Imported African Histoplasmosis in an Immunocompetent Patient 40 Years after Staying in a Disease-Endemic Area

Abstract

Abstract. Histoplasmosis caused by Histoplasma capsulatum var. duboisii is a rare disease outside central and western Africa. In Europe, all cases are imported. We report a case of an African histoplasmosis with isolated pulmonary involvement in a non-immunocompromised patient that occurred 40 years after his stay in a disease-endemic area. The patient was given itraconazole. 18F-fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography was used to assess evolution during treatment. The outcome for the patient was favorable.African histoplasmosis may occur in persons without identified immunodeficiency, even a long time after exposure. African histoplasmosis caused by Histoplasma capsulatum var. duboiisi, a dimorphic fungus, is an invasive fungal disease endemic to central and western Africa and Madagascar. About thirty cases were reported in Europe and all are imported were cases. [1][2][3][4][5][6][7][8] We report an immunocompetent Caucasian patient without identified immunodeficiency who had chronic pulmonary African histoplasmosis diagnosed four decades after a stay in western Africa.A 60-year-old man from Portugal was admitted to an emergency department in October 2006 for cough with clear sputum and chest pain. His medical history indicated a gastroduodenal ulcer. He still visited his native country each year even though he had lived in France for 40 years. Forty years ago, he lived in Guinea-Bissau for two years during his military service. He is now a factory worker and enjoys gardening.The functional pulmonary symptoms occurred gradually without chills, sweats or fever for several weeks. Results of a clinical examination were normal. Oxygen saturation was 96%, temperature was 37 C, and there was no weight loss. A chest radiograph showed bilateral diffuse opacities with nodular cavitations. Chest computed tomography confirmed the presence of disseminated nodules (3-6 cm in diameter), some with cavitations and one of them calcified, but no adenopathy, pleural effusion, nor underlying parenchymal abnormalities (Figure 1).Laboratory tests showed normal blood cell counts: 5,400 leukocytes/mm 3 with 3,400 neutrophils/mm 3 , 1,400 lymphocytes/mm 3 , and 200 eosinophils/mm 3 . The C-reactive protein level was 138 mg/L, and serum levels of liver enzymes, bilirubin, and lactate dehydrogenase were within reference ranges. Sputum cultures were negative for bacteria, mycobacteria, and fungi. Serologic test results for aspergillosis and hydatidosis were negative. Abdominal and cardiac ultrasound and bronchoscopic evaluations show normal results. Bronchoalveolar lavage fluid contained 223 + 10 3 cells/mL, 93% alveolar macrophages, 5% lymphocytes, 2% neutrophils, and no neoplastic cells. Specific staining and/or cultures were negative for Pneumocystis jirovecii, mycobacteria, and bacterial microorganisms. Gomori-Grocott staining showed oval-shaped yeast 8-10 μm in diameter with narrow budding compatible with H. capsulatum var. duboisii (Figure 2). The culture yielded growth of a mycelial phase with tub...

Timely Diagnosis of Histoplasmosis in Non-endemic Countries: A Laboratory Challenge

“…Risk of reactivation exists even decades after the initial infection (Loulergue et al, 2007;Richaud et al, 2014). Up to 25% of cases registered in European travelers developed 5 years after exposure, and 41% of disseminated forms were reactivations of infections occurring at least 5 years before (Ashbee et al, 2008).…”

How Environmental Fungi Cause a Range of Clinical Outcomes in Susceptible Hosts

“…There is some evidence that Histoplasma spp. can remain latent within granulomas for decades with potential for reactivation [208][209][210][211]. Reactivated histoplasmosis in transplant recipients from endogenous and donor-derived infections has also been documented [103,212,213].…”

“…Due to the high likelihood of repeat exposure in endemic regions, it is difficult to assess the frequency of latent infections. Evidence for latency is also derived from imported cases in non-endemic regions that occur years after the patient left an endemic area [208][209][210][211]. A new assay for Histoplasma latency assesses interferon gamma (IFN-γ) release by a patient's T lymphocytes when stimulated with H. capsulatum crude antigens; latently infected patients should exhibit increased IFN-γ [214].…”

Phylogenetic analysis of Histoplasma capsulatum var duboisii in baboons from archived formalin-fixed, paraffin embedded tissues

“…Cases in people living in nonendemic regions have been reported up to 18-and even 40-year lag after presumed exposure during a stay in an endemic African country and the demonstration of clinical illness. 9,14 These cases presumably represent reactivation of latent infection. 14 The majority of cases of histoplasmosis reported in the United States are caused by Histoplasma capsulatum var.…”

“…9,14 These cases presumably represent reactivation of latent infection. 14 The majority of cases of histoplasmosis reported in the United States are caused by Histoplasma capsulatum var. capsulatum, which infects a wide variety of species and is predominantly within the NAm-1 and NAm-2 clades.…”