Trypanosoma vivax Ziemann is a parasite that affects both wild and domestic ungulates and is transmitted mechanically via tabanids and other blood-sucking insects in the Americas. A total of 621 blood samples from water buffaloes (Bubalus bubalis (Linnaeus) (Artiodactyla: Bovidae), and 184 ectoparasite samples (Amblyomma cajennense (Fabricius) sensu stricto and Rhipicephalus (Boophilus) microplus (Canestrini) (Acari: Ixodidae), and Haematopinus tuberculatus (Burmeister) (Phthiraptera: Haematopinidae)) were obtained from 60 farms in the State of Pará, Brazilian Amazon. Twelve buffalo blood samples (1.89%) and 11 ectoparasites (6%) were positive for T. vivax based on the cathepsin L-like gene. All sequences were 99% similar to T. vivax from northeastern Brazil (EU753788) in amplified PCR assays on each of the hosts tested.

Species of the Leishmania genus parasitize mammals in the New World and have life cycles alternating between vertebrates and invertebrates. Visceral Leishmaniasis is an important zoonosis which has wild and domestic canids as important known reservoirs, and the genetic diversity of Leishmania (Leishmania) infantum in Brazil it is not yet known. Leishmaniasis is a serious disease with a wide geographical distribution and an incidence of two million cases per year. In the current study we address the main aspects of Visceral Leishmaniasis.

Species of the genus Leishmania parasitize mammals and have life cycles that alternate between vertebrate and invertebrate hosts. Most species develop in a hematophagous arthropod and infect a specific vertebrate host that may belong to diverse orders and families. Visceral leishmaniasis is a chronic zoonosis with a wide geographic distribution, affecting 350 million people globally, mostly in areas with a high risk of infection. In Brazil, this disease not only has a high incidence but is also expanding to new areas, both in urban centers and rural areas, including territories with tribal communities, due to increasing human intervention. The objective of this study was to perform cathepsin L-like gene-based molecular diagnosis of Leishmania infantum in the indigenous Tapirapé ethnic group in the state of Mato Grosso. From the 372 individuals assessed, only 0.8% (3/372) tested positive for L. infantum, all from the same village (Urubu Branco). Despite the small number of infected individuals, this study demonstrates the first human cases of Leishmania infantum infection in this population, suggesting the need for regular monitoring of visceral leishmaniasis in the area and leading to a broad discussion on the planning and implementation of public health measures for the indigenous population, while respecting their distinctive territories and culture.

OBJECTIVE: The aim of the present study was to determine the current seroprevalence of canine leishmaniasis (CanL) among domiciled dogs, factors associated with seropositivity, circulating Leishmania species and spatial analysis, in six municipalities in the Sertão and São Francisco mesoregions, which are located in the state of Pernambuco, Brazil. METHODS: Blood samples from 330 dogs were analyzed using serological and molecular assays: dual path platform (DPP®); enzyme-linked immunosorbent assay (ELISA), indirect fluorescent antibody test (IFAT) and polymerase chain reaction (PCR). The nucleotide sequences of four gene markers (kDNA, cathepsin L-like, SSU-rDNA and gGAPDH) were explored to perform a phylogenetic analysis. RESULTS: The overall seroprevalence was 13% (43/330) in dogs that were simultaneously positive according to DPP® ELISA and IFAT, consisting of 13.9% (23/165) in Sertão and 12.1% (20/165) in São Francisco. The factors associated with high prevalence of L. infantum antibodies in dogs comprised living in the municipality of Petrolina (P = 0.045) and presenting ocular lesions (P = 0.049) (P ≤ 0.05). Significant clusters of positive dogs were found in rural areas. The positivity values obtained through PCR based on the genes kDNA and cathepsin L-like were 6.7% (22/330) and 2.4% (8/330), respectively. In the phylogenetic analysis, it was observed that all the isolates obtained showed 100% similarity to Leishmania infantum. CONCLUSION: For the first time, L. infantum was confirmed as the etiological agent of CanL in this region. Thus, assessment of the genetic structure of populations of Leishmania spp. is important for understanding the patterns for transmission of CanL.