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Leptospirosis (caused by pathogenic bacteria in the genus Leptospira ) is prevalent worldwide but more common in tropical and subtropical regions. Transmission can occur following direct exposure to infected urine from reservoir hosts, such as rats, or a urine-contaminated environment, which then can serve as an infection source for additional rats and other mammals, including humans. The brown rat, Rattus norvegicus , is an important reservoir of leptospirosis in urban settings. We investigated leptospirosis among brown rats in Boston, Massachusetts and hypothesized that rat dispersal in this urban setting influences the movement, persistence, and diversity of Leptospira . We analyzed DNA from 328 rat kidney samples collected from 17 sites in Boston over a seven-year period (2016-2022); 59 rats representing 12 of 17 sites were positive for Leptospira . We used 21 neutral microsatellite loci to genotype 311 rats and utilized the resulting data to investigate genetic connectivity among sampling sites. We generated whole genome sequences for 28 Leptospira isolates obtained from frozen and fresh tissue from some of the 59 Leptospira -positive rat kidneys. When isolates were not obtained, we attempted Leptospira genomic DNA capture and enrichment, which yielded 14 additional Leptospira genomes from rats. We also generated an enriched Leptospira genome from a 2018 human case in Boston. We found evidence of high genetic structure and limited dispersal among rat populations that is likely influenced by major roads and/or other unknown dispersal barriers, resulting in distinct rat population groups within the city; at certain sites these groups persisted for multiple years. We identified multiple distinct phylogenetic clades of L. interrogans among rats, with specific clades tightly linked to distinct rat populations. This pattern suggests L. interrogans persists in local rat populations and movement of leptospirosis in this urban rat community is driven by rat dispersal. Finally, our genomic analyses of the 2018 human leptospirosis case in Boston suggests a link to rats as the source. These findings will be useful for guiding rat control and human leptospirosis mitigation efforts in this and other urban settings.
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Gripe Aviar , Animales , Gripe Aviar/epidemiología , Cambio Climático , Aves , Animales SalvajesRESUMEN
H5Nx highly pathogenic avian influenza (HPAI) viruses of clade 2.3.4.4 have caused outbreaks in Europe among wild and domestic birds since 2016 and were introduced to North America via wild migratory birds in December 2021. We examined the spatiotemporal extent of HPAI viruses across continents and characterized ecological and environmental predictors of virus spread between geographic regions by constructing a Bayesian phylodynamic generalized linear model (phylodynamic-GLM). The findings demonstrate localized epidemics of H5Nx throughout Europe in the first several years of the epizootic, followed by a singular branching point where H5N1 viruses were introduced to North America, likely via stopover locations throughout the North Atlantic. Once in the United States (US), H5Nx viruses spread at a greater rate between US-based regions as compared to prior spread in Europe. We established that geographic proximity is a predictor of virus spread between regions, implying that intercontinental transport across the Atlantic Ocean is relatively rare. An increase in mean ambient temperature over time was predictive of reduced H5Nx virus spread, which may reflect the effect of climate change on declines in host species abundance, decreased persistence of the virus in the environment, or changes in migratory patterns due to ecological alterations. Our data provide new knowledge about the spread and directionality of H5Nx virus dispersal in Europe and the US during an actively evolving intercontinental outbreak, including predictors of virus movement between regions, which will contribute to surveillance and mitigation strategies as the outbreak unfolds, and in future instances of uncontained avian spread of HPAI viruses.
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Subtipo H5N1 del Virus de la Influenza A , Subtipo H5N2 del Virus de la Influenza A , Virus de la Influenza A , Gripe Aviar , Animales , Estados Unidos/epidemiología , Gripe Aviar/epidemiología , Teorema de Bayes , Brotes de Enfermedades/veterinaria , Animales Salvajes , Aves , Europa (Continente)/epidemiología , FilogeniaRESUMEN
We report the spillover of highly pathogenic avian influenza A(H5N1) into marine mammals in the northeastern United States, coincident with H5N1 in sympatric wild birds. Our data indicate monitoring both wild coastal birds and marine mammals will be critical to determine pandemic potential of influenza A viruses.
