Ecobiology of Haemagogus leucocelaenus arbovirus vector in the golden lion tamarin translocation area of Rio de Janeiro, Brazil.

Significant pathogens that have resurfaced in humans originate from transmission from animal to human populations. In the Americas, yellow fever cases in humans are usually associated with spillover from non-human primates via mosquitoes. The present study characterized the prevalence of the yellow fever vector Haemagogus leucocelaenus in Rio de Janeiro, Brazil. The Atlantic Forest fragment chosen is an area of translocation of the golden lion tamarin (Leontopithecus rosalia), where 10 ovitraps were installed to collect mosquito eggs in Fazenda Três Irmãos, at Silva Jardim city, from March 2020 to October 2022. A total of 1514 eggs were collected, of which 1153 were viable; 50% belonged to medically important mosquito species and 24% to the yellow fever vector species, Hg. leucocelaenus. The months of December 2020 (n = 252), November 2021 (n = 188), and January 2022 (n = 252) had the highest densities of this vector. Haemagogus leucocelaenus was positively correlated with temperature (r = 0.303) and humidity (r = 0.48), with eggs hatching up to the 15th immersion with higher abundance of females. Implementing mosquito monitoring for arbovirus activity can help protect both the golden lion tamarin and human populations from the threat of arbovirus transmission.

Interaction of Haemagogus leucocelaenus (Diptera: Culicidae) and Other Mosquito Vectors in a Forested Area, Rio de Janeiro, Brazil.

The yellow fever (YF) virus has been detected throughout Brazil, with the occurrence of human cases, cyclic epizootics, and its isolation from Haemagogus janthinomys and Hg. leucocelaenus. We assessed the seasonal occurrence, egg abundancy, and oviposition interaction of mosquito vector species captured at a Private Natural Heritage Reserve in the Atlantic Forest biome. A total of 2943 eggs and 1538 mosquito larvae were collected from which 1231 belonged to entomologically important species. Ovitraps were used to collect immature mosquitoes from September 2019 to January 2021. The Mann-Whitney test was used to assess the differences in the abundance of eggs between rainy and dry seasons. Kruskal-Wallis and Dunn's post hoc tests were used to evaluate the significance of the differences in the number of individuals from vector species. The highest percentage of mosquito vector eggs were collected during the rainy season, from December to February. Most eggs recovered from ovitraps belonged to the species Hg. leucocelaenus, representing 85% of all mosquito eggs identified. The other species had lower abundances and percentages: Aedes terrens (7%), Haemagogus janthinomys (5%) and Aedes albopictus (3%). The species that shared breeding sites with a higher frequency were Hg. leucocelaenus and Hg. janthinomys, with a statistically positive correlation (ρ = 0.74). This finding suggests that maybe the presence of Hg. leucocelaenus eggs acted as an attractant for Hg. janthinomys or vice versa. An understanding of mosquito oviposition behavior is necessary for the development of surveillance and control approaches directed against specific pathogen vectors of medical and veterinary importance.

Bionomy of Mosquitoes in Bamboo Internodes in an Atlantic Forest Remnant of the State of Rio De Janeiro, Brazil.

Living bamboo stalks are one of the most specialized habitats for mosquito oviposition and immature development. Most of the mosquito species that breed in these habitats are sylvatic, and some are of importance for public health as possible vectors of pathogens. Perforated internodes are a very specialized environment due to the difficulty of access. Furthermore, due to their relatively simple fauna, they represent a valuable model for ecological studies that may be applicable to more complex environments. This study aims to assess the mosquito bionomics of species raised in bamboo internodes. Therefore, the diversity of mosquito species and the influence of abiotic variables (pH and temperature) on the distribution of mosquitoes that breed in this habitat were analyzed. The study area is a fragment of Atlantic Forest within the Association of da Armada (ATA) in Nova Iguaçu, state of Rio de Janeiro, Brazil. Immature mosquitoes were sampled with suction tubes (mouth aspirators) between August 2017 and July 2018. A total of 3,170 larvae were collected in 5 bamboo plants, each with 8 stalks perforated. Of these, 688 larvae reached the adult stage, representing 10 genera and 19 species. The most common species were Culex neglectus (43%), Trichoprosopon digitatum (22%), Culex iridescens (8%), Sabethes identicus (7%), and Orthopodomyia albicosta (7%). The richness of the immatures collected in the ATA was 19 species, with a diversity of 1.10 and Shannon evenness of 0.57. A diverse composition of Culicidae in bamboo stalks was found, although dominance was low.

Expression and antigenic analysis of the recombinant TRP36 protein from Ehrlichia canis São Paulo strain for serologic tests.

Ehrlichia canis is the main etiological agent of canine monocytic ehrlichiosis (CME), a globally canine infectious disease. In Brazil, CME is considered to be endemic, and its prevalence can reach 65% in some states. The diagnosis of ehrlichiosis is important for treatment and epidemiological purposes. The E. canis TRP36 (Tandem Repeat Protein) protein elicits the earliest acute-phase antibody response observed during the course of the disease. This study aimed to generate the recombinant TRP36 protein from E. canis São Paulo strain and to evaluate its potential as a tool for the serologic diagnosis of CME. The E. canis São Paulo isolate was cultivated in DH82 lineage cells, and its genomic DNA was obtained. The bacterial DNA fragment encoding the entire ORF of TRP36 was cloned into the pBAD/Thio-TOPO vector and transformed into Escherichia coli DH10B competent cells with the trp36-bearing plasmid for protein expression. To evaluate the protein antigenicity, 16 canine serum samples were previously tested (by PCR and the commercial SNAP®4Dx® serological test). The results were in accordance with the SNAP®4Dx® test. Experiments using this recombinant protein as an antigen, targeting the development of a serologic test based on ELISA methodology, are the next step to produce a reliable, affordable and useful diagnostic tool for CME in Brazil.

