RESUMEN

Antibodies are an essential component of the antiviral response in many species, but to date, there is no compelling evidence that bats are capable of eliciting a robust humoral immunity, including neutralizing antibodies. Here, we report that infection of Jamaican fruit bats with the bat influenza A virus H18N11 elicits a rapid and stable humoral immune response with a strong neutralizing capacity, associated with no detectable viral shedding after repeat challenge infection. Thus, the neutralizing antibody response of bats might play an important role in the bat immunity.

Asunto(s)

Anticuerpos Neutralizantes , Anticuerpos Antivirales , Quirópteros , Infecciones por Orthomyxoviridae , Quirópteros/virología , Quirópteros/inmunología , Animales , Anticuerpos Neutralizantes/inmunología , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/virología , Infecciones por Orthomyxoviridae/veterinaria , Anticuerpos Antivirales/inmunología , Virus de la Influenza A/inmunología , Esparcimiento de Virus/inmunología

RESUMEN

Deadly outbreaks among poultry, wild birds, and carnivorous mammals by the highly pathogenic H5N1 virus of the clade 2.3.4.4b have been reported in South America. The increasing virus incidence in various mammal species poses a severe zoonotic and pandemic threat. In Uruguay, the clade 2.3.4.4b viruses were first detected in February 2023, affecting wild birds and backyard poultry. Three months after the first reported case in Uruguay, the disease affected a population of 23 coatis (Nasua) in an ecological park. Most animals became infected, likely directly or indirectly from wild birds in the park, and experienced sudden death. Five animals from the colony survived, and four of them developed antibodies. The genomes of the H5N1 strains infecting coatis belonged to the B3.2 genotype of the clade 2.3.4.4b. Genomes from coatis were closely associated with those infecting backyard poultry, but transmission likely occurred through wild birds. Notable, two genomes have a 627K substitution in the RNA polymerase PB2 subunit, a hallmark amino acid linked to mammalian adaptation. Our findings support the ability of the avian influenza virus of the 2.3.4.4b clade to infect and transmit among terrestrial mammals with high pathogenicity and undergo rapid adaptive changes. It also highlights the coatis' ability to develop immunity and naturally clear the infection.

Asunto(s)

Animales Salvajes , Genoma Viral , Subtipo H5N1 del Virus de la Influenza A , Gripe Aviar , Mutación , Filogenia , Procyonidae , Animales , Procyonidae/virología , Gripe Aviar/virología , Subtipo H5N1 del Virus de la Influenza A/genética , Subtipo H5N1 del Virus de la Influenza A/patogenicidad , Subtipo H5N1 del Virus de la Influenza A/aislamiento & purificación , Genoma Viral/genética , Uruguay , Animales Salvajes/virología , Aves/virología , Infecciones por Orthomyxoviridae/virología , Infecciones por Orthomyxoviridae/veterinaria , Aves de Corral/virología , Genotipo , Mamíferos/virología , América del Sur , Brotes de Enfermedades/veterinaria

RESUMEN

Influenza A virus (IAV) is an important pathogen in Brazilian swine herds, and monitoring the viral circulation is essential to control and reduce the transmission. Surveillance programs for IAV are often based on individual piglets level sampling, making the evaluation of the available diagnostic tools crucial to assessing IAV circulation in herds. Thus, two sample collection methodologies were compared in pig herds in southern Brazil to detect IAV by RT-qPCR: nasal swab (NS) and nasal wipe (NW). A Bayesian latent class model (BLCM) was set for two tests and two populations. The NW and NS used are more specific (higher than 95 % for both) than sensitive. The sensitivity for NW was lower than the NS, 84.14 % (70 % - 95 %; posterior probability interval (PPI): 95 %) and 87.15 % (73 % - 97 %; PPI: 95 %), respectively, and the specificity was 95 % (90 % - 99 %; PPI: 95 %) and 99 % (96 % - 100 %; PPI: 95 %), respectively. Although the wipe sample collection loses both sensitivity and specificity compared with nasal swab, differences in test performance were very limited and PPIs largely overlapped. Therefore NW can also be considered a valuable tool. The decision about the use of both techniques should be based on the trade-off between their performance limitations and feasibility in routine monitoring.