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Subtipo H5N1 del Virus de la Influenza A , Virus de la Influenza A , Gripe Aviar , Phocidae , Animales , Gripe Aviar/epidemiología , Aves , Brotes de Enfermedades , Animales Salvajes , New England/epidemiologíaRESUMEN
Emerging RNA virus infections are a growing concern among domestic poultry industries due to the severe impact they can have on flock health and economic livelihoods. Avian paramyxoviruses (APMV; avulaviruses, AaV) are pathogenic, negative-sense RNA viruses that cause serious infections in the respiratory and central nervous systems. APMV was detected in multiple avian species during the 2017 wild bird migration season in Ukraine and studied using PCR, virus isolation, and sequencing. Of 4090 wild bird samples collected, mostly from southern Ukraine, eleven isolates were grown in ovo and identified for APMV serotype by hemagglutinin inhibition test as: APMV-1, APMV-4, APMV-6, and APMV-7. To build One Health's capacity to characterize APMV virulence and analyze the potential risks of spillover to immunologically naïve populations, we sequenced virus genomes in veterinary research labs in Ukraine using a nanopore (MinION) platform. RNA was extracted and amplified using a multiplex tiling primer approach to specifically capture full-length APMV-1 (n = 5) and APMV-6 (n = 2) genomes at high read depth. All APMV-1 and APMV-6 fusion (F) proteins possessed a monobasic cleavage site, suggesting these APMVs were likely low virulence, annually circulating strains. Utilization of this low-cost method will identify gaps in viral evolution and circulation in this understudied but important critical region for Eurasia.
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Avulavirus , Virus de la Enfermedad de Newcastle , Animales , Ucrania/epidemiología , Filogenia , Animales Salvajes , AvesRESUMEN
Influenza A viruses (IAV) circulate endemically among many wild aquatic bird populations that seasonally migrate between wintering grounds in southern latitudes to breeding ranges along the perimeter of the circumpolar arctic. Arctic and subarctic zones are hypothesized to serve as ecologic drivers of the intercontinental movement and reassortment of IAVs due to high densities of disparate populations of long distance migratory and native bird species present during breeding seasons. Iceland is a staging ground that connects the East Atlantic and North Atlantic American flyways, providing a unique study system for characterizing viral flow between eastern and western hemispheres. Using Bayesian phylodynamic analyses, we sought to evaluate the viral connectivity of Iceland to proximal regions and how inter-species transmission and reassortment dynamics in this region influence the geographic spread of low and highly pathogenic IAVs. Findings demonstrate that IAV movement in the arctic and subarctic reflects wild bird migration around the perimeter of the circumpolar north, favouring short-distance flights between proximal regions rather than long distance flights over the polar interior. Iceland connects virus movement between mainland Europe and North America, consistent with the westward migration of wild birds from mainland Europe to Northeastern Canada and Greenland. Though virus diffusion rates were similar among avian taxonomic groups in Iceland, gulls play an outsized role as sinks of IAVs from other avian hosts prior to onward migration. These data identify patterns of virus movement in northern latitudes and inform future surveillance strategies related to seasonal and emergent IAVs with potential public health concern.
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Virus de la Influenza A , Gripe Aviar , Animales , Virus de la Influenza A/genética , Gripe Aviar/epidemiología , Teorema de Bayes , Animales Salvajes , Aves , Migración Animal , FilogeniaRESUMEN
Similar to many zoonotic pathogens which transmit from animals to humans, SARS-CoV-2 (CoV-2), the virus responsible for the COVID-19 pandemic, most likely originated in Rhinolophus bats before spreading among humans globally. Early into the pandemic, reports of CoV-2 diagnoses in animals from various countries emerged. While most CoV-2 positive animals were confirmed to have been in close contact with CoV-2 positive humans, there has been a paucity of published evidence to-date describing risk factors associated with CoV-2 transmission among humans and animals. The COVID-19 Human-Animal Interactions Survey (CHAIS) was developed to provide a standardized instrument describing human-animal interactions during the pandemic and to evaluate behavioral, spatiotemporal, and biological risk factors associated with bi-directional zoonotic transmission of CoV-2 within shared environments, predominantly households with limited information about human-wildlife or human-livestock interactions. CHAIS measures four broad domains of transmission risk: 1) risk and intensity of infection in human hosts, 2) spatial characteristics of shared environments, 3) behaviors and human-animal interactions, and 4) susceptible animal subpopulations. Following the development of CHAIS, with a One Health approach, a multidisciplinary group of experts (n = 20) was invited to review and provide feedback on the survey for content validity. Expert feedback was incorporated into two final survey formats-an extended version and an abridged version for which specific core questions addressing zoonotic and reverse zoonotic transmission were identified. Both versions are modularized, with each section having the capacity to serve as independent instruments, allowing researchers to customize the survey based on context and research-specific needs. Further adaptations for studies seeking to investigate other zoonotic pathogens with similar routes of transmission (i.e. respiratory, direct contact) are also possible. The CHAIS instrument is a standardized human-animal interaction survey developed to provide important data on risk factors that guide transmission of CoV-2, and other similar pathogens, among humans and animals.
