Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 472
Filtrar
1.
Vector Borne Zoonotic Dis ; 23(1): 18-28, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36633561

RESUMO

Background: Chagas disease is one of the world's most neglected tropical diseases, infecting over six million people across the Americas. The hemoparasite Trypanosoma cruzi is the etiological agent for the disease, circulating in domestic, peridomestic, and sylvatic transmission cycles that are maintained by triatomine vectors and a diversity of wild and synanthropic hosts. Public health and wildlife management interventions targeting the interruption of T. cruzi transmission rely on an understanding of the dynamics driving the ecology of this zoonotic pathogen. One wildlife host that purportedly plays a role in the transmission of Chagas disease within the southern United States is the striped skunk (Mephitis mephitis), although infection prevalence in this species is poorly understood. Materials and Methods: To this end, we conducted a PCR-based surveillance of T. cruzi in 235 wild skunks, representing 4 species, across 76 counties and 10 ecoregions in Texas, United States, along with an evaluation of risk factors associated with the infection. Results: We recovered an overall T. cruzi prevalence of 17.9% for all mephitid taxa aggregated, ranging between 6.7% for plains spotted skunks (Spilogale putorius interrupta) and 42.9% for western spotted skunks (Spilogale gracilis). We report the first cases of T. cruzi infection in plains spotted and American hog-nosed skunks (Conepatus leuconotus), of important note for conservation medicine since populations of both species are declining within Texas. Although not statistically significant, we also detected trends for juveniles to exhibit greater infection risk than adults and for differential sex biases in T. cruzi prevalence between taxa, which align with variations in species-specific seasonal activity patterns. No geographic or taxonomic risk factors were identified. Conclusion: Our study contributed key data for population viability analyses and epidemiologic models in addition to providing a baseline for future T. cruzi surveillance among skunks and other wildlife species.


Assuntos
Animais Selvagens , Doença de Chagas , Mephitidae , Animais , Animais Selvagens/parasitologia , Doença de Chagas/epidemiologia , Doença de Chagas/veterinária , Doença de Chagas/parasitologia , Prevalência , Texas/epidemiologia , Trypanosoma cruzi
2.
Integr Comp Biol ; 62(4): 998-1011, 2022 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-35803500

RESUMO

Animals vary considerably in the amount of behavioral plasticity they exhibit in daily activity timing and temporal niche switching. It is not well understood how environmental factors drive changes in temporal activity or how interspecific differences in the plasticity of activity timing ultimately manifest in free-living animals. Here, we investigated the temporal structure and organization of activity patterns of two insular mammalian carnivores living in sympatry, the island fox (Urocyon littoralis) and island spotted skunk (Spilogale gracilis amphiala). Using collar-mounted accelerometers, we assessed the plasticity of behavioral activity rhythms in foxes and skunks by investigating how environmental factors drive the distribution of locomotor activity across the day and year, and subsequently examined the dynamics of temporal niche overlap between the two species. We documented that foxes express phenotypic plasticity in daily activity timing across the year, ranging from nocturnal to diurnal to crepuscular rhythms depending on the individual and time of year. Most notably, foxes increased the proportion of daytime activity as seasonal temperatures decreased. Overall, activity patterns of foxes were consistent with the circadian thermoenergetics hypothesis, which posits that animals that switch their patterns of activity do so to coincide with the most energetically favorable time of day. In contrast to foxes, skunks exhibited little behavioral plasticity, appearing strictly nocturnal across the year. While the duration of skunk activity bouts increased with the duration of night, timing of activity onset and offset extended into daytime hours during summer when the duration of darkness was shortest. Analysis of temporal niche overlap between foxes and skunks suggested that niche overlap was highest during summer and lowest during winter and was dictated primarily by temporal niche switching in foxes, rather than skunks. Collectively, our results highlight how interspecific asymmetries in behavioral plasticity drive dynamic patterns of temporal niche overlap within an island carnivore community.


