Paediatric invasive group A streptococcal infections and associations with viral infections in 15 European countries after lifting non-pharmaceutical interventions against SARS-CoV-2: an interrupted time-series analysis

Léa Lenglart; Izel Özmen; David Aguilera-Alonso; Daniel Blazquez-Gamero; Navin P Boeddha; Emilie Pauline Buddingh; Danilo Buonsenso; Cristina Calvo; Riccardo Castagnoli; Marta Daina; Maria-Myrto Dourdouna; Marieke Emonts; Carmen Ezinwoke; Catarina Gouveia; David Grandioso Vas; Jeroen Hol; Mette Holm; Christian R Kahlert; Benno Kohlmaier; Kamila Ludwikowska; Gian Luigi Marseglia; Andrew McArdle; Rachel McGalliard; Athanasios Michos; Anda Nagle; Anita Niederer-Loher; Ulrikka Nygaard; Rianne Oostenbrink; Tina Plankar Srovin; Sandrine Roisin; Jesús Saavedra-Lozano; Adriana Shan; Valtyr Stefansson Thors; Volker Strenger; Angeliki Syngelou; Anne Tilmanne; Monika Tokarczyk; Christo Tsilifis; Maria Tsolia; Adam Tulling; Evelien van Kempen; Mirjam Van Veen; Katarina Vincek; Ulrich Von Both; Dace Zavadska; Mohammed Zaman; Ruud G Nijman; Naim Ouldali; Dorine Borensztajn; PEGASUS Consortium

doi:10.1016/j.lanepe.2025.101497

Paediatric invasive group A streptococcal infections and associations with viral infections in 15 European countries after lifting non-pharmaceutical interventions against SARS-CoV-2: an interrupted time-series analysis

Léa Lenglart, Izel Özmen, David Aguilera-Alonso, Daniel Blazquez-Gamero, Navin P Boeddha, Emilie Pauline Buddingh, Danilo Buonsenso, Cristina Calvo, Riccardo Castagnoli, Marta Daina, Maria-Myrto Dourdouna, Marieke Emonts, Carmen Ezinwoke, Catarina Gouveia, David Grandioso Vas, Jeroen Hol, Mette Holm, Christian R Kahlert, Benno Kohlmaier, Kamila LudwikowskaGian Luigi Marseglia, Andrew McArdle, Rachel McGalliard, Athanasios Michos, Anda Nagle, Anita Niederer-Loher, Ulrikka Nygaard, Rianne Oostenbrink, Tina Plankar Srovin, Sandrine Roisin, Jesús Saavedra-Lozano, Adriana Shan, Valtyr Stefansson Thors, Volker Strenger, Angeliki Syngelou, Anne Tilmanne, Monika Tokarczyk, Christo Tsilifis, Maria Tsolia, Adam Tulling, Evelien van Kempen, Mirjam Van Veen, Katarina Vincek, Ulrich Von Both, Dace Zavadska, Mohammed Zaman, Ruud G Nijman, Naim Ouldali, Dorine Borensztajn^*, PEGASUS Consortium

^*Corresponding author for this work

Department of Paediatrics and Adolescent Medicine

9 Citations (Scopus)

Abstract

BACKGROUND: After lifting non-pharmaceutical interventions (NPIs) against the transmission of SARS-CoV-2, various countries experienced an increase in invasive Group A Streptococcal (iGAS) infections. We aimed to characterise the paediatric outbreak across Europe and to analyse the influence of viral infections.

METHODS: We conducted an interrupted time-series analysis based on data from 15 European countries from the PEGASUS consortium. We assessed the evolution of the number of iGAS cases aged 1 month to 18 years between 01/01/2018 and 03/31/2024, comparing the post-NPIs period (01-04-2022 until 31-03-2024) to the baseline period (01-01-2018 until 31-03-2020). Further analyses were performed by country, clinical phenotype, age and severity, including sensitivity analyses. We then explored whether certain iGAS phenotypes correlated with trends in RSV, influenza and VZV across countries over time using Google Trends data.