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Arctic regions are ecologically significant for the environmental persistence and geographic dissemination of influenza A viruses (IAVs) by avian hosts and other wildlife species. Data describing the epidemiology and ecology of IAVs among wildlife in the arctic are less frequently published compared to southern temperate regions, where prevalence and subtype diversity are more routinely documented. Following PRISMA guidelines, this systematic review addresses this gap by describing the prevalence, spatiotemporal distribution, and ecological characteristics of IAVs detected among wildlife and the environment in this understudied region of the globe. The literature search was performed in PubMed and Google Scholar using a set of pre-defined search terms to identify publications reporting on IAVs in Arctic regions between 1978 and February 2022. A total of 2125 articles were initially screened, 267 were assessed for eligibility, and 71 articles met inclusion criteria. IAVs have been detected in multiple wildlife species in all Arctic regions, including seabirds, shorebirds, waterfowl, seals, sea lions, whales, and terrestrial mammals, and in the environment. Isolates from wild birds comprise the majority of documented viruses derived from wildlife; however, among all animals and environmental matrices, 26 unique low and highly pathogenic subtypes have been characterized in the scientific literature from Arctic regions. Pooled prevalence across studies indicates 4.23% for wild birds, 3.42% among tested environmental matrices, and seroprevalences of 9.29% and 1.69% among marine and terrestrial mammals, respectively. Surveillance data are geographically biased, with most data from the Alaskan Arctic and many fewer reports from the Russian, Canadian, North Atlantic, and Western European Arctic. We highlight multiple important aspects of wildlife host, pathogen, and environmental ecology of IAVs in Arctic regions, including the role of avian migration and breeding cycles for the global spread of IAVs, evidence of inter-species and inter-continental reassortment at high latitudes, and how climate change-driven ecosystem shifts, including changes in the seasonal availability and distribution of dietary resources, have the potential to alter host-pathogen-environment dynamics in Arctic regions. We conclude by identifying gaps in knowledge and propose priorities for future research.
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Virus de la Influenza A , Gripe Aviar , Animales , Animales Salvajes , Regiones Árticas , Aves , Canadá , Ecosistema , Gripe Aviar/epidemiología , MamíferosRESUMEN
Avian influenza viruses can pose serious risks to agricultural production, human health, and wildlife. An understanding of viruses in wild reservoir species across time and space is important to informing surveillance programs, risk models, and potential population impacts for vulnerable species. Although it is recognized that influenza A virus prevalence peaks in reservoir waterfowl in late summer through autumn, temporal and spatial variation across species has not been fully characterized. We combined two large influenza databases for North America and applied spatiotemporal models to explore patterns in prevalence throughout the annual cycle and across the continental United States for 30 waterfowl species. Peaks in prevalence in late summer through autumn were pronounced for dabbling ducks in the genera Anas and Spatula, but not Mareca. Spatially, areas of high prevalence appeared to be related to regional duck density, with highest predicted prevalence found across the upper Midwest during early fall, though further study is needed. We documented elevated prevalence in late winter and early spring, particularly in the Mississippi Alluvial Valley. Our results suggest that spatiotemporal variation in prevalence outside autumn staging areas may also represent a dynamic parameter to be considered in IAV ecology and associated risks.
