Title: Visceral leishmaniasis in an immunocompetent patient

Domingos Sousa¹, Miguel Seruca², Ana Isabel Rodrigues¹, Mourão Carvalho¹, Sara Aleixo Duarte¹, Sérgio Antunes Silva¹, Micael Mendes¹, Alejandra Pereira², Amparo Mingo³, Elena Rios¹, Mário Lázaro¹

¹ Internal Medicine Department, Centro Hospitalar e Universitário do Algarve, Unidade de Faro, Portugal

² Clinical Pathology Department, Centro Hospitalar e Universitário do Algarve, Unidade de Faro, Portugal.

³ Infeccious Diseases Department, Centro Hospitalar e Universitário do Algarve, Unidade de Faro, Portugal.

Email address of Corresponding author: domingos.sousaa@gmail.com

orcid.org/ 0000-0001-6657-5921 telephone: +351 913334854

Key clinical words: fever, anemia, leishmaniasis, immunocompetent

Key clinical message: Visceral leishmaniasis in immunocompetent patients is rare and should be suspected in patients with fever, bicytopenia and elevated inflammatory markers.

A previously healthy man with 26-year-old presented to the emergency department with a 6-month history of fever, fatigue and an unintentional 12 kilogram weight loss. At physical examination, an enlarged spleen was notable. Further studies revealed a leucocyte count of 2200 per cubic millimeter, a hemoglobin level of 9.4 g per deciliter, a platelet count of 200,000 per cubic millimeter and hyperglobulinemia. Blood cultures as well as serologies for human immunodeficiency virus, hepatitis B virus, hepatitis C virus, Epstein–Barr virus, and cytomegalovirus came back negative. Computed tomography (CT) of the abdomen confirmed the presence of a heterogeneous hepatosplenomegaly (Figure 1A). Examination of a bone marrow aspirate revealed the presence of amastigotes within the macrophages’ cytoplasm, a classic appearance of Leishmania spp ( Figure 1B). Leishmaniasis is a globally widespread zoonosis that is transmitted by the bite of an infected female phlebotomine sandfly. Domestic dogs are the parasite reservoirs. Clinically, leishmaniasis is subdivided into cutaneous, mucocutaneous and visceral (kala-azar) forms. The most severe form is Visceral leishmaniasis(VL) that is characterized by a a disseminated intracellular protozoan infection that targets tissue macrophages in the liver, spleen and bone marrow. BothLeishmania infantum   and Leishmania donovani   can cause VL, being Leishmania infantum  the most prevalent pathogen in Portugal and remaining Mediterranean countries. The patient started treatment with liposomal amphotericin B leading to complete symptom resolution and splenomegaly on physical examination. Moreover, the differential diagnosis in a patient with fever and splenomegaly must include other infective causes such as typhoid, tuberculosis, leptospirosis; autoimmune disorders such as rheumatoid arthritis, sarcoidosis, amyloidosis and systemic erythematous lupus and haematological disorders such as leukaemia, lymphoma, polycythaemia vera and myelofibrosis. The present report intends to raise awareness of VL in immunocompetent patients that should be included in the diagnostic workup of patients with splenomegaly.