Animal Histoplasmosis in Europe: Review of the Literature and Molecular Typing of the Etiological Agents

Abstract

Histoplasmosis has been previously diagnosed in animals from Europe. The aim of this study is to review the literature on these reports, to analyze cases diagnosed at our laboratory (2000–2022) and to improve molecular typing of Histoplasma capsulatum directly from tissue to study the molecular epidemiology of Histoplasma capsulatum causing animal infections in Europe. Including 15 cases studied in our laboratory, we identified 39 cases of animal histoplasmosis between 1968 and 2022. They were diagnosed mostly in superficial tissue biopsies from cats and badgers from Central Europe. Using phylogenetic analyses of six partial genes, we were able to classify eight of the etiological agents as belonging to a highly supported lineage within the Eurasian clade. This study confirms the occurrence of autochthonous histoplasmosis in animals in Central Europe and proposes the addition of new loci to the MLST scheme to study the molecular epidemiology of histoplasmosis using either formalin-fixed paraffin-embedded tissue and fresh or cadaveric biopsies.

A multicentre external quality assessment: A first step to standardise PCR protocols for the diagnosis of histoplasmosis and coccidioidomycosis

“…In the present multicentre study, we evaluated 13 different in‐house PCR protocols for detecting H. capsulatum and Coccidioides spp. Techniques based on PCR are essential to achieve a rapid diagnosis of imported 12,34,35,40,79,80 and autochthonous 26 endemic mycosis cases.…”

“…Molecular diagnostic testing on clinical samples has shown its usefulness in diagnosing fungal infections in animals 26,27 and humans 12,[28][29][30][31][32][33][34][35] and detecting environmental niches. [36][37][38][39] Besides existing broad-range fungal PCRs that rely upon amplicon identification by sequencing, multiple specific in-house assays were developed during the past years to detect H. capsulatum and Coccidioides spp.…”

Disseminated histoplasmosis in an imported Maine Coon cat in western continental Europe

“…PCR represents additional confirmatory testing that can be performed, preferentially on fresh tissue samples, and in human medicine can be utilised for providing epidemiological insights. 7,27 PCR is not frequently used in veterinary medicine, likely due to cost, availability, ability to identify the organism on cytology/histology and growing availability of antigen tests. 1,4,5,10 This case reminds us that imported domestic animals may carry endemic diseases that are relatively unknown in the destination country.…”

“…6 In Europe, histoplasmosis is still considered to be predominantly imported; however, sporadic reports of suspected autochthonous cases exist, though these predominate in local wildlife in Central Europe with portions of Italy, Germany and Turkey having potentially endemic regions for H. capsulatum. [6][7][8] The few case reports of histoplasmosis in cats in Europe are in those with known travel history. 2,3 While animal histoplasmosis is considered a public health risk due to a potential, theoretical, zoonosis, particularly for immunocompromised humans, there are no known reports of direct animal-to-human transmission.…”

“…In Europe, histoplasmosis is still considered to be predominantly imported; however, sporadic reports of suspected autochthonous cases exist, though these predominate in local wildlife in Central Europe with portions of Italy, Germany and Turkey having potentially endemic regions for H. capsulatum 6–8 . The few case reports of histoplasmosis in cats in Europe are in those with known travel history 2,3 .…”