LAUSR

Purpose: Canine leishmaniosis is caused by Leishmania infantum, or also called in the New World L. chagasi. It is considered to be a major potentially fatal zoonotic infection where the domestic dog is the main reservoir. This infection is worldwide and reported with a higher incidence in tropical and subtropical areas such as South America where the number of infected dogs is estimated in the millions. No molecular data has been available on this disease in French Guiana. The aim of this study was molecular investigation of occurrence of leishmania in the blood of dogs in this region. Methods & Materials: Since 2016, blood samples were collected on a total of 98 dogs from French Guiana and 26 other dogs coming from continental France, were sampled before and after a 4-month mission in the same region. The samples were tested by a qPCR to quantify L. infantum kinetoplast DNA. Some positive samples were confirmed and species were identified, after sequencing, by using two standard PCR systems: i) a pan-Leishmania system was designed, targeting 28S rRNA gene and ii) PCR generic primers to amplify a segment of the rRNA internal transcribed spacer 2 (ITS2) from multiple Leishmania species. Results: The results show at least 4.08% (3/98) were positive to this pathogen and two (2/26) dogs returned positive although they were negative to begin with; one of them had an ulcer on the pastern. This last had 9 × 107 Leish/mL of blood, 1.3 × 1010 Leish/mL from ulcer swab and around 4.3 × 106 Leish/g of bone marrow. In general, the parasite load was from 2.5 Leish/mL to 8 × 1013 Leish/mL of dog’s blood. Sequencing analyses identified L. infantum specie. Conclusion: The detection of L. infantum in local dogs in French Guiana and in dogs from metropolitan France after coming back from French Guiana, provide evidence that this region is endemic for canine leishmaniosis. It highlights the need for active surveillance in canine population and implementation of control measures. Competent vectors in this region are yet to be identified.