Domestic mammals as reservoirs for Leishmania donovani on the Indian subcontinent: Possibility and consequences on elimination

Abstract

Leishmania donovani is the causative agent of historically anthroponotic visceral leishmaniasis (VL) on the Indian subcontinent (ISC). L. donovani is transmitted by the sand fly species Phlebotomus argentipes. Our collaborative group and others have shown that sand flies trapped outside in endemic villages have fed on cattle and dogs in addition to people. Domestic animals are reservoirs for L. donovani complex spp., particularly L. infantum, in other endemic areas. Multiple studies using quantitative PCR or serological detection methods have demonstrated that goats, cattle, rats and dogs were diagnostically positive for L. donovani infection or exposure in eastern Africa, Bangladesh, Nepal and India. There is a limited understanding of the extent to which L. donovani infection of domestic animals drives transmission to other animals or humans on the ISC. Evidence from other vector‐borne disease elimination strategies indicated that emerging infections in domestic species hindered eradication. The predominant lesson learned from these other situations is that non‐human reservoirs must be identified, controlled and/or prevented. Massive efforts are underway for VL elimination on the Indian subcontinent. Despite these herculean efforts, residual VL incidence persists. The spectre of an animal reservoir complicating elimination efforts haunts the final push towards full VL control. Better understanding of L. donovani transmission on the Indian subcontinent and rigorous consideration of how non‐human reservoirs alter VL ecology are critical to sustain elimination goals.

Anti-trypanosomatid drug discovery: progress and challenges

“…Visceral leishmaniasis caused by L. infantum is thought to be primarily a zoonotic disease, with the main reservoir being dogs 98 . L. donovani has been found in various agricultural animals and dogs on the Indian subcontinent 99 . Cutaneous leishmaniasis is caused by different species and subspecies of Leishmania , which have a variety of different reservoirs, including rodents, sloths and armadillos 98 .…”

Precision Medicine in Control of Visceral Leishmaniasis Caused by L. donovani

“…Both in the ISC and in East Africa there is no consensus on the existence of an animal reservoir. While leishmania parasites have been demonstrated in animals, no evidence exist that these animals contribute to transmission ( Bourdeau et al., 2020 ; Kushwaha et al., 2021 ).…”

Transmission patterns of Leishmania tropica around the Mediterranean basin: Could Morocco be impacted by a zoonotic spillover?

“…Since 60% of emerging human diseases have an animal origin, a deep understanding of the intertwined relationship between mammalian host distribution, pathogen repartition, and human disease pattern is essential [ 63 , 64 ]. For instance, a potential zoonotic cycle for Leishmania donovani in the Indian subcontinent was raised since nonhuman mammalian hosts were found to be infected by this predominantly anthroponotic species [ 65 ].…”