Disseminated histoplasmosis in an immunocompetent Nigerian child diagnosed on a peripheral blood smear

Ekeng, Bassey; Brown, Ekaete; Ekaette, Nsa; Ide, Christian; Obok, Felicia; Kokelu, Anthony; Ekpang, Oritsegbemi; Ifeanyi, Ekeocha; Eshiet, Ubokobong

doi:10.21608/mid.2024.336455.2347

Disseminated histoplasmosis in an immunocompetent Nigerian child diagnosed on a peripheral blood smear

Articles in Press

Document Type : Short Reports (case reports)

Authors

¹ Department of Medical Microbiology and Parasitology, University of Calabar Teaching Hospital, Calabar, Nigeria

² Department of Paediatrics, University of Calabar Teaching Hospital, Calabar, Nigeria

³ Department of Pediatrics, University of Calabar Teaching Hospital, Calabar, Nigeria

⁴ Department of Haematology and Blood Transfusion, University of Calabar Teaching Hospital, Calabar, Nigeria

⁵ Department of Pediatrics, Ninewells Hospitals, Dundee, UK

10.21608/mid.2024.336455.2347

Abstract

Disseminated histoplasmosis is commonly associated with immunocompromised individuals but can also affect immunocompetent persons. However, the diagnosis may be missed as is often not expected in the non-immunocompromised. Our case report highlights the need to consider histoplasmosis as a differential in immunocompetent individuals. A 17-year-old female with symptoms of persistent fever and fatigue of 3 weeks duration. Examination findings were significant pallor, jaundice, and cervical lymphadenopathy. The chest X-ray, stool for Gene Xpert and urine for lipoarabinomannan assay were not supportive of tuberculosis. The retroviral screening was negative. Blood culture yielded no pathogen. A complete blood count showed leukocytosis with anaemia. The reticulocyte count was greater than 2%. Initial peripheral blood smear showed, neutrophilia with toxic granulations and atypical lymphocytes. However, as the fever was unrelenting, a repeat blood smear was requested which revealed numerous yeast cells with a narrow budding base and tuberculated macroconidia morphologically similar to Histoplasma capsulatum. A diagnosis of disseminated histoplasmosis was made and the patient was commenced on itraconazole. The fever abated and the anaemia resolved. The patient was to be followed up in the clinic a month later. Her complete blood count levels were now within normal, and a repeat peripheral blood smear showed no atypical lymphocytes. This case report affirms the need to promptly diagnose and initiate appropriate treatment in a patient with invasive mycosis and the role of microscopy in a setting where classical diagnostics are not routinely available.

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