Group A streptococcal disease in paediatric inpatients: a European perspective

Complicated pneumonia caused by group A Streptococcus in children - 2022/2023 infectious season outbreak and update on clinical characteristics

BACKGROUND

An increased incidence of group A Streptococcus (GAS) infections has been observed in pediatric population post-COVID-19 pandemic. While the majority of reports refer to scarlet fever or invasive GAS disease, detailed data on pulmonary manifestations such as complicated community-acquired pneumonia (CAP) are scarce. The aim of this study was to assess the contribution of GAS to complicated CAP in children during the 2022/2023 infectious season.

METHODS

We retrospectively analyzed the etiology and clinical presentation of complicated CAP patients hospitalized in our tertiary care center in Warsaw, Poland, between August 2022 and May 2023.

RESULTS

Among 91 patients with complicated CAP, GAS was the dominant cause constituting 24.2% (22/91; 95% CI 15.8-34.3%) of the study group. 68.2% of GAS pneumonia patients presented symptoms of scarlet fever, and 27.3% had preceding or concurrent viral infection. GAS complicated CAP was associated with longer hospitalization, higher incidence of chest tube insertion, but shorter duration of chest tube drainage than complicated CAP of other etiology. Children with GAS complicated CAP had higher procalcitonin concentration (28.1 vs. 1.5 ng/dL; p<0.0001) and a lower platelets level (254.5 vs. 422 × 103/μL; p = 0.0031) than those with non-GAS infection.

CONCLUSIONS

GAS is currently the predominant pathogen of complicated CAP in children. Clinicians should be aware of the current epidemiological situation and a more severe course of GAS pneumonia in this age group, and should monitor patients presenting with symptoms of scarlet fever and preceding viral infection closely.

Clinical, microbiological, and molecular characterization of pediatric invasive infections by Streptococcus pyogenes in Spain in a context of global outbreak

In December 2022, an alert was published in the UK and other European countries reporting an unusual increase in the incidence of Streptococcus pyogenes infections. Our aim was to describe the clinical, microbiological, and molecular characteristics of group A Streptococcus invasive infections (iGAS) in children prospectively recruited in Spain (September 2022-March 2023), and compare invasive strains with strains causing mild infections. One hundred thirty isolates of S. pyogenes causing infection (102 iGAS and 28 mild infections) were included in the microbiological study: emm typing, antimicrobial susceptibility testing, and sequencing for core genome multilocus sequence typing (cgMLST), resistome, and virulome analysis. Clinical data were available from 93 cases and 21 controls. Pneumonia was the most frequent clinical syndrome (41/93; 44.1%), followed by deep tissue abscesses (23/93; 24.7%), and osteoarticular infections (11/93; 11.8%). Forty-six of 93 cases (49.5%) required admission to the pediatric intensive care unit. iGAS isolates mainly belonged to emm1 and emm12; emm12 predominated in 2022 but was surpassed by emm1 in 2023. Spread of M1UK sublineage (28/64 M1 isolates) was communicated for the first time in Spain, but it did not replace the still predominant sublineage M1global (36/64). Furthermore, a difference in emm types compared with the mild cases was observed with predominance of emm1, but also important representativeness of emm12 and emm89 isolates. Pneumonia, the most frequent and severe iGAS diagnosed, was associated with the speA gene, while the ssa superantigen was associated with milder cases. iGAS isolates were mainly susceptible to antimicrobials. cgMLST showed five major clusters: ST28-ST1357/emm1, ST36-ST425/emm12, ST242/emm12.37, ST39/emm4, and ST101-ST1295/emm89 isolates.

IMPORTANCE

Group A Streptococcus (GAS) is a common bacterial pathogen in the pediatric population. In the last months of 2022, an unusual increase in GAS infections was detected in various countries. Certain strains were overrepresented, although the cause of this raise is not clear. In Spain, a significant increase in mild and severe cases was also observed; this study evaluates the clinical characteristics and the strains involved in both scenarios. Our study showed that the increase in incidence did not correlate with an increase in resistance or with an emm types shift. However, there seemed to be a rise in severity, partly related to a greater rate of pneumonia cases. These findings suggest a general increase in iGAS that highlights the need for surveillance. The introduction of whole genome sequencing in the diagnosis and surveillance of iGAS may improve the understanding of antibiotic resistance, virulence, and clones, facilitating its control and personalized treatment.

