RESUMEN
Usutu virus (USUV) is an emerging flavivirus that is maintained in an enzootic cycle with mosquitoes as vectors and birds as amplifying hosts. In Europe, the virus has caused mass mortality of wild birds, mainly among Common Blackbird (Turdus merula) populations. While mosquitoes are the primary vectors for USUV, Common Blackbirds and other avian species are exposed to other arthropod ectoparasites, such as ticks. It is unknown, however, if ticks can maintain and transmit USUV. We addressed this question using in vitro and in vivo experiments and field collected data. USUV replicated in IRE/CTVM19 Ixodes ricinus tick cells and in injected ticks. Moreover, I. ricinus nymphs acquired the virus via artificial membrane blood-feeding and maintained the virus for at least 70 days. Transstadial transmission of USUV from nymphs to adults was confirmed in 4.9% of the ticks. USUV disseminated from the midgut to the haemocoel, and was transmitted via the saliva of the tick during artificial membrane blood-feeding. We further explored the role of ticks by monitoring USUV in questing ticks and in ticks feeding on wild birds in the Netherlands between 2016 and 2019. In total, 622 wild birds and the Ixodes ticks they carried were tested for USUV RNA. Of these birds, 48 (7.7%) carried USUV-positive ticks. The presence of negative-sense USUV RNA in ticks, as confirmed via small RNA-sequencing, showed active virus replication. In contrast, we did not detect USUV in 15,381 questing ticks collected in 2017 and 2019. We conclude that I. ricinus can be infected with USUV and can transstadially and horizontally transmit USUV. However, in comparison to mosquito-borne transmission, the role of I. ricinus ticks in the epidemiology of USUV is expected to be minor.
Asunto(s)
Enfermedades de las Aves , Infecciones por Flavivirus , Flavivirus , Ixodes , Ninfa , Animales , Ixodes/virología , Ixodes/fisiología , Flavivirus/fisiología , Flavivirus/genética , Infecciones por Flavivirus/transmisión , Infecciones por Flavivirus/veterinaria , Infecciones por Flavivirus/virología , Ninfa/virología , Enfermedades de las Aves/virología , Enfermedades de las Aves/transmisión , Aves/virología , Vectores Arácnidos/virología , Vectores Arácnidos/fisiología , Países Bajos , FemeninoRESUMEN
BACKGROUND: Accelerating biodiversity loss necessitates monitoring the potential pathogens of vulnerable species. With a third of New Zealand's avifauna considered at risk of extinction, a greater understanding of the factors that influence microbial transmission in this island ecosystem is needed. We used metatranscriptomics to determine the viruses, as well as other microbial organisms (i.e. the infectomes), of seven bird species, including the once critically endangered black robin (Petroica traversi), on two islands in the remote Chatham Islands archipelago, New Zealand. RESULTS: We identified 19 likely novel avian viruses across nine viral families. Black robins harboured viruses from the Flaviviridae, Herpesviridae, and Picornaviridae, while introduced starlings (Sturnus vulgaris) and migratory seabirds (Procellariiformes) carried viruses from six additional viral families. Potential cross-species virus transmission of a novel passerivirus (family: Picornaviridae) between native (black robins and grey-backed storm petrels) and introduced (starlings) birds was also observed. Additionally, we identified bacterial genera, apicomplexan parasites, as well as a novel megrivirus linked to disease outbreaks in other native New Zealand birds. Notably, island effects were outweighed by host taxonomy as a significant driver of viral composition, even among sedentary birds. CONCLUSIONS: These findings underscore the value of surveillance of avian populations to identify and minimise escalating threats of disease emergence and spread in these island ecosystems. Importantly, they contribute to our understanding of the potential role of introduced and migratory birds in the transmission of microbes and associated diseases, which could impact vulnerable island-endemic species.
Asunto(s)
Enfermedades de las Aves , Aves , Islas , Animales , Nueva Zelanda/epidemiología , Aves/virología , Enfermedades de las Aves/virología , Enfermedades de las Aves/transmisión , Enfermedades de las Aves/microbiología , Enfermedades de las Aves/epidemiología , Virus/aislamiento & purificación , Virus/genética , Virus/clasificación , BiodiversidadRESUMEN
Avian rotaviruses A (RVAs) are occasionally transmitted to animals other than the original hosts across species barriers. Information on RVAs carried by various bird species is important for identifying the origin of such interspecies transmission. In this study, to facilitate an understanding of the ecology of RVAs from wild birds, we characterized all of the genes of an RVA strain, JC-105, that was detected in a fecal sample of a large-billed crow (Corvus macrorhynchos) in Japan. All of the genes of this strain except for the VP4 and VP7 genes, which were classified as novel genotypes (P[56] and G40, respectively), were closely related to those of the avian-like RVA strain detected from a raccoon, indicating the possibility that crows had been involved in the transmission of avian RVAs to raccoons. Our findings highlight the need for further viral investigations in wild birds and mammals to understand the mechanisms of avian-to-mammal RVA transmission.
