A 67-year-old woman with Crohn disease develops fever and chills after starting parenteral hyperalimentation, with blood culture showing yeast. What is the most likely organism responsible?

The scenario presented involves a 67-year-old woman with Crohn disease who develops fever and chills following the initiation of parenteral hyperalimentation, with subsequent blood cultures revealing the presence of yeast. The most likely organism responsible for such a presentation is Candida albicans.

Candida albicans is a common opportunistic pathogen that is particularly associated with patients undergoing parenteral nutrition, especially when they have underlying health conditions like Crohn disease. In this context, parenteral hyperalimentation can disrupt normal gut flora and lead to an overgrowth of Candida, which can then enter the bloodstream causing candidemia. The risk factors associated with Crohn disease, such as malnutrition and potentially compromised immune status due to the disease or its treatment, further increase susceptibility to infections by this yeast.

Other potential organisms listed, such as Aspergillus fumigatus, Blastomyces dermatitidis, and Cryptococcus neoformans, are less commonly involved in bloodstream infections in this context. Aspergillus typically affects immunocompromised patients through inhalation rather than bloodstream infections related to parenteral nutrition. Blastomyces and Cryptococcus also present in different clinical features and demographics, and although they can infect immunocompromised individuals, they are not as