Invasive group A streptococcal infections in children and adolescents in Denmark during 2022-23 compared with 2016-17 to 2021-22: a nationwide, multicentre, population-based cohort study

BACKGROUND

A historic increase in paediatric invasive group A streptococcal (iGAS) infections was reported globally in 2022. iGAS infections can lead to severe manifestations (eg, pleural empyema, necrotising fasciitis, toxic shock syndrome, osteomyelitis, septic arthritis, and meningitis). We aimed to compare the incidence and severity of iGAS infections overall, for distinct clinical phenotypes, and for GAS emm variants in Denmark in 2022-23 with reference to the previous six seasons (ie, 2016-17, 2017-18, 2018-19, 2019-20, 2020-21, and 2021-22).

METHODS

In this nationwide, multicentre, population-based cohort study, we included all children and adolescents in Denmark aged 0-17 years with a positive culture of GAS or GAS confirmed through PCR-based methods from otherwise sterile sites in 2022-23 and the previous six seasons from 2016-17 to 2021-22. For all seven seasons, data were obtained from week 21 to week 20 of the next year. Patients at all 18 paediatric hospital departments in Denmark were identified through the Danish Microbiology Database, in which iGAS isolates from sterile sites are prospectively registered, including emm typing. We obtained electronic medical health records for each patient admitted with a diagnosis of iGAS. We calculated the incidence of iGAS per 1 000 000 inhabitants aged 0-17 years in each season from week 21 to week 20 of the next year and the risk ratios (RRs) for incidence of iGAS, distinct disease manifestations, and emm variants in 2022-23 versus the three pre-COVID-19 seasons in 2016-17, 2017-18, and 2018-19 using Fisher's exact test and Pearson's χ2 test.

FINDINGS

Among the Danish population of 1 152 000 children and adolescents aged 0-17 years, 174 with iGAS disease were included. 76 children and adolescents with iGAS during 2022-23 were identified; 31 (41%) of 76 were female and 45 (59%) were male. 98 children and adolescents with iGAS during 2016-17 to 2021-22 were identified; 41 (42%) of 98 were female and 57 (58%) were male. There was an increase in incidence of iGAS from mean 22·6 (95% CI 14·7-33·1) per 1 000 000 children and adolescents during 2016-17 to 2018-19 to 66·0 (52·0-82·6) per 1 000 000 during 2023-23 (RR 2·9, 95% CI 1·9-4·6; p<0·0001). During the COVID-19 pandemic in 2019-20, 2020-21, and 2021-22, the mean incidence of iGAS was 6·1 (95% CI 2·4-12·5) per 1 000 000 children and adolescents. In 2022-23, there was a 9·5-fold increase in emm-12 (95% CI 2·2-40·8; p=0·0002) and a 2·7-fold increase in emm-1 (1·3-5·5; p=0·0037). The most common clinical manifestations of iGAS in 2022-23 were soft-tissue infections, which increased by 4·5-fold (1·9-10·9; p=0·0003), and complicated pneumonia with parapneumonic effusion, which increased by 4·0-fold (1·4-11·4; p=0·0059), both compared with the three pre-COVID-19 seasons. Overall, there was no increased severity of iGAS in 2022-23 compared with the previous six seasons as measured by median duration of hospital stay (8 days, IQR 4-14 vs 9 days, 5-15; p=0·39), paediatric intensive care unit (PICU) admission (17 [22%] of 76 vs 17 [17%] of 98; p=0·53), duration of stay in PICU (4 days, IQR 2-10 vs 4 days, 2-11; p=0·84), or mortality (three [4%] of 76 vs three [3%] of 98; p=1·00). In 2022-23, there was a 3·6-fold (95% CI 1·8-7·3; p=0·0001) increase in children with a preceding upper respiratory tract infection and a 4·6-fold (1·5-14·1; p=0·0034) increase in children with a preceding varicella-zoster infection, both compared with the three pre-COVID-19 seasons.

