs.

Human bocavirus 1 epidemiology in children in relation to virus load and codetection.

AIM: Human bocavirus 1 (HBoV1) has been associated with respiratory tract infections in children. We aimed at retrospectively describing patient characteristics, seasonality, pre-existing medical conditions, codetections, clinical manifestations and complications of HBoV1 infection in relation to viral load in the child population in Stockholm, with the overarching aim of elucidating the clinical significance of HBoV1. METHODS: We included all hospitalised children 0-17 years testing positive for HBoV1 by real-time polymerase chain reaction on nasopharyngeal aspirates 1 July 2008-30 June 2019. Patients with HBoV1 single detection, high viral load expressed as an HBoV1-DNA cycle threshold (Ct) < 25, or both, were separately analysed. We retrieved information on pre-existing conditions and clinical course from the medical records. RESULTS: We found 768 episodes in 727 children, 496 (64.6%) male and 441 (60.7%) previously healthy. The median age was 17.6 months. Most (476/768, 62.0%) episodes occurred during December-March. HBoV1 was in 549 episodes (71.5%) codetected with other viruses. Ct < 25 was independently associated with young age, single detection of HBoV1 and presentation early in the epidemic season. We saw few differences in clinical manifestations between the subgroups. CONCLUSION: Our findings are consistent with primary HBoV1 infection causing mild-to-severe respiratory tract manifestations in young children.

Reduction of rotavirus as a cause of nosocomial diarrhoea in northern Stockholm after introducing the rotavirus vaccine.

Background: Vaccination against rotavirus was offered in Stockholm to children born on 1 March 2014 and onwards with 85% coverage after two years. We investigated changes in nosocomial diarrhoea 2010-2018 in children admitted to Astrid Lindgren Children's Hospital, Stockholm, Sweden. Methods: We retrospectively identified cases from diagnostic and virology department registers. Complications and chronic medical conditions were retrieved from the case records. Children <18 years of age who developed diarrhoea ≥48 h after admission for another diagnosis and had a faecal sample submitted to the virology department were included. Results: There were 474 episodes of nosocomial diarrhoea. Of these, 401 (85%) occurred in children with chronic medical conditions. In children <5 years the rates of nosocomial rotavirus gastroenteritis, with 95% confidence intervals, significantly decreased from 0.34 (0.25-0.45) per 100 admissions prevaccination to 0.09 (0.04-0.17) postvaccination and from 0,66 (0.48-0.88) to 0.16 (0.07-0.30) cases per 1000 hospital days. Postvaccination norovirus became the most frequent pathogen. Virus-positive cases were more common in young children and in winter months. Conclusions: Before the initiation of rotavirus vaccination, norovirus and rotavirus were equally common causes of nosocomial diarrhoea. Postvaccination, rotavirus was reduced by approximately 75% while the frequency of other viruses did not change.

All-cause gastroenteritis hospitalisations of children decreased after the introduction of rotavirus vaccine in Stockholm.

BACKGROUND: In Stockholm, Sweden, rotavirus vaccination was offered to children born after 1 March 2014. Our aim was to describe rates of hospitalisation due to community-acquired gastroenteritis before and after the introduction of the vaccine, and aetiology, underlying medical conditions and complications in admitted children. METHODS: We retrospectively included patients from our catchment area hospitalised with a diagnosis of gastroenteritis during ten infection seasons 2008/2009-2017/2018, whereof six seasons prevaccination and four seasons postvaccination. We studied virus detection data and the patients' medical records. RESULTS: We included 3718 episodes in 3513 children. In 2967 (80%), stools were tested with virus isolation, ELISA, PCR, or bacterial culture; 479 (16%) tested negative. The incidence rates, with 95% confidence intervals, for children <5 years hospitalised for rotavirus gastroenteritis were 2.9 (2.8-3.1) per 1000 person-years prevaccination and 0.65 (0.56-0.74) postvaccination, for a rate ratio (RR) of 0.22 (0.19-0.26, p < .001). The rates for all-cause gastroenteritis were 5.6 (5.4-5.9) prevaccination and 2.5 (2.3-2.7) postvaccination, RR 0.45 (0.42-0.50, p < .001). In 5-17-year-old children norovirus dominated with little change over time. Of patients <5 years, those with underlying conditions constituted a larger proportion postvaccination than prevaccination (30.7% vs. 24.2%, p < .001). A complication other than dehydration, most commonly seizures, arose in 8.8% of the patients <5 years prevaccination and 11.4% postvaccination (p < .05). CONCLUSIONS: Rotavirus vaccination reduced the number of children <5 years requiring hospital care for gastroenteritis. We saw no replacement of rotavirus by other viruses.

