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Biting midges (Culicoides) are vectors of many pathogens of medical and veterinary importance, but their viromes are poorly characterized compared to certain other hematophagous arthropods, e.g., mosquitoes and ticks. The goal of this study was to use metagenomics to identify viruses in Culicoides from Mexico. A total of 457 adult midges were collected in Chihuahua, northern Mexico, in 2020 and 2021, and all were identified as female Culicoides reevesi. The midges were sorted into five pools and homogenized. An aliquot of each homogenate was subjected to polyethylene glycol precipitation to enrich for virions, then total RNA was extracted and analyzed by unbiased high-throughput sequencing. We identified six novel viruses that are characteristic of viruses from five families (Nodaviridae, Partitiviridae, Solemoviridae, Tombusviridae, and Totiviridae) and one novel virus that is too divergent from all classified viruses to be assigned to an established family. The newly discovered viruses are phylogenetically distinct from their closest known relatives, and their minimal infection rates in female C. reevesi range from 0.22 to 1.09. No previously known viruses were detected, presumably because viral metagenomics had never before been used to study Culicoides from the Western Hemisphere. To conclude, we discovered multiple novel viruses in C. reevesi from Mexico, expanding our knowledge of arthropod viral diversity and evolution.

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Bluetongue Virus (BTV) and Epizootic Hemorrhagic Disease Virus (EHDV) are Orbiviruses primarily transmitted by their biological vector, Culicoides spp. Latreille, 1809 (Diptera: Ceratopogonidae). These viruses can infect a diverse range of vertebrate hosts, leading to disease outbreaks in domestic and wild ruminants worldwide. This study, conducted at the Belo Horizonte Municipal Parks and Zoobotany Foundation (FPMZB-BH), Minas Gerais, Brazil, focused on Orbivirus and its vectors. Collections of Culicoides spp. were carried out at the FPMZB-BH from 9 December 2021 to 18 November 2022. A higher prevalence of these insects was observed during the summer months, especially in February. Factors such as elevated temperatures, high humidity, fecal accumulation, and proximity to large animals, like camels and elephants, were associated with increased Culicoides capture. Among the identified Culicoides spp. species, Culicoides insignis Lutz, 1913, constituted 75%, and Culicoides pusillus Lutz, 1913, 6% of the collected midges, both described as competent vectors for Orbivirus transmission. Additionally, a previously unreported species in Minas Gerais, Culicoides debilipalpis Lutz, 1913, was identified, also suspected of being a transmitter of these Orbiviruses. The feeding preferences of some Culicoides species were analyzed, revealing that C. insignis feeds on deer, Red deer (Cervus elaphus) and European fallow deer (Dama dama). Different Culicoides spp. were also identified feeding on humans, raising concerns about the potential transmission of arboviruses at the site. In parallel, 72 serum samples from 14 susceptible species, including various Cervids, collected between 2012 and 2022 from the FPMZB-BH serum bank, underwent Agar Gel Immunodiffusion (AGID) testing for BTV and EHDV. The results showed 75% seropositivity for BTV and 19% for EHDV. Post-testing analysis revealed variations in antibody presence against BTV in a tapir and a fallow deer and against EHDV in a gemsbok across different years. These studies confirm the presence of BTV and EHDV vectors, along with potential virus circulation in the zoo. Consequently, implementing control measures is essential to prevent susceptible species from becoming infected and developing clinical diseases.

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Culicoides species adults were collected in light traps located on the coast of Elota, Sinaloa, Mexico, in February 2022. All specimens were females, and it was determined based on their morphology that they belonged to the Culicoides variipennis complex. The identification of the species was carried out by means of a comparative analysis of genetic sequences of the cytochrome c oxidase subunit I gene, which resulted in C. occidentalis, this being its first report in Sinaloa and its third nationwide.