Assuntos
Comportamento Animal , Raposas , Mephitidae , Animais , Estações do Ano , Temperatura , Locomoção , Periodicidade , Ilhas
3.
J Wildl Dis ; 58(3): 562-574, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35675483

RESUMO

Canine distemper is a widespread disease affecting both domestic and wild carnivores. This investigation of the geographic distribution, wildlife species infected, and relative prevalence rates was conducted over an 11-yr period and helps to document the disease spread, most highly infected wildlife species, and histologic lesions. Animals were collected as found dead, hunter and trapper harvested, and euthanized for displaying signs of abnormal behavior or neurologic disease. This disease appeared to spread from the Lower Peninsula of Michigan into the Upper Peninsula, was most frequently documented in raccoons (Procyon lotor), striped skunks (Mephitis mephitis), and gray fox (Urocyon cinereoargenteus), but also involved additional wildlife species. Three unique wildlife virus strains were identified. Two of these grouped within a separate subclade of the America 2 lineage. A third strain appeared to be a unique sequence type that is not associated with any existing subclade of America 2. We recommend the combined use of routine histology and immunohistochemical staining to confirm the diagnosis, and further recommend that both the lungs and spleen be collected as the optimal tissues to utilize for surveillance purposes.


Assuntos
Carnívoros , Vírus da Cinomose Canina , Cinomose , Doenças do Cão , Animais , Animais Selvagens , Cinomose/epidemiologia , Cães , Raposas , Mephitidae , Michigan/epidemiologia , Guaxinins
4.
J Am Vet Med Assoc ; 260(10): 1157-1165, 2022 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-35522584

RESUMO

OBJECTIVE: To provide epidemiological information on animal and human cases of rabies in the US during 2020 and summaries of 2020 rabies surveillance for Canada and Mexico. ANIMALS: All animals submitted for laboratory diagnosis of rabies in the US during 2020. PROCEDURES: State and territorial public health departments and USDA Wildlife Services provided 2020 rabies surveillance data. Data were analyzed temporally and geographically to assess trends in domestic and wildlife rabies cases. RESULTS: During 2020, 54 jurisdictions submitted 87,895 animal samples for rabies testing, of which 85,483 (97.3%) had a conclusive (positive or negative) test result. Of these, 4,479 (5.2%) tested positive for rabies, representing a 4.5% decrease from the 4,690 cases reported in 2019. Texas (n = 580 [12.9%]), Pennsylvania (371 [8.3%]), Virginia (351 [7.8%]), New York (346 [7.7%]), North Carolina (301 [6.7%]), New Jersey (257 [5.7%]), Maryland (256 [5.7%]), and California (248 [5.5%]) together accounted for > 60% of all animal rabies cases reported in 2020. Of the total reported rabid animals, 4,090 (91.3%) involved wildlife, with raccoons (n = 1,403 [31.3%]), bats (1,400 [31.3%]), skunks (846 [18.9%]), and foxes (338 [7.5%]) representing the primary hosts confirmed with rabies. Rabid cats (288 [6.4%]), cattle (43 [1.0%]), and dogs (37 [0.8%]) accounted for 95% of rabies cases involving domestic animals in 2020. No human rabies cases were reported in 2020. CONCLUSIONS AND CLINICAL RELEVANCE: For the first time since 2006, the number of samples submitted for rabies testing in the US was < 90,000; this is thought to be due to factors related to the COVID-19 pandemic, as similar decreases in sample submission were also reported by Canada and Mexico.


Assuntos
COVID-19 , Doenças do Gato , Doenças dos Bovinos , Quirópteros , Doenças do Cão , Raiva , Gatos , Cães , Animais , Estados Unidos , Bovinos , Humanos , Raiva/epidemiologia , Raiva/veterinária , Animais Domésticos , Pandemias , Doenças do Gato/epidemiologia , Doenças do Cão/epidemiologia , Doenças dos Bovinos/epidemiologia , Equidae , Vigilância da População , COVID-19/veterinária , Guaxinins , Mephitidae , Animais Selvagens , Raposas , New York
5.
Transbound Emerg Dis ; 69(5): e1758-e1767, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35279956