A Swedish population-based study of complications due to acute rhinosinusitis in children 5-18 years old.

BACKGROUND: There are few population-based studies of complications due to acute rhinosinusitis in children. The aim was to clarify the admission and complication rate and analyze bacterial cultures in children five to 18 years old in Stockholm, Sweden. METHODS: This was a population-based observational cohort study with retrospectively collected data from individual medical records, from 1 July 2003 to 30 June 2016 in Stockholm, Sweden. Hospital admissions of children with a discharge diagnosis of rhinosinusitis and related complications were reviewed. RESULTS: Incidence of admission due to acute rhinosinusitis was 7.8 per 100 000 children per year (boys 9.2, girls 6.2) and 61% of the admitted children were boys. A severe - postseptal orbital, intracranial or osseous - complication, was present in 34% of admissions (postseptal orbital 28%, intracranial 6%, osseous 4%), resulting in an incidence of 2.6 severe complications per 100 000 children per year (boys 3.6, girls 1.6). Orbital preseptal cellulitis was present in 88% of admissions. Incidence of surgery was 1.3 per 100 000 per year (boys 1.8, girls 0.8) and the percentage of admitted children that had surgery increased with age. S. pyogenes was the most common pathogen found in the whole cohort (29 admissions), while S. milleri was the most common pathogen found among the children with severe complication and surgery. CONCLUSIONS: There is a relative high risk of severe complications in children between five to 18 years that are admitted due to acute rhinosinusitis. There is a need for prospective studies to further analyze the pathogens involved in complications due to acute rhinosinusitis.

Children hospitalised with four common viral diseases showed epidemiological differences but few socio-economic variations.

AIM: This study explored the differences in demographic and socio-economic factors between children hospitalised due to four common viral infections. METHODS: Demographic data were obtained from Statistics Sweden on >3000 children admitted to Astrid Lindgren Children's Hospital in 2009-2014 with rotavirus, influenza, respiratory syncytial virus (RSV) or chickenpox. We compared demographic and socio-economic factors between case groups using logistic regression with rotavirus cases as reference. RESULTS: There were differences in the median age at admission; RSV cases were younger (0.4 years), influenza (2.4 years) and chickenpox cases (2.7 years) older than rotavirus cases (1.2 years). RSV, influenza and chickenpox cases lived in families with more children than rotavirus cases. RSV and influenza cases were more likely to have underlying chronic conditions. Mothers of RSV cases were more likely to be born in Sweden. Further socio-economic differences were not robustly confirmed in sensitivity analyses. CONCLUSION: We found a few differences in demographic factors between children hospitalised with the four common infections, which were mainly explained by the epidemiology and transmission patterns of these infections.

Rates and risk factors of severe respiratory syncytial virus infection in 2008-2016 compared with 1986-1998.

AIM: Since the introduction in 1979 of rapid testing using immunofluorescence, we have collected information about children hospitalised for confirmed respiratory syncytial virus (RSV) infection in the northern Stockholm area. We here report hospitalisation rates, risk factors and complications in 2008-2016 compared with 1986-1998. METHODS: Microbiological laboratory reports and retrospective chart review. Comparison of the two periods was complicated by changing testing routines, with a more sensitive method and increased testing of older children in the late period. RESULTS: In infants, there was an 12.3% increase in the population-based rate of hospital admission for RSV infection from 12.2 to 13.7/1000. Including all children <5 years, there was a 48% increase from 2.7 to 4.0/1000. The median length of stay remained unchanged at 3 days. The need of intensive care decreased in healthy infants but remained high in older children with comorbidity. CONCLUSION: Considering the changed diagnosis routines, we believe that the rate of hospital admission of infants for RSV infection was unchanged throughout the observed years. The increased rates of older children with confirmed RSV likely resulted from increased testing of children with risk factors for a complicated course.

Acute infection as cause of hospitalization of asylum-seeking children and adolescents in Stockholm, Sweden 2015-2016.

