Dogs play an important role in the transmission of Leishmania infantum but epidemiologic and clinical studies of canine tegumentary leishmaniasis (CTL) are scarce. In an endemic area of human American Tegumentary Leishmaniasis (ATL) caused by Leishmania braziliensis, we determine the prevalence and incidence of both CTL and subclinical (SC) L. braziliensis infection in dogs and evaluated if the presence of dogs with the CTL or the SC L. braziliensis infection is associated with the occurrence of human ATL. SC infection in healthy animals and CTL in animals with ulcers was determined by PCR on biopsied healthy skin or on the ulcer or detecting antibodies against soluble leishmania antigen. We compared the occurrence of human ATL in homes with dogs with CTL or SC infection with control homes without dogs or with dogs without CTL or SC infection. The prevalence of SC infection was 35% and of CTL 31%. The incidence of SC infection in dogs was 4.6% and of CTL was 9.3%. The frequency of ATL in humans was 50% in homes with infected dogs and 13% in homes without L. braziliensis infection in dogs. CTL and SC infection is highly prevalent, and dogs may participate in the transmission chain of L. braziliensis.

Leishmaniasis is a disease caused by parasites of Leishmania genus and transmitted by sand fly vectors. Tegumentary leishmaniasis is the most prevalent clinical outcome in Latin America afflicting people from 18 countries. In Panama, leishmaniasis has annual incidence rates as high as 3000 cases, representing therefore one of the major public health problems. In endemic regions, L. panamensis is responsible for almost eighty percent of the human cases that present different clinical outcomes. This differences in disease outcomes could be result of the local interplay between L. panamensis variants and human hosts with different genetic backgrounds. The genetic diversity of L. panamensis in Panama has only been partially explored, and the variability reported for this species is based on few studies restricted to small populations and/or with poor resolutive markers at low taxonomic levels. Accordingly, in this study we explored the genetic diversity of sixty-nine L. panamensis isolates from different endemic regions of Panama using a MLST approach based on four housekeeping genes (Aconitase, ALAT, GPI and HSP70). Two to seven haplotypes per locus were identified, and regional differences in L. panamensis genetic diversity were observed. Genotype analysis evidenced the circulation of thirteen L. panamensis genotypes, a fact that might have important implications for the local control of the disease.