Antibodies against Lutzomyia longipalpis saliva in the fox Cerdocyon thous and the sylvatic cycle of Leishmania chagasi

Abstract

Sera of 11 wild Cerdocyon thous foxes from an endemic area for American visceral leishmaniasis were tested for the presence of antibodies against salivary gland homogenates (SGH) of Lutzomyia longipalpis. All foxes had higher levels of anti-Lu. longipalpis SGH antibodies than foxes from non-endemic areas, suggesting contact between foxes and the vector of visceral leishmaniasis. Sera of humans and dogs living in the same area were also tested for reactivity against Lu. longipalpis SGHs and had a lower proportion of reactivity than foxes. Antibodies against Leishmania chagasi were not detected in any of the foxes, but three foxes showed the presence of parasites in the bone marrow by direct examination, PCR or by infecting the vector. Both humans and dogs had higher levels of anti-Le. chagasi IgG antibodies than C. thous. The finding of an antibody response against saliva of Lu. longipalpis among C. thous together with the broad distribution of the vector in resting areas of infected foxes suggests that the natural foci of transmission of Le. chagasi exists independently of the transmission among dogs and humans.

Insights into the sand fly saliva: Blood-feeding and immune interactions between sand flies, hosts, and Leishmania

“…The existence of a sylvatic cycle independent of the previously well-known domestic cycle was confirmed by using this approach in Brazil [127] and Spain [131]. In both cases, dogs were expected to be the main reservoir hosts of L .…”

“…In Brazil, sylvatic cycle of L . chagasi has been revealed among wild foxes ( Cerdocyon thous ) [127]; high levels of anti– Lu . longipalpis SGH antibodies were found among local foxes but not among those living in regions where Lu .…”

Characterization and speculations on the urbanization of visceral leishmaniasis in Brazil

“…In fact, we recently described the presence of high levels of antibodies against Lu. longipalpis saliva in fox specimens from the periphery of Teresina with evidence of natural infection 22 .…”

Phlebotomus papatasi exposure cross-protects mice against Leishmania major co-inoculated with Phlebotomus duboscqi salivary gland homogenate

“…Sand fly salivary antigens are known to induce specific antibody response in experimentally bitten animals (Volf and Rohousová, 2001), as well as in humans (Gomes et al, 2002;Rohousova et al, 2005) and wild animals (Gomes et al, 2007;Martín-Martín et al, 2014). This antibody response can be utilized as a marker of exposure (reviewed in Gomes and Oliveira (2012)).…”