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.

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.

Outbreak of enterovirus D68 of the new B3 lineage in Stockholm, Sweden, August to September 2016.

We report an enterovirus D68 (EV-D68) outbreak in Stockholm Sweden in 2016. Between 22 August and 25 September EV-D68 was detected in 74/495 respiratory samples analysed at the Karolinska University Hospital. During the peak week, 30/91 (33%) samples were EV-D68 positive. Viral protein (VP)P4/VP2 sequencing revealed that cases were caused by B3 lineage strains. Forty-four (59%) EV-D68-positive patients were children aged ≤ 5 years. Ten patients had severe respiratory or neurological symptoms and one died.

The aetiology of paediatric bloodstream infections changes after pneumococcal vaccination and group B streptococcus prophylaxis.

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.

Clinical manifestations of invasive pneumococcal disease by vaccine and non-vaccine types.

Pneumococcal conjugated vaccines (PCVs) have shown protection against invasive pneumococcal disease by vaccine serotypes, but an increase in non-vaccine serotype disease has been observed. Type-specific effects on clinical manifestation need to be explored. Clinical data from 2096 adults and 192 children with invasive pneumococcal disease were correlated to pneumococcal molecular serotypes. Invasive disease potential for pneumococcal serotypes were calculated using 165 invasive and 550 carriage isolates from children. The invasive disease potential was lower for non-PCV13 compared to vaccine-type strains. Patients infected with non-PCV13 strains had more underlying diseases, were less likely to have pneumonia and, in adults, tended to have a higher mortality. Furthermore, patients infected with pneumococci belonging to clonal serotypes only expressing non-PCV13 capsules had a higher risk for septicaemia and mortality. PCV vaccination will probably lead to a decrease in invasive pneumococcal disease but an alteration in the clinical manifestation of invasive pneumococcal disease. Genetic lineages causing invasive pneumococcal disease in adults often express non-vaccine serotypes, which can expand after vaccination with an increased risk of infection in patients with underlying diseases.

Age and risk factors influence the microbial aetiology of bloodstream infection in children.

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.

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.

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.

Palivizumab prophylaxis and hospitalization for respiratory syncytial virus disease in the Stockholm infant population, 1999 through 2002.

BACKGROUND: There are few independent, population-based reports that estimate the risk of hospitalization of respiratory syncytial virus (RSV)-infected infants before and during the palivizumab era. We present figures from the greater Stockholm area during the three seasons after the introduction of palivizumab and relate them to data based on 1400 hospitalizations for RSV disease in the same population area during 1987 through 1998. METHODS: The number of births, neonatal complications and palivizumab prescriptions was obtained. We retrieved information about all infant hospitalizations for confirmed RSV infections with risk factors and complications. Chronic lung disease (CLD) in preterm infants was defined as oxygen dependency beyond 36 weeks of postconceptional age. RESULTS: Eight hundred eighteen infants (1.3% of the population) were hospitalized for confirmed RSV infection. The hospitalization rates were 3.7% (24 of 642) among preterm infants with gestational age <33 weeks without CLD and 7.2% (14 of 195) in those with CLD. Palivizumab had been given to 235 infants, usually those with CLD and in need of continuous oxygen or steroid treatment or the <6 month-old infants with extremely preterm birth (gestational age <26 weeks). The risk of hospitalization for RSV disease was low, but this was the case also before the introduction of palivizumab. CONCLUSIONS: In countries with a low baseline risk of hospitalization for RSV infection, the benefit of palivizumab might not justify the cost of its widespread use. We advocate defining more rigorous prescription criteria.