An unusual presentation of filariasis as pyrexia of unknown origin: Case report

Filariasis is a common, yet neglected tropical disease and has a wide spectrum of clinical presentations. It is particularly endemic in certain regions of India. We report this case due to the rare isolation of Microfilariae from the bone marrow aspirate preparation. Here, we report a patient with a history of pyrexia of unknown origin (PUO). The relevant investigations done failed to identify the causative organism. After ruling out routine causes of fever, bone marrow analysis was done and it revealed Microfilariae in the aspirate. The surprising aspect of the case is the absence of eosinophilia in the complete blood picture. The patient was treated with anthelmintics and the fever subsided within 48 h. This case emphasizes the importance of bone marrow study in patients with PUO and the presence of microfilaria in the absence of eosinophilia.