RESUMO

Striped skunks (Mephitis mephitis) densely populate the human-animal interface of suburbia throughout North America. Skunks share that habitat with numerous related mesocarnivores, where increased contact, competition for shared food and water sources and other stressors contribute to increased exposure and susceptibility to viral infection. The recently identified skunk amdoparvovirus (SKAV) has been detected at high prevalence in skunks and occasionally in mink, but its distribution in North America is unknown. To understand the impact of SKAV in striped skunks and the risk posed to related species, we investigated the geographic distribution of SKAV, analysed its genetic diversity and evolutionary dynamics and evaluated viral distribution in tissues of infected animals to identify possible mechanisms of transmission. SKAV was detected in 72.5% (37/51) skunks and was present at high rates at all locations tested across North America. Analysis of the complete genomic sequence of 29 strains showed a clear geographic segregation, frequent recombination and marked differences in the evolutionary dynamics of the major structural (VP2) and non-structural (NS1) proteins. NS1 was characterized by a higher variability and a higher percentage of positively selected codons. This could indicate that antibody-mediated enhancement of infection occurs in SKAV, an infection strategy that may be conserved across amdoparvoviruses. Finally, in situ hybridization revealed virus in epithelium of the gastrointestinal tract, urinary tract and skin, indicating that viral transmission could occur via oronasal, faecal and/or urinary secretions, as well as from skin and hair. The endemicity of SKAV over large geographic distances and its high genetic diversity suggest a long-term virus-host association. Persistent shedding and high environmental stability likely contribute to efficient viral spread, simultaneously offering opportunities for cross-species transmission with consequent risk to sympatric species, including domestic animals and wildlife.


Assuntos
Animais Selvagens , Mephitidae , Animais , Fezes , Humanos , Vison , América do Norte/epidemiologia
6.
Vector Borne Zoonotic Dis ; 22(2): 69-75, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35175137

RESUMO

In pre-Hispanic Mexico, dogs were not identified as an important source of rabies. We know from codexes and chronicles of the conquerors that at that time, rabies cases in humans and domestic animals were caused by local wildlife species such as bats. Canine-rabies virus variant seems to have arrived with Europeans. The first documented case of canine rabies in the Americas is found in Mexico in the Annals of the Holy Inquisition (16th century). During Mexico's independence, cases were frequently reported. In the 19th century the first attempts to control human rabies were made through sanitary measures such as elimination of rabid dogs and applying postexposure vaccination. During the first half of the 20th century, the efficacy of canine vaccination to prevent human rabies was established. However, in Mexico, despite reports of numerous human cases (>70/year), canine vaccination did not have enough coverage. It was only during the 1990s that Mexico made a serious commitment to eliminate dog-transmitted human rabies. Since the beginning, vaccination campaigns have been free and massive. Coverage increased from 7,100,000 doses in 1990 to more than 18,000,000 since 2017. This culminated in the elimination of dog-mediated human rabies cases since 2006. Subsequently, the epidemiology of rabies had changed. Nowadays, it is wildlife species (mainly bats and skunks) that are the source of human rabies. As a mega-biodiverse country Mexico has numerous wildlife species with potential to transmit rabies virus. Thus it is paramount to remain vigilant with respect to canine vaccination campaigns and to promote rabies research in wildlife.


Assuntos
Doenças do Cão , Vacina Antirrábica , Raiva , Animais , Animais Domésticos , Doenças do Cão/epidemiologia , Doenças do Cão/prevenção & controle , Cães , Humanos , Mephitidae , México/epidemiologia , Raiva/epidemiologia , Raiva/prevenção & controle , Raiva/veterinária , Estados Unidos
7.
J Wildl Dis ; 58(2): 356-367, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35104340

RESUMO

Skunk adenovirus-1 (SkAdV-1) has been reported infecting several North American wildlife species; however, lesions associated with disease have not yet been completely characterized, particularly in porcupines. We describe and characterize the tissue distribution and lesions associated with SkAdV-1 infection in 24 wildlife diagnostic cases submitted between 2015 and 2020, including 16 North American porcupines (Erethizon dorsatum), three striped skunks (Mephitis mephitis), and five raccoons (Procyon lotor), which constitute a new host species. The most common lesion in all species was severe necrotizing bronchopneumonia with (n=12) or without (n=10) interstitial involvement. Intranuclear inclusion bodies were common in respiratory epithelium (n=21) and less often in renal tubular (n=6) and biliary epithelium (n=1). Several cases (n=4) had secondary bacterial infections, including Bordetella bronchiseptica, Pasteurella multocida, and Streptococcus zooepidemicus. In situ hybridization in porcupine (n=6), raccoon (n=1), and skunk (n=1) revealed SkAdV-1 DNA in multiple tissue types, including lung, trachea, turbinates, liver, kidney, lymph node, and brain, and multiple cell types including epithelial, endothelial, and mesothelial cells. These findings were consistent across species. Comparison of viral genomes from a porcupine and a raccoon with that originally isolated from a skunk demonstrated DNA point mutations affecting several viral genes, including the fiber protein gene. Our findings show the spectrum of disease associated with SkAdV-1 infection in a broad host range of wildlife species.