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Virus de la Influenza A , Gripe Aviar , Migración Animal , Animales , Animales Salvajes , Patos , Humanos , Gripe Aviar/epidemiología , Prevalencia , Estados Unidos/epidemiologíaRESUMEN
The diversity of influenza A viruses (IAV) is primarily hosted by two highly divergent avian orders: Anseriformes (ducks, swans and geese) and Charadriiformes (gulls, terns and shorebirds). Studies of IAV have historically focused on Anseriformes, specifically dabbling ducks, overlooking the diversity of hosts in nature, including gull and goose species that have successfully adapted to human habitats. This study sought to address this imbalance by characterizing spillover dynamics and global transmission patterns of IAV over 10 years at greater taxonomic resolution than previously considered. Furthermore, the circulation of viral subtypes in birds that are either host-adapted (low pathogenic H13, H16) or host-generalist (highly pathogenic avian influenza-HPAI H5) provided a unique opportunity to test and extend models of viral evolution. Using Bayesian phylodynamic modelling we uncovered a complex transmission network that relied on ecologically divergent bird hosts. The generalist subtype, HPAI H5 was driven largely by wild geese and swans that acted as a source for wild ducks, gulls, land birds, and domestic geese. Gulls were responsible for moving HPAI H5 more rapidly than any other host, a finding that may reflect their long-distance, pelagic movements and their immuno-naïve status against this subtype. Wild ducks, long viewed as primary hosts for spillover, occupied an optimal space for viral transmission, contributing to geographic expansion and rapid dispersal of HPAI H5. Evidence of inter-hemispheric dispersal via both the Pacific and Atlantic Rims was detected, supporting surveillance at high latitudes along continental margins to achieve early detection. Both neutral (geographic expansion) and non-neutral (antigenic selection) evolutionary processes were found to shape subtype evolution which manifested as unique geographic hotspots for each subtype at the global scale. This study reveals how a diversity of avian hosts contribute to viral spread and spillover with the potential to improve surveillance in an era of rapid global change.
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Charadriiformes , Virus de la Influenza A , Gripe Aviar , Animales , Animales Salvajes , Teorema de Bayes , Aves , Patos , Humanos , Virus de la Influenza A/genéticaRESUMEN
Gulls are ubiquitous in urban areas due to a growing reliance on anthropogenic feeding sites, which has led to changes in their abundance, distribution, and migration ecology, with implications for disease transmission. Gulls offer a valuable model for testing hypotheses regarding the dynamics of influenza A virus (IAV) - for which gulls are a natural reservoir in urban areas. We sampled sympatric populations of Ring-billed (Larus delawarensis), Herring (L. argentatus), and Great Black-backed Gulls (L. marinus) along the densely populated Atlantic rim of North America to understand how IAV transmission is influenced by drivers such as annual cycle, host species, age, habitat type, and their interplay. We found that horizontal transmission, rather than vertical transmission, played an outsized role in the amplification of IAV due to the convergence of gulls from different breeding grounds and age classes. We detected overlapping effects of age and season in our prevalence model, identifying juveniles during autumn as the primary drivers of the seasonal epidemic in gulls. Gulls accumulated immunity over their lifespan, however short-term fluctuations in seroprevalence were observed, suggesting that migration may impose limits on the immune system to maintain circulating antibodies. We found that gulls in coastal urban habitats had higher viral prevalence than gulls captured inland, correlating with higher richness of waterbird species along the coast, a mechanism supported by our movement data. The peak in viral prevalence in newly fledged gulls that are capable of long-distance movement has important implications for the spread of pathogens to novel hosts during the migratory season as well as for human health as gulls increasingly utilize urban habitats.