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Bluetongue virus (BTV) is an arbovirus that is transmitted between domestic and wild ruminants by Culicoides spp. Its worldwide distribution depends on competent vectors and suitable environmental ecosystems that are becoming affected by climate change. Therefore, we evaluated whether climate change would influence the potential distribution and ecological niche of BTV and Culicoides insignis in Peru. Here, we analyzed BTV (n = 145) and C. insignis (n = 22) occurrence records under two shared socioeconomic pathway scenarios (SSP126 and SSP585) with five primary general circulation models (GCMs) using the kuenm R package v.1.1.9. Then, we obtained binary presence-absence maps and represented the risk of transmission of BTV and niche overlapping. The niche model approach showed that north and east Peru presented suitability in the current climate scenario and they would have a decreased risk of BTV, whilst its vector would be stable and expand with high agreement for the five GCMs. In addition, its niche overlap showed that the two niches almost overlap at present and would completely overlap with one another in future climate scenarios. These findings might be used to determine the areas of highest priority for entomological and virological investigations and surveillance in order to control and prevent bluetongue infections in Peru.

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An updated list of biting midges of the genus Culicoides inhabiting Ecuador is provided. Entomological investigations were carried out from July 2010 to May 2019 using CDC light traps in three Ecuadorian regions (Amazon basin, Andean (foothills and highlands) and Pacific Coast). A total of 12,073 Culicoides specimens from seven subgenera and nine species groups were collected. More species and higher variation were found in the Amazon basin than in either of the Andes regions or coastal sites. A total of 53 species were identified. Of these, 15 are herein reported as new species records for Ecuador: Culicoides acotylus Lutz, C. aitkeni Wirth & Blanton, C. benarrochi Ortiz & Mirsa, C. carvalhoi Wirth & Blanton, C. freitasi Wirth & Blanton, C. ginesi Ortíz, C. lopesi Barretto, C. lyrinotatus Wirth & Blanton, C. profundus Santarém, Felippe-Bauer & Trindade, C. pseudoreticulatus Santarém, Felippe-Bauer & Castellón, C. quasiparaensis Clastrier, C. vernoni Wirth & Blanton, C. youngi Wirth & Barreto and two new species. Our results show that the updated list of the Ecuadorian Culicoides fauna comprises 70 species. This inventory highlights the presence of species that have been incriminated as vectors of disease elsewhere in animals and humans, mainly C. insignis and C. paraensis.

Title: Une liste actualisée de la faune des Culicoides (Diptera, Ceratopogonidae) de l'Équateur. Abstract: Une liste actualisée des Culicoides vivant en Équateur est fournie. Des enquêtes entomologiques ont été menées de juillet 2010 à mai 2019 à l'aide de pièges lumineux CDC dans trois régions équatoriennes (le bassin amazonien, les Andes (piémont et hautes terres) et la côte Pacifique). Au total, 12 073 spécimens de Culicoides de sept sous-genres et neuf groupes d'espèces ont été collectés. Plus d'espèces et une variation plus élevée ont été trouvées dans le bassin amazonien que dans les régions des Andes ou les sites côtiers. Au total, 53 espèces ont été identifiées. Parmi celles-ci, 15 sont signalées ici comme nouvelles espèces pour l'Équateur : Culicoides acotylus Lutz, C. aitkeni Wirth & Blanton, C. benarrochi Ortiz & Mirsa, C. carvalhoi Wirth & Blanton, C. freitasi Wirth & Blanton, C. ginesi Ortíz, C. lopesi Barretto, C. lyrinotatus Wirth & Blanton, C. profundus Santarém, Felippe-Bauer & Trindade, C. pseudoreticulatus Santarém, Felippe-Bauer & Castellón, C. quasiparaensis Clastrier, C. vernoni Wirth & Blanton, C. youngi Wirth & Barreto et deux nouvelles espèces. Nos résultats montrent que la liste actualisée de la faune culicoïde équatorienne comprend 70 espèces. Cet inventaire met en évidence la présence d'espèces qui ont été incriminées ailleurs comme vecteurs de maladies chez l'animal et l'homme, principalement C. insignis et C. paraensis.