Assuntos
Infecções por Adenoviridae , Porcos-Espinhos , Doenças dos Roedores , Adenoviridae , Infecções por Adenoviridae/epidemiologia , Infecções por Adenoviridae/veterinária , Animais , Animais Selvagens , Hibridização In Situ/veterinária , Mephitidae , América do Norte , Guaxinins
8.
Mol Phylogenet Evol ; 167: 107266, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34302947

RESUMO

Four species of spotted skunks (Carnivora, Mephitidae, Spilogale) are currently recognized: Spilogale angustifrons, S. gracilis, S. putorius, and S. pygmaea. Understanding species boundaries within this group is critical for effective conservation given that regional populations or subspecies (e.g., S. p. interrupta) have experienced significant population declines. Further, there may be currently unrecognized diversity within this genus as some taxa (e.g., S. angustifrons) and geographic regions (e.g., Central America) never have been assessed using DNA sequence data. We analyzed species limits and diversification patterns in spotted skunks using multilocus nuclear (ultraconserved elements) and mitochondrial (whole mitogenomes and single gene analysis) data sets from broad geographic sampling representing all currently recognized species and subspecies. We found a high degree of genetic divergence among Spilogale that reflects seven distinct species and eight unique mitochondrial lineages. Initial divergence between S. pygmaea and all other Spilogale occurred in the Early Pliocene (~ 5.0 million years ago). Subsequent diversification of the remaining Spilogale into an "eastern" and a "western" lineage occurred during the Early Pleistocene (~1.5 million years ago). These two lineages experienced temporally coincident patterns of diversification at ~0.66 and ~0.35 million years ago into two and ultimately three distinct evolutionary units, respectively. Diversification was confined almost entirely within the Pleistocene during a timeframe characterized by alternating glacial-interglacial cycles, with the origin of this diversity occurring in northeastern Mexico and the southwestern United States of America. Mitochondrial-nuclear discordance was recovered across three lineages in geographic regions consistent with secondary contact, including a distinct mitochondrial lineage confined to the Sonoran Desert. Our results have direct consequences for conservation of threatened populations, or species, as well as for our understanding of the evolution of delayed implantation in this enigmatic group of small carnivores.


Assuntos
Carnívoros , Mephitidae , Animais , Carnívoros/genética , Mudança Climática , DNA Mitocondrial/genética , Variação Genética , Mephitidae/genética , México , Filogenia , Análise de Sequência de DNA
9.
Parasitol Res ; 121(1): 483-489, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34750653

RESUMO

Cryptosporidium spp. are significant zoonotic parasites in humans and animals worldwide. This study aimed to investigate the prevalence of Cryptosporidium infection among raccoon (Procyon lotor) in north of Iran. The fecal samples (n = 30) were collected from raccoons. After DNA extraction, all samples were examined by nested PCR amplification of the 18S ribosomal RNA (rRNA) gene. From 30 raccoon samples, 4 (13.3%) were positive, and the isolates were identified as Cryptosporidium skunk genotype based on sequence analysis. The large distribution of raccoons in northern provinces of Iran and their potency for carrying some human-infecting parasites like Cryptosporidium spp. propose this mammalian as a source for zoonotic parasites.


Assuntos
Criptosporidiose , Cryptosporidium , Animais , Fezes , Genótipo , Irã (Geográfico) , Mephitidae , Guaxinins
10.
PLoS One ; 16(11): e0259260, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34739496