FINDINGS: We included 2091 iGAS cases over the study period; 79 children (3.6%) died and 580 (27.7%) required PICU admission. We estimated an overall increase of +229.8% (95% CI (141.9-341.6)) among iGAS cases from October 2022 to March 2024, compared to the baseline period. The observed increases varied across clinical phenotypes, ranging from +62.7% (95% CI (8.3-157.9)) for osteo-articular infections to +238.7% (95% CI 75.8-464.8) for pneumonia. We observed a strong correlation between the incidence of iGAS pneumonia and RSV (Rho: 0.57, 95% CI [0.11-0.79]) and influenza (Rho 0.69, 95% CI 0.35-0.87); and between skin and soft tissue infections and VZV (Rho: 0.73, 95% CI [0.42-0.89]).

INTERPRETATION: The patterns observed across Europe during this outbreak demonstrate an association between respiratory viruses as well as VZV, and iGAS.

FUNDING: This study has received funding from ESPID, INOPSU and the Northwest Clinics. The COPP study group was supported by grants of the Dutch National Health Council (ZonMW) project number 10430072110007 and the Christine Bader Foundation.

Original language	English
Article number	101497
Journal	The Lancet regional health. Europe
Volume	59
DOIs	https://doi.org/10.1016/j.lanepe.2025.101497
Publication status	Published - Dec 2025

Keywords

Europe
Flu
Group A streptococcus
Immunity debt
Influenza
Invasive streptococcal disease
Non pharmaceutical interventions
Outbreak
Paediatrics
RSV
Respiratory syncytial virus
Streptococcus pyogenes
VZV
Varicella
Viral infections
Viruses

Access to Document

10.1016/j.lanepe.2025.101497Licence: CC BY

Fingerprint

Dive into the research topics of 'Paediatric invasive group A streptococcal infections and associations with viral infections in 15 European countries after lifting non-pharmaceutical interventions against SARS-CoV-2: an interrupted time-series analysis'. Together they form a unique fingerprint.

Cite this

Lenglart, L., Özmen, I., Aguilera-Alonso, D., Blazquez-Gamero, D., Boeddha, N. P., Buddingh, E. P., Buonsenso, D., Calvo, C., Castagnoli, R., Daina, M., Dourdouna, M.-M., Emonts, M., Ezinwoke, C., Gouveia, C., Vas, D. G., Hol, J., Holm, M., Kahlert, C. R., Kohlmaier, B., ... PEGASUS Consortium (2025). Paediatric invasive group A streptococcal infections and associations with viral infections in 15 European countries after lifting non-pharmaceutical interventions against SARS-CoV-2: an interrupted time-series analysis. The Lancet regional health. Europe, 59, Article 101497. https://doi.org/10.1016/j.lanepe.2025.101497

Paediatric invasive group A streptococcal infections and associations with viral infections in 15 European countries after lifting non-pharmaceutical interventions against SARS-CoV-2: an interrupted time-series analysis. / Lenglart, Léa; Özmen, Izel; Aguilera-Alonso, David et al.
In: The Lancet regional health. Europe, Vol. 59, 101497, 12.2025.

Research output: Contribution to journal › Journal article › Research › peer-review

Lenglart, L, Özmen, I, Aguilera-Alonso, D, Blazquez-Gamero, D, Boeddha, NP, Buddingh, EP, Buonsenso, D, Calvo, C, Castagnoli, R, Daina, M, Dourdouna, M-M, Emonts, M, Ezinwoke, C, Gouveia, C, Vas, DG, Hol, J, Holm, M, Kahlert, CR, Kohlmaier, B, Ludwikowska, K, Marseglia, GL, McArdle, A, McGalliard, R, Michos, A, Nagle, A, Niederer-Loher, A, Nygaard, U, Oostenbrink, R, Srovin, TP, Roisin, S, Saavedra-Lozano, J, Shan, A, Thors, VS, Strenger, V, Syngelou, A, Tilmanne, A, Tokarczyk, M, Tsilifis, C, Tsolia, M, Tulling, A, van Kempen, E, Van Veen, M, Vincek, K, Von Both, U, Zavadska, D, Zaman, M, Nijman, RG, Ouldali, N, Borensztajn, D & PEGASUS Consortium 2025, 'Paediatric invasive group A streptococcal infections and associations with viral infections in 15 European countries after lifting non-pharmaceutical interventions against SARS-CoV-2: an interrupted time-series analysis', The Lancet regional health. Europe, vol. 59, 101497. https://doi.org/10.1016/j.lanepe.2025.101497