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Charadriiformes , Virus de la Influenza A , Infecciones por Orthomyxoviridae , Factores de Edad , Animales , Charadriiformes/virología , Ecosistema , Infecciones por Orthomyxoviridae/veterinaria , Estaciones del Año , Estudios SeroepidemiológicosRESUMEN
Understanding transmission dynamics that link wild and domestic animals is a key element of predicting the emergence of infectious disease, an event that has highest likelihood of occurring wherever human livelihoods depend on agriculture and animal trade. Contact between poultry and wild birds is a key driver of the emergence of highly pathogenic avian influenza (HPAI), a process that allows for host switching and accelerated reassortment, diversification, and spread of virus between otherwise unconnected regions. This study addresses questions relevant to the spillover of HPAI at a transmission hotspot: what is the nature of the wild bird-poultry interface in Egypt and adjacent Black Sea-Mediterranean countries and how has this contributed to outbreaks occurring worldwide? Using a spatiotemporal model of infection risk informed by satellite tracking of waterfowl and viral phylogenetics, this study identified ecological conditions that contribute to spillover in this understudied region. Results indicated that multiple ducks (Northern Shoveler and Northern Pintail) hosted segments that shared ancestry with HPAI H5 from both clade 2.2.1 and clade 2.3.4 supporting the role of Anseriformes in linking viral populations in East Asia and Africa over large distances. Quantifying the overlap between wild ducks and H5N1-infected poultry revealed an increasing interface in late winter peaking in early spring when ducks expanded their range before migration, with key differences in the timing of poultry contact risk between local and long-distance migrants.
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Phocine distemper virus (PDV) is a morbillivirus that circulates within pinnipeds in the North Atlantic. PDV has caused two known unusual mortality events (UMEs) in western Europe (1988, 2002), and two UMEs in the northwest Atlantic (2006, 2018). Infrequent cross-species transmission and waning immunity are believed to contribute to periodic outbreaks with high mortality in western Europe. The viral ecology of PDV in the northwest Atlantic is less well defined and outbreaks have exhibited lower mortality than those in western Europe. This study sought to understand the molecular and ecological processes underlying PDV infection in eastern North America. We provide phylogenetic evidence that PDV was introduced into northwest Atlantic pinnipeds by a single lineage and is now endemic in local populations. Serological and viral screening of pinniped surveillance samples from 2006 onward suggest there is continued circulation of PDV outside of UMEs among multiple species with and without clinical signs. We report six full genome sequences and nine partial sequences derived from harbour and grey seals in the northwest Atlantic from 2011 through 2018, including a possible regional variant. Work presented here provides a framework towards greater understanding of how recovering populations and shifting species may impact disease transmission.
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Caniformia , Moquillo , Morbillivirus , Phocidae , Animales , Moquillo/epidemiología , Virus del Moquillo Focino/genética , Morbillivirus/genética , FilogeniaRESUMEN
Ferrets (Mustela putorius furo) are mustelids of special relevance to laboratory studies of respiratory viruses and have been shown to be susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and onward transmission. Here, we report the results of a natural experiment where 29 ferrets in one home had prolonged, direct contact and constant environmental exposure to two humans with symptomatic disease, one of whom was confirmed positive for SARS-CoV-2. We observed no evidence of SARS-CoV-2 transmission from humans to ferrets based on viral and antibody assays. To better understand this discrepancy in experimental and natural infection in ferrets, we compared SARS-CoV-2 sequences from natural and experimental mustelid infections and identified two surface glycoprotein Spike (S) mutations associated with mustelids. While we found evidence that angiotensin-converting enzyme II provides a weak host barrier, one mutation only seen in ferrets is located in the novel S1/S2 cleavage site and is computationally predicted to decrease furin cleavage efficiency. These data support the idea that host factors interacting with the novel S1/S2 cleavage site may be a barrier in ferret SARS-CoV-2 susceptibility and that domestic ferrets are at low risk of natural infection from currently circulating SARS-CoV-2. We propose two mechanistically grounded hypotheses for mustelid host adaptation of SARS-CoV-2, with possible effects that require additional investigation.
