Protothecosis after liver transplantation.

Prototheca species are unicellular algae of low virulence that are rarely associated with human infections. We report a liver transplant recipient with disseminated protothecosis and review the literature on this unusual opportunistic infection in transplant recipients. Of 9 cases, including ours, 5 had a localized infection, and 4 had disseminated protothecosis. Seven cases were due to Prototheca wickerhamii, and 2 were due to Prototheca zopfii. Overall mortality in transplant recipients with Prototheca infections was 88% (7/8). All 4 cases of disseminated protothecosis died despite therapy with amphotericin B. Posttransplant protothecosis is a rare but significant infection that is associated with a grave prognosis.