Autochthonous Outbreak and Expansion of Canine Visceral Leishmaniasis, Uruguay.

We report an outbreak of canine visceral leishmaniasis in Uruguay. Blood specimens from 11/45 dogs tested positive for Leishmania spp. Specimens of Lutzomyia longipalpis sand flies were captured; typing revealed Leishmania infantum. Our findings document an expansion of visceral leishmaniasis to southern South America and risk for vectorborne transmission to humans.

Genetic variability highlights the invasion route of the Lutzomyia longipalpis complex, the main vector of Visceral Leishmaniasis in Uruguay.

In the Americas, the sandfly Lutzomyia longipalpis is the main vector of the parasitic protozoa Leishmania infantum, the etiological agent of visceral leishmaniasis (VL). The Lu. longipalpis species complex is currently discontinuously distributed across the Neotropical region, from Mexico to the north of Argentina and Uruguay. During its continental spreading, it must have adapted to several biomes and temperature amplitudes, when founder events should have contributed to the high genetic divergence and geographical structure currently observed, reinforcing the speciation process. The first report of Lu. longipalpis in Uruguay was in 2010, calling the attention of Public Health authorities. Five years later, the parasite Le. infantum was recorded and in 2015 the first case of VL in canids was reported. Hitherto seven human cases by VL have been reported in Uruguay. Here, we publish the first DNA sequences from the mitochondrial genes ND4 and CYTB of Lu. longipalpis collected in Uruguay, and we used these molecular markers to investigate their genetic variability and population structure. We described four new ND4 haplotypes in a total of 98 (4/98) and one CYTB in a total of 77 (1/77). As expected, we were able to establish that the Lu. longipalpis collected in two localities (i.e. Salto and Bella Unión) from the north of Uruguay are closely related to the populations from neighbouring countries. We also propose that the possible route for the vector arrival to the region may have been through vegetation and forest corridors of the Uruguay River system, as well as it may have benefited from landscape modifications generated by commercial forestation. The ecological-scale processes shaping Lu. longipalpis populations, the identification of genetically homogeneous groups and the gene flow among them must be carefully investigated by using highly sensible molecular markers (i.e. genome wide SNPs) since it will help to the understanding of VL transmission and contribute to the planification of public policies on its control.

Serological and virological survey of hepatitis E virus (HEV) in animal reservoirs from Uruguay reveals elevated prevalences and a very close phylogenetic relationship between swine and human strains.

Hepatitis E virus (HEV) infection is an issue of public health concern in high-income and non-endemic countries. Increasing evidence supports the hypothesis of a zoonotic route as the main mode of infection in this epidemiological setting, since the transmission of genotypes HEV-3 and HEV-4 from reservoirs to humans has been demonstrated. In America, studies have confirmed the circulation of HEV in pig herds but the zoonotic role of wild boars has never been evaluated. Uruguay has a high burden of HEV- associated acute hepatitis, and a close phylogenetic relationship was observed among human HEV-3 strains and European isolates detected in swine. However in this context, swine herds have never been surveyed. Herein is reported a survey of HEV in swine herds, pigs at slaughter-house and free-living wild boar populations. Two-hundred and twenty sera and 150 liver tissue samples from domestic pigs, and 140 sera from wild boars were tested for HEV by ELISA and PCR-based approaches. All tested swine farms resulted seropositive with an overall rate of 46.8%. In turn, 22.1% of the wild boars had anti-HEV antibodies. HEV RNA was detected in 16.6% and 9.3% of liver samples from slaughter-age pigs and adult wild boars sera, respectively. Three strains from domestic pig were also amplified by nested-PCR approaches. By contrast, none of the positive samples obtained from wild boars could be confirmed by nested-PCR. Phylogenetic analysis revealed a very high nucleotide identity among swine strains and sequences obtained from humans in Uruguay. Results showed that HEV is widely distributed among swine herds in Uruguay. Additionally, this study evidences for the first time in the American continent that wild boar populations are a reservoir for HEV, though its zoonotic role remains to be elucidated. Altogether, data presented here suggest a high zoonotic risk of HEV transmission from swine to humans.