We aimed to identify hospitalizations due to infectious diseases among asylum seekers and compare them to those of the resident population 1.6.2015-31.10.2016. Administrative numbers assigned to hospitalized non-resident children made them identifiable in the discharge register. The examined populations, expressed as person-years, were 334,573 residents and 7565 asylum seekers. There were 2500 episodes of infectious disease in 2240 resident children and 139 episodes in 121 asylum seekers. Among prevalent infections contracted before or during migration, there were 33 cases of tuberculosis, four of malaria, and one of louse-borne relapsing fever, all of which occurred in 13-17-year-old unaccompanied minors. Among younger asylum seekers, there were no significant differences in the spectrum of infectious discharge diagnoses compared to residents, but across all incident infections, 0-6-year-old asylum seekers had 3.2-fold and 7-12-year-old a 4.7-fold greater risk of being admitted. Screening for multidrug-resistant bacteria showed that 45/160 (28%) of the asylum seekers were colonized, but clinical infections caused by these species were rare.Conclusion: There was a high rate of hospitalizations for acute infectious diseases in asylum-seeking children, but the spectrum and severity of infections were similar to that in resident children. What is known: • Mental and physical health problems are common in immigrant children and adolescents. What is new: • Hospitalizations due to acute infections in asylum-seeking children and adolescents are common. In the context of this study, the severity and spectrum of infectious diseases seemed to be the same in the two groups; the increased hospitalization rate in asylum seekers may be due to social factors and perceived need for more support.

Trends of Pediatric Bloodstream Infections in Stockholm, Sweden: A 20-year Retrospective Study.

BACKGROUND: The etiology of bloodstream infections (BSIs) changes over time due to updated immunization programs, new antibiotic-use strategies, changes in patient mix and travel. Continuous surveillance can guide empiric therapy and identify targets for prevention. METHOD: We conducted a descriptive retrospective analysis among children <18 years of age who were detected with BSI between July 1998 and June 2018 for changes in the incidence, risk factors, and etiology of BSI in a Swedish tertiary hospital (Karolinska University Hospital). RESULTS: We evaluated 2079 episodes of BSI. During the study period, the incidence of BSI in children 0-17 years of age decreased (τ = -0.45, P = 0.016), which was most evident among children 3 months to 2 years of age (τ = -0.59, P = 0.0006) and in early neonatal period (0-7 days; τ = -0.44, P = 0.0069). These were explained by the reduced occurrence of Streptococcus pneumoniae in children 3 months to 2 years of age and Streptococcus agalactiae and Candida spp. in neonates. Staphylococcus aureus was the commonest pathogen, accounting for 31.6% of episodes. The proportion of hospital-acquired infection was higher in patients with underlying risk factors (47.6% vs. 2.6%). The etiology of hospital-acquired infection BSI was more diverse than that of community-acquired infections and was related to underlying risk factors. The crude mortality rate was 5.7%. For children admitted to the neonatal ward, the mortality was 17.6%, but declined (τ = -0.469, P = 0.004) over the study period. CONCLUSIONS: There was a decreasing trend of pediatric BSI and mortality over last 20 years, which was associated with pneumococcal immunization and antimicrobial prophylaxis for high-risk patients.

A 10-year retrospective survey of acute childhood osteomyelitis in Stockholm, Sweden.

AIM: Children with osteomyelitis present with a range of signs and symptoms and with varying degree of severity. The purpose of this study was to provide data on a population-based 10-year material of children with acute osteomyelitis. METHODS: All children, 0-14 years in Stockholm Region with acute osteomyelitis hospitalised in July 2005-June 2015, were retrospectively studied. Time to hospital presentation, disease localization, inflammation markers, imaging procedures, microbiology, severity classified by the presence of complications, surgical procedures, hospital length of stay and seasonal variation were recorded. RESULTS: There were 430 children with acute osteomyelitis; 61% were boys. The incidence per 100 000 person-years was 11.6; 9.3 in girls and 13.1 in boys. Median age at admission was 2.9 years with no peak later in childhood. Median time from first symptom to diagnosis was 4 days (range 1-21) and 48% of the cases were localised to femur or tibia. Mean C-reactive protein was 59 mg/L (range 1-376). Blood (n = 82) or tissue cultures (n = 54) were positive in 118 (28%) children. The most common pathogen was Staphylococcus aureus (n = 88) followed by Streptococcus pyogenes (n = 12). Surgery was performed in 71 children (17%). There was no mortality. Severe complications were seen in 14 (3.3%) children, five of whom were admitted to intensive care. Median hospital length of stay was 4 days (range 1-60). CONCLUSIONS: Osteomyelitis in children is a diagnostic challenge with a low yield of positive bacterial cultures. Few children with uncomplicated disease need surgery, but the risk of severe complications is not negligible.

