European Union's Seventh Framework programme.

Osteoarticular infections in paediatric patients are associated with significant morbidity. Pyogenic sacroiliitis is rare and accounts for approximately 1-2% of osteoarticular infections in children. Diagnosis of this disease has been difficult in the past due to its deep location and may be delayed due to the lack of specific clinical signs and symptoms. We identified 11 paediatric patients with clinical-radiological signs of pyogenic sacroiliitis during an 8-year period and observed an unusual cluster of four cases during the last 11 months. Early diagnosis was possible due to a reproducible clinical pattern as well as radiological evidences of infection using magnetic resonance imaging and/or bone scintigraphy; most patients having predisposing factors. Staphylococcus aureus was the sole causative agent identified. All patients including two children with associated muscle abscesses were managed conservatively with antibiotic therapy only and showed good clinical response with no sequelae during follow-up. An algorithm for the correct and prompt diagnosis of this pathology is proposed. Standardised optimal therapy remains to be defined.

Group A streptococcal (GAS) disease shows increasing incidence worldwide. We characterised children admitted with GAS infection to European hospitals and studied risk factors for severity and disability. This is a prospective, multicentre, cohort study (embedded in EUCLIDS and the Swiss Pediatric Sepsis Study) including 320 children, aged 1 month to 18 years, admitted with GAS infection to 41 hospitals in 6 European countries from 2012 to 2016. Demographic, clinical, microbiological and outcome data were collected. A total of 195 (61%) patients had sepsis. Two hundred thirty-six (74%) patients had GAS detected from a normally sterile site. The most common infection sites were the lower respiratory tract (LRTI) (22%), skin and soft tissue (SSTI) (23%) and bone and joint (19%). Compared to patients not admitted to PICU, patients admitted to PICU more commonly had LRTI (39 vs 8%), infection without a focus (22 vs 8%) and intracranial infection (9 vs 3%); less commonly had SSTI and bone and joint infections ( p < 0.001); and were younger (median 40 (IQR 21–83) vs 56 (IQR 36–85) months, p = 0.01). Six PICU patients (2%) died. Sequelae at discharge from hospital were largely limited to patients admitted to PICU (29 vs 3%, p < 0.001; 12% overall) and included neurodisability, amputation, skin grafts, hearing loss and need for surgery. More patients were recruited in winter and spring ( p < 0.001). Conclusion : In an era of observed marked reduction in vaccine-preventable infections, GAS infection requiring hospital admission is still associated with significant severe disease in younger children, and short- and long-term morbidity. Further advances are required in the prevention and early recognition of GAS disease. What is Known: • Despite temporal and geographical variability, there is an increase of incidence of infection with group A streptococci. However, data on the epidemiology of group A streptococcal infections in European children is limited. What is New: • In a large, prospective cohort of children with community-acquired bacterial infection requiring hospitalisation in Europe, GAS was the most frequent pathogen, with 12% disability at discharge, and 2% mortality in patients with GAS infection. • In children with GAS sepsis, IVIG was used in only 4.6% of patients and clindamycin in 29% of patients. Supplementary Information The online version contains supplementary material available at 10.1007/s00431-022-04718-y.

In the original published version of the above article, the names of members of the EUCLIDS consortium were not introduced in the authorship section. The names are now properly displayed.The original article has been corrected.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.