INTERPRETATION

In Denmark, the incidence of paediatric iGAS increased in 2022-23 compared with the three pre-COVID-19 seasons of 2016-17, 2017-18, and 2018-19. However, the course of iGAS disease in children and adolescents in 2022-23 was not more severe than in previous seasons. The high morbidity across all seasons highlights iGAS as a major invasive bacterial infection in children and adolescents.

FUNDING

Innovation Fund Denmark.

Clinical and molecular epidemiological features of critically ill patients with invasive group A Streptococcus infections: a Belgian multicenter case-series

BACKGROUND

Recent alerts have highlighted an increase in group A streptococcal (GAS) infections since 2022 in Europe and the United States. Streptococcus pyogenes can cause limited skin or mucosal disease, but can also present as severe invasive disease necessitating critical care. We performed a multicenter retrospective study of patients with GAS infections recently admitted to Belgian intensive care units (ICUs) since January 2022. We describe patient characteristics and investigate the molecular epidemiology of the S. pyogenes strains involved.

RESULTS

Between January 2022 and May 2023, a total of 86 cases (56 adults, 30 children) with GAS disease were admitted to critical care in the university hospitals of Leuven, Antwerp and Liège. We noted a strikingly high incidence of severe community-acquired pneumonia (sCAP) (45% of adults, 77% of children) complicated with empyema in 45% and 83% of adult and pediatric cases, respectively. Two-thirds of patients with S. pyogenes pneumonia had viral co-infection, with influenza (13 adults, 5 children) predominating. Other disease presentations included necrotizing fasciitis (23% of adults), other severe skin/soft tissue infections (16% of adults, 13% of children) and ear/nose/throat infections (13% of adults, 13% of children). Cardiogenic shock was frequent (36% of adults, 20% of children). Fifty-six patients (65%) had toxic shock syndrome. Organ support requirements were high and included invasive mechanical ventilation (77% of adults, 50% of children), renal replacement therapy (29% of adults, 3% of children) and extracorporeal membrane oxygenation (20% of adults, 7% of children). Mortality was 21% in adults and 3% in children. Genomic analysis of S. pyogenes strains from 55 out of 86 patients showed a predominance of emm1 strains (73%), with a replacement of the M1global lineage by the toxigenic M1UK lineage (83% of emm1 strains were M1UK).

CONCLUSIONS

The recent rise of severe GAS infections (2022-23) is associated with introduction of the M1UK lineage in Belgium, but other factors may be at play-including intense circulation of respiratory viruses and potentially an immune debt after the COVID pandemic. Importantly, critical care physicians should include S. pyogenes as causative pathogen in the differential diagnosis of sCAP.

Invasive group A streptococcal infections requiring admission to ICU: a nationwide, multicenter, retrospective study (ISTRE study)

BACKGROUND

Group A Streptococcus is responsible for severe and potentially lethal invasive conditions requiring intensive care unit (ICU) admission, such as streptococcal toxic shock-like syndrome (STSS). A rebound of invasive group A streptococcal (iGAS) infection after COVID-19-associated barrier measures has been observed in children. Several intensivists of French adult ICUs have reported similar bedside impressions without objective data. We aimed to compare the incidence of iGAS infection before and after the COVID-19 pandemic, describe iGAS patients' characteristics, and determine ICU mortality associated factors.

METHODS

We performed a retrospective multicenter cohort study in 37 French ICUs, including all patients admitted for iGAS infections for two periods: two years before period (October 2018 to March 2019 and October 2019 to March 2020) and a one-year after period (October 2022 to March 2023) COVID-19 pandemic. iGAS infection was defined by Group A Streptococcus isolation from a normally sterile site. iGAS infections were identified using the International Classification of Diseases and confirmed with each center's microbiology laboratory databases. The incidence of iGAS infections was expressed in case rate.