RESUMO

Interspecific interactions among mesocarnivores can influence community dynamics and resource partitioning. Insights into these interactions can enhance understanding of local ecological processes that have impacts on pathogen transmission, such as the rabies lyssavirus. Host species ecology can provide an important baseline for disease management strategies especially in biologically diverse ecosystems and heterogeneous landscapes. We used a mesocarnivore guild native to the southwestern United States, a regional rabies hotspot, that are prone to rabies outbreaks as our study system. Gray foxes (Urocyon cinereoargenteus), striped skunks (Mephitis mephitis), bobcats (Lynx rufus), and coyotes (Canis latrans) share large portions of their geographic ranges and can compete for resources, occupy similar niches, and influence population dynamics of each other. We deployed 80 cameras across two mountain ranges in Arizona, stratified by vegetation type. We used two-stage modeling to gain insight into species occurrence and co-occurrence patterns. There was strong evidence for the effects of elevation, season, and temperature impacting detection probability of all four species, with understory height and canopy cover also influencing gray foxes and skunks. For all four mesocarnivores, a second stage multi-species co-occurrence model better explained patterns of detection than the single-species occurrence model. These four species are influencing the space use of each other and are likely competing for resources seasonally. We did not observe spatial partitioning between these competitors, likely due to an abundance of cover and food resources in the biologically diverse system we studied. From our results we can draw inferences on community dynamics to inform rabies management in a regional hotspot. Understanding environmental factors in disease hotspots can provide useful information to develop more reliable early-warning systems for viral outbreaks. We recommend that disease management focus on delivering oral vaccine baits onto the landscape when natural food resources are less abundant, specifically during the two drier seasons in Arizona (pre-monsoon spring and autumn) to maximize intake by all mesocarnivores.


Assuntos
Raiva/prevenção & controle , Raiva/transmissão , Animais , Animais Selvagens/virologia , Arizona , Coiotes/virologia , Gerenciamento Clínico , Ecossistema , Comportamento Alimentar , Raposas/virologia , Lynx/virologia , Mephitidae/virologia , Vacina Antirrábica/administração & dosagem , Vírus da Raiva/patogenicidade
11.
Viruses ; 13(10)2021 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-34696445

RESUMO

In summer 2020, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) was detected on mink farms in Utah. An interagency One Health response was initiated to assess the extent of the outbreak and included sampling animals from on or near affected mink farms and testing them for SARS-CoV-2 and non-SARS coronaviruses. Among the 365 animals sampled, including domestic cats, mink, rodents, raccoons, and skunks, 261 (72%) of the animals harbored at least one coronavirus. Among the samples that could be further characterized, 127 alphacoronaviruses and 88 betacoronaviruses (including 74 detections of SARS-CoV-2 in mink) were identified. Moreover, at least 10% (n = 27) of the coronavirus-positive animals were found to be co-infected with more than one coronavirus. Our findings indicate an unexpectedly high prevalence of coronavirus among the domestic and wild free-roaming animals tested on mink farms. These results raise the possibility that mink farms could be potential hot spots for future trans-species viral spillover and the emergence of new pandemic coronaviruses.


Assuntos
Alphacoronavirus/isolamento & purificação , COVID-19/epidemiologia , COVID-19/veterinária , SARS-CoV-2/isolamento & purificação , Alphacoronavirus/classificação , Alphacoronavirus/genética , Animais , Animais Domésticos/virologia , Animais Selvagens/virologia , Gatos , Hotspot de Doença , Feminino , Masculino , Mephitidae/virologia , Camundongos , Vison/virologia , Guaxinins/virologia , SARS-CoV-2/classificação , SARS-CoV-2/genética , Utah/epidemiologia
12.
Ecol Appl ; 31(6): e02393, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34164878

RESUMO

People and wildlife are living in an increasingly urban world, replete with unprecedented human densities, sprawling built environments, and altered landscapes. Such anthropogenic pressures can affect multiple processes within an ecological community, from spatial patterns to interspecific interactions. We tested two competing hypotheses, human shields vs. human competitors, to characterize how humans affect the carnivore community using multispecies occupancy models. From 2017 to 2020, we conducted the first camera survey of city parks in Detroit, Michigan, and collected spatial occurrence data of the local native carnivore community. Our 12,106-trap night survey captured detection data for coyotes (Canis latrans), red foxes (Vulpes vulpes), raccoons (Procyon lotor), and striped skunks (Mephitis mephitis). Overall occupancy varied across species (Ψcoyote = 0.40, Ψraccoon = 0.54, Ψred fox = 0.19, Ψstriped skunk = 0.09). Contrary to expectations, humans did not significantly affect individual occupancy for these urban carnivores. However, co-occurrence between coyote and skunk increased with human activity. The observed positive spatial association between an apex and subordinate pair supports the human shield hypothesis. Our findings demonstrate how urban carnivores can exploit spatial refugia and coexist with humans in the cityscape.


