Search

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., (© 2024 The Authors. Acta Paediatrica published by John Wiley & Sons Ltd on behalf of Foundation Acta Paediatrica.)

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., (© 2024 The Authors. Acta Paediatrica published by John Wiley & Sons Ltd on behalf of Foundation Acta Paediatrica.)

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., (© 2023 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)

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., (© 2021 The Authors. Acta Paediatrica published by John Wiley & Sons Ltd on behalf of Foundation Acta Paediatrica.)

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., (© 2020 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)

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., (© 2020 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)

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., (©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)

Aim: Encephalitis is a rare, serious condition, and antiviral therapies, increased knowledge of inflammatory pathways and improved diagnostics have increased the therapeutic possibilities. We describe 40 years of childhood encephalitis in Sweden, covering the diagnostics, aetiology and outcomes., Methods: We reviewed the clinical data that were available for all children discharged from the Karolinska University Hospital in Stockholm following treatment for encephalitis from 1970 to 2009. The hospital treated all children in the region with the condition during the study period., Results: There were 408 episodes of encephalitis from 1970 to 2009 and the incidence was similar over the whole period, ranging from 6.4 to 8.7 per 100 000 child years. Although mortality markedly decreased from 10% in the first decade to zero in the last decade, and aetiologies shifted, no clear long-term improvements in outcome were seen. The need for intensive care was unchanged (18-20%) for each of the study intervals, possibly indicating that the severity of cases remained unaltered., Conclusion: Understanding the pathophysiological mechanisms of encephalitis is vitally important for developing more efficient treatment regimens. As well as reporting the results of this 40-year study, this study considers possible explanations, addresses current therapeutic options and explores directions for central nervous system infection research., (©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)

Aim: This study described the epidemiology and clinical features of childhood tuberculosis (TB) in Stockholm over a 45-year period, when there was a resurge of tuberculosis concomitant with increased immigration., Methods: We describe 220 children up to the age of 16 years with active TB, seen at the Astrid Lindgren Children's Hospital from 1971 to 2015. The study period was divided into three 15-year periods., Results: Cases increased from ten children in 1971-1985 to 76 in 1986-2000 and 134 in 2001-2015, with overall incidence increasing from <1 to four per 100 000. From 2001 to 2015, 79% of cases, or at least one parent, were born in high-incidence countries. The incidence in this group was 35 per 100 000, but remained at 0.9 per 100 000 in other children. After 2000, most cases were detected by active contact tracing and immigrant screening. The most common manifestation was from the lungs. Meningitis and miliary tuberculosis were found in 7%, with two deaths. Antimicrobial resistance was an increasing problem., Conclusion: The increasing incidence of TB in Stockholm was largely limited to children with a background in high-incidence countries. Most children today have subclinical forms of TB. Although preventive measures are effective, severe cases still occur, especially among adolescent immigrants., (©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)

Aim: Increasing numbers of migrants to Sweden are screened for tuberculosis (TB), and a rational approach to screening is required. We evaluated positive tuberculin skin tests (TSTs) and interferon-gamma release assays (IGRAs) on paediatric migrants in relation to the TB incidence in the corresponding foreign-born populations in Stockholm., Methods: This study examined the characteristics of migrants under the age of 18 who were referred to a paediatric TB clinic at Karolinska University Hospital from 2008 to 2014 by primary care centres in Stockholm County., Results: We saw 943 TST-positive children with a median age of 14 years at the TB clinic and performed IGRAs on 557. IGRA positivity ranged from 64% in migrants from Somalia to 20% in those from the former Soviet Union and eastern Europe, with an estimated population level prevalence of 18.8% and 4.2%, respectively. These were significantly correlated to TB incidence in foreign-born Stockholm children. We diagnosed active TB in 20 screened migrants, and advanced, symptomatic TB was diagnosed in 10 recently arrived migrants without screening., Conclusion: IGRAs showed higher specificity than TST in identifying tuberculosis. TB screening should focus on migrants from high-incidence countries, but this may be inadequate to detect advanced TB cases., (©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)