Asunto(s)
Enfermedades de las Aves , Cuervos , Heces , Genotipo , Filogenia , Infecciones por Rotavirus , Rotavirus , Animales , Cuervos/virología , Japón , Rotavirus/genética , Rotavirus/clasificación , Rotavirus/aislamiento & purificación , Infecciones por Rotavirus/virología , Infecciones por Rotavirus/veterinaria , Infecciones por Rotavirus/transmisión , Enfermedades de las Aves/virología , Enfermedades de las Aves/transmisión , Heces/virologíaRESUMEN
Although wild bird rehabilitation facilities are important for the conservation of wild species, individuals may be kept within the facilities for long periods, consequently posing a risk for the bird to be infected with pathogens to which they are not naturally exposed. In turn, novel pathogens may be introduced through rescued migratory species. Avian malaria and West Nile fever are important avian diseases transmitted by mosquitoes. To understand the transmission dynamics of such diseases at rehabilitation facilities, the ecology of vector mosquitoes, including species composition, seasonality, and feeding behaviors, were explored. Mosquitoes were collected at a wild bird rehabilitation facility and wildlife sanctuary in Japan from 2019 to 2020 using mouth aspirators, sweep nets, and light traps. A total of 2,819 mosquitoes of 6 species were captured, all of which are potential vectors of avian diseases. Culex pipiens pallens and Cx. pipiens form molestus were the dominant species (82.9% of all collected mosquitoes). Density and seasonality differed between sampling locations, presumably because of differences in mosquito behaviors including feeding preferences and responses to climatic factors. Blood-fed Culex mosquitoes fed solely on birds, and many mosquito species are thought to have fed on birds within the facility. Particularly, Cx. pipiens group probably fed on both rescued and free-living birds. The rehabilitation facility may be an important site for the introduction and spread of pathogens because 1) numerous mosquitoes inhabit the hospital and its surroundings; 2) blood-fed mosquitoes are caught within the hospital; 3) there is direct contact between birds and mosquitoes; 4) both birds within the hospital and wild birds are fed upon. Furthermore, blood-fed Cx. pipiens form molestus were observed in the winter, suggesting that pathogens might be transmitted even during the winter when other mosquito species are inactive.
Asunto(s)
Animales Salvajes , Enfermedades de las Aves , Aves , Conducta Alimentaria , Mosquitos Vectores , Animales , Japón/epidemiología , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/transmisión , Culicidae/fisiología , Estaciones del Año , Fiebre del Nilo Occidental/transmisión , Fiebre del Nilo Occidental/veterinaria , Fiebre del Nilo Occidental/epidemiologíaRESUMEN
Disease transmission prediction across wildlife is crucial for risk assessment of emerging infectious diseases. Susceptibility of host species to pathogens is influenced by the geographic, environmental, and phylogenetic context of the specific system under study. We used machine learning to analyze how such variables influence pathogen incidence for multihost pathogen assemblages, including one of direct transmission (coronaviruses and bats) and two vector-borne systems (West Nile Virus [WNV] and birds, and malaria and birds). Here we show that this methodology is able to provide reliable global spatial susceptibility predictions for the studied host-pathogen systems, even when using a small amount of incidence information (i.e., [Formula: see text] of information in a database). We found that avian malaria was mostly affected by environmental factors and by an interaction between phylogeny and geography, and WNV susceptibility was mostly influenced by phylogeny and by the interaction between geographic and environmental distances, whereas coronavirus susceptibility was mostly affected by geography. This approach will help to direct surveillance and field efforts providing cost-effective decisions on where to invest limited resources.