RESULTS

Two hundred and twenty-two patients were admitted to ICU for iGAS infections: 73 before and 149 after COVID-19 pandemic. Their case rate during the period before and after COVID-19 pandemic was 205 and 949/100,000 ICU admissions, respectively (p < 0.001), with more frequent STSS after the COVID-19 pandemic (61% vs. 45%, p = 0.015). iGAS patients (n = 222) had a median SOFA score of 8 (5-13), invasive mechanical ventilation and norepinephrine in 61% and 74% of patients. ICU mortality in iGAS patients was 19% (14% before and 22% after COVID-19 pandemic; p = 0.135). In multivariate analysis, invasive mechanical ventilation (OR = 6.08 (1.71-21.60), p = 0.005), STSS (OR = 5.75 (1.71-19.22), p = 0.005), acute kidney injury (OR = 4.85 (1.05-22.42), p = 0.043), immunosuppression (OR = 4.02 (1.03-15.59), p = 0.044), and diabetes (OR = 3.92 (1.42-10.79), p = 0.008) were significantly associated with ICU mortality.

CONCLUSION

The incidence of iGAS infections requiring ICU admission increased by 4 to 5 after the COVID-19 pandemic. After the COVID-19 pandemic, the rate of STSS was higher, with no significant increase in ICU mortality rate.

Increased rates of invasive bacterial disease in late 2022

Invasive bacterial disease is associated with significant morbidity and mortality. In winter 2022, there was an apparent increased rate of invasive bacterial disease compared to preceding years. Cross-site retrospective analysis of the three Children's Health Ireland (CHI) hospitals looking at children admitted between 1st October 2022-31st December 2022 (Q4) with community-acquired invasive bacterial disease, defined as an abscess in a normally sterile site in the head, neck and chest or isolation or PCR detection of Streptococcus pneumoniae, Neisseria meningitidis, Streptococcus pyogenes (Group A streptococcus) or Haemophilus influenzae from a normally sterile site. Case numbers were compared to Q4 in each of 2018-2021. Eighty-two children met the case definition in Q4 2022 vs 97 (Q4 2018-2021). In 2022, 42/82 (51%) were female, median age 3.75 years (1.5-8.25 years). Only 2 (2%) were immunosuppressed and 2 others (2%) had underlying neurodisability. Fifty (61%) were admitted on second or subsequent presentation to a healthcare setting. Fifty-six (68%) had an abscess in a sterile site. Bloodstream infection (positive blood culture or PCR: 24 (29%)) was the most common site of infection, followed by neck 22 (27%) and intracranial 12 (15%). Group A streptococcus (GAS) 27 (33%) was the most common organism isolated. Seven cases (9%) died in 2022 compared to 2 patients (2%) from 2018 to 2021 (p < 0.05). More children had Paediatric Overall Performance Category (POPC) scores > 1 in 2022 than 2018-2021 (p = 0.003).  Conclusion: Invasive bacterial diseases increased in Q4 2022 with higher morbidity and mortality than in the preceding 4 years. Group A streptococcal infection was the most significant organism in 2022. What is known: • Invasive bacterial disease is the leading cause of childhood mortality globally. • There was an increase in cases of invasive Group A streptococcus infections reported in many countries (including Ireland) during the winter of 2022/23. What is new: • Head, neck and chest abscesses increased in Q4 of 2022 compared to the previous 4 years combined. • Invasive bacterial infections in Q4 of 2022 were associated with higher rates of mortality (9%), paediatric intensive care unit (PICU) admission (24%) and requirement for surgical drainage or intervention (67%) than in the preceding years.

Increase in Invasive Group a Streptococcal Infections in Children in the Netherlands, A Survey Among 7 Hospitals in 2022

Following an increase in notifiable invasive group A streptococcal (iGAS) infections in the Netherlands, we conducted a survey among 7 hospitals. Pediatric iGAS case numbers were 2-fold higher between July 2021 and June 2022 versus pre-COVID-19. A sharp increase occurred early 2022, most pronounced in <5 years old and for diagnoses empyema and necrotizing fasciitis. This recent pediatric iGAS surge warrants investigation and vigilance.