An autochthonous case of malaria in Petrópolis, Rio de Janeiro, Brazil

In Brazil, about 99% of malaria cases occur in Brazil's Legal Amazon. In all other states malaria has been noted but with imported cases. Here we describe an autochthonous case of malaria in Petropolis city, Rio de Janeiro. The clinical symptoms and epidemiological aspects were compatible with malaria and the presence of Plasmodium was confirmed through molecular diagnostic testing performed on a blood sample from a local resident after an ecological hike in the Atlantic Forest on the outskirts of town. After treatment with chloroquine and primaquine, the symptoms ceased. This city was regarded malaria free for many years although it still presents the malaria vectors. Considering that Plasmodium sp. is an important cause of morbidity and mortality worldwide, this clinical case serves as an epidemiological alert.

Pesquisa de hemoglobinopatias em cães da região metropolitana do Rio de Janeiro portadores de anemia crônica / Search for hemoglobinopathies in dogs with chronic anemia in the metropolitan region of Rio de Janeiro

Talassemias e hemoglobinopatias são condições hereditárias encontradas em humanos de todo o mundo. Em medicina veterinária, o polimorfismo de hemoglobinas tem sido estudado em animais de produção, mas não existem relatos de hemoglobinopatias em cães, e os estudos envolvendo o polimorfismo de hemoglobinas nesta espécie são escassos. Com o objetivo de pesquisar variantes da hemoglobina em cães, foram coletadas amostras de sangue de 202 caninos de variadas raças, sendo 130 portadores de anemia crônica (Grupo Experimental) e 72 animais clinicamente saudáveis (Grupo Controle). Estas amostras foram submetidas à eletroforese alcalina de hemoglobinas, que permitiu a separação e quantificação das frações de hemoglobina por densitometria, e posteriormente submetidas à eletroforese de hemoglobinas em meio ácido, técnica utilizada em medicina humana para a separação de frações de hemoglobinas variantes que não se diferenciam em meio alcalino. O eritrograma e índices hematimétricos foram obtidos concomitantemente. Os métodos utilizados demonstraram que a HbA é o maior componente da hemoglobina canina, e que uma pequena quantidade de HbA2 pode ser detectada em uma parcela dos animais avaliados, sendo que a maioria dos caninos apresentava exclusivamente HbA em sua composição. Concluiu-se que a presença ou ausência de HbA2 não interfere nos índices hematimétricos dos animais avaliados, e que quando comparadas as hemoglobinas dos grupos Experimental e Controle, não são observadas diferenças na distribuição das frações destas, além de não serem observadas hemoglobinas variantes nos caninos avaliados.(AU)

Thalassemias and hemoglobinopathies are hereditary conditions found in humans throughout the world. In veterinary medicine, hemoglobin polymorphism has been studied in production animals, but there are no reports of hemoglobinopathies in dogs, and studies involving hemoglobin polymorphism in this species are scarce. In order to search for hemoglobin variants in dogs, blood samples were collected from 202 dogs of various breeds, being 130 patients with chronic anemia (Experimental Group) and 72 clinically healthy animals (Control Group). These samples were subjected to alkaline electrophoresis of hemoglobin, which permitted separation and quantification of hemoglobin fractions by densitometry, and then subjected to hemoglobin electrophoresis in an acid medium, a technique used in human medicine for the separation of variant fractions of hemoglobin that do not differentiate in an alkaline medium. The erythrogram and RBC indices were obtained concurrently. The methods demonstrated that HbA is the major component of canine hemoglobin, and a small amount of HbA2 can be detected in some of the evaluated animals, and most dogs showed only HbA in its composition. It was concluded that the presence or absence of HbA2 does not interfere with RBC indices of evaluated animals, and the comparison between the hemoglobin of Experimental and Control groups showed no differences in fractions distribution between them, and there was no hemoglobin variants in evaluated canines.(AU)

Rickettsiae-infected ticks in an endemic area of spotted fever in the State of Minas Gerais, Brazil

A study on tick-borne rickettsiosis was developed in the county of Santa Cruz do Escalvado, State of Minas Gerais, Brazil, where a clinical case of the disease, confirmed by necropsy, had been reported. Of the 1,254 ticks collected 1,061 belonged to the Amblyomma genus, 57 to the Rhipicephalus sanguineus species, 81 to Boophilus microplus, and 46 to Anocentor nitens. The hemolymph test associated with Gimenez staining showed that 18 of the 221 A. cajennense specimens, 1 of the 16 R. sanguineous, 1 of the 22 B. microplus, 3 of the A. nitens, and 1 of the A. ovale contanined rickettsia-like microorganisms. Only 3 A. cajennense ticks were positive under direct immunofluorescence. A. cajennense was the only species found on humans.