Absract and Introduction

Absract

Group A Streptococcus (GAS) primary peritonitis is a rare cause of pediatric acute abdomen (sudden onset of severe abdominal pain); only 26 pediatric cases have been reported in the English language literature since 1980. We discuss 20 additional cases of pediatric primary peritonitis caused by GAS among patients at Starship Children’s Hospital, Auckland, New Zealand, during 2010–2022. We compare identified cases of GAS primary peritonitis to cases described in the existing pediatric literature. As rates of rates of invasive GAS increase globally, clinicians should be aware of this cause of unexplained pediatric acute abdomen.

Introduction

Streptococcus pyogenes, or group A Streptococcus (GAS), causes a wide spectrum of disease ranging from superficial skin infection and pharyngitis to invasive infections, such as sepsis, empyema, necrotizing fasciitis, meningitis, osteomyelitis, and septic arthritis^[1]. GAS is responsible for the toxin-mediated complications of scarlet fever and streptococcal toxic shock syndrome, as well as the postinfectious sequelae rheumatic fever and poststreptococcal glomerulonephritis^[2].

Primary peritonitis is defined as a bacterial infection within the peritoneal cavity in the absence of ascites or an intraabdominal source of infection, such as appendicitis^[3,4]. Primary peritonitis is an uncommon manifestation of invasive GAS (iGAS) disease; a 2016 report found it accounted for 4.6% of children with iGAS in Finland^[5]. Pediatric primary peritonitis itself is rare, reportedly accounting for 1%–3% of children experiencing acute abdomen (sudden onset of severe abdominal pain), and is most commonly caused by S. pneumoniae, gram-negative organisms, and staphylococcal species^[3].

In late 2022, the United Kingdom, United States, Australia, and several countries in Europe reported unexpectedly high rates of iGAS and scarlet fever, particularly in children <10 years of age^[6–10]. Rates of iGAS in the United Kingdom during this period are reported to be higher than in the years before the COVID-19 pandemic (2017–2019) and substantially higher than those reported during 2020–2021^[11]. With increased GAS circulation, media coverage, and heightened community awareness, clinicians globally should be aware of the vast spectrum of invasive disease caused by GAS, including primary peritonitis.

In New Zealand, iGAS disease is not notifiable to Public Health authorities^[12]. Surveillance relies on individual laboratories sending clinically relevant iGAS isolates to the Institute of Environmental Science and Research (ESR) for typing^[13]. The most recent ESR report (2016) describes an iGAS incidence of 9.0/100,000 population in New Zealand; rates were inequitably high among New Zealand Māori (23.5/100,000 population) and Pacific peoples (73.9/100,000 population) compared with rates among persons of European or other ethnicities (4.3/100,000 population)^[13]. Incidence of iGAS is highest in children <1 year of age^[13]. Although ESR laboratory surveillance provides some information on the burden of iGAS in New Zealand, its passive nature suggests that reported rates are likely to be an underestimate.

Consistent with the high burden of iGAS disease in children in New Zealand, clinicians at Starship Children’s Hospital in Auckland have observed that GAS is a major cause of primary peritonitis in the pediatric population. We evaluated the incidence, clinical features, and management of children admitted to this tertiary pediatric center with GAS primary peritonitis during January 1, 2010–June 30, 2022, to provide a better understanding of the clinical features of GAS primary peritonitis in a contemporary setting with a high burden of iGAS disease. In addition, we reviewed and compared identified cases with reports in the English language literature.