Fever of unknown origin and splenomegaly in an immunosuppressed Swiss patient: case report of a Neoehrlichia mikurensis infection in a changing climate and review of the literature.

Neoehrlichia mikurensis is an emerging tick-borne pathogen that is increasingly reported and can cause fever of unknown origin in immunocompromised individuals. We report a case of neoehrlichiosis occurring after B-cell-depleting treatment. Despite the availability of effective and inexpensive treatment, patients often experience significant care delays due to diagnostic challenges and insufficient awareness.