Asunto(s)
Animales Salvajes , Enfermedades Transmisibles Emergentes , Susceptibilidad a Enfermedades , Animales , Animales Salvajes/parasitología , Animales Salvajes/virología , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/transmisión , Quirópteros/virología , Enfermedades Transmisibles Emergentes/epidemiología , Enfermedades Transmisibles Emergentes/transmisión , Enfermedades Transmisibles Emergentes/veterinaria , Coronavirus , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/transmisión , Infecciones por Coronavirus/veterinaria , Bases de Datos Factuales , Ambiente , Monitoreo Epidemiológico , Geografía , Interacciones Huésped-Patógeno , Incidencia , Aprendizaje Automático , Malaria/epidemiología , Malaria/transmisión , Malaria/veterinaria , Filogenia , Medición de Riesgo , Fiebre del Nilo Occidental/epidemiología , Fiebre del Nilo Occidental/transmisión , Fiebre del Nilo Occidental/veterinaria , Virus del Nilo OccidentalRESUMEN
Black flies (Diptera: Simuliidae) are among the most bothersome blood-sucking dipterans causing severe irritation and distress to poultry, wild birds, animals, and humans globally. These insects are vectors of viruses, bacteria, parasitic protozoans, and nematodes of humans and animals. Parasitic protozoa belonging to Haemosporida (Apicomplexa) are distributed worldwide and black flies are the principal vectors of avian haemosporidian parasites of the genus Leucocytozoon, a common parasite of birds. Based on the detection of parasite DNA in insects, 13 black fly species were reported to be potential vectors of Leucocytozoon in Europe. Information about which species of Simulium can play a role in the transmission of Leucocytozoon parasites is insufficient and needs to be developed. The aim of our study was to determine which black fly species are involved in the transmission of Leucocytozoon parasites in the Eastern Europe. The black fly females were collected in Lithuania using entomological net. They were morphologically identified, dissected to prepare salivary glands preparations, and then screened for the presence of Leucocytozoon parasites using microscopy and PCR-based methods. In all, we collected 437 black fly females belonging to eight species. The DNA of Leucocytozoon (genetic lineage lCOCO18) was detected in one of analysed females identified as Simulium maculatum. All salivary gland preparations were negative for the presence of Leucocytozoon sporozoites. Our results included S. maculatum as a potential vector of Leucocytozoon parasites. Increasing the knowledge on vector ecology, behaviour and improving collection methods may be the key to understand the evolution and diversity of these parasites.
Asunto(s)
Enfermedades de las Aves/parasitología , Haemosporida/fisiología , Insectos Vectores/parasitología , Infecciones Protozoarias en Animales/transmisión , Simuliidae/parasitología , Animales , Enfermedades de las Aves/transmisión , Aves , ADN/aislamiento & purificación , ADN Protozoario/aislamiento & purificación , Femenino , Haemosporida/genética , Humanos , Lituania , Filogenia , Infecciones Protozoarias en Animales/parasitología , Glándulas Salivales/parasitologíaRESUMEN
Parasitism is one of the most common consumer strategies and contributes a large portion to biological diversity. Trematodes in the family Diplostomidae are common in freshwater ecosystems worldwide, often residing in the eyes or brain of fish and then infecting fish-eating birds as adults. As a result, some species have broad geographic distributions due to the bird host's motility. In contrast to the cosmopolitan nature of diplostomids, only a single species, Tylodelphys darbyi, has been identified in New Zealand to date, and only from the South Island. Tylodelphys darbyi has a 3-host life cycle consisting of an unidentified snail, a freshwater fish (Gobiomorphus cotidianus), and the Australasian crested grebe (Podiceps cristatus australis). To date, T. darbyi has been found in 2 locations, Lake Hayes, in the eyes of G. cotidianus, and Lake Wanaka, adults recovered from grebes. Considering the near ubiquity of the fish host in New Zealand, it is likely the bird, listed as nationally vulnerable, is the limiting factor in the range of T. darbyi. Up to 10 G. cotidianus were sampled from 10 mountain lakes known to have populations of grebe in the Otago and Canterbury regions of New Zealand's South Island. The eyes of all fish were examined and any metacercariae present were set aside for genetic analysis. In addition to expanding the known range of T. darbyi to at least 4 water bodies across the South Island, 2 new taxa of diplostomid were identified. A lens-infecting metacercariae clustered with Diplostomum spathaceum, while the metacercariae from the humor clustered with Diplostomum baeri.
