Fatal endocarditis in a neonate caused by the dematiaceous fungus Phialemonium obovatum: case report and review of the literature.

Phialemonium species are grouped by most authorities among the dematiaceous fungi. Like several other darkly pigmented fungi, they appear to be an emerging cause of human disease, especially in the immunocompromised host. As numbers of immunocompromised patients increase, the trend of unusual fungi emerging as new pathogens is set to continue. Previous experience suggests that reports of rare fungal infections among selected patients often heralds the emergence of infection in a wider population of patients. We report a case of fatal endocarditis caused by Phialemonium obovatum in a premature neonate. To our knowledge this is the first documented case of native valve endocarditis due to this species, and we review the literature on invasive disease caused by the species. Unfamiliar fungal isolates are frequently misidentified or mistaken for environmental contaminants, and because of their relative rarity, data upon which to base antifungal treatment are limited. Thus, the diagnosis and treatment of unusual fungal pathogens present a significant challenge to clinicians and microbiologists alike. Early referral of such isolates to a specialist reference laboratory is advisable.