RESUMO
Widespread human SARS-CoV-2 infections combined with human-wildlife interactions create the potential for reverse zoonosis from humans to wildlife. We targeted white-tailed deer (Odocoileus virginianus) for serosurveillance based on evidence these deer have angiotensin-converting enzyme 2 receptors with high affinity for SARS-CoV-2, are permissive to infection, exhibit sustained viral shedding, can transmit to conspecifics, exhibit social behavior, and can be abundant near urban centers. We evaluated 624 prepandemic and postpandemic serum samples from wild deer from four US states for SARS-CoV-2 exposure. Antibodies were detected in 152 samples (40%) from 2021 using a surrogate virus neutralization test. A subset of samples tested with a SARS-CoV-2 virus neutralization test showed high concordance between tests. These data suggest white-tailed deer in the populations assessed have been exposed to SARS-CoV-2.
Assuntos
Cervos/virologia , SARS-CoV-2/isolamento & purificação , Animais , COVID-19/epidemiologia , COVID-19/veterinária , Great Lakes Region/epidemiologia , Estudos SoroepidemiológicosRESUMO
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) emerged as the cause of a global pandemic in 2019-2020. In March 2020, New York City became the epicenter in the United States for the pandemic. On 27 March 2020, a Malayan tiger (Panthera tigris jacksoni) at the Bronx Zoo in New York City developed a cough and wheezing with subsequent inappetence. Over the next week, an additional Malayan tiger and two Amur tigers (Panthera tigris altaica) in the same building and three lions (Panthera leo krugeri) in a separate building also became ill. The index case was anesthetized for diagnostic workup. Physical examination and bloodwork results were unremarkable. Thoracic radiography and ultrasonography revealed a bronchial pattern with peribronchial cuffing and mild lung consolidation with alveolar-interstitial syndrome, respectively. SARS-CoV-2 RNA was identified by real-time, reverse transcriptase PCR (rRT-PCR) on oropharyngeal and nasal swabs and tracheal wash fluid. Cytologic examination of tracheal wash fluid revealed necrosis, and viral RNA was detected in necrotic cells by in situ hybridization, confirming virus-associated tissue damage. SARS-CoV-2 was isolated from the tracheal wash fluid of the index case, as well as the feces from one Amur tiger and one lion. Fecal viral RNA shedding was confirmed in all seven clinical cases and an asymptomatic Amur tiger. Respiratory signs abated within 1-5 days for most animals, although they persisted intermittently for 16 days in the index case. Fecal RNA shedding persisted for as long as 35 days beyond cessation of respiratory signs. This case series describes the clinical presentation, diagnostic evaluation, and management of tigers and lions infected with SARS-CoV-2 and describes the duration of viral RNA fecal shedding in these cases. This report documents the first known natural transmission of SARS-CoV-2 from humans to nondomestic felids.
Assuntos
COVID-19/veterinária , Fezes/virologia , Leões/virologia , SARS-CoV-2 , Tigres/virologia , Animais , Animais de Zoológico , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , COVID-19/diagnóstico , COVID-19/epidemiologia , COVID-19/transmissão , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/isolamento & purificação , Cidade de Nova Iorque/epidemiologia , Fatores de Transcrição/genética , Fatores de Transcrição/isolamento & purificaçãoRESUMO
Senecavirus A (SVA) is an emerging picornavirus that causes vesicular disease (VD) in swine. The virus has been circulating in swine in the United Stated (USA) since at least 1988, however, since 2014 a marked increase in the number of SVA outbreaks has been observed in swine worldwide. The factors that led to the emergence of SVA remain unknown. Evolutionary changes that accumulated in the SVA genome over the years may have contributed to the recent increase in disease incidence. Here we compared full-genome sequences of historical SVA strains (identified before 2010) from the USA and global contemporary SVA strains (identified after 2011). The results from the genetic analysis revealed 6.32â% genetic divergence between historical and contemporary SVA isolates. Selection pressure analysis revealed that the SVA polyprotein is undergoing selection, with four amino acid (aa) residues located in the VP1 (aa 735), 2A (aa 941), 3C (aa 1547) and 3D (aa 1850) coding regions being under positive/diversifying selection. Several aa substitutions were observed in the structural proteins (VP1, VP2 and VP3) of contemporary SVA isolates when compared to historical SVA strains. Some of these aa substitutions led to changes in the surface electrostatic potential of the structural proteins. This work provides important insights into the molecular evolution and epidemiology of SVA.
