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Leishmania are intracellular protozoan parasites that cause the vectorborne disease leishmaniasis, which occurs in [approximately equal to] 88 countries (1). Human infection can result in 2 main forms of disease, [...]

Tegumentary leishmaniasis (TL) is endemic but neglected in southern Europe. Therefore, this study aimed to analyze the Leishmania strains causing TL cases in northeastern Italy, where an upsurge of TL cases has been observed in the last decade. Sections from 109 formalin-fixed and paraffin-embedded (FFPE) biopsies of skin and mucosal tissues were collected from TL cases in the selected area. Two DNA targets were amplified and sequenced: the ribosomal internal transcribed spacer 1 (ITS1) and the heat-shock protein 70 gene (hsp70). An in silico analysis was also performed on 149 genomes belonging to the Leishmania donovani complex. A total of 88 out of 109 (80.7%) samples from 83 TL cases were successfully typed by ITS1 and/or hsp70. ITS1 analysis identified L. infantum in 67 cases (91.8%), while L. major (n = 4, 5.5%) and L. tropica (n = 2, 2.7%) were detected in the remaining cases that were categorized as imported. Further, the hsp70 typing of 75 autochthonous cases showed the presence of eight distinct sequence variants belonging to the Leishmania donovani complex, with high genetic variability when compared to known L. infantum populations. In conclusion, our findings show that peculiar L. infantum variants are emerging in the novel focus on TL in northeastern Italy. [ABSTRACT FROM AUTHOR]

Background: Cutaneous leishmaniasis (CL) is frequent in travellers and can involve oro-nasal mucosae. Clinical presentation impacts therapeutic management. Methodology: Demographic and clinical data from 459 travellers infected in 47 different countries were collected by members of the European LeishMan consortium. The infecting Leishmania species was identified in 198 patients. Principal findings: Compared to Old World CL, New World CL was more frequently ulcerative (75% vs 47%), larger (3 vs 2cm), less frequently facial (17% vs 38%) and less frequently associated with mucosal involvement (2.7% vs 5.3%). Patients with mucosal lesions were older (58 vs 30 years) and more frequently immunocompromised (37% vs 3.5%) compared to patients with only skin lesions. Young adults infected in Latin America with L. braziliensis or L. guyanensis complex typically had an ulcer of the lower limbs with mucosal involvement in 5.8% of cases. Typically, infections with L. major and L. tropica acquired in Africa or the Middle East were not associated with mucosal lesions, while infections with L. infantum, acquired in Southern Europe resulted in slowly evolving facial lesions with mucosal involvement in 22% of cases. Local or systemic treatments were used in patients with different clinical presentations but resulted in similarly high cure rates (89% vs 86%). Conclusion/Significance: CL acquired in L. infantum-endemic European and Mediterranean areas displays unexpected high rates of mucosal involvement comparable to those of CL acquired in Latin America, especially in immunocompromised patients. When used as per recommendations, local therapy is associated with high cure rates. Author summary: Cutaneous and muco-cutaneous leishmaniasis (CL and MCL) are disfiguring diseases caused by a worldwide distributed parasite called Leishmania and its 20 species. Clinical manifestations span a wide continuum from single nodular lesion to disseminated form with mucosal involvement. No randomized clinical trial has ever been done exclusively in travellers and medical management is poorly evidence-based or based very predominantly on data obtained in endemic countries. Articles and reviews almost invariably propose a dichotomic view, with Old World CL described as a benign disease in contrast to New World CL strongly associated with destructive mucosal lesions. Our study is the first prospective clinical study providing a detailed description of the clinical presentation and risk of mucosal involvement in CL in several hundreds of patients , with frequent formal identification of the infecting Leishmania species. The harmonized data collection in patients infected in many transmission foci worldwide enabled direct comparisons of clinical patterns induced by different Leishmania species, and on the outcome following treatment with either local or systemic regimens. The study is based on an international harmonized data collection that allowed a wide capture of parasitologically confirmed cases. In striking contrast with previous assumptions, the study shows that CL acquired in Europe displays unexpected high rates of mucosal involvement comparable to those of CL acquired in Latin America, especially in immunocompromised travellers. It also shows that when used as per recommendations, local therapy is associated with high cure rates. [ABSTRACT FROM AUTHOR]

BackgroundSurveillance of human leishmaniasis in Europe is mostly limited to country-specific information from autochthonous infections in the southern part. As at the end of 2021, no integrated analysis has been performed for cases seen across centres in different European countries.AimTo provide a broad perspective on autochthonous and imported leishmaniasis cases in endemic and non-endemic countries in Europe.MethodsWe retrospectively collected records from cutaneous, mucosal and visceral leishmaniasis cases diagnosed in 15 centres between 2014 and 2019. Centres were located in 11 countries: Belgium, France, Germany, Italy, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Data on country of infection, reason for travelling, infecting species, age and sex were analysed.ResultsWe obtained diagnostic files from 1,142 cases, of which 76%, 21% and 3% had cutaneous, visceral, and mucosal disease, respectively. Of these, 68% were men, and 32% women, with the median age of 37 years (range: 0-90) at diagnosis. Visceral leishmaniasis was mainly acquired in Europe (88%; 167/190), while cutaneous leishmaniasis was primarily imported from outside Europe (77%; 575/749). Sixty-two percent of cutaneous leishmaniasis cases from outside Europe were from the Old World, and 38% from the New World. Geographic species distribution largely confirmed known epidemiology, with notable exceptions.ConclusionsOur study confirms previous reports regarding geographic origin, species, and traveller subgroups importing leishmaniasis into Europe. We demonstrate the importance of pooling species typing data from many centres, even from areas where the aetiology is presumably known, to monitor changing epidemiology.