Lenglart L, Özmen I, Aguilera-Alonso D, Blazquez-Gamero D, Boeddha NP, Buddingh EP et al. Paediatric invasive group A streptococcal infections and associations with viral infections in 15 European countries after lifting non-pharmaceutical interventions against SARS-CoV-2: an interrupted time-series analysis. The Lancet regional health. Europe. 2025 Dec;59:101497. doi: 10.1016/j.lanepe.2025.101497

@article{7c83bbbbc09e4fa0aed5eaa6898e75b4,

title = "Paediatric invasive group A streptococcal infections and associations with viral infections in 15 European countries after lifting non-pharmaceutical interventions against SARS-CoV-2: an interrupted time-series analysis",

abstract = "BACKGROUND: After lifting non-pharmaceutical interventions (NPIs) against the transmission of SARS-CoV-2, various countries experienced an increase in invasive Group A Streptococcal (iGAS) infections. We aimed to characterise the paediatric outbreak across Europe and to analyse the influence of viral infections.METHODS: We conducted an interrupted time-series analysis based on data from 15 European countries from the PEGASUS consortium. We assessed the evolution of the number of iGAS cases aged 1 month to 18 years between 01/01/2018 and 03/31/2024, comparing the post-NPIs period (01-04-2022 until 31-03-2024) to the baseline period (01-01-2018 until 31-03-2020). Further analyses were performed by country, clinical phenotype, age and severity, including sensitivity analyses. We then explored whether certain iGAS phenotypes correlated with trends in RSV, influenza and VZV across countries over time using Google Trends data.FINDINGS: We included 2091 iGAS cases over the study period; 79 children (3.6\%) died and 580 (27.7\%) required PICU admission. We estimated an overall increase of +229.8\% (95\% CI (141.9-341.6)) among iGAS cases from October 2022 to March 2024, compared to the baseline period. The observed increases varied across clinical phenotypes, ranging from +62.7\% (95\% CI (8.3-157.9)) for osteo-articular infections to +238.7\% (95\% CI 75.8-464.8) for pneumonia. We observed a strong correlation between the incidence of iGAS pneumonia and RSV (Rho: 0.57, 95\% CI [0.11-0.79]) and influenza (Rho 0.69, 95\% CI 0.35-0.87); and between skin and soft tissue infections and VZV (Rho: 0.73, 95\% CI [0.42-0.89]).INTERPRETATION: The patterns observed across Europe during this outbreak demonstrate an association between respiratory viruses as well as VZV, and iGAS.FUNDING: This study has received funding from ESPID, INOPSU and the Northwest Clinics. The COPP study group was supported by grants of the Dutch National Health Council (ZonMW) project number 10430072110007 and the Christine Bader Foundation.",

keywords = "Europe, Flu, Group A streptococcus, Immunity debt, Influenza, Invasive streptococcal disease, Non pharmaceutical interventions, Outbreak, Paediatrics, RSV, Respiratory syncytial virus, Streptococcus pyogenes, VZV, Varicella, Viral infections, Viruses",