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Culicoides biting midges are capable to transmit Oropouche virus, Bluetongue virus and Mansonella spp. This study aimed to assess the utility of DNA barcode as an alternative method in the Culicoides species identification. The study was conducted in Jamari National Forest. Biting midges were collected using HP light traps during four months, February, April, August and October 2018. Insects were morphologically identified to the species level, and rest of the body were subjected to DNA extraction and PCR targeting a fragment of the cytochrome c oxidase subunit I (COI) gene, which were analyzed and deposited in GenBank. A phylogenetic gene tree was reconstructed using RAxML software, and the sequences were assigned at Molecular Operational Taxonomic Unit (MOTU) level by species delimitation algorithms. According to morphological approach, 18 species of 2 subgenera and 7 species groups were identified. A total of 191 new COI barcodes from 18 species were generated. Of these, fifteen species have been deposited for the first time in all datasets in the world. These sequences allowed the correct identification of 188 and 187 specimens according to the BM and BCM criteria, respectively. The intraspecific genetic distances ranged from 0 to 16.5%, while the interspecific ones ranged from 2.1 to 27.1%. The nominal species Culicoides glabellus and C. tetrathyris splitted into three and two MOTUs, respectively, except for mPTP, indicating a cryptic diversity in these species. Also, sequences of C. pseudodiabolicus formed two MOTUs using all algorithms, except for PTP and ABGD, suggesting the existence of two potential species. In contrast, some barcodes of C. quasiparaensis and C. paraensis merged into a single MOTU, which can be explained by the complex characteristics of the paraensis group, since these species have similar morphological characters. Here, we provided the first COI barcodes for biting midges in Rondônia and Brazil, and demonstrates that these are sufficient to discriminate between some species.

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Haematophagous insects cause major economic losses by both direct damage and the transmission of pathogens. However, the biting Diptera species in the Caribbean region have been poorly documented. During 2021, CDC downdraft suction traps with UV light were employed to assess both the species occurrence and blood meal sources across three different habitats in the Dominican Republic. Eighteen species of mosquitoes (n = 274), six species of Culicoides (n = 803), two black fly species (n = 2), and one species of muscid fly (n = 25) were identified at species-level by morphology and/or molecular phylogenetic approaches based on the mitochondrial cytochrome c oxidase subunit 1 (COI). Engorged mosquito (n = 5) and Culicoides (n = 28) females showed host preferences derived exclusively from mammals (cows and pigs), except Culex species containing the blood of chickens. Our study provides new records of the Diptera Dominican catalogue (Culex salinarius for the Greater Antilles, Culicoides jamaicensis for Hispaniola, and Culicoides haitiensis and Culicoides borinqueni for the Dominican Republic), the first available COI DNA sequences of different Diptera in the GenBank, some pictures of diagnostic features of closely related specimens, spatial distribution across the habitats studied, and new insights on their feeding preferences in the Caribbean region.

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Culicoides biting midges (Diptera: Ceratopogonidae) are biting nuisances and arbovirus vectors of both public health and veterinary significance in Trinidad. We compared sampling methods to define the behaviour and bionomics of adult Culicoides populations at a commercial dairy goat farm. Three static trap designs were compared: (a) Centre for Disease Control (CDC) downdraft UV trap; (b) CDC trap with an incandescent bulb and (c) CDC trap with semiochemical lure consisting of R-(-)-1-octen-3-ol and CO2 (no bulb). Sweep netting was used to define diel periodicity. A total of 30,701 biting midges were collected using static traps, dominated by female Culicoides furens (>70% of trap collections across all three designs). There was no significant difference in the Margalef's index between the three traps; however, trap designs A and C collected a significantly greater number of individuals than trap B, and trap C gained highest species richness. The greatest species richness and abundance of Culicoides collected by sweep net was observed between 6:00 and 6:15 pm and notable differences in the crepuscular activity pattern of several species were identified. Comparative data on Culicoides species richness, abundance, sex and reproductive status is discussed and can be used to improve surveillance strategies, research designs and risk management.