Assuntos
Carnívoros , Parques Recreativos , Animais , Cidades , Coiotes , Raposas , Mephitidae , Michigan , Guaxinins
13.
J Forensic Sci ; 66(4): 1420-1426, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33885151

RESUMO

Scavenging is a known behavior of striped skunks (Mephitis mephitis), though it is rarely documented. Striped skunks were observed and documented scavenging nine human donors at the Forensic Investigation Research Station (FIRS) in Whitewater, Colorado from October 2017 through September 2019. Human remains are placed on the surface, outdoors, in a fenced area, and monitored daily through notes, photographs, and multiple systems for scoring decomposition. Motion-activated game cameras are strategically positioned to monitor potential scavenger activity within the facility. When scavenging occurred, game camera images were temporally correlated to daily photographs and notes to confirm the source of observed defects. Striped skunks at the FIRS scavenged the soft tissue of the arms, legs, genitals, and torso. Game camera images documented skunks digging, climbing on top of remains, repositioning limbs, and using their paws to manipulate tissue. These activities impacted soft tissue, bone, and the surrounding environment. Scavenging patterns varied seasonally, with higher frequency and lower selectivity in the winter. Striped skunks are common throughout most of North America and are likely to scavenge human remains when available. Understanding patterns and behaviors of specific scavengers can help investigators accurately interpret defects found on and around human remains.


Assuntos
Restos Mortais , Comportamento Alimentar , Mephitidae , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Osso e Ossos/patologia , Colorado , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estações do Ano
14.
J Wildl Dis ; 57(2): 376-379, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33822146

RESUMO

Targeted surveillance for raccoon rabies virus was conducted between February and May 2017, near Waweig, New Brunswick, Canada, in response to detection of a rabid striped skunk (Mephitis mephitis) on 8 February 2017. A total of six skunks, 11 raccoons (Procyon lotor), and two porcupines (Erethizon dorsatum) were live-trapped, euthanized, and tested for rabies virus antigens using the direct rapid immunohistochemical test. Of these, only two skunks tested positive for rabies. All three rabid skunks came from the same location, an abandoned barn used as a denning site. Four of five skunks removed from this barn were males. Feeding, aggression, extreme response to noise and light stimuli, and exposure to porcupine quills were observed in two rabid skunks. No additional cases of rabies in wildlife were detected in the area since 8 March 2017. A targeted surveillance approach that removed potentially infected wildlife followed by localized oral rabies vaccine distribution was implemented in this locality.


Assuntos
Mephitidae/virologia , Vírus da Raiva/classificação , Raiva/veterinária , Guaxinins/virologia , Animais , Feminino , Masculino , Novo Brunswick/epidemiologia , Vigilância da População , Raiva/epidemiologia , Raiva/virologia
15.
Acta Biomed ; 92(1): e2021045, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33682816

RESUMO

Human rabies disease is caused by Rabies Lyssavirus, a virus belonging to Rhabdoviridae family. The more frequent means of contagion is through bites of infected mammals (especially dogs, but also bats, skunks, foxes, raccoons and wolves) which, lacerating the skin, directly inoculate virus-laden saliva into the underlying tissues. Immediately after inoculation, the Rabies virus enters neural axons and migrates along peripheral nerves towards the central nervous system, where it preferentially localizes and injuries neurons of brainstem, thalamus, basal ganglia and spinal cord. After an initial prodromic period, the infection evolves towards two distinct clinical entities, encompassing encephalitic (i.e., "furious"; ~70-80% of cases) and paralytic (i.e., "dumb"; ~20-30% of cases) rabies disease. The former subtype is characterized by fever, hyperactivity, hydrophobia, hypersalivation, deteriorated consciousness, phobic or inspiratory spasms, autonomic stimulation, irritability, up to aggressive behaviours. The current worldwide incidence and mortality of rabies disease are estimated at 0.175×100,000 and 0.153×100,000, respectively. The incidence is higher in Africa and South-East Asia, nearly double in men than in women, with a higher peak in childhood. Mortality remains as high as ~90%. Since patients with encephalitic rabies remind the traditional image of "Zombies", we need to think out-of-the-box, in that apocalyptic epidemics of mutated Rabies virus may be seen as an imaginable menace for mankind. This would be theoretically possible by either natural or artificial virus engineering, producing viral strains characterized by facilitated human-to-human transmission, faster incubation, enhanced neurotoxicity and predisposition towards developing highly aggressive behaviours.


