Molecular typing reveals the co-existence of two transmission cycles of American cutaneous leishmaniasis in the Andean Region of Venezuela with Lutzomyia migonei as the vector

Abstract

BACKGROUND The transmission routes for American cutaneous leishmaniasis (ACL) are in flux, so studies examining its transmission in humans, mammalian hosts, and sand fly vectors are urgently needed. OBJECTIVES The aim of this work was understand the epidemiological cycles of Leishmania spp., which causes ACL in the Andean Region of Venezuela, by identifying the Leishmania and the sand fly species involved in human and dog infections. METHODS Thirty-one biopsies from patients in Mérida and Táchira states with suspected ACL were studied by both parasitological tests (cultures and hamster inoculation) and a molecular test [Internal transcribed spacer 1 (ITS1) nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)]. We also conducted a survey to detect Leishmania infection in dogs (Immunifluorescence antibody test and ITS1 nested PCR-RFLP) and sand flies (ITS1 nested PCR-RFLP) from El Carrizal, a highly endemic focus of ACL in Venezuela. FINDINGS Three different Leishmania species were identified in the clinical samples from humans (Leishmania braziliensis, L. guyanensis, and L. mexicana) and dogs (L. guyanensis and L. mexicana). The predominant sand fly species found were those from the Verrucarum group (infected with L. mexicana) and Lutzomyia migonei (infected with L. guyanensis and L. mexicana). MAIN CONCLUSIONS We show that Lu. migonei may be the putative vector in two ACL epidemiological cycles, involving L. guyanensis and L. mexicana. We also report for the first time the presence of L. guyanensis in domestic animals.

Morphological aspects of immature stages of Migonemyia migonei (Diptera: Psychodidae, Phlebotominae), an important vector of Leishmaniosis in South America, described by scanning electron microscopy

“…migonei (França) is an important vector of Leishmania (Viannia) braziliensis, and one of the causative agents of cutaneous leishmaniasis in South America, especially in Brazil [17][18][19]. Torrellas et al [20] found Mg. migonei infected with Le. (V.) guyanensis and Le.…”

Cryptic diversity in sympatric Migonemyia migonei (Diptera: Psychodidae: Phlebotominae), eventual meaning for leishmaniasis transmission

“…In western Venezuela, it was described as anthropophilic adapted to both humid and dry mountain forests with wide altitudinal distribution (Chaves and Añez 2004), and was incriminated as vector in two epidemiological cycles, involving L. mexicana Biagi 1953 and L. guyanensis Floch 1954 (TL etiological agents) (Torrellas et al 2018). In northeastern Brazil, Mg. migonei was found in high abundance in remote indigenous villages in a semiarid region associated with transmission cycles of L. braziliensis Vianna 1911 (TL agent) (Sales et al 2019) and also in the Atlantic coast adapted to indoor environment suspected to be involved in L. infantum (VL agent) transmission (Silva et al 2014).…”

Canine leishmaniasis in the Americas: etiology, distribution, and clinical and zoonotic importance

“…reported in dogs in the Americas, with their proven or suspected animal reservoirs and sand fly vectors Leishmania spp. Proven or suspected wild reservoirs a Proven or suspected vectors b Geographical distribution (in dogs) L. amazonensis Several species of small rodents, opossums, and other wildlife Bichromomyia flaviscutellata , Bichromomyia olmeca olmeca , and Pintomyia nuneztovari Brazil [ 43 , 44 ] and Colombia [ 15 , 92 ] L. braziliensis Several species of small rodents, opossums, and other wildlife Nyssomyia intermedia , Nyssomyia neivai , Nyssomyia whitmani , Migonemyia migonei , Psychodopygus complexus , Psychodopygus davisi , and Psychodopygus wellcomei Argentina [ 93 ], Bolivia [ 94 ], Brazil [ 95 ], Colombia [ 15 , 45 ], Mexico [ 96 ], Panama [ 13 ], Paraguay [ 97 ] c , Peru [ 65 ], and Venezuela [ 98 ] L. guyanensis Linnaeus’s two-toed sloth ( Choloepus didactylus ), southern tamandua ( Tamandua tetradactyla ), and other wildlife Nyssomyia anduzei and Nyssomyia umbratilis Brazil [ 17 ], Colombia [ 14 ] and Venezuela [ 99 ] L. infantum Several species of carnivores (mainly canids), rodents, opossums, monkeys, and other wildlife Lutzomyia cruzi , Lutzomyia longipalpis , Migonemyia migonei , Pintomyia evansi , and Psathyromyia shannoni Argentina [ 100 ], Bolivia [ 94 ], Brazil [ 101 ], Canada [ …”