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Biting midges are widespread in Brazilian natural ecosystems. However, deforestation and other activities that impact the environment are reducing natural habitats where biting midges proliferate. The objective of this study was to verify whether there is variation in the composition, richness, abundance, and seasonality of biting midges between wild and rural environments, in a forest area with intense deforestation. Biting midges were captured using 6 traps installed at an average height of 1.5 m in the peridomicile, intradomicile, and deciduous seasonal forests, once a month from May 2012 to April 2013. In total, 2,182 specimens of 13 species of the genus Culicoides were captured. Species richness was similar in the intradomicile (13 species), forest (12), and peridomicile (11), but species diversity was greater in the peridomicile (H' = 0.803) compared with the intradomicile (H' = 0.717) and forest (H' = 0.687). The order of species dominance varied between the forest (Culicoides paucienfuscatus Barbosa > Culicoides leopodoi Ortiz > Culicoides foxi Ortiz > Culicoides ignacioi Forattini) and peridomicile + intradomicile habitats (C. paucienfuscatus > C. foxi > C. filariferus Hoffman > C. ignacioi). The activity of these dipterans was strongly influenced by meteorological variables, as biting midges are predominant in the rainy season (80.7% of specimens), when higher rainfall, relative humidity, and lower temperatures prevail. The abundance of biting midges was higher in the peridomicile + intradomicile (83.7% of specimens) compared with the degraded forest (16.3%), a result that reflects the loss of forest habitat due to intense and progressive deforestation.

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Culicoides biting midges are insects involved in the transmission of filarial nematodes, protozoans, and viruses. Greater knowledge of Culicoides blood meal sources could improve our understanding of parasite transmission cycles. Our study used molecular tools to evaluate the blood meal sources of Culicoides biting midges from sylvatic environments. This study was conducted in Jamari National Forest, Rondônia, Brazil. Culicoides were captured using HP light traps positioned at ground level (1.5 m above ground) and in canopy (15 m above ground). To identify blood meal sources, females were subjected to DNA extraction and PCR targeting the cytb gene fragment, and the obtained sequences were analyzed and compared with sequences from GenBank. DNA extraction and PCR were performed on 455 Culicoides females, and blood meal sources were identified in 186 females. Thirty Culicoides specimens were collected from the Potosi trail and 156 were collected from the Santa Maria trail. A total of 22 species were captured; all 22 species were collected in canopy (100%) but only three species were collected at ground level (13.6%). The cytb fragment was amplified in 162 of 186 samples. Sample sequencing identified cytb DNA from nine blood-meal sources: Pauxi sp., Psophia viridis, Ramphastos tucanus tucanus, Choloepus didactylus, Choloepus hoffmanni, Tamandua tetradactyla, Ateles chamek, Homo sapiens and Pithecia irrorata. We observed that several different blood meal sources were utilized by a high diversity of Culicoides species. The abundance of Culicoides in the canopy may be related to the fact that the majority of blood meal hosts feed in treetops. We observed that C. (Hoffmania) sp. and C. coutinhoi tend to be more generalist, feeding on a range of mammals and piciform, gruiform and galliform birds. This data improves our knowledge of the feeding profile of biting midges from forest environments and should serve as a future basis for defining zoonotic transmission cycles.

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The species of the Culicoides genus are hematophagous, and some of them are vectors of important human and animal diseases. This group of insects is distributed worldwide, varying according to local species. Knowledge of the geographic distribution of specific species is crucial for the development and implementation of control strategies. The aim of this work was to investigate the occurrence of Culicoides in the state of Alagoas in northeast Brazil. Midges were captured with CDC light traps, and their identification and morphological analyses were performed by the Ceratopogonidae Collection of the Oswaldo Cruz Foundation (FIOCRUZ/CCER) in Rio de Janeiro, Brazil. Morphological analyses were performed using the key to Culicoides from the guttatus group and comparison with other deposited specimens. DNA sequencing, genetic analysis and comparison with sequences in the Genbank database, confirmed the identification of the flies as Culicoides insignis. This was the first formal report of C. insignis being found in Alagoas.

