Mortality from Listeria monocytogenes meningoencephalitis following escalation to alemtuzumab therapy for relapsing-remitting Multiple Sclerosis.

We report the case of a patient who died from the rare complication of Listeriosis in the immediate phase following alemtuzumab administration one month after discontinuing dimethyl fumarate (DMF). There is considerable overlap with typical post-infusion symptoms therefore high surveillance and low threshold for empirical or possible prophylactic antibiotic therapy is advocated.