Asunto(s)

Teorema de Bayes , Virus de la Influenza A , Análisis de Clases Latentes , Infecciones por Orthomyxoviridae , Sensibilidad y Especificidad , Enfermedades de los Porcinos , Animales , Enfermedades de los Porcinos/virología , Enfermedades de los Porcinos/diagnóstico , Porcinos , Infecciones por Orthomyxoviridae/veterinaria , Infecciones por Orthomyxoviridae/virología , Infecciones por Orthomyxoviridae/diagnóstico , Infecciones por Orthomyxoviridae/epidemiología , Virus de la Influenza A/aislamiento & purificación , Brasil/epidemiología , Manejo de Especímenes/veterinaria , Manejo de Especímenes/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Nariz/virología

RESUMEN

Clade 2.3.4.4b highly pathogenic avian influenza (HPAI) H5N1 virus was detected in the South American sea lions found dead in Santa Catarina, Brazil, in October 2023. Whole genome sequencing and comparative phylogenetic analysis were conducted to investigate the origin, genetic diversity, and zoonotic potentials of the H5N1 viruses. The H5N1 viruses belonged to the genotype B3.2 of clade 2.3.4.4b H5N1 virus, which was identified in North America and disseminated to South America. They have acquired new amino acid substitutions related to mammalian host affinity. Our study provides insights into the genetic landscape of HPAI H5N1 viruses in Brazil, highlighting the continuous evolutionary processes contributing to their possible adaptation to mammalian hosts.

Asunto(s)

Subtipo H5N1 del Virus de la Influenza A , Filogenia , Leones Marinos , Secuenciación Completa del Genoma , Animales , Leones Marinos/virología , Brasil , Subtipo H5N1 del Virus de la Influenza A/genética , Subtipo H5N1 del Virus de la Influenza A/clasificación , Infecciones por Orthomyxoviridae/veterinaria , Infecciones por Orthomyxoviridae/virología , Genoma Viral , Genotipo , Variación Genética

RESUMEN

Influenza A viruses (IAV) impose significant respiratory disease burdens in both swine and humans worldwide, with frequent human-to-swine transmission driving viral evolution in pigs and highlighting the risk at the animal-human interface. Therefore, a comprehensive One Health approach (interconnection among human, animal, and environmental health) is needed for IAV prevention, control, and response. Animal influenza genomic surveillance remains limited in many Latin American countries, including Colombia. To address this gap, we genetically characterized 170 swine specimens from Colombia (2011-2017). Whole genome sequencing revealed a predominance of pandemic-like H1N1 lineage, with a minority belonging to H3N2 and H1N2 human seasonal-like lineage and H1N1 early classical swine lineages. Significantly, we have identified reassortant and recombinant viruses (H3N2, H1N1) not previously reported in Colombia. This suggests a broad genotypic viral diversity, likely resulting from reassortment between classical endemic viruses and new introductions established in Colombia's swine population (e.g. the 2009 H1N1 pandemic). Our study highlights the importance of a One Health approach in disease control, particularly in an ecosystem where humans are a main source of IAV to swine populations, and emphasizes the need for continued surveillance and enhanced biosecurity measures. The co-circulation of multiple subtypes in regions with high swine density facilitates viral exchange, underscoring the importance of monitoring viral evolution to inform vaccine selection and public health policies locally and globally.

Asunto(s)

Evolución Molecular , Variación Genética , Subtipo H1N1 del Virus de la Influenza A , Subtipo H3N2 del Virus de la Influenza A , Infecciones por Orthomyxoviridae , Filogenia , Enfermedades de los Porcinos , Animales , Porcinos , Colombia/epidemiología , Infecciones por Orthomyxoviridae/virología , Infecciones por Orthomyxoviridae/veterinaria , Infecciones por Orthomyxoviridae/epidemiología , Enfermedades de los Porcinos/virología , Enfermedades de los Porcinos/epidemiología , Subtipo H3N2 del Virus de la Influenza A/genética , Subtipo H3N2 del Virus de la Influenza A/clasificación , Subtipo H3N2 del Virus de la Influenza A/aislamiento & purificación , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/clasificación , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Salud Única , Humanos , Virus de la Influenza A/genética , Virus de la Influenza A/clasificación , Virus de la Influenza A/aislamiento & purificación , Secuenciación Completa del Genoma , Genoma Viral , Monitoreo Epidemiológico , Virus Reordenados/genética , Virus Reordenados/clasificación , Virus Reordenados/aislamiento & purificación , Subtipo H1N2 del Virus de la Influenza A/genética , Subtipo H1N2 del Virus de la Influenza A/aislamiento & purificación , Subtipo H1N2 del Virus de la Influenza A/clasificación , Gripe Humana/virología , Gripe Humana/epidemiología