Aim: This study explored the incidence and aetiology of bloodstream infections after patients received the pneumococcal conjugate vaccination and a risk-based intrapartum antibiotic prophylaxis against early onset sepsis caused by group B streptococcus. We also monitored clinically relevant antimicrobial resistance., Method: We studied 3986 positive blood cultures from children up to 17 years of age at a paediatric hospital in Stockholm, Sweden, using data from medical records before and after the initiatives, to reduce early onset sepsis, were introduced in 2007 and 2008., Results: Bloodstream infections caused by Streptococcus pneumoniae declined by 42% overall (5.6 to 3.2/100 000) and by 62% in previously healthy children under 36 months of age (24.2 to 9.2/100 000). Early onset sepsis caused by group B streptococcus declined by 60% (0.5 to 0.2/1000 live born children). Bacterial meningitis caused by these bacteria decreased by 70%. Staphylococcus aureus and various Gram-negative bacteria became the dominant pathogens, in both previously healthy children and those with underlying disease. Overall, antimicrobial resistance remained low between the two 5-year study periods., Conclusion: Pneumococcal conjugate vaccination and risk-based intrapartum antibiotic prophylaxis against group B streptococcus effectively decreased the incidence of bloodstream infections. Empirical antibiotic therapy should target Staphylococcus aureus in both community and hospital-acquired invasive bacterial infections., (©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)

Aim: To study the aetiology of bloodstream infections (BSI) in children 0-17 years, the influence of age and underlying co-morbidity on BSI rate, distribution of pathogens and outcome; and to provide data on antimicrobial susceptibility patterns., Methods: A retrospective population-based study. Data on blood cultures were collected at yearly intervals during 1998-2008. Information about risk factors, focal infection and outcome was retrieved from the patient charts., Results: We identified 1097 BSI. The incidence of BSI was 0.4/1000. The age-specific incidence was 2.3/1000 in neonates (0-28 days old) and 0.2/1000 in the age group 6-17 years. Staphylococcus aureus was the most common pathogen. The number of species causing BSI in previously healthy children was lower compared with children with co-morbidity. Most children requiring intensive care had a serious underlying illness. Antimicrobial resistance was rare and did not influence outcome. The case-fatality rate was 14.4% in neonates, 5.4% in children with co-morbidity and 1.7% in previously healthy children., Conclusion: Mortality from BSI is low, and a limited spectrum of pathogens is isolated from previously healthy children compared with children with co-morbidity. When choosing empirical therapy for suspected BSI, age and presence of risk factors should be taken into account., (©2012 The Author(s)/Acta Paediatrica ©2012 Foundation Acta Paediatrica.)

Aim: To present our experience of nerve dysfunction following surgical treatment among 126 children with microbiologically verified non-tuberculous mycobacterial (NTM) lymphadenitis., Methods: We retrieved data from medical records, and a questionnaire with an invitation to a clinical follow-up was returned by 88 families., Results: The time from onset of symptoms to diagnosis was more than 3 months in 24% of subjects. Mycobacterium avium complex was isolated from 105, Mycobacterium malmoense from 12 and Mycobacterium scrofulaceum from one cervical lymph node. A total of 89% of the children underwent surgery and were examined in particular with regard to cranial motor nerve functions. Major persisting nerve dysfunction occurred in 3/51 (6%) children who underwent radical surgery, and minor dysfunction in seven (14%). In nine children, the marginal mandibular branch of the facial nerve was affected, and the accessory nerve was affected in one child. There were no neurological signs in 25 children treated with incision and drainage alone or in 12 followed with observation alone. Healing took >6 months in 2/76 (3%) surgically treated and 3/12 (25%) non-surgically treated children., Conclusion: Considering the risk of nerve dysfunction following extirpation, incision with drainage and observation alone should both be included among the management options for cervical NTM lymphadenitis in children., (© 2010 The Author(s)/Acta Paediatrica © 2010 Foundation Acta Paediatrica.)