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PURPOSE: Mexico is considered endemic for Leishmania; recent reports indicate autochthonous human and canine leishmaniasis caused by Leishmania mexicana in Sinaloa state. Lutzomyia sand fly are the primary vector of the parasite, although no records of phlebotomine vectors of Leishmania exist from Sinaloa. Other hematophagous dipterans, like Culicoides, could represent possible vectors of Leishmania in absence of phlebotomines. The known distribution of Culicoides includes the southern portion of Sinaloa state, in northwestern Mexico, with records of Culicoides furens. However, no studies have demonstrated the presence of Leishmania in C. furens or its possible participation in the parasite's life cycle in Mexico. This study, therefore, sought to detect DNA of Leishmania in C. furens captured in an endemic area of autochthonous canine leishmaniasis in northwestern Mexico. METHODS: Culicoides were captured with CDC light traps, identified morphologically, and organized in pools. DNA was extracted, and used to amplify the ribosomal ITS1 region of Leishmania. PCR products were digested with HaeIII endonuclease; the banding patterns obtained were compared to reference strains. RESULTS: Leishmania mexicana DNA was detected in five out of nine pools (55%) of female C. furens. CONCLUSION: This study offers the first evidence of L. mexicana DNA in C. furens, in an endemic area of canine leishmaniasis in northwestern Mexico, where no evidence exists of the presence of phlebotomine sand fly.

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BACKGROUND: We assessed the impact of two sand fly insecticide interventions (insecticide spraying and insecticide-impregnated dog collars) on the peridomestic abundance and distribution of mosquitoes (Culicidae) and biting midges (Ceratopogonidae) in western São Paulo (Brazil) in a long-term (42-month) evaluation. Both of these dipteran groups are vectors of diseases of medical and veterinary relevance to humans and domestic animals in Brazil. METHODS: The interventions in the 3-arm stratified randomised control trial were: pheromone + insecticide (PI) (chicken roosts were sprayed with microencapsulated lambda-cyhalothrin; pheromone lure has no effect on the Diptera pests studied here); dog-collars (DC) (dogs fitted with deltamethrin-impregnated collars); and control (C) (unexposed to pyrethroids) were extended by 12 months. During that time, adult mosquitoes and midges were sampled along 280 households at three household locations (inside human dwellings, dog sleeping sites and chicken roosts). RESULTS: We collected 3145 culicids (9 genera, 87.6% Culex spp.) distributed relatively uniformly across all 3 arms: 41.9% at chicken roosts; 37.7% inside houses; and 20.3% at dog sleeping sites. We collected 11,464 Culicoides (15 species) found mostly at chicken roosting sites (84.7%) compared with dog sleeping sites (12.9%) or houses (2.4%). Mosquitoes and Culicoides were most abundant during the hot and rainy season. Increased daytime temperature was marginally associated with increased mosquito abundance (Z = 1.97, P = 0.049) and Culicoides abundance (Z = 1.71, P = 0.087). There was no significant association with daily average rainfall for either group. Household-level mosquito and midge numbers were both significantly reduced by the PI intervention 56% [incidence rate ratio, IRR = 0.54 (95% CI: 0.30-0.97), P ≤ 0.05] and 53% [IRR = 0.47 (95% CI: 0.26-0.85), P ≤ 0.05], respectively, compared to the control intervention. The abundance of both dipteran groups at dog sleeping sites was largely unaffected by the PI and DC interventions. The PI intervention significantly reduced abundance of mosquitoes inside houses (41%) and at chicken roosting sites (48%) and reduced midge abundance by 51% in chicken roosting sites. CONCLUSIONS: Sprayed insecticide at chicken roosting sites reduced the abundance of mosquitoes and midges at the peridomestic level while dog collars had no effect on numbers for any group.

