Pneumococcal Infective Endocarditis in two vaccinated Irish children; The Challenge of Non-Vaccine Serotypes and the Role of Host Immunity

Paediatric infective endocarditis is a rare but life-threatening condition. We describe cases of previously well, fully-vaccinated children who developed pneumococcal endocarditis. Case one, 11-year-old-boy, developed multi-focal osteomyelitis and septic arthritis, followed by infective endocarditisrequiring signifi cant surgical intervention of an aortic root abscess, coupled with marked ischemic changes onelectrocardiogram. These events identifi ed two unique, non-vaccine serotype Streptococcus pneumoniae isolates –23B and 20, respectively. Indicating two unique infections despite an extensive immunological workup, which wasunable to identify any inborn error of immunity. Case two, a three-year-old-girl, developed ocular manifestations ofinfective endocarditis with subsequent need for mitral valvuloplasty, with another non-vaccine serotype,Streptococcus pneumoniaeisolate – serotype 31, identifi ed as the off ending organism. Additionally, her treatmentcourse was complicated by a diagnosis of Drug Rash with Eosinophilia and Systemic Symptoms. In this casehowever, we identifi ed a defect in the alternative complement pathway activity. These cases highlight the increasing burden of invasive pneumococcal disease caused by non-vaccine serotypes. Wealso detail Irish national data which demonstrates a rise in non-vaccine serotype invasive pneumococcal disease inchildren since 2008. This report highlights the importance of expanded vaccine programs and the role of hostimmunity in invasive disease.