Assuntos
Doenças Transmissíveis Emergentes , Infecções por Picornaviridae/veterinária , Picornaviridae/genética , Doenças dos Suínos/virologia , Substituição de Aminoácidos/genética , Animais , Doenças Transmissíveis Emergentes/veterinária , Doenças Transmissíveis Emergentes/virologia , Surtos de Doenças , Evolução Molecular , Variação Genética , Genoma Viral , Filogenia , Infecções por Picornaviridae/epidemiologia , Suínos , Doenças dos Suínos/epidemiologia , Estados Unidos/epidemiologia , Proteínas Virais/genética , Proteínas Estruturais Virais/genéticaRESUMO
Background: A single subtype of canine influenza virus (CIV), A(H3N8), was circulating in the United States until a new subtype, A(H3N2), was detected in Illinois in spring 2015. Since then, this CIV has caused thousands of infections in dogs in multiple states. Methods: In this study, genetic and antigenic properties of the new CIV were evaluated. In addition, structural and glycan array binding features of the recombinant hemagglutinin were determined. Replication kinetics in human airway cells and pathogenesis and transmissibility in animal models were also assessed. Results: A(H3N2) CIVs maintained molecular and antigenic features related to low pathogenicity avian influenza A(H3N2) viruses and were distinct from A(H3N8) CIVs. The structural and glycan array binding profile confirmed these findings and revealed avian-like receptor-binding specificity. While replication kinetics in human airway epithelial cells was on par with that of seasonal influenza viruses, mild-to-moderate disease was observed in infected mice and ferrets, and the virus was inefficiently transmitted among cohoused ferrets. Conclusions: Further adaptation is needed for A(H3N2) CIVs to present a likely threat to humans. However, the potential for coinfection of dogs and possible reassortment of human and other animal influenza A viruses presents an ongoing risk to public health.
Assuntos
Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/veterinária , Animais , Células Cultivadas , Doenças do Cão/virologia , Cães/virologia , Células Epiteliais/virologia , Furões/virologia , Hemaglutininas/genética , Hemaglutininas/metabolismo , Humanos , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/fisiologia , Camundongos , Neuraminidase/genética , Neuraminidase/metabolismo , Filogenia , Conformação Proteica , Estados Unidos/epidemiologia , Replicação ViralRESUMO
As part of a longitudinal household transmission study of pets living with persons with COVID-19 in Texas, two pets were confirmed to be infected with the SARS-CoV-2 B.1.1.7 variant of concern (VOC). The pets were a dog and a cat from the same household, sampled two days after their owner tested positive for COVID-19. The oral, nasal and fur swabs for both pets tested positive for SARS-CoV-2 by qRT-PCR and consensus whole-genome sequences from the dog and cat were 100% identical and matched the B.1.1.7 VOC. Virus was isolated from the cat's nasal swab. One month after initial detection of infection, the pets were re-tested twice at which time only the fur swabs (both pets) and oral swab (dog only) remained positive, and neutralizing antibodies for SARS-CoV-2 were present in both animals. Sneezing by both pets was noted by the owner in the weeks between initial and follow-up testing. This study documents the first detection of B.1.1.7. in companion animals in the United States, and the first genome recovery and isolation of B.1.1.7 variant of concern globally in any animal.
Assuntos
COVID-19 , Doenças do Gato , Doenças do Cão , Animais , COVID-19/diagnóstico , COVID-19/veterinária , Doenças do Gato/diagnóstico , Doenças do Gato/epidemiologia , Gatos , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologia , Cães , Humanos , SARS-CoV-2 , TexasRESUMO
To provide more complete data on SARS-CoV-2 infections in dogs and cats in the U.S., we conducted a serosurvey on convenience serum samples from dogs (n=1336) and cats (n=956) collected from 48 states of the USA in 2020. An ELISA targeting the antibody against nucleocapsid identified eleven positive and two doubtful samples in cats, and five positive and five doubtful samples in dogs. A surrogate neutralization assay detecting antibodies blocking the attachment of the spike protein to ACE2 was positive with three of the ELISA positive and doubtful samples, and one of 463 randomly selected ELISA negative samples. These four positive samples were confirmed by SARS-CoV-2 virus neutralization testing. All were from cats, in New York, Florida, and New Jersey (n=2). The serosurvey results, one of the largest yet completed on dogs and cats globally, support the OIE and CDC positions that currently there is no evidence that pets play a role in the spread of SARS CoV-2 in humans.