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Bluetongue (BT) is an infectious and non-contagious disease caused by bluetongue virus (BTV) belonging to the genus Orbivirus. It is transmitted by a hematophagous vector, Culicoides sp., to ruminants, particularly to sheep, which are most susceptible to this disease. The main serological tests are agar gel immunodiffusion (AGID), which is recommended by the World Organization for Animal Health (OIE), and the competitive enzyme-linked immunosorbent assay (cELISA), which has the advantage of no cross-reaction with other orbiviruses. The aim was to compare the results of these two tests by conducting them on sera collected from sheep in the state of Paraná, Brazil. From March to October 2017, serum samples were collected from 270 sheep from 10 farms in six mesoregions of Paraná. The samples were subjected to AGID and cELISA to detect antibodies against BTV. Based on the test results, we classified the sheep as low, moderate, and high occurrence. The results demonstrated that 64.81% (175/270) of the sheep were seropositive through the cELISA test, showing a high occurrence, and 41.11% (111/270) were seropositive through the AGID test, indicating a moderate occurrence. The concordance between the tests was moderate (0.51) as determined by the Kappa coefficient. Among the studied farms, 90% (9/10) presented at least one seropositive sheep, and the number of animals tested positive by the cELISA test was higher than those by the AGID test. Favorable climate, which favors the presence and multiplication of the culicoid vector and the occurrence of infection, was the biggest predominant factor responsible for the obtained results. The low occurrence in farms with milder climate suggest that the presence of antibodies also occurs due to the low pathogenicity of circulating serotypes in the different mesoregions studied. It is concluded that BTV infection is present in the sheep herds in Paraná, and the occurrence...(AU)

A língua azul (LA) é uma enfermidade infecciosa e não contagiosa causada por um vírus (VLA) do gênero Orbivirus, transmitida por vetores hematófagos Culicoides sp., aos ruminantes sobretudo aos ovinos, espécie mais susceptível. Os principais testes sorológicos utilizados são a Imunodifusão em Gél de Ágar (IDGA), preconizada pela OIE, e o teste Imunoensaio Enzimático Competitivo (ELISAc), sendo que este tem como vantagem não ocorrer reação cruzada contra outros orbivírus. O objetivo do trabalho foi detectar a presença de anticorpos contra o VLA em ovinos no estado do Paraná através dos testes diagnósticos IDGA e ELISAc. Durante os meses de março a outubro de 2017, colheu-se sangue de 270 ovinos, em 10 propriedades localizadas em seis mesorregiões paranaenses. As amostras foram submetidas aos testes de IDGA e ELISAc para detecção de anticorpos contra o VLA. Baseado nos resultados classificaram-se os rebanhos como baixa, moderada ou elevada ocorrência. Os resultados demonstraram elevada ocorrência através do teste de ELISAc, que apresentou 64,81% (175/270) de ovinos positivos, e moderada ocorrência através do IDGA, com 41,11% (111/270) de ovinos soropositivos. A concordância obtida entre os testes foi moderada (0,51) através do coeficiente Kappa. O número de ovinos reagentes no exame de ELISAc foi maior que o teste de IDGA em todas as propriedades positivas, demonstrando ser superior. O clima propício foi um dos fatores favoráveis para as ocorrências observadas, pois favorece a presença e multiplicação do vetor Culicoide e a ocorrência da infecção. A baixa ocorrência nas propriedades com clima mais ameno sugere que a presença de anticorpos provavelmente ocorra também pela baixa patogenicidade dos sorotipos circulantes nas diferentes mesorregiões estudadas. Conclui-se que há infecção de VLA no rebanho ovino paranaense, e a detecção de anticorpos para o VLA foi moderada, através do teste de IDGA, e elevada, através do teste ELISAc.(AU)

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Bluetongue (BT) is an infectious and non-contagious disease caused by bluetongue virus (BTV) belonging to the genus Orbivirus. It is transmitted by a hematophagous vector, Culicoides sp., to ruminants, particularly to sheep, which are most susceptible to this disease. The main serological tests are agar gel immunodiffusion (AGID), which is recommended by the World Organization for Animal Health (OIE), and the competitive enzyme-linked immunosorbent assay (cELISA), which has the advantage of no cross-reaction with other orbiviruses. The aim was to compare the results of these two tests by conducting them on sera collected from sheep in the state of Paraná, Brazil. From March to October 2017, serum samples were collected from 270 sheep from 10 farms in six mesoregions of Paraná. The samples were subjected to AGID and cELISA to detect antibodies against BTV. Based on the test results, we classified the sheep as low, moderate, and high occurrence. The results demonstrated that 64.81% (175/270) of the sheep were seropositive through the cELISA test, showing a high occurrence, and 41.11% (111/270) were seropositive through the AGID test, indicating a moderate occurrence. The concordance between the tests was moderate (0.51) as determined by the Kappa coefficient. Among the studied farms, 90% (9/10) presented at least one seropositive sheep, and the number of animals tested positive by the cELISA test was higher than those by the AGID test. Favorable climate, which favors the presence and multiplication of the culicoid vector and the occurrence of infection, was the biggest predominant factor responsible for the obtained results. The low occurrence in farms with milder climate suggest that the presence of antibodies also occurs due to the low pathogenicity of circulating serotypes in the different mesoregions studied. It is concluded that BTV infection is present in the sheep herds in Paraná, and the occurrence...

