Abstract
We report a 9-year-old boy who presented with mitral valve perforation secondary to Ustilago species fungal infective endocarditis. Subsequent evaluation revealed previously undiagnosed HIV infection. Fungal endocarditis due to Ustilago species is exceedingly rare, and presentation as the initial manifestation of HIV has not been previously described in the pediatric population. The atypical presentation posed significant diagnostic challenges, emphasizing the need to consider underlying immunodeficiency, including HIV infection, in children presenting with unusual or opportunistic infections. To our knowledge, this represents the first reported case of Ustilago infective endocarditis unveiling pediatric HIV infection in a child with a structurally normal heart.