Assuntos
Anticorpos Antivirais/imunologia , COVID-19/veterinária , Doenças do Gato/epidemiologia , Doenças do Gato/imunologia , Doenças do Cão/epidemiologia , Doenças do Cão/imunologia , SARS-CoV-2/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Doenças do Gato/virologia , Gatos , Doenças do Cão/virologia , Cães , Ensaio de Imunoadsorção Enzimática , Humanos , Testes de Neutralização , Vigilância em Saúde Pública , Estudos Soroepidemiológicos , Estados Unidos/epidemiologiaRESUMO
Understanding the ecological and epidemiological roles of pets in the transmission of SARS-CoV-2 is critical for animal and human health, identifying household reservoirs, and predicting the potential enzootic maintenance of the virus. We conducted a longitudinal household transmission study of 76 dogs and cats living with at least one SARS-CoV-2-infected human in Texas and found that 17 pets from 25.6% of 39 households met the national case definition for SARS-CoV-2 infections in animals. This includes three out of seventeen (17.6%) cats and one out of fifty-nine (1.7%) dogs that were positive by RT-PCR and sequencing, with the virus successfully isolated from the respiratory swabs of one cat and one dog. Whole-genome sequences of SARS-CoV-2 obtained from all four PCR-positive animals were unique variants grouping with genomes circulating among people with COVID-19 in Texas. Re-sampling showed persistence of viral RNA for at least 25 d-post initial test. Additionally, seven out of sixteen (43.8%) cats and seven out of fifty-nine (11.9%) dogs harbored SARS-CoV-2 neutralizing antibodies upon initial sampling, with relatively stable or increasing titers over the 2-3 months of follow-up and no evidence of seroreversion. The majority (82.4%) of infected pets were asymptomatic. 'Reverse zoonotic' transmission of SARS-CoV-2 from infected people to animals may occur more frequently than recognized.
Assuntos
COVID-19/epidemiologia , COVID-19/veterinária , Animais de Estimação/virologia , Animais , Anticorpos Neutralizantes/imunologia , Doenças do Gato/epidemiologia , Doenças do Gato/imunologia , Doenças do Gato/virologia , Gatos/virologia , Doenças do Cão/epidemiologia , Doenças do Cão/imunologia , Doenças do Cão/virologia , Cães/virologia , Humanos , Estudos Longitudinais , Animais de Estimação/imunologia , SARS-CoV-2/imunologia , SARS-CoV-2/patogenicidade , Texas/epidemiologiaRESUMO
Human-to-animal and animal-to-animal transmission of SARS-CoV-2 has been documented; however, investigations into SARS-CoV-2 transmission in congregate animal settings are lacking. We investigated four animal shelters in the United States that had identified animals with exposure to shelter employees with laboratory-confirmed COVID-19. Of the 96 cats and dogs with specimens collected, only one dog had detectable SARS-CoV-2 neutralizing antibodies; no animal specimens had detectable viral RNA. These data indicate a low probability of human-to-animal transmission events in cats and dogs in shelter settings with early implementation of infection prevention interventions.
RESUMO
Approximately 67% of U.S. households have pets. Limited data are available on SARS-CoV-2 in pets. We assessed SARS-CoV-2 infection in pets during a COVID-19 household transmission investigation. Pets from households with ≥1 person with laboratory-confirmed COVID-19 were eligible for inclusion from April-May 2020. We enrolled 37 dogs and 19 cats from 34 households. All oropharyngeal, nasal, and rectal swabs tested negative by rRT-PCR; one dog's fur swabs (2%) tested positive by rRT-PCR at the first sampling. Among 47 pets with serological results, eight (17%) pets (four dogs, four cats) from 6/30 (20%) households had detectable SARS-CoV-2 neutralizing antibodies. In households with a seropositive pet, the proportion of people with laboratory-confirmed COVID-19 was greater (median 79%; range: 40-100%) compared to households with no seropositive pet (median 37%; range: 13-100%) (p = 0.01). Thirty-three pets with serologic results had frequent daily contact (≥1 h) with the index patient before the person's COVID-19 diagnosis. Of these 33 pets, 14 (42%) had decreased contact with the index patient after diagnosis and none were seropositive; of the 19 (58%) pets with continued contact, four (21%) were seropositive. Seropositive pets likely acquired infection after contact with people with COVID-19. People with COVID-19 should restrict contact with pets and other animals.