A língua azul (LA) é uma enfermidade infecciosa e não contagiosa causada por um vírus (VLA) do gênero Orbivirus, transmitida por vetores hematófagos Culicoides sp., aos ruminantes sobretudo aos ovinos, espécie mais susceptível. Os principais testes sorológicos utilizados são a Imunodifusão em Gél de Ágar (IDGA), preconizada pela OIE, e o teste Imunoensaio Enzimático Competitivo (ELISAc), sendo que este tem como vantagem não ocorrer reação cruzada contra outros orbivírus. O objetivo do trabalho foi detectar a presença de anticorpos contra o VLA em ovinos no estado do Paraná através dos testes diagnósticos IDGA e ELISAc. Durante os meses de março a outubro de 2017, colheu-se sangue de 270 ovinos, em 10 propriedades localizadas em seis mesorregiões paranaenses. As amostras foram submetidas aos testes de IDGA e ELISAc para detecção de anticorpos contra o VLA. Baseado nos resultados classificaram-se os rebanhos como baixa, moderada ou elevada ocorrência. Os resultados demonstraram elevada ocorrência através do teste de ELISAc, que apresentou 64,81% (175/270) de ovinos positivos, e moderada ocorrência através do IDGA, com 41,11% (111/270) de ovinos soropositivos. A concordância obtida entre os testes foi moderada (0,51) através do coeficiente Kappa. O número de ovinos reagentes no exame de ELISAc foi maior que o teste de IDGA em todas as propriedades positivas, demonstrando ser superior. O clima propício foi um dos fatores favoráveis para as ocorrências observadas, pois favorece a presença e multiplicação do vetor Culicoide e a ocorrência da infecção. A baixa ocorrência nas propriedades com clima mais ameno sugere que a presença de anticorpos provavelmente ocorra também pela baixa patogenicidade dos sorotipos circulantes nas diferentes mesorregiões estudadas. Conclui-se que há infecção de VLA no rebanho ovino paranaense, e a detecção de anticorpos para o VLA foi moderada, através do teste de IDGA, e elevada, através do teste ELISAc.

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Abstract INTRODUCTION: The Culicoides transmit a variety of pathogens. Our aim was to survey the Culicoides species occurring in an Amazonian rural settlement, comparing abundance, richness, and diversity in different environments. METHODS: Culicoides were captured using CDC light traps. The Shannon-Wiener (H') and Rényi indices were used to compare species diversity and evenness between environments, the equitability (J') index was used to calculate the uniformity of distribution among species, and similarity was estimated using the Jaccard similarity index. A permutational multivariate analysis of variance was applied to assess the influence of environment on species composition. A non-metric dimensional scale was used to represent the diversity profiles of each environment in a multidimensional space. RESULTS: 6.078 Culicoides were captured, representing 84 species (45 valid species/39 morphotypes). H' values showed the following gradient: forest > capoeira > peridomicile > forest edge. The equitability J' was greater in capoeira and forests compared to peridomiciles and the forest edge. The population compositions of each environment differed statistically, but rarefaction estimates indicate that environments of the same type possessed similar levels of richness. Species of medical and veterinary importance were found primarily in peridomiciles: C. paraensis, vector of Oropouche virus; C. insignis and C. pusillus, vectors of Bluetongue virus; C. filariferus, C. flavivenula, C. foxi, and C. ignacioi, found carrying Leishmania DNA. CONCLUSIONS: This study indicates that diversity was higher in natural environments than in anthropized environments, while abundance and richness were highest in the most anthropized environment. These findings suggest that strictly wild Culicoides can adapt to anthropized environments.