Foreign background and older age of children were associated with infection in Swedish tuberculosis contacts.

AIM: We present our results using interferon-gamma release assays in any child <18 years or tuberculin skin tests in Bacille Calmette-Guérin unvaccinated children for tuberculosis contact investigation in Stockholm, Sweden. METHODS: During 2000-2019, we investigated 892 children with a median age of seven years. We explored associations between TB infection and characteristics such as closeness to contact, age, sex, BCG status and foreign origin. RESULTS: The overall rates were for TB infection 10.2% (n = 91) and for TB disease 1.1% (n = 10). In addition to infectiousness of index case and closeness of contact, foreign background, male sex and increasing age were independently associated with infection. In foreign-born children, the rates of tuberculosis infection and disease were 18.7% and 3.9%, respectively. In 18/46 (39%) infected foreign-born children, a baseline negative tuberculosis test supported a diagnosis of recent infection. CONCLUSION: Foreign background, older age and male sex were associated with infection. In a significant proportion of infected children, a previous negative test made recent infection likely.

Antimicrobial Use in a Swedish Pediatric Hospital: Results From Eight Point-prevalence Surveys Over a 15-Year Period (2003-2017).

BACKGROUND: Antimicrobial resistance is increasing, and data on antimicrobial use in Swedish children are limited. We evaluated trends in antimicrobial use and attempted to identify targets for improving the quality of antimicrobial prescribing in a tertiary care center. METHODS: One-day hospital-wide point prevalence surveys were conducted 8 times during 2003-2017 at Astrid Lindgren Children's Hospital. Children <17 years old were included. Medical records were evaluated for risk factors, indications for treatment, and antibiotic agents used. RESULTS: Among 946 admitted patients, 36% (336/946) received antimicrobial treatment. The total number of prescriptions increased (P = 0.031), but the proportion of patients treated remained unchanged. The proportion of patients receiving prophylactic treatment increased from 11% to 43% (P = 0.005). The rate of hospital-acquired infections remained unchanged. The primary indication for antimicrobial therapy was sepsis, fever of unknown origin, or fever in neutropenia, followed by intra-abdominal infections and pneumonia. The most frequently used antibiotics were cephalosporins, but consumption decreased, and in 2017 piperacillin-tazobactam was the most frequently used. Antimicrobial use was generally appropriate, although guidelines were often missing. The number of pediatric hospital beds decreased, and the bed occupancy was 71% (101/142) in 2003 and 121% (110/91) in 2017. The patient mix changed toward more patients with underlying risk factors for infectious diseases. CONCLUSIONS: Antimicrobial use changed during the study period, mainly due to increased prophylactic use in at-risk patients. Antimicrobial stewardship programs including infection control interventions and increasing the availability of guidelines may reduce and improve antimicrobial therapy.

Long-term Prognosis of Tuberculosis Infection and Disease in Swedish Children.

BACKGROUND: Reports of the outcome of treatment of tuberculosis (TB) disease and infection (TBI) in children are scarce. Since 2010, we routinely use interferon-gamma release assays in addition to clinical history for the exclusion of TBI, although the safety of this approach has been questioned. We present the frequency of recurrent TB or progression to TB after treatment for TB disease or TB infection, respectively, and progression to disease in children considered TB uninfected at our pediatric TB clinic. METHODS: We included 4707 patients from 1990 to 2017. At the initial assessment, 96 (2.0%) had previously received TB treatment, 253 (5.4%) had TB disease, 1625 (35%) had TBI and 2733 (58%) children were considered uninfected. Patients were passively followed at our clinic, at the adult TB clinics in Stockholm and at the Swedish national TB registry. RESULTS: During a median follow-up time of 8.4 years, we found 36 cases of TB disease, with true relapses in 3/243 (1.2%) successfully treated TB patients. Preventive treatment of TBI reduced the risk of progression to TB by 85%, from 4.3% (15/349) to 0.6% (8/1262). In children considered uninfected, the risk of later developing TB was 0.07% (2/2733). CONCLUSIONS: The effectiveness of TB management was acceptable. Our routine procedures for the exclusion of TBI appear safe.

Effective Tuberculosis Contact Investigation Using Interferon-Gamma Release Assays.