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COVID-19/transmisión , Hurones/virología , Adaptación al Huésped , Mutación , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus/genética , Enzima Convertidora de Angiotensina 2/fisiología , Animales , Susceptibilidad a Enfermedades , HumanosRESUMEN
Meloxicam is the most frequently used NSAID in birds; however, its elimination t1/2 is highly variable among species. Because zebra finches that require analgesia could benefit from receiving meloxicam, we performed a pharmacokinetic study involving a single intramuscular dose of 1 or 2 mg/kg. Data analysis showed that Cmax, t1/2, and elimination rate constants were not significantly different between the 2 doses. In contrast, Cmax for 1- and 2-mg/kg doses of meloxicam approached a significant difference, and those for AUC0-∞ were significantly different. Importantly, a plasma concentration of 3500 ng/mL, considered a target level for meloxicam in other avian species, was maintained for approximately 9.5 h in finches that received 2 mg/kg, which was 4 h longer than in birds given 1 mg/kg. Both doses reached low plasma concentrations by 12 h after administration. Subsequently, 8 total doses of 1 or 2 mg/kg were administered to birds at 12-h intervals; these regimens caused no significant changes in select biochemical analytes or the Hct of meloxicam-treated birds. In addition, histopathologic changes for injection sites, kidney, liver, proventriculus, and ventriculus were minimal and similar between control and experimental groups after the multiple doses. These results suggest a 12-h or more frequent dosing interval is likely needed in zebra finches and that meloxicam at 1 or 2 mg/kg IM twice daily for 4 d is safe. The higher dose might provide longer analgesia compared with the lower dose, but a pharmacodynamics evaluation of meloxicam in zebra finches is needed to confirm analgesic efficacy.
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Antiinflamatorios no Esteroideos/farmacocinética , Pinzones/sangre , Meloxicam/farmacocinética , Animales , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/sangre , Semivida , Ciencia de los Animales de Laboratorio , Masculino , Meloxicam/administración & dosificación , Meloxicam/sangreRESUMEN
Influenza A virus (IAV) is known to circulate among human and animal reservoirs, yet there are few studies that address the potential for urban rodents to carry and shed IAV. Rodents are often used as influenza models in the lab, but the few field studies that have looked for evidence of IAV in rodents have done so primarily in rural areas following outbreaks of IAV in poultry. This study sought to assess the prevalence of IAV recovered from wild Norway rats in a dense urban location (Boston). To do this, we sampled the oronasal cavity, paws, and lungs of Norway rats trapped by the City of Boston's Inspectional Services from December 2016 to September 2018. All samples were screened by real-time, reverse transcriptase PCR targeting the conserved IAV matrix segment. A total of 163 rats were trapped, 18 of which (11.04%) were RT-PCR positive for IAV in either oronasal swabs (9), paw swabs (9), both (2), or lung homogenates (2). A generalized linear model indicated that month and geographic location were correlated with IAV-positive PCR status of rats. A seasonal trend in IAV-PCR status was observed with the highest prevalence occurring in the winter months (December-January) followed by a decline over the course of the year, reaching its lowest prevalence in September. Sex and weight of rats were not significantly associated with IAV-PCR status, suggesting that rodent demography is not a primary driver of infection. This pilot study provides evidence of the need to further investigate the role that wild rats may play as reservoirs or mechanical vectors for IAV circulation in urban environments across seasons.
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Although zebra finches (Taeniopygia guttata) have been used in biomedical research for many years, no published reports are available about euthanizing these small birds. In this study, we compared 5 methods for zebra finch euthanasia: sodium pentobarbital (NaP) given intracoelomically with physical restraint but no anesthesia; isoflurane anesthesia followed by intracoelomic injection of NaP; and CO2 asphyxiation at 20%, 40%, and 80% chamber displacement rates (percentage of chamber volume per minute). Birds undergoing euthanasia were videorecorded and scored by 2 observers for behaviors potentially related to discomfort or distress. Time to recumbency and time until respiratory arrest (RA) were also assessed. RA was achieved faster by using NaP in a conscious bird compared to using isoflurane anesthesia followed by NaP; however, neither method caused behaviors that might affect animal welfare, such as open-mouth breathing, to any appreciable extent. Among the CO2 treatment groups, there was an inverse correlation between the chamber displacement rate used and the duration of open-mouth breathing, onset of head retroflexion, and time to RA. The results demonstrate that the intracoelomic administration of NaP in an awake, restrained zebra finch is a rapid and effective method of euthanasia. If CO2 is used to euthanize these birds, a high displacement rate (for example, 80%) will minimize the duration of the procedure and associated behaviors.
