Cardiac rupture and toxic shock syndrome by invasive group a Streptococcus in a Fontan patient with Asplenia syndrome.

The incidence of invasive group A Streptococcus (iGAS) infection has been increasing across all age groups, including pediatric patients, and is associated with high mortality rates. Although iGAS infection leads to streptococcal toxic shock syndrome and necrotizing soft tissue infections, iGAS-associated infective endocarditis (IE) is rare. Here, we report a case of iGAS-associated IE, streptococcal toxic shock syndrome, and pyomyositis that occurred after the Fontan procedure in a 7-year-old patient. Initial treatment included antibiotics and surgical intervention for pyomyositis. Despite her overall condition's improvement, persistent fever led to the discovery of IE. Furthermore, this patient developed cardiac rupture due to the progression of IE but was successfully rescued. No neurological complications occurred, and the patient was discharged without recurrence of infection. To our knowledge, this is the first case report of successful life-saving treatment for cardiac rupture due to IE caused by iGAS in a pediatric Fontan patient. This case suggests that iGAS infections in patients with complex congenital heart disease warrant a crucial search for complications of iGAS-associated IE. Learning objective: The incidence of invasive group A Streptococcus (iGAS) infection is increasing globally. While infective endocarditis (IE) caused by iGAS is rare, the risk may be elevated among patients with complex congenital heart disease. This underscores the importance of searching for iGAS-associated IE and the need for treatment with consideration for exacerbation.