Assuntos
COVID-19/epidemiologia , COVID-19/virologia , Animais de Estimação/virologia , SARS-CoV-2 , Animais , COVID-19/história , COVID-19/transmissão , Gatos , Cães , Características da Família , História do Século XXI , Humanos , Animais de Estimação/história , Filogenia , Vigilância da População , RNA Viral , SARS-CoV-2/classificação , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Estudos Soroepidemiológicos , Utah/epidemiologia , Zoonoses Virais/epidemiologia , Wisconsin/epidemiologiaRESUMO
Influenza A pandemic (H1N1) 2009 virus continues to rapidly spread worldwide. In 2009, pandemic (H1N1) 2009 infection in a domestic cat from Iowa was diagnosed by a novel PCR assay that distinguishes between Eurasian and North American pandemic (H1N1) 2009 virus matrix genes. Human-to-cat transmission is presumed.
Assuntos
Animais Domésticos/virologia , Doenças do Gato/virologia , Surtos de Doenças , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Infecções por Orthomyxoviridae/veterinária , Animais , Líquido da Lavagem Broncoalveolar/virologia , Doenças do Gato/diagnóstico por imagem , Gatos , Linhagem Celular , Humanos , Vírus da Influenza A Subtipo H1N1/classificação , Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/transmissão , Influenza Humana/virologia , Masculino , Infecções por Orthomyxoviridae/diagnóstico por imagem , Infecções por Orthomyxoviridae/virologia , Reação em Cadeia da Polimerase/métodos , RNA Viral/análise , RNA Viral/isolamento & purificação , RadiografiaRESUMO
Respiratory swab samples were collected from 5 pet ferrets (Mustela putorius furo) exhibiting influenza-like illness. The ferrets represented 3 households in 2 states. In each case, the owners reported influenza-like illness in themselves or family members prior to the onset of a similar illness in the ferrets. Real-time reverse transcription polymerase chain reaction assays designed for the detection of the 2009 H1N1 Influenza A virus were conducted in the state animal health laboratories. The assays included detection of the matrix gene of Influenza A virus and neuraminidase gene specific for 2009 H1N1 virus. Samples were positive for both screening assays. The samples were confirmed positive by the National Veterinary Services Laboratories. The history of illness in family members prior to illness in the ferrets suggests that Influenza A virus was transmitted from humans to the ferrets.
Assuntos
Influenza Humana/transmissão , Infecções por Orthomyxoviridae/diagnóstico , Animais , Animais Domésticos/virologia , Transmissão de Doença Infecciosa/veterinária , Furões , Hemaglutininas Virais/genética , Humanos , Vírus da Influenza A Subtipo H1N1/enzimologia , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Neuraminidase/genética , Oregon , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/transmissão , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The natural infections and epidemiological roles of household pets in SARS-CoV-2 transmission are not understood. We conducted a longitudinal study of dogs and cats living with at least one SARS-CoV-2 infected human in Texas and found 47.1% of 17 cats and 15.3% of 59 dogs from 25.6% of 39 households were positive for SARS-CoV-2 via RT-PCR and genome sequencing or neutralizing antibodies. Virus was isolated from one cat. The majority (82.4%) of infected pets were asymptomatic. Re-sampling of one infected cat showed persistence of viral RNA at least 32 d-post human diagnosis (25 d-post initial test). Across 15 antibody-positive animals, titers increased (33.3%), decreased (33.3%) or were stable (33.3%) over time. A One Health approach is informative for prevention and control of SARS-CoV-2 transmission.
RESUMO
Despite numerous barriers to transmission, zoonoses are the major cause of emerging infectious diseases in humans. Among these, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and ebolaviruses have killed thousands; the human immunodeficiency virus (HIV) has killed millions. Zoonoses and human-to-animal cross-species transmission are driven by human actions and have important management, conservation, and public health implications. The current SARS-CoV-2 pandemic, which presumably originated from an animal reservoir, has killed more than half a million people around the world and cases continue to rise. In March 2020, New York City was a global epicenter for SARS-CoV-2 infections. During this time, four tigers and three lions at the Bronx Zoo, NY, developed mild, abnormal respiratory signs. We detected SARS-CoV-2 RNA in respiratory secretions and/or feces from all seven animals, live virus in three, and colocalized viral RNA with cellular damage in one. We produced nine whole SARS-CoV-2 genomes from the animals and keepers and identified different SARS-CoV-2 genotypes in the tigers and lions. Epidemiologic and genomic data indicated human-to-tiger transmission. These were the first confirmed cases of natural SARS-CoV-2 animal infections in the United States and the first in nondomestic species in the world. We highlight disease transmission at a nontraditional interface and provide information that contributes to understanding SARS-CoV-2 transmission across species.IMPORTANCE The human-animal-environment interface of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an important aspect of the coronavirus disease 2019 (COVID-19) pandemic that requires robust One Health-based investigations. Despite this, few reports describe natural infections in animals or directly link them to human infections using genomic data. In the present study, we describe the first cases of natural SARS-CoV-2 infection in tigers and lions in the United States and provide epidemiological and genetic evidence for human-to-animal transmission of the virus. Our data show that tigers and lions were infected with different genotypes of SARS-CoV-2, indicating two independent transmission events to the animals. Importantly, infected animals shed infectious virus in respiratory secretions and feces. A better understanding of the susceptibility of animal species to SARS-CoV-2 may help to elucidate transmission mechanisms and identify potential reservoirs and sources of infection that are important in both animal and human health.