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Culicoides biting midges, small hematophagous dipterans, are the demonstrated or putative vectors of multiple arboviruses of veterinary and public health importance. Despite its relevance in disease spread, the ceratopogonid genus Culicoides is still a largely neglected group of species, predominantly because the major human-affecting arboviruses are considered to be transmitted by mosquitoes. However, when a pathogen is detected in a certain vector species, a thorough search for further vectors often remains undone and, therefore, the relevant vector species may remain unknown. Furthermore, for many hematophagous arthropods, true vector competence is often merely suspected and not experimentally proven. Therefore, we aim to illuminate the general impact of Culicoides biting midges and to summarize the knowledge about biting midge-borne disease agents using the order Bunyavirales, the largest and most diverse group of RNA viruses, as an example. When considering only viruses evidentially transmitted by Culicoides midges, the Simbu serogroup (genus Orthobunyavirus) is presumably the most important group within the virus order. Its members are of great veterinary importance, as a variety of simbuviruses, e.g., the species Akabane orthobunyavirus or Schmallenberg orthobunyavirus, induces severe congenital infections in pregnant animals. The major zoonotic representative of this serogroup occurs in South and Central America and causes the so-called Oropouche fever, an acute febrile illness in humans.

Assuntos

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Equine encephalosis (EE) is an acute, arthropod-borne, noncontagious, febrile disease of equids. The clinical signs of EE are similar to milder forms of African horse sickness (AHS) and the two diseases can be easily confused. The Equine encephalosis virus (EEV) is a distinct virus species within the genus Orbivirus, family Reoviridae, with ten linear segments of dsRNA genome. Seven distinct serotypes of EEV have been recognised on the basis of sequence analyses of Seg-2. The need for differential diagnosis of similar forms of EE and AHS warranted the development of molecular diagnostic methods for specific detection and identification of EEV. We report the development of quantitative real-time RT-PCR assay for detection of any member of the EEV species targeting the highly conserved EEV Seg-9. Similar serotype-specific qRT-PCR assays were designed for each of the seven EEV serotypes targeting genome Seg-2, encoding the serotype determining VP2 protein. These assays were evaluated using different EEV serotypes and other closely related orbiviruses. They were shown to be EEV virus species-specific, or EEV type-specific capable of detecting 1 to 13 copies of viral RNA in clinical samples. The assays failed to detect RNA from closely related orbiviruses, including AHSV and Peruvian horse sickness virus (PHSV) isolates.

Assuntos

RESUMO

Epizootic hemorrhagic disease virus (EHDV) is an economically important virus that can cause severe clinical disease in deer and to a lesser extent cattle. This study set out to determine and characterize which EHDV serotypes were circulating in Trinidad. Serum and whole blood samples were collected monthly for six months from a cohort of cattle imported to Trinidad from the USA. Results revealed that all the cattle seroconverted to EHDV within six months of their arrival, with EHDV RNA being detected in the samples just prior to antibodies, as expected. Serotyping assays revealed that a single serotype (EHDV-6) was circulating in the cattle. Sequencing of the surface viral protein (VP2) of EHDV-6, followed by phylogenetic analysis, revealed that the Trinidad EHDV-6 strain was closely related to EHDV-6 viruses found in Guadeloupe (2010), Martinique (2010) and USA (2006), with 96-97.2% nucleotide identity. The Trinidad EHDV-6 VP-2 shared 97.2% identity with the Australian EHDV-6 prototype strain, classifying it within the eastern topotype clade. Bayesian coalescent analysis support Australia as the most probable source for the EHDV-6 VP2 sequences in the Americas and Caribbean region and suggests that the they diverged from the Australian prototype strain around 1966 (95% HPD 1941-1979).

Assuntos