During 2000 to 2018, 1831 children were screened as part of tuberculosis contact investigation at the Stockholm Northern Clinic. The risk of a child having a positive tuberculin skin test was 33% and positive interferon-gamma release assay 12%. The risk of tuberculosis disease was 6.1% (tuberculin skin test) and 13% (interferon-gamma release assay) in positive-testing children.

Impact on affected families and society of severe rotavirus infections in Swedish children assessed in a prospective cohort study.

BACKGROUND: Few prospective cohort studies have estimated the overall impact of severe rotavirus gastroenteritis (RVGE) leading to hospitalization on families and society. We assessed human and economic resources needed to care for an affected average child aged <5 years in Sweden. METHODS: The study was conducted in Astrid Lindgren Children's Hospital which serves approximately 14% of all Swedish children <5 years of age. All children admitted with acute gastroenteritis in the study period were tested for rotavirus. Health care consumption was collected prospectively and publically available unit costs used to calculate direct costs. Non-medical and indirect costs were collected in interviews with families using a standardized questionnaire during the hospital stay and approximately 14 days post-discharge. RESULTS: 144/206 children (70%) with laboratory-confirmed RVGE were included. The median age was 14 months. The average total cost per hospitalized child was €3894, of which €2169 (56%) was due to direct healthcare-related costs (including Emergency Department visits and in-patient care), €104 (2%) to non-medical direct costs and €1621 (42%) to indirect costs due to productivity loss. Carers of children with severe RVGE were absent from work on average five days per study child: four days during hospitalization of affected child and one day due to gastroenteritis in the carer. CONCLUSIONS: Costs for RVGE are dominated by direct costs which are similar to some other countries in Europe, but indirect costs due to productivity loss are also important, and should be considered in decisions to introduce rotavirus vaccines into national vaccination programmes.

Changing diagnosis coding routines may confound the results of longitudinal childhood pneumonia studies.

AIM: This Swedish study compared the discharge diagnosis codes used for children up to the age of five hospitalised for acute lower respiratory tract infections before and after the introduction of the pneumococcal conjugate vaccine in 2007. METHODS: The International Classification of Diseases-10th revision codes were used. We compared the discharge diagnosis codes at the Astrid Lindgren Children's Hospital from 1 July 2005 to 30 June 2007 (n=1,127) and 1 July 2011 to 30 June 2013 (n=1,240) in relation to the diagnostic methods used. RESULTS: There was a 54% reduction in the rate of all-cause pneumonia from the first to the second period in children aged 0-1 years, but some of this could have been due to the improved diagnosis of viral infections and us changing the code for respiratory syncytial virus infection from pneumonia to bronchiolitis. The overall rate of acute lower respiratory tract infections was unchanged. CONCLUSION: We could not determine how much of the reduction in bacterial pneumonia in children under one was because of the introduction of the pneumococcal conjugate vaccine, based solely on discharge codes. Longitudinal register studies should take changes in diagnosis codes into account.

Tuberculosis infection and disease in the 2015 cohort of unaccompanied minors seeking asylum in Northern Stockholm, Sweden.

BACKGROUND: Minors with a stated age <18 years unaccompanied by a responsible adult form an increasing part of refugees to Europe. They are older than other asylum-seeking children and many come from countries with a high tuberculosis (TB) incidence. During the 2015 refugee crisis, 35,369 of 162,877 refugees (22%) seeking asylum in Sweden were unaccompanied minors, which gave us the opportunity to study their burden of TB infection and disease. METHODS: Of the unaccompanied minors seeking asylum in Sweden during 2015, 2936 (8.3%) were allocated to northern Stockholm. Of these, 2422 were from countries with an incidence of TB exceeding 100/105, and were screened for TB infection with a Mantoux tuberculin skin test or a QuantiFERON-TB Gold®. Those from countries with a lower TB incidence were screened only if they had other risk factors for TB exposure. RESULTS: Of those screened, 349 had a positive test and were referred to the northern paediatric TB clinic at Astrid Lindgren Children's Hospital. Of these, 16 had TB disease and 278 latent tuberculosis infection (LTBI), while we considered 53 uninfected. In addition, eight sought medical attention with symptomatic TB outside the screening system. Cohort rates were 6.8% of LTBI and 0.5% of TB in minors from Afghanistan and 26-32% of LTBI and 3.4-3.5% of TB among those from Eritrea, Ethiopia or Somalia. CONCLUSION: We conclude that TB infection and disease is common among asylum-seeking unaccompanied minors, especially among those from the Horn of Africa.