Assuntos
Animais de Zoológico/virologia , Betacoronavirus/fisiologia , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/veterinária , Pandemias/veterinária , Panthera/virologia , Pneumonia Viral/transmissão , Pneumonia Viral/veterinária , Animais , Betacoronavirus/classificação , Betacoronavirus/genética , Betacoronavirus/isolamento & purificação , COVID-19 , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Genoma Viral/genética , Haplótipos , Humanos , Cidade de Nova Iorque/epidemiologia , Saúde Única , Filogenia , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia , SARS-CoV-2 , Zoonoses/epidemiologia , Zoonoses/transmissão , Zoonoses/virologiaRESUMO
In November 2004, tissues were collected from a hunter-killed white-tailed deer in St. Mary Parish, Louisiana. Bluetongue virus (BTV) was isolated from the tissues; however, the isolate could not be identified as any of the US domestic serotypes. Subsequent testing by virus neutralization using serotype-specific antiserum tentatively identified the isolate as BTV serotype 1 (BTV-1), which had not previously been found in the United States. Primers were designed based on the sequence of an outer capsid protein gene of a South African BTV-1 strain. Reverse transcription-polymerase chain reaction testing with the BTV-1 primers and product sequencing confirmed the Louisiana isolate as BTV-1. This is the first report of BTV-1 in the United States.
Assuntos
Vírus Bluetongue/classificação , Vírus Bluetongue/isolamento & purificação , Bluetongue/virologia , Cervos/virologia , Animais , Bluetongue/diagnóstico , Ovinos , Estados UnidosRESUMO
The probability of detecting influenza A virus (IAV) in oral fluid (OF) specimens was calculated for each of 13 assays based on real-time reverse-transcription polymerase chain reaction (rRT-PCR) and 7 assays based on virus isolation (VI). The OF specimens were inoculated with H1N1 or H3N2 IAV and serially diluted 10-fold (10(-1) to 10(-8)). Eight participating laboratories received 180 randomized OF samples (10 replicates × 8 dilutions × 2 IAV subtypes plus 20 IAV-negative samples) and performed the rRT-PCR and VI procedure(s) of their choice. Analysis of the results with a mixed-effect logistic-regression model identified dilution and assay as variables significant (P < 0.0001) for IAV detection in OF by rRT-PCR or VI. Virus subtype was not significant for IAV detection by either rRT-PCR (P = 0.457) or VI (P = 0.101). For rRT-PCR the cycle threshold (Ct) values increased consistently with dilution but varied widely. Therefore, it was not possible to predict VI success on the basis of Ct values. The success of VI was inversely related to the dilution of the sample; the assay was generally unsuccessful at lower virus concentrations. Successful swine health monitoring and disease surveillance require assays with consistent performance, but significant differences in reproducibility were observed among the assays evaluated.
La probabilité de détecter le virus de l'influenza A (VIA) dans des échantillons de fluide oral (FO) a été calculée pour chacune des 13 épreuves basées sur une réaction d'amplification en chaine en temps réel utilisant la polymérase réverse (rRT-PCR) et 7 épreuves basées sur l'isolement viral (IV). Les échantillons de FO ont été inoculés avec du VIA H1N1 ou H3N2 et dilués en série par facteur de 10 (10−1 à 10−8). Huit laboratoires participants ont reçu 180 échantillons randomisés de FO (10 réplicats × 8 dilutions × 2 sous-types de VIA plus 20 échantillons témoins négatifs sans VIA) et ont réalisé la méthode de rRT-PCR et d'IV de leur choix. L'analyse des résultats à l'aide d'un modèle de régression logistique pour les effets mélangés a identifié la dilution et l'épreuve comme étant des variables significatives (P < 0,0001) pour la détection de VIA dans du FO par rRT-PCR ou IV. Le sous-type de virus n'était pas significatif pour la détection de VIA soit par rRT-PCR (P = 0,457) ou par IV (P = 0,101). Pour les épreuves rRT-PCR les valeurs seuils de cycle (Ct) augmentaient de manière constante avec la dilution mais variaient énormément. Ainsi, il n'était pas possible de prédire le succès de l'IV sur la base des valeurs de Ct. Le succès de l'IV était inversement relié à la dilution de l'échantillon; l'épreuve était généralement négative aux faibles concentrations de virus. Pour avoir du succès dans la surveillance des maladies et de la santé des porcs il est nécessaire d'avoir des épreuves avec des performances constantes, mais des différences significatives dans la reproductibilité ont été observées parmi les épreuves évaluées.(Traduit par Docteur Serge Messier).
