Epidemiology, clinical pattern and impact of species-specific molecular diagnosis on management of leishmaniasis in Belgium, 2010-2018: A retrospective study

Background: Species-directed therapy of leishmaniasis has been recommended for travelers since 2014, but little is known about species distribution and treatment practices in non-endemic countries. We aimed to describe leishmaniasis cases in Belgium since species typing became available and evaluate its impact on patient management. Method: Retrospective analysis of all patients diagnosed by PCR at our national reference laboratory from 2010 to 2018. Species were typed by Hsp-70 sequencing. Results: We identified 18 visceral leishmaniasis (VL) and 147 (muco)cutaneous leishmaniasis ((M)CL) cases. VL was exclusively due to L. infantum and consistently treated with liposomal amphotericin B, with four observed failures. (M)CL was caused by ten different species. Of 62 cases diagnosed and species typed after 2014 with timing information, 28 (45.2%) were treated before the species result was available. Therapy was not speciesdirected in 10/32(28.1%) of those treated after species identification. Patients treated according to the guidelines tended to have a favorable outcome more often than those who were not (36/44, 81.8% versus 8/19, 57.9%; p = 0.045). Conclusions: In contrast to VL, various species caused (M)CL in our setting and species result was often not considered for treatment. Outcome tended to be better however when therapy was species-directed.