Assuntos
Vírus da Raiva , Raiva , África , Animais , Cães , Humanos , Mephitidae , Raiva/epidemiologia , Guaxinins
16.
Am J Trop Med Hyg ; 104(3): 1048-1054, 2021 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-33534764

RESUMO

Powassan virus (POWV) is a tick-borne virus maintained in sylvatic cycles between mammalian wildlife hosts and ticks (primarily Ixodes spp.). There are two currently recognized lineages, POWV-lineage 1 (POWV-L1) and deer tick virus (DTV; lineage 2), both of which can cause fatal neurologic disease in humans. Increased numbers of human case reports in the northeastern and north central United States in recent years have fueled questions into POWV epidemiology. We inoculated three candidate wildlife POWV reservoir hosts, groundhogs (Marmota monax), striped skunks (Mephitis mephitis), and fox squirrels (Sciurus niger), with either POWV-L1 or DTV. Resulting viremia, tissue tropism, and pathology were minimal in most inoculated individuals of all three species, with low (peak titer range, 101.7-103.3 plaque-forming units/mL serum) or undetectable viremia titers, lack of detection in tissues except for low titers in spleen, and seroconversion in most individuals by 21 days postinoculation (DPI). Pathology was limited and most commonly consisted of mild inflammation in the brain of POWV-L1- and DTV-inoculated skunks on four and 21 DPI, respectively. These results reveal variation in virulence and host competence among wild mammalian species, and a likely limited duration of host infectiousness to ticks during enzootic transmission cycles. However, POWV can transmit rapidly from tick to host, and tick co-feeding may be an additional transmission mechanism. The rare and low-level detections of viremia in these three, common, wild mammal species suggest that vector-host dynamics should continue to be explored, along with eco-epidemiological aspects of enzootic POWV transmission in different regions and virus lineages.


Assuntos
Animais Selvagens/virologia , Encefalite Transmitida por Carrapatos/epidemiologia , Encefalite Transmitida por Carrapatos/virologia , Ixodes/virologia , Mamíferos/virologia , Marmota/virologia , Mephitidae/virologia , Sciuridae/virologia , Animais , Estados Unidos/epidemiologia
17.
Viruses ; 13(2)2021 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-33499059

RESUMO

Since the 1990s, oral rabies vaccination (ORV) has been used successfully to halt the westward spread of the raccoon rabies virus (RV) variant from the eastern continental USA. Elimination of raccoon RV from the eastern USA has proven challenging across targeted raccoon (Procyon lotor) and striped skunk (Mephitis mephitis) populations impacted by raccoon RV. Field trial evaluations of the Ontario Rabies Vaccine Bait (ONRAB) were initiated to expand ORV products available to meet the rabies management goal of raccoon RV elimination. This study describes the continuation of a 2011 trial in West Virginia. Our objective was to evaluate raccoon and skunk response to ORV occurring in West Virginia for an additional two years (2012-2013) at 75 baits/km2 followed by three years (2014-2016) of evaluation at 300 baits/km2. We measured the change in rabies virus-neutralizing antibody (RVNA) seroprevalence in targeted wildlife populations by comparing levels pre- and post-ORV during each year of study. The increase in bait density from 75/km2 to 300/km2 corresponded to an increase in average post-ORV seroprevalence for raccoon and skunk populations. Raccoon population RVNA levels increased from 53% (300/565, 95% CI: 50-57%) to 82.0% (596/727, 95% CI: 79-85%) during this study, and skunk population RVNA levels increased from 11% (8/72, 95% CI: 6-20%) to 39% (51/130, 95% CI: 31-48%). The RVNA seroprevalence pre-ORV demonstrated an increasing trend across study years for both bait densities and species, indicating that multiple years of ORV may be necessary to achieve and maintain RVNA seroprevalence in target wildlife populations for the control and elimination of raccoon RV in the eastern USA.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Mephitidae/imunologia , Vacina Antirrábica/imunologia , Vírus da Raiva/imunologia , Guaxinins/imunologia , Administração Oral , Animais , Animais Selvagens/imunologia , Raiva/prevenção & controle , Raiva/veterinária , Vacina Antirrábica/administração & dosagem , Estudos Soroepidemiológicos , Vacinação/veterinária , West Virginia
18.
Anim Cogn ; 24(3): 555-568, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33231749