Asunto(s)
Infecciones Parasitarias del Ojo/veterinaria , Enfermedades de los Peces/parasitología , Trematodos/fisiología , Infecciones por Trematodos/veterinaria , Animales , Biodiversidad , Enfermedades de las Aves/parasitología , Enfermedades de las Aves/transmisión , Aves , Infecciones Parasitarias del Ojo/parasitología , Infecciones Parasitarias del Ojo/transmisión , Enfermedades de los Peces/transmisión , Peces , Lagos/parasitología , Nueva Zelanda , Alineación de Secuencia/veterinaria , Trematodos/anatomía & histología , Trematodos/clasificación , Trematodos/genética , Infecciones por Trematodos/parasitología , Infecciones por Trematodos/transmisiónRESUMEN
In this study, changes in cloacal temperature and clinical manifestations due to very virulent infectious bursal disease virus (vvIBDV) infection in pigeons (Columba livia domestica) and transmission to chickens were demonstrated. Thirty pigeons (3-6 weeks old) and thirty chickens (3 weeks old) divided into 4 groups (I-IV) were used for this study. Group I comprised of 10 uninoculated pigeons only; II comprised of 10 inoculated pigeons and 10 sentinel chickens; III comprised of 10 sentinel pigeons and 10 inoculated chickens, while IV comprised of 10 uninoculated chickens only. Pigeons in group II and chickens in group III were each inoculated with 0.20 mL (titre of 109.76CID50/mL) of vvIBDV (Nigerian strain). Cloacal temperature was monitored and clinical manifestations scored post-inoculation (pi). Results indicated significant (P < 0.05) pyrexia at 2 days pi (dpi), mild clinical signs and no mortality in inoculated pigeons. Significant (P < 0.05) pyrexia at 2-4 dpi, severe clinical signs and mortality (50%; 60%) were observed in inoculated and sentinel chickens. IBDV antigen and antibody were detected in pigeons and chickens. Pigeons showed response to vvIBDV infection thus suggesting susceptibility of pigeons to IBD. Sentinel chickens presented clinical manifestations of IBD and this suggests transmission from pigeons to chickens. This study therefore documents pyrexia and clinical manifestations due to vvIBDV infection in pigeons and successful transmission of the virus between pigeons and chickens.
Asunto(s)
Enfermedades de las Aves/virología , Infecciones por Birnaviridae/veterinaria , Pollos , Cloaca/fisiología , Columbidae , Virus de la Enfermedad Infecciosa de la Bolsa/patogenicidad , Animales , Enfermedades de las Aves/fisiopatología , Enfermedades de las Aves/transmisión , Infecciones por Birnaviridae/fisiopatología , Infecciones por Birnaviridae/transmisión , Infecciones por Birnaviridae/virología , Virus de la Enfermedad Infecciosa de la Bolsa/fisiología , Enfermedades de las Aves de Corral/fisiopatología , Enfermedades de las Aves de Corral/transmisión , Enfermedades de las Aves de Corral/virología , TemperaturaRESUMEN
Arthropod vectors are frequently exposed to a diverse assemblage of parasites, but the consequence of these infections on their biology and behavior are poorly understood. We experimentally evaluated whether the ingestion of a common protozoan parasite of avian hosts (Haemoproteus spp.; Haemosporida: Haemoproteidae) impacted the survivorship of Culex quinquefasciatus (Say) (Diptera: Culicidae). Blood was collected from wild northern cardinals (Cardinalis cardinalis) in College Station, Texas, and screened for the presence of Haemoproteus spp. parasites using microscopic and molecular methods. Experimental groups of Cx. quinquefasciatus mosquitoes were offered Haemoproteus-positive cardinal blood through an artificial feeding apparatus, while control groups received Haemoproteus-negative cardinal blood or domestic canary (Serinus canaria domestica) blood. Culex quinquefasciatus mosquitoes exposed to Haemoproteus infected cardinal blood survived significantly fewer days than mosquitoes that ingested Haemoproteus-negative cardinal blood. The survival of mosquitoes fed on positive cardinal blood had a median survival time of 18 days post-exposure and the survival of mosquitoes fed on negative cardinal blood exceeded 50% across the 30 day observation period. Additionally, mosquitoes that fed on canary controls survived significantly fewer days than cardinal negative controls, with canary control mosquitoes having a median survival time of 17 days. This study further supports prior observations that Haemoproteus parasites can be pathogenic to bird-biting mosquitoes, and suggests that Haemoproteus parasites may indirectly suppress the transmission of co-circulating vector-borne pathogens by modulating vector survivorship. Our results also suggest that even in the absence of parasite infection, bloodmeals from different bird species can influence mosquito survivorship.
Asunto(s)
Culex/fisiología , Culex/parasitología , Haemosporida/fisiología , Mosquitos Vectores/fisiología , Mosquitos Vectores/parasitología , Passeriformes/parasitología , Animales , Enfermedades de las Aves/parasitología , Enfermedades de las Aves/transmisión , Canarios/sangre , Canarios/parasitología , ADN Protozoario/sangre , Passeriformes/sangre , Reacción en Cadena de la Polimerasa/veterinaria , Probabilidad , Modelos de Riesgos Proporcionales , Infecciones Protozoarias en Animales/parasitología , Infecciones Protozoarias en Animales/transmisión , TexasRESUMEN
Philophthalmus is a genus of globally distributed parasitic eye flukes with some members of the genus found in disparate locales. In particular, Philophthalmus gralli, a zoonotic trematode, appears to be a relatively new introduction to the Americas, facilitated by spillover from the invasive snails Melanoides tuberculata (red-rimmed melania) and Tarebia granifera (quilted melania), which were introduced via the aquarium trade, and perhaps furthered by avian dispersal. Given that two known intermediate hosts of Philophthalmus flukes are actively expanding their range as a result of human activities, we hypothesize that this spread is also associated with the spread of Philophthalmus flukes. To address this, we systematically reviewed the literature and examined whether the global expansion of P. gralli flukes is associated with the spread of invasive snails M. tuberculata and T. granifera. Here, we show that (1) specimens of P. gralli are only found in intermediate snail hosts M. tuberculata or T. granifera, suggesting intermediate host specificity for these 2 species, and (2) specimens of P. gralli have rarely been found outside the ranges (native and introduced) of M. tuberculata or T. granifera. Given the importance of distribution information of parasites in the role of identifying parasite invasions, we also review the known distribution of all Philophthalmus species. Considering recent outbreaks in humans and wild and domestic animal species, the continued spread of Philophthalmus presents a potential threat to veterinary and public health and conservation.