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Bienestar del Animal , Dióxido de Carbono/administración & dosificación , Eutanasia Animal/métodos , Pinzones/fisiología , Isoflurano/administración & dosificación , Pentobarbital/administración & dosificación , Animales , Animales de Laboratorio , Femenino , Pinzones/clasificación , MasculinoRESUMEN
We used surveillance data collected in California before, concurrent with, and subsequent to an outbreak of highly pathogenic (HP) clade 2.3.4.4 influenza A viruses (IAVs) in 2014-2015 to (i) evaluate IAV prevalence in waterfowl, (ii) assess the evidence for spill-over infections in marine mammals and (iii) genetically characterize low-pathogenic (LP) and HP IAVs to refine inference on the spatiotemporal extent of HP genome constellations and to evaluate possible evolutionary pathways. We screened samples from 1496 waterfowl and 1142 marine mammals collected from April 2014 to August 2015 and detected IAV RNA in 159 samples collected from birds (n=157) and pinnipeds (n=2). HP IAV RNA was identified in three samples originating from American wigeon (Anas americana). Genetic sequence data were generated for a clade 2.3.4.4 HP IAV-positive diagnostic sample and 57 LP IAV isolates. Phylogenetic analyses revealed that the HP IAV was a reassortant H5N8 virus with gene segments closely related to LP IAVs detected in mallards (Anas platyrhynchos) sampled in California and other IAVs detected in wild birds sampled within the Pacific Americas Flyway. In addition, our analysis provided support for common ancestry between LP IAVs recovered from waterfowl sampled in California and gene segments of reassortant HP H5N1 IAVs detected in British Columbia, Canada and Washington, USA. Our investigation provides evidence that waterfowl are likely to have played a role in the evolution of reassortant HP IAVs in the Pacific Americas Flyway during 2014-2015, whereas we did not find support for spill-over infections in potential pinniped hosts.
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Aves/virología , Caniformia/virología , Monitoreo Epidemiológico/veterinaria , Subtipo H5N1 del Virus de la Influenza A/genética , Gripe Aviar/epidemiología , Gripe Aviar/transmisión , Infecciones por Orthomyxoviridae/veterinaria , Américas/epidemiología , Animales , California/epidemiología , Canadá/epidemiología , Brotes de Enfermedades/veterinaria , Evolución Molecular , Genoma Viral , Subtipo H5N1 del Virus de la Influenza A/aislamiento & purificación , Virus de la Influenza A/genética , Virus de la Influenza A/aislamiento & purificación , Virus de la Influenza A/patogenicidad , Gripe Aviar/virología , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/virología , Filogenia , Virus Reordenados , Análisis de Secuencia de ADN , Análisis Espacio-TemporalRESUMEN
Wellfleet Bay virus (WFBV) is a recently described orthomyxovirus isolated from the tissues of Common Eiders (Somateria mollissima) collected during recurrent mortality events on Cape Cod, Massachusetts, US. Coastal Massachusetts is the only location where disease or mortality associated with this virus has been detected in wild birds, and a previous seroprevalence study found a significantly higher frequency of viral exposure in eiders from this location than from other areas sampled in North America. This suggests that coastal Massachusetts is an epicenter of WFBV exposure, but the reason for this is unknown. Opportunistic sampling of sympatric species and testing of banked serum was used to investigate potential host range and spatiotemporal patterns of WFBV exposure. Antibodies were detected in Herring Gulls (Larus argentatus), Ring-billed Gulls (Larus delawarensis), a White-winged Scoter (Melanitta fusca), and a Black Scoter (Melanitta nigra). These findings demonstrate the likely occurrence of fall/winter transmission, expand our understanding of the host range of the virus, and provide further insight into the epidemiology of WFBV in the northeastern US.
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Anseriformes , Enfermedades de las Aves/virología , Charadriiformes , Infecciones por Orthomyxoviridae/veterinaria , Orthomyxoviridae/inmunología , Animales , Anticuerpos Antivirales/sangre , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/inmunología , Massachusetts/epidemiología , New Jersey/epidemiología , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/inmunologíaRESUMEN
Sampling of mallards in Alaska during September 2014-April 2015 identified low pathogenic avian influenza A virus (subtypes H5N2 and H1N1) that shared ancestry with highly pathogenic reassortant H5N2 and H5N1 viruses. Molecular dating indicated reassortment soon after interhemispheric movement of H5N8 clade 2.3.4.4, suggesting genetic exchange in Alaska or surrounds before outbreaks.