Assuntos
Vírus da Influenza A Subtipo H1N1 , Vírus da Influenza A Subtipo H3N2 , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Saliva/virologia , Doenças dos Suínos/virologia , Animais , Feminino , Infecções por Orthomyxoviridae/diagnóstico , Infecções por Orthomyxoviridae/veterinária , Infecções por Orthomyxoviridae/virologia , Suínos , Doenças dos Suínos/diagnósticoRESUMO
In February and March 2009, approximately 1,500 backyard pigs of variable age became sick, and approximately 700 of them died or were euthanized in the Lower Artibonite Valley and the Lower Plateau of the Republic of Haiti. The main clinical sign was posterior ataxia followed by paresis and/or paralysis on the second or third day of illness. No gross lesions were observed at postmortem examinations. The morbidity and mortality were approximately 60% and 40%, respectively. Diagnostic samples (whole blood, brain, tonsil, lymph nodes, spleen, and lung) were negative for Classical swine fever virus and African swine fever virus. Porcine teschovirus type 1 was detected by reverse transcription polymerase chain reactions in brain samples. Results of virus isolation, electron microscopy of virus particles, histopathological analysis on brain tissues, nucleic acid sequencing, and phylogenetic analysis of the viral isolate supported the diagnosis of teschovirus encephalomyelitis. The outbreak of the disease in Haiti is the first appearance of the severe form of teschovirus encephalomyelitis in the Americas. This disease poses a potential threat to the swine industries in other Caribbean countries, as well as to Central and North American countries.
Assuntos
Encefalomielite/veterinária , Infecções por Picornaviridae/veterinária , Doenças dos Suínos/virologia , Teschovirus/isolamento & purificação , Animais , Anticorpos Antivirais/análise , Surtos de Doenças/veterinária , Encefalomielite/diagnóstico , Encefalomielite/epidemiologia , Encefalomielite/virologia , Haiti/epidemiologia , Histocitoquímica/veterinária , Microscopia Eletrônica/veterinária , Filogenia , Infecções por Picornaviridae/diagnóstico , Infecções por Picornaviridae/epidemiologia , Infecções por Picornaviridae/virologia , RNA Viral/química , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Análise de Sequência de DNA , Suínos , Doenças dos Suínos/epidemiologia , Teschovirus/genética , Teschovirus/ultraestruturaRESUMO
Retinoids bind to nuclear receptors [retinoic acid receptors (RARs) and retinoid X receptors]. RARbeta, one of three isoforms of RARs (alpha, beta, and gamma), is expressed in the fetal and adult lung. We hypothesized that RARbeta plays a role in alveolarization. Using morphometric analysis, we determined that there was a significant increase in the volume density of airspace in the alveolar region of the lung at 28, 42, and 56 d postnatal age in RARbeta null mice when compared with wild-type controls. The mean cord length of the respiratory airspaces was increased in RARbeta null animals at 42 d postnatal age. Respiratory gas-exchange surface area per unit lung volume was significantly decreased in RARbeta null animals at 28, 42, and 56 d postnatal age. In addition, alveolar ducts tended to comprise a greater proportion of the lung airspaces in the RARbeta null mice. The RARbeta null mice also had impaired respiratory function when compared with wild-type control mice. There was no effect of RARbeta gene deletion on lung platelet-derived growth factor (PDGF) receptor alpha mRNA levels in postnatal lung tissue at several postnatal ages. However PDGF-A protein levels were significantly lower in the RARbeta null mice than in wild-type controls. Thus, deletion of the RARbeta gene impairs the formation of the distal airspaces during the postnatal phase of lung maturation in mice via a pathway that may involve PDGF-A.