Asunto(s)
Enfermedades de las Aves/parasitología , Echinostomatidae/fisiología , Gastrópodos/parasitología , Infecciones por Trematodos/veterinaria , Zoonosis/transmisión , Animales , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/transmisión , Salud Global , Humanos , Infecciones por Trematodos/epidemiología , Infecciones por Trematodos/transmisión , Zoonosis/epidemiología , Zoonosis/parasitologíaRESUMEN
We describe for the first time the genetic and antigenic characterization of 18 avian avulavirus type-6 viruses (AAvV-6) that were isolated from wild waterfowl in the Americas over the span of 12 years. Only one of the AAvV-6 viruses isolated failed to hemagglutinate chicken red blood cells. We were able to obtain full genome sequences of 16 and 2 fusion gene sequences from the remaining 2 isolates. This is more than double the number of full genome sequences available at the NCBI database. These AAvV-6 viruses phylogenetically grouped into the 2 existing AAvV-6 genotype subgroups indicating the existence of an intercontinental epidemiological link with other AAvV-6 viruses isolated from migratory waterfowl from different Eurasian countries. Antigenic maps made using HI assay data for these isolates showed that the two genetic groups were also antigenically distinct. An isolate representing each genotype was inoculated in specific pathogen free (SPF) chickens, however, no clinical symptoms were observed. A duplex fusion gene based real-time assay for the detection and genotyping of AAvV-6 to genotype 1 and 2 was developed. Using the developed assay, the viral shedding pattern in the infected chickens was examined. The chickens infected with both genotypes were able to shed the virus orally for about a week, however, no significant cloacal shedding was detected in chickens of both groups. Chickens in both groups developed detectable levels of anti-hemagglutinin antibodies 7 days after infection.
Asunto(s)
Animales Salvajes/virología , Antígenos Virales/inmunología , Infecciones por Avulavirus/veterinaria , Avulavirus/genética , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/virología , Genotipo , Migración Animal , Animales , Avulavirus/clasificación , Avulavirus/inmunología , Avulavirus/aislamiento & purificación , Enfermedades de las Aves/transmisión , Canadá/epidemiología , Pollos/virología , Cloaca/virología , Genoma Viral , Pruebas de Hemaglutinación , Filogenia , Enfermedades de las Aves de Corral/virología , Organismos Libres de Patógenos Específicos , Esparcimiento de VirusRESUMEN
Although parrot species are infrequently infected by hemoparasites in the wild, some fatal infections have been reported in captive individuals. Conversely birds of prey are frequently infected by hemoparasites. In this study, 193 captive birds from Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) centers in Madrid, Spain, belonging to orders Psittaciformes, Accipitriformes, Strigiformes, and Falconiformes, were blood-sampled in search of parasite infections. Molecular and microscopic analyses were conducted to detect parasites of the following genera: Haemoproteus, Plasmodium, Leucocytozoon, Trypanosoma, Babesia, and Lankesterella. Infections by microfilariae and Coccidia were also searched in blood samples. Surprisingly, infections by Haemoproteus syrnii, a common parasite from owls, were detected in the cadavers of two species of parrots, Trichoglossus haematodus and Psittacula cyanocephala. The same haplotype was also detected in the cadavers of two owl species, Tyto alba and Strix rufipes. All these birds were housed and died in the same center. Infections by species of Plasmodium, Leucocytozoon, and Trypanosoma were also found in different species of raptors. Nocturnal raptors (Strigiformes) show significantly higher prevalence of infection by blood parasites than diurnal raptors (Falconiformes and Accipitriformes). In conclusion, a potential fatal transmission of Haemoproteus syrnii, from Strigiformes to Psittaciformes species, is reported and several infections by different blood parasites were detected in birds of prey. These results emphasize the importance of increasing prevention measures to avoid or reduce the transmission of blood parasites among birds from different species housed in these types of centers.
