Original article Leishmania tropica in the black rat (Rattus rattus): persistence and transmission from asymptomatic host to sand fly vector

Black rats (Rattus rattus) receiving Leishmania tropica injected intradermally into the ear were studied for the persistence of parasites and infectivity to natural sand fly vector. The mammalian host, the parasite, and the vector all originated from the endemic focus of Urfa, Turkey. Rats did not d...

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Bibliographic Details
Main Authors: Phlebotomus Sergenti, Milena Svobodová A, Jan Votýpka A, Luc Nicolas B, Petr Volf A
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Published: 2002
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.568.1322
http://www.parazitologie.cz/protozoologie/Personal homepages/Votypka/L-tropica in rats QRT-PCR.pdf
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Summary:Black rats (Rattus rattus) receiving Leishmania tropica injected intradermally into the ear were studied for the persistence of parasites and infectivity to natural sand fly vector. The mammalian host, the parasite, and the vector all originated from the endemic focus of Urfa, Turkey. Rats did not develop lesions or any apparent signs of disease, although at the site of inoculation they harboured live parasites capable of infecting sand flies. The number of L. tropica amastigotes detected in the inoculated ear by quantitative real-time PCR ranged from 5 × 103 to 106. Parasite DNA was also present in the tail and contralateral ear, sites distant from inoculation. After feeding on the ears of asymptomatic rats, Phlebotomus sergenti became infected with L. tropica. The average infection rate was 2.9%, and rats were infective for sand flies even 24 months post infection. The infectivity of the vertebrate host for insect vector was therefore not linked to the symptomatic stage of the infection. Such lack of correlation between clinical symptoms and infectivity to sand flies was reported previously for Leishmania infantum, the agent of visceral leishmaniasis; for species causing cutaneous leishmaniasis, however, this is the first evidence of transmission from a host without any visible cutaneous changes. If confirmed in the field, transmission from the asymptomatic host would be of great epidemiological significance. © 2003 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.