author = "L{\'e}a Lenglart and Izel {\"O}zmen and David Aguilera-Alonso and Daniel Blazquez-Gamero and Boeddha, \{Navin P\} and Buddingh, \{Emilie Pauline\} and Danilo Buonsenso and Cristina Calvo and Riccardo Castagnoli and Marta Daina and Maria-Myrto Dourdouna and Marieke Emonts and Carmen Ezinwoke and Catarina Gouveia and Vas, \{David Grandioso\} and Jeroen Hol and Mette Holm and Kahlert, \{Christian R\} and Benno Kohlmaier and Kamila Ludwikowska and Marseglia, \{Gian Luigi\} and Andrew McArdle and Rachel McGalliard and Athanasios Michos and Anda Nagle and Anita Niederer-Loher and Ulrikka Nygaard and Rianne Oostenbrink and Srovin, \{Tina Plankar\} and Sandrine Roisin and Jes{\'u}s Saavedra-Lozano and Adriana Shan and Thors, \{Valtyr Stefansson\} and Volker Strenger and Angeliki Syngelou and Anne Tilmanne and Monika Tokarczyk and Christo Tsilifis and Maria Tsolia and Adam Tulling and \{van Kempen\}, Evelien and \{Van Veen\}, Mirjam and Katarina Vincek and \{Von Both\}, Ulrich and Dace Zavadska and Mohammed Zaman and Nijman, \{Ruud G\} and Naim Ouldali and Dorine Borensztajn and \{PEGASUS Consortium\}",

note = "{\textcopyright} 2025 The Author(s).",

year = "2025",

month = dec,

doi = "10.1016/j.lanepe.2025.101497",

language = "English",

volume = "59",

journal = "The Lancet regional health. Europe",

issn = "2666-7762",

publisher = "Elsevier Ltd",

}

TY - JOUR

T1 - Paediatric invasive group A streptococcal infections and associations with viral infections in 15 European countries after lifting non-pharmaceutical interventions against SARS-CoV-2