Asunto(s)
Enfermedades de las Aves/parasitología , Haemosporida/genética , Infecciones Protozoarias en Animales/parasitología , Psittaciformes/parasitología , Estrigiformes/parasitología , Animales , Enfermedades de las Aves/transmisión , Haplotipos , FilogeniaRESUMEN
Beginning 01 January 2016, for all animals transferred into the collection, Disney's Animal Kingdom used a risk-based process that relies on pathogen hazard identification and then assessment and mitigation of the risk for each identified pathogen hazard. Data on morbidity, mortality, and disease introduction was compared for birds transferred in pre- and post-risk-based processes used during the period 2013-2018. When assessing morbidity within 3 mo of acquisition, logistic regression revealed that birds entering "straight to collection" had lower morbidity rates than those entering with either "standard quarantine" or "risk-based standard quarantine" methods (P = 0.032). Mortality within 3 mo of acquisition was not significantly different between straight-to-collection and standard quarantine or risk-based standard quarantine methods (P = 0.40). In addition, no transmissible pathogens of concern were introduced with acquired birds using either method. Implementation of a risk-based approach to animal transfers between zoos and aquariums may be an alternative method that does not pose a greater risk to animal morbidity or mortality while still protecting the collection from disease introduction.
Asunto(s)
Crianza de Animales Domésticos , Animales de Zoológico , Enfermedades de las Aves/prevención & control , Cuarentena/veterinaria , Bienestar del Animal , Animales , Enfermedades de las Aves/mortalidad , Enfermedades de las Aves/transmisión , Aves , Estudios Retrospectivos , Factores de RiesgoRESUMEN
BACKGROUND: Culicoides biting midges (Diptera, Ceratopogonidae) are known vectors of avian Haemoproteus parasites. These parasites cause diseases, pathology and even mortality in birds. The diversity of biting midges in Europe is great, but only four Culicoides species are known to be vectors of avian Haemoproteus parasites. In general, our knowledge about the role of the particular Culicoides species in the transmission of Haemoproteus parasites remains insufficient. Information gaps hinder a better understanding of parasite biology and the epizootiology of parasite-caused diseases. The aim of this study was to determine new Culicoides species involved in the transmission of Haemoproteus parasites. METHODS: Biting midges were collected using a UV trap as well as sticky traps installed in bird nest boxes. Individual parous females were diagnosed for the presence of haemoproteids using both PCR-based and microscopic methods. RESULTS: We collected and dissected 232 parous Culicoides females from 9 species using a UV trap and 293 females from 11 species from bird nest boxes. Culicoides obsoletus was the dominant species collected using a UV trap, and Culicoides kibunensis dominated among midges collected in nest boxes. PCR-based screening showed that 5.2% of parous biting midges collected using a UV trap and 4.4% of midges collected from nest boxes were infected with avian haemosporidian parasites. Haemoproteid DNA was detected in C. kibunensis, Culicoides pictipennis, Culicoides punctatus, Culicoides segnis and Culicoides impunctatus females. The sporozoites of Haemoproteus minutus (genetic lineages hTURDUS2 and hTUPHI01) were detected in the salivary glands of two C. kibunensis females using microscopy, and this finding was confirmed by PCR. CONCLUSIONS: Culicoides kibunensis was detected as a new natural vector of Haemoproteus minutus (hTURDUS2 and hTUPHI01). Haemoproteid DNA was detected in females from five Culicoides species. This study contributes to the epizootiology of avian Haemoproteus infections by specifying Culicoides species as vectors and species that are likely to be responsible for the transmission of haemoproteids in Europe.
Asunto(s)
Enfermedades de las Aves/transmisión , Aves/parasitología , Ceratopogonidae/parasitología , Haemosporida/aislamiento & purificación , Insectos Vectores/parasitología , Infecciones Protozoarias en Animales/transmisión , Animales , Enfermedades de las Aves/parasitología , Citocromos b/genética , Femenino , Haemosporida/clasificación , Haemosporida/genética , FilogeniaRESUMEN
Studies contrasting parasite prevalence and host-parasite community structure between pristine and disturbed environments will improve our understanding of how deforestation affects disease transmission and parasite extinction. To determine how infection rates of a common and diverse group of avian blood parasites (Plasmodium and Haemoproteus) respond to changes in avian host composition after mining, we surveyed 25 bird communities from pristine forests (two forest types: plateau and hillside) and reforested sites in Northeast Amazonia. Infection rates and both parasite and avian host community structure exhibited considerable variation across the deforestation gradient. In opposition to the emerging pattern of lower avian haemosporidian prevalence in disturbed tropical forests in Africa, we show that secondary forests had higher haemosporidian prevalence in one of the largest mining areas of Amazonia. The dissimilarity displayed by bird communities may explain, in part, the higher prevalence of Haemoproteus in reforested areas owing to the tolerance of some bird species to open-canopy forest habitat. On the other hand, deforestation may cause local extinction of Plasmodium parasites due to the loss of their avian hosts that depend on closed-canopy primary forest habitats. Our results demonstrate that forest loss induced by anthropogenic changes can affect a host-parasite system and disturb both parasite transmission and diversity.
