Brazil, the largest Latin American country, is underrepresented in genomic research despite boasting the world’s largest recently admixed population. In this study, we generated 2723 high-coverage whole-genome sequences from the Brazilian population, including urban, rural, and riverine communities representing diverse ethnic backgrounds. We reveal the impressive genomic diversity of Brazilians, identifying >8 million previously unknown variants, including 36,637 predicted deleterious and potentially affecting population health. We found a positive correlation between these deleterious variants and ancestry. Brazilian genomes are a global haplotype mosaic shaped by nonrandom mating, with peak admixture in the 18th and 19th centuries. Within this diversity, ancestry-specific haplotypes exhibit an uneven spatiotemporal distribution. We also identified putatively selected genes in this diverse population, primarily linked to fertility, immune response, and metabolic traits.

Mucosal leishmaniosis (ML) is a severe clinical form of leishmaniosis. Complex factors related to the parasite and the host are attributed to the development of mucosal lesions. Leishmania RNA virus 1 (LRV1) can disrupt immune response, and may be the main determinant of severity of the disease; it should be investigated. To study the existence of clinical differences between patients with ML with endosymbiosis by LRV1 and. those without it. A cross-sectional cohort study with clinical evaluation, polymerase chain reaction (PCR) detection of Leishmania, species classification, and search of LRV1 was performed. Only patients with confirmed diagnosis of ML by positive PCR and with nasal mucosa injuries were included in this analysis. Out of 37 patients, 30 (81.1%) were diagnosed with Leishmania braziliensis, five (13.5%) with Leishmania guyanensis, and two (5.4%) with mixed infection of L. braziliensis and L. guyanensis. LVR1 virus was present in 26 (70.3%) of the cases. Correlation between clinical phenotype and presence of LRV1 was not observed, although the frequency of the virus is two-fold higher in mucosal lesions than that found in the literature on skin lesions in the same geographical area.

This study had the aim of ascertaining the sandfly fauna and possible presence of Leishmania in these insects, collected in caves in the state of Rondônia, Brazil. Collections were conducted in eight caves located in two different areas of this state. Leishmania in the sandflies collected was detected using the polymerase chain reaction (PCR). This was the first study on sandflies from caves in Rondônia and, among the total of 1,236 individuals collected, 24 species and 10 genera were identified. The species Evandromyia georgii was collected for the first time in Rondônia and the most abundant species were Trichophoromyia ubiquitalis with 448 individuals (36.2%), followed by T. octavioi with 283 (22.9%) and E. georgii with 179 (14.5%). For the PCR, 17 pools were analyzed and five pools were positive (for T. auraensis in three pools and for Nyssomyia shawi and N. antunesi in one pool each). The kDNA region was amplified and the presence of Leishmania DNA was confirmed. The sandfly fauna in these caves can be considered diverse in comparison with similar studies in other regions. It may be that some species use caves as a temporary shelter and breeding site, while other species live exclusively in this environment. The detection of Leishmania DNA indicates that this pathogen is circulating in cave environments and that further studies are needed in order to ascertain the risks of infection by leishmaniasis in these locations with high touristic potential.

Blood samples were collected from 99 domestic dogs from the urban and rural areas of the Lábrea municipality, state of Amazonas, Brazil. Canine serum samples were tested by immunofluorescence assay against Rickettsia spp., which revealed that only 3.0% (1/33) and 7.6% (5/66) of the dogs from urban and rural areas, respectively, reacted positively to at least one Rickettsia species. DNA was extracted from canine blood and tested by a battery of PCR assays targeting protozoa of the genera Babesia and Hepatozoon, and bacteria of the genera Rickettsia and Ehrlichia and family Anaplasmataceae. All samples were negative in the PCR assays targeting the genera Babesia, Hepatozoon, Ehrlichia and Rickettsia. For Anaplasmataceae, 3% (1/33) and 39.4% (26/66) of the urban and rural dogs, respectively, yielded amplicons that generated DNA sequences 100% identical to the corresponding sequence of Wolbachia endosymbiont of Dirofilaria immitis. Because of these results, all canine DNA samples were further tested in a PCR assay targeting filarial nematodes, which was positive for 18.2% (6/33) and 57.6% (38/66) urban and rural dogs, respectively. Filarial-PCR products generated DNA sequences 100% identical to D. immitis. While tick-borne infections were rare in Lábrea, D. immitis infection rates were among the highest reported in South America.

O presente artigo descreve o primeiro relato de larvas de Eustrongylides sp. em Hoplias malabaricus Bloch, 1794 (Characiformes: Erythrinidae) no Estado de Rondônia, Amazônia Ocidental, Brasil, sendo mais um parasita com a possibilidade de contaminar humanos no Estado

The Amazon region may present a high diversity of endoparasites with a high degree of endemism. In this sense, this study describes the endoparasite fauna in freshwater fish from the Upper Juruá, in the Western Amazon. The study was carried out around the municipalities of Cruzeiro do Sul, state of Acre, and Guajará, state of Amazonas, Brazil. Fish were caught between periods of droughts and floods, using passive and active sampling methods. In the laboratory, specimens were biometrically analysed and necropsied. As a result, a total of 23,740 endoparasites were recorded, belonging to 62 species, with 91 new host reports and 91 new occurrences for the Western Amazon. Nematoda and Digenea were the most diverse and abundant groups, and the increase in host fish richness and diversity influenced the diversity and richness of endoparasites in the environments. In this sense, the present study expands the number of new reports, and contributes data on the distribution and richness of endoparasites for South America.