T2 - an interrupted time-series analysis

AU - Lenglart, Léa

AU - Özmen, Izel

AU - Aguilera-Alonso, David

AU - Blazquez-Gamero, Daniel

AU - Boeddha, Navin P

AU - Buddingh, Emilie Pauline

AU - Buonsenso, Danilo

AU - Calvo, Cristina

AU - Castagnoli, Riccardo

AU - Daina, Marta

AU - Dourdouna, Maria-Myrto

AU - Emonts, Marieke

AU - Ezinwoke, Carmen

AU - Gouveia, Catarina

AU - Vas, David Grandioso

AU - Hol, Jeroen

AU - Holm, Mette

AU - Kahlert, Christian R

AU - Kohlmaier, Benno

AU - Ludwikowska, Kamila

AU - Marseglia, Gian Luigi

AU - McArdle, Andrew

AU - McGalliard, Rachel

AU - Michos, Athanasios

AU - Nagle, Anda

AU - Niederer-Loher, Anita

AU - Nygaard, Ulrikka

AU - Oostenbrink, Rianne

AU - Srovin, Tina Plankar

AU - Roisin, Sandrine

AU - Saavedra-Lozano, Jesús

AU - Shan, Adriana

AU - Thors, Valtyr Stefansson

AU - Strenger, Volker

AU - Syngelou, Angeliki

AU - Tilmanne, Anne

AU - Tokarczyk, Monika

AU - Tsilifis, Christo

AU - Tsolia, Maria

AU - Tulling, Adam

AU - van Kempen, Evelien

AU - Van Veen, Mirjam

AU - Vincek, Katarina

AU - Von Both, Ulrich

AU - Zavadska, Dace

AU - Zaman, Mohammed

AU - Nijman, Ruud G

AU - Ouldali, Naim

AU - Borensztajn, Dorine

AU - PEGASUS Consortium

PY - 2025/12

Y1 - 2025/12

N2 - BACKGROUND: After lifting non-pharmaceutical interventions (NPIs) against the transmission of SARS-CoV-2, various countries experienced an increase in invasive Group A Streptococcal (iGAS) infections. We aimed to characterise the paediatric outbreak across Europe and to analyse the influence of viral infections.METHODS: We conducted an interrupted time-series analysis based on data from 15 European countries from the PEGASUS consortium. We assessed the evolution of the number of iGAS cases aged 1 month to 18 years between 01/01/2018 and 03/31/2024, comparing the post-NPIs period (01-04-2022 until 31-03-2024) to the baseline period (01-01-2018 until 31-03-2020). Further analyses were performed by country, clinical phenotype, age and severity, including sensitivity analyses. We then explored whether certain iGAS phenotypes correlated with trends in RSV, influenza and VZV across countries over time using Google Trends data.FINDINGS: We included 2091 iGAS cases over the study period; 79 children (3.6%) died and 580 (27.7%) required PICU admission. We estimated an overall increase of +229.8% (95% CI (141.9-341.6)) among iGAS cases from October 2022 to March 2024, compared to the baseline period. The observed increases varied across clinical phenotypes, ranging from +62.7% (95% CI (8.3-157.9)) for osteo-articular infections to +238.7% (95% CI 75.8-464.8) for pneumonia. We observed a strong correlation between the incidence of iGAS pneumonia and RSV (Rho: 0.57, 95% CI [0.11-0.79]) and influenza (Rho 0.69, 95% CI 0.35-0.87); and between skin and soft tissue infections and VZV (Rho: 0.73, 95% CI [0.42-0.89]).INTERPRETATION: The patterns observed across Europe during this outbreak demonstrate an association between respiratory viruses as well as VZV, and iGAS.FUNDING: This study has received funding from ESPID, INOPSU and the Northwest Clinics. The COPP study group was supported by grants of the Dutch National Health Council (ZonMW) project number 10430072110007 and the Christine Bader Foundation.

AB - BACKGROUND: After lifting non-pharmaceutical interventions (NPIs) against the transmission of SARS-CoV-2, various countries experienced an increase in invasive Group A Streptococcal (iGAS) infections. We aimed to characterise the paediatric outbreak across Europe and to analyse the influence of viral infections.METHODS: We conducted an interrupted time-series analysis based on data from 15 European countries from the PEGASUS consortium. We assessed the evolution of the number of iGAS cases aged 1 month to 18 years between 01/01/2018 and 03/31/2024, comparing the post-NPIs period (01-04-2022 until 31-03-2024) to the baseline period (01-01-2018 until 31-03-2020). Further analyses were performed by country, clinical phenotype, age and severity, including sensitivity analyses. We then explored whether certain iGAS phenotypes correlated with trends in RSV, influenza and VZV across countries over time using Google Trends data.FINDINGS: We included 2091 iGAS cases over the study period; 79 children (3.6%) died and 580 (27.7%) required PICU admission. We estimated an overall increase of +229.8% (95% CI (141.9-341.6)) among iGAS cases from October 2022 to March 2024, compared to the baseline period. The observed increases varied across clinical phenotypes, ranging from +62.7% (95% CI (8.3-157.9)) for osteo-articular infections to +238.7% (95% CI 75.8-464.8) for pneumonia. We observed a strong correlation between the incidence of iGAS pneumonia and RSV (Rho: 0.57, 95% CI [0.11-0.79]) and influenza (Rho 0.69, 95% CI 0.35-0.87); and between skin and soft tissue infections and VZV (Rho: 0.73, 95% CI [0.42-0.89]).INTERPRETATION: The patterns observed across Europe during this outbreak demonstrate an association between respiratory viruses as well as VZV, and iGAS.FUNDING: This study has received funding from ESPID, INOPSU and the Northwest Clinics. The COPP study group was supported by grants of the Dutch National Health Council (ZonMW) project number 10430072110007 and the Christine Bader Foundation.

KW - Europe

KW - Flu

KW - Group A streptococcus

KW - Immunity debt

KW - Influenza

KW - Invasive streptococcal disease

KW - Non pharmaceutical interventions

KW - Outbreak

KW - Paediatrics

KW - RSV

KW - Respiratory syncytial virus

KW - Streptococcus pyogenes

KW - VZV

KW - Varicella

KW - Viral infections

KW - Viruses

UR - https://www.scopus.com/pages/publications/105019088852

U2 - 10.1016/j.lanepe.2025.101497

DO - 10.1016/j.lanepe.2025.101497

M3 - Journal article

C2 - 41170145

SN - 2666-7762

VL - 59

JO - The Lancet regional health. Europe

JF - The Lancet regional health. Europe

M1 - 101497

ER -

Paediatric invasive group A streptococcal infections and associations with viral infections in 15 European countries after lifting non-pharmaceutical interventions against SARS-CoV-2: an interrupted time-series analysis

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this