Experimental and field investigations on the role of birds as hosts of Leishmania infantum, with emphasis on the domestic chicken.

In this study, 19 chickens were experimentally infected by Leishmania infantum and tissue samples, collected at different times, were cultured and subjected to conventional PCR and/or real time PCR (qPCR) to assess their susceptibility to infection. In addition, 121 serum samples from rural chickens (n=73) and backyard birds (n=48) were tested for anti-L. infantum antibodies by indirect immunofluorescence test. All the 19 animals showed to be molecularly positive at least at one tissue sample. In particular, 26 tissue samples from the experimentally infected chickens were positive on conventional PCR and/or qPCR but no clinical signs or seroconversion were detected and all tissue cultures were negative. Accordingly, all serum samples from rural chickens were negative whereas four (8.4%) from game birds (three Anser anser and one Phasianus colchicus) were positive. These results indicate that chickens are not suitable hosts for L. infantum under experimental condition. The occurrence of anti-L. infantum antibodies in domestic gooses (A. anser) and in a pheasant (P. colchicus) points out their possible role in the epidemiology of visceral leishmaniasis.