RESUMO

Urbanization imposes novel challenges for wildlife, but also provides new opportunities for exploitation. Generalist species are commonly found in urban habitats, but the cognitive mechanisms facilitating their successful behavioral adaptations and exploitations are largely under-investigated. Cognitive flexibility is thought to enable generalists to be more plastic in their behavior, thereby increasing their adaptability to a variety of environments, including urban habitats. Yet direct measures of cognitive flexibility across urban wildlife are lacking. We used a classic reversal-learning paradigm to investigate the cognitive flexibility of three generalist mesocarnivores commonly found in urban habitats: striped skunks (Mephitis mephitis), raccoons (Procyon lotor), and coyotes (Canis latrans). We developed an automated device and testing protocol that allowed us to administer tests of reversal learning in captivity without extensive training or experimenter involvement. Although most subjects were able to rapidly form and reverse learned associations, we found moderate variation in performance and behavior during trials. Most notably, we observed heightened neophobia and a lack of habituation expressed by coyotes. We discuss the implications of such differences among generalists with regard to urban adaptation and we identify goals for future research. This study is an important step in investigating the relationships between cognition, generalism, and urban adaptation.


Assuntos
Coiotes , Reversão de Aprendizagem , Animais , Animais Selvagens , Mephitidae , Guaxinins
19.
Acta Vet Hung ; 68(3): 323-327, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-33128521

RESUMO

The complete genomic sequence along with phylogenetic analyses of an adenovirus (AdV), isolated from a dead captive pygmy marmoset (Callithrix pygmaea) from a Hungarian zoo is reported. Earlier, based on the phylogenetic analysis of the sequence of a PCR-amplified fragment from the DNA polymerase gene, the pygmy marmoset AdV (PMAdV) has been reported to cluster closest to certain chiropteran AdVs. In the following years similar AdVs were discovered in additional mammalian hosts, including a skunk (Mephitis mephitis), African pygmy hedgehogs (Atelerix albiventris), North American porcupines (Erethizon dorsatum) and grey fox (Urocyon cinereoargenteus). After the full genome analysis of the skunk adenovirus (SkAdV-1), a novel species Skunk mastadenovirus A (SkAdV-A) has been established. The AdVs, originating from the African pygmy hedgehogs, have been found to belong to virus species SkAdV-A. Partial gene sequences from the porcupine AdVs have also implied their very close genetic relatedness to SkAdV-A. The complete genomic sequence of PMAdV, examined in this study, was found to share 99.83% nucleotide identity with SkAdV-1, thus unequivocally represents a genomic variant of SkAdV-1. The observation that viruses classifiable as SkAdV-A are able to infect and cause diseases in several, distantly related mammals seems to deserve further studies to elucidate the infection biology of this intriguing AdV.


Assuntos
Callithrix/virologia , Genoma Viral , Mastadenovirus/genética , Mephitidae/virologia , Animais , Mastadenovirus/classificação , Sequenciamento Completo do Genoma/veterinária
20.
J Wildl Dis ; 56(4): 918-921, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32402233

RESUMO

Total genomic (g)DNA from 100 American dog ticks (Dermacentor variabilis) collected from humans, dogs, raccoons, and skunks near Minnedosa (Manitoba, Canada) in 2005 was tested for the presence of Moellerella wisconsensis (Gammaproteobacteria: Enterobacteriales) using PCR. Although two gDNA samples derived from ticks attached to two striped skunks (Mephitis mephitis) contained M. wisconsensis DNA, it is unlikely that D. variabilis is a vector of this bacterium. Genomic DNA prepared from the washes of the external surfaces of these two ticks (i.e., before DNA extraction from the whole tick) and another two ticks attached to same skunks were also PCR positive for M. wisconsensis. This suggests that ticks acquired the bacterium by physical contact with contaminated or infected skunks. However, it does not exclude the possibility that the ticks may have also imbibed the bacterium from their host blood and lymph. Nonetheless, the results of this molecular study suggest that the four adult D. variabilis represent biological indicators of the presence of M. wisconsensis in association with their vertebrate hosts (i.e., striped skunks). Additional work is needed to determine if M. wisconsensis is present in the blood and lymph of striped skunks in southwestern Manitoba and if there are potential health risks for persons coming into contact with infected animals.


Assuntos
Dermacentor/microbiologia , Gammaproteobacteria/isolamento & purificação , Mephitidae/microbiologia , Animais , DNA Bacteriano/genética , Cães , Interações Hospedeiro-Patógeno , Humanos , Manitoba , Filogenia , Guaxinins
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...