Asunto(s)
Apicomplexa/aislamiento & purificación , Enfermedades de las Aves/epidemiología , Interacciones Huésped-Parásitos , Animales , Apicomplexa/genética , Biodiversidad , Enfermedades de las Aves/parasitología , Enfermedades de las Aves/transmisión , Aves , Brasil/epidemiología , Código de Barras del ADN Taxonómico/veterinaria , Ecosistema , Bosques , Geografía , Haemosporida/genética , Haemosporida/aislamiento & purificación , Minería , Plasmodium/genética , Plasmodium/aislamiento & purificación , PrevalenciaRESUMEN
West Nile virus (WNV) is a mosquito-borne Flavivirus that can affect birds, horses, and humans, and is the only zoonotic Flavivirus that has been identified in six continents. In Brazil, until 2010, there was no evidence of WNV circulation. Recently, the virus was isolated from a horse with encephalitis, and the first human cases were registered in Brazil. Despite that, there is still no information on the enzootic cycle of this virus in birds or wildlife. This study aimed to investigate whether there is evidence of WNV circulation among wild birds from Southern Brazil. For this, we used free-living wild raptors (live-trapped or rescued) as potential sentinels to investigate the presence of WNV antibodies using ELISA and plaque reduction neutralization test (PRNT) assay. In addition, the presence of nucleic acids from Flavivirus family members was investigated. None of the birds sampled presented clinical findings compatible with WNV. Of the 200 serum samples from birds of prey belonging to 21 species, ten (5%) were positive for the presence of WNV antibodies on ELISA testing. The PRNT test did not confirm the ELISA results, but indicated that three birds had possibly been exposed to Saint Louis encephalitis virus (SLEV). All samples were negative for Flavivirus RNA. The results presented here evince the need for permanent surveillance for emerging flaviviruses in Brazil, as well as for a contingency policy in the case of human/animal outbreaks, particularly in high-risk areas.
Asunto(s)
Animales Salvajes/virología , Enfermedades de las Aves/virología , Rapaces/inmunología , Rapaces/virología , Fiebre del Nilo Occidental/veterinaria , Virus del Nilo Occidental/inmunología , Animales , Animales Salvajes/inmunología , Anticuerpos Antivirales/sangre , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/transmisión , Brasil , Flavivirus/clasificación , Flavivirus/inmunología , Flavivirus/aislamiento & purificación , Humanos , Estudios Seroepidemiológicos , Fiebre del Nilo Occidental/epidemiología , Virus del Nilo Occidental/genética , Virus del Nilo Occidental/aislamiento & purificaciónRESUMEN
Microfilariae (MF) are the immature stages of filarial nematode parasites and inhabit the blood and dermis of all classes of vertebrates, except fish. Concurrent ingestion of MF and arboviruses by mosquitoes can enhance mosquito transmission of virus compared to when virus is ingested alone. Shortly after being ingested, MF penetrate the mosquito's midgut and may introduce virus into the mosquito's hemocoel, creating a disseminated viral infection much sooner than normal. This phenomenon is known as microfilarial enhancement. Both American Robins and Common Grackles harbor MF-that is, Eufilaria sp. and Chandlerella quiscali von Linstow (Spirurida: Onchocercidae), respectively. We compared infection and dissemination rates in Culex pipiens L. mosquitoes that fed on birds with and without MF infections that had been infected with West Nile virus (WNV). At moderate viremias, about 107 plaque-forming units (pfu)/ml of blood, there were no differences in infection or dissemination rates among mosquitoes that ingested viremic blood from a bird with or without microfilaremia. At high viremias, >108.5 pfu/ml, mosquitoes feeding on a microfilaremic Grackle with concurrent viremia had significantly higher infection and dissemination rates than mosquitoes fed on viremic Grackles without microfilaremia. Microfilarial enhancement depends on the specific virus, MF, and mosquito species examined. How virus is introduced into the hemocoel by MF differs between the avian/WNV systems described here (i.e., leakage) and various arboviruses with MF of the human filarid, Brugia malayi (Brug) (Spirurida: Onchocercidae) (i.e., cotransport). Additional studies are needed to determine if other avian species and their MF are involved in the microfilarial enhancement of WNV in nature.
