Competence of non-human primates to transmit Leishmania infantum to the invertebrate vector Lutzomyia longipalpis

Abstract

Leishmaniasis is a zoonotic disease of worldwide relevance. Visceral leishmaniasis is endemic in Brazil, where it is caused by Leishmania infantum with Lutzomyia longipalpis being the most important invertebrate vector. Non-human primates are susceptible to L . infantum infection. However, little is known about the role of these species as reservoirs. The aim of this study was to evaluate the transmissibility potential of visceral leishmaniasis by non-human primates through xenodiagnosis using the phlebotomine Lu . longipalpis as well as to identify phlebotomine species prevalent in the area where the primates were kept in captivity, and assess infection by Leishmania in captured phlebotomine specimens. Fifty two non-human primates kept in captivity in an endemic area for leishmaniasis were subjected to xenodiagnosis. All primates were serologically tested for detection of anti- Leishmania antibodies. Additionally, an anti- Lu . longipalpis saliva ELISA was performed. Sand flies fed on all animals were tested by qPCR to identify and quantify L . infantum promastigotes. Eight of the 52 non-human primates were positive by xenodiagnosis, including three Pan troglodytes , three Leontopithecus rosalia , one Sapajus apella , and one Miopithecus talapoin , with estimated numbers of promastigotes ranging from 5.67 to 1,181.93 per μg of DNA. Positive animals had higher levels of IgG anti- Lu . longipalpis saliva when compared to negative animals, prior to xenodiagnosis. Captive non-human primates are capable of infecting Lu . longipalpis with L . infantum . Our findings also demonstrate the relevance of non-human primates as sentinels to zoonotic diseases. Several phlebotomine species, including Lu . longipalpis , have been identified in the area where the primates were maintained, but only one pool of Lutzomyia lenti was infected with L . infantum . This study has implications for public health strategies and conservation medicine.

Infectiousness of Asymptomatic Meriones shawi, Reservoir Host of Leishmania major

“…Until now, the infectiousness of asymptomatic hosts has been studied almost exclusively in visceral leishmaniasis. Xenodiagnostic experiments showed the transmissibility of L. donovani from asymptomatic BALB/c mice [18] and L. infantum from different mammalian hosts [36][37][38][39][40][41]. The infectiousness of asymptomatic dogs infected with L. infantum has been studied most intensively, and meta-analysis of data published up to 2009 by Quinnell and Courtenay [13] showed that the proportion of infectious dogs increased significantly with clinical severity, but asymptomatic dogs were also infectious and infected a similar proportions of flies as sick dogs.…”

An overview of the trypanosomatid (Kinetoplastida: Trypanosomatidae) parasites infecting several mammal species in Colombia

“…Some authors have concluded, for instance, that the circulating phlebotomine sand fly species are critical for the vectorial transmission of Leishmania spp. [95]; likewise, the mammals' role in parasite transmission concerns the vector, their meal preferences, and feeding behavior [96,97].…”

Infectious diseases of neotropical primates

“…In wildlife there are serologic and molecular evidence of Leishmania infantum, Leishmania mexicana, Leishmania shawi, L. amazonensis, and Leishmania braziliensis in a wide range of NWP from endemic areas (4,23,28,78,89,90,112,120,154,172,182,212), but no symptomatic animals were identified. These findings could represent a public health concern once some species of NWP were competent in transmitting L. infantum to the invertebrate vector Lutzomyia longipalpis (150,182), being a potential reservoir of this parasite contributing to its maintenance in the environment. Trypanosoma cruzi is a mammal parasite, being the etiological agent of Chagas disease in humans, endemic throughout Latin America and classicaly transmitted by wound bites contaminated with feces of blood-sucking triatomine bugs (125).…”

“…Leishmaniosis, caused by Leishmania spp., has been reported in captive NWP from endemic regions with serology and molecular detection in asymptomatic animals, with few symptomatic cases, sometimes resulting in death (98,101,109,150,182). Pathological findings in a lethal case of a captive titi-monkey (Callicebus nigrifrons) infected by L. infantum were marked emaciation, severe pulmonary edema and hemorrhage, moderate splenomegaly, and lymphadenopathy, hepatic (109).…”