Invasive Group A streptococcal infections: are we facing a new outbreak? A case series with the experience of a single tertiary center

Background: In pediatric age, Group A Streptococcus (GAS) is responsible for a wide spectrum of clinical manifestations, from mild localized infections to life-threatening invasive diseases. In December 2022, the World Health Organization reported an increased incidence of scarlet fever and invasive GAS infections (iGAS) cases in Europe and the United States. In line with these observations, surveillance has been strengthened in our Region, allowing the identification of certified or highly suspected forms of iGAS. Case presentation: We report here 4 emblematic cases of iGAS admitted to our Intensive Care Unit (ICU) in the short time span from mid-February to mid-March 2023. Particularly, we describe a case of pleuropneumonia (4 year old boy) and a case of respiratory failure (2 year old boy), who necessitated Non-Invasive Ventilation support, a case of Streptococcal Toxic Shock Syndrome (6 year old girl), presenting with multi-organ failure, who needed Invasive Ventilation, and a case of meningitis (5 year old girl). All these patients needed intensive care support. Conclusions: Accurate differential diagnosis and early treatment both could help to reduce the transmission of GAS and consequently the risk of severe iGAS. These cases confirmed the need for close monitoring and appropriate notification, in order to verify their actual increased incidence.