Asunto(s)
Enfermedades de las Aves/transmisión , Filariasis/veterinaria , Pájaros Cantores , Fiebre del Nilo Occidental/veterinaria , Virus del Nilo Occidental/fisiología , Animales , Enfermedades de las Aves/parasitología , Enfermedades de las Aves/virología , Filariasis/parasitología , Microfilarias/fisiología , Especificidad de la Especie , Fiebre del Nilo Occidental/transmisión , Fiebre del Nilo Occidental/virologíaRESUMEN
Introduction. Chlamydia psittaci is primarily a pathogen of birds but can also cause disease in other species. Equine reproductive loss caused by C. psittaci has recently been identified in Australia where cases of human disease were also reported in individuals exposed to foetal membranes from an ill neonatal foal in New South Wales.Hypothesis/Gap Statement. The prevalence of C. psittaci in association with equine reproductive over time and in different regions of Australia is not known.Aim. This study was conducted to detect C. psittaci in equine abortion cases in Australia using archived samples spanning 25 years.Methodology. We tested for C. psittaci in 600 equine abortion cases reported in Australia between 1994 to 2019 using a Chlamydiaceae real-time quantitative PCR assay targeting the 16S rRNA gene followed by high-resolution melt curve analysis. Genotyping and phylogenetic analysis was performed on positive samples.Results. The overall prevalence of C. psittaci in material from equine abortion cases was 6.5â%. C. psittaci-positive cases were detected in most years that were represented in this study and occurred in Victoria (prevalence of 7.6â%), New South Wales (prevalence of 3.9â%) and South Australia (prevalence of 15.4â%). Genotyping and phylogenetic analysis showed that the C. psittaci detected in the equine abortion cases clustered with the parrot-associated 6BC clade (genotype A/ST24), indicating that infection of horses may be due to spillover from native Australian parrots.Conclusion. This work suggests that C. psittaci has been a signiï¬cant agent of equine abortion in Australia for several decades and underscores the importance of taking appropriate protective measures to avoid infection when handling equine aborted material.
Asunto(s)
Aborto Séptico/microbiología , Enfermedades de las Aves/transmisión , Chlamydophila psittaci/clasificación , Enfermedades de los Caballos/epidemiología , Psitacosis/veterinaria , Animales , Proteínas de la Membrana Bacteriana Externa/genética , Enfermedades de las Aves/microbiología , Chlamydophila psittaci/genética , Chlamydophila psittaci/aislamiento & purificación , Femenino , Enfermedades de los Caballos/microbiología , Caballos , Control de Infecciones , Nueva Gales del Sur/epidemiología , Loros/microbiología , Filogenia , Embarazo , Psitacosis/epidemiología , ARN Ribosómico 16S/genética , Estudios RetrospectivosRESUMEN
BACKGROUND: Usutu virus (USUV) is a rapidly spreading zoonotic arbovirus (arthropod-borne virus) and a considerable threat to the global avifauna and in isolated cases to human health. It is maintained in an enzootic cycle involving ornithophilic mosquitoes as vectors and birds as reservoir hosts. Despite massive die-offs in wild bird populations and the detection of severe neurological symptoms in infected humans, little is known about which mosquito species are involved in the propagation of USUV. METHODS: In the present study, the vector competence of a German (i.e. "Central European") and a Serbian (i.e. "Southern European") Culex pipiens biotype molestus laboratory colony was experimentally evaluated. For comparative purposes, Culex torrentium, a frequent species in Northern Europe, and Aedes aegypti, a primarily tropical species, were also tested. Adult female mosquitoes were exposed to bovine blood spiked with USUV Africa 2 and subsequently incubated at 25 °C. After 2 to 3 weeks saliva was collected from each individual mosquito to assess the ability of a mosquito species to transmit USUV. RESULTS: Culex pipiens biotype molestus mosquitoes originating from Germany and the Republic of Serbia and Cx. torrentium mosquitoes from Germany proved competent for USUV, as indicated by harboring viable virus in their saliva 21 days post infection. By contrast, Ae. aegypti mosquitoes were relatively refractory to an USUV infection, exhibiting low infection rates and lacking virus in their saliva. CONCLUSIONS: Consistent with the high prevalences and abundances of Cx. pipiens biotype molestus and Cx. torrentium in Central and Northern Europe, these two species have most likely played a historic role in the spread, maintenance, and introduction of USUV into Germany. Identification of the key USUV vectors enables the establishment and implementation of rigorous entomological surveillance programs and the development of effective, evidence-based vector control interventions.