Emergence of an unusual cutaneous leishmaniasis and new endemic foci of Leishmania donovani infections in the Himalayan mountains - Biotic and abiotic determinants. – MANDALA

Considered a major global public health issue, infection by the Leishmania parasite is complex, with more than 20 pathogenic species affecting humans and causing several clinical forms. Visceral leishmaniasis (or Kala-azar) is fatal if left untreated. Cutaneous leishmaniasis, on the other hand, leads to lesions that can be disfiguring and stigmatizing, causing psychosocial distress.
Despite the efforts made and a significant decrease in reported cases of visceral leishmaniasis caused by Leishmania (L.) donovani, the parasite does not seem to have been defeated.
Indeed, our recent study in Nepal revealed the worrying emergence of an unusual cutaneous leishmaniasis caused by L. donovani, which was previously associated only with visceral leishmaniasis in the Terai (plains) region. Most of these patients came from districts in the mountainous regions of Western Nepal not considered endemic for visceral leishmaniasis by the national Kala-azar elimination program, in contrast to districts located in the Terai. This increasing complexity of L. donovani parasite infection poses significant challenges to the sustainability of Kala-azar elimination program. The emergence of cutaneous leishmaniasis caused by L. donovani, with a modified spatial transmission as the presence of the vector insect now extends to the Himalayan mountain regions, calls for integrated and transdisciplinary research efforts.
MANDALA's main objectives are to understand the mechanisms behind the emergence of cutaneous leishmaniasis caused by L. donovani in the Himalayan mountains of Western Nepal and to address the urgent need for the development of effective diagnostic and intervention tools. These tools will include, in particular, mapping and short-term predictive models that account for regional and climate changes, facilitating the early detection of new cases and their management, as well as the implementation of targeted vector control interventions. These actions are particularly crucial in the mountainous regions of Nepal, where access to villages and numerous hamlets is challenging.
To achieve this, MANDALA proposes an integrated EcoHealth approach, supported by a multidisciplinary and interdisciplinary consortium.