RESUMEN

The tissue tropism and the wide host range of influenza A viruses are determined by the presence of sialic acid (SA) α2,3-Gal and SA α2,6-Gal receptors. Recent studies have shown that animals possessing both receptors allow for the rearrangement and emergence of new viral strains of public health importance. This study aimed to evaluate the expression and distribution of human and avian influenza A receptors in nine Neotropical snake species using lectin immunohistochemistry. We selected 17 snakes that were examined post mortem at the Veterinary Pathology Sector of the Universidade Federal de Minas Gerais between 2019 and 2023. Sections of nasal turbinate, trachea, lung, oral mucosa, stomach and intestine were subjected to immunohistochemical analysis using the lectins Maackia amurensis and Sambucus nigra. This research detected, for the first time, co-expression of SA α2,3-Gal and SA α2,6-Gal receptors in the respiratory and digestive tracts of snakes, indicating the possible susceptibility of these species to influenza A virus of avian and human origin. Consequently, snakes can be considered important species for monitoring influenza A in wild, urban and peri-urban environments. More studies should be conducted to investigate the role of snakes in influenza A epidemiology.

Asunto(s)

Virus de la Influenza A , Receptores de Superficie Celular , Serpientes , Animales , Receptores de Superficie Celular/metabolismo , Infecciones por Orthomyxoviridae/veterinaria , Receptores Virales/metabolismo

RESUMEN

Equine influenza is a viral disease caused by the equine influenza virus (EIV), and according to the WOAH, it is mandatory to report these infections. In Latin America and Colombia, EIV risk factors have not been analyzed. The objective of this research is to perform an epidemiological and molecular analysis of the EIV in horses with respiratory symptoms from 2020 to 2023 in Colombia. Molecular EIV detection was performed using RT-qPCR and nanopore sequencing. A risk analysis was also performed via the GEE method. A total of 188 equines with EIV respiratory symptoms were recruited. The positivity rate was 33.5%. The descriptive analysis showed that only 12.8% of the horses were vaccinated, and measures such as the quarantine and isolation of symptomatic animals accounted for 91.5% and 88.8%, respectively. The variables associated with the EIV were the non-isolation of positive individuals (OR = 8.16, 95% CI (1.52-43.67), p = 0.014) and sharing space with poultry (OR = 2.16, 95% CI (1.09-4.26), p = 0.027). In conclusion, this is the first EIV investigation in symptomatic horses in Colombia, highlighting the presence of the virus in the country and the need to improve preventive and control measures.

Asunto(s)

Enfermedades de los Caballos , Subtipo H3N8 del Virus de la Influenza A , Infecciones por Orthomyxoviridae , Caballos , Animales , Colombia/epidemiología , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/veterinaria , Infecciones por Orthomyxoviridae/virología , Enfermedades de los Caballos/virología , Enfermedades de los Caballos/epidemiología , Subtipo H3N8 del Virus de la Influenza A/aislamiento & purificación , Subtipo H3N8 del Virus de la Influenza A/genética , Femenino , Masculino , Filogenia , Secuenciación de Nanoporos/métodos , Factores de Riesgo

RESUMEN

Jamaican fruit bats (Artibeus jamaicensis) naturally harbor a wide range of viruses of human relevance. These infections are typically mild in bats, suggesting unique features of their immune system. To better understand the immune response to viral infections in bats, we infected male Jamaican fruit bats with the bat-derived influenza A virus (IAV) H18N11. Using comparative single-cell RNA sequencing, we generated single-cell atlases of the Jamaican fruit bat intestine and mesentery. Gene expression profiling showed that H18N11 infection resulted in a moderate induction of interferon-stimulated genes and transcriptional activation of immune cells. H18N11 infection was predominant in various leukocytes, including macrophages, B cells, and NK/T cells. Confirming these findings, human leukocytes, particularly macrophages, were also susceptible to H18N11, highlighting the zoonotic potential of this bat-derived IAV. Our study provides insight into a natural virus-host relationship and thus serves as a fundamental resource for future in-depth characterization of bat immunology.

Asunto(s)

Quirópteros , Infecciones por Orthomyxoviridae , Análisis de la Célula Individual , Animales , Quirópteros/virología , Quirópteros/inmunología , Quirópteros/genética , Masculino , Humanos , Infecciones por Orthomyxoviridae/virología , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/veterinaria , Macrófagos/inmunología , Macrófagos/virología , Virus de la Influenza A/genética , Virus de la Influenza A/inmunología , Perfilación de la Expresión Génica

RESUMEN

Inactivated influenza A virus (IAV) vaccines help reduce clinical disease in suckling piglets, although endemic infections still exist. The objective of this study was to evaluate the detection of IAV in suckling and nursery piglets from IAV-vaccinated sows from farms with endemic IAV infections. Eight nasal swab collections were obtained from 135 two-week-old suckling piglets from four farms every other week from March to September 2013. Oral fluid samples were collected from the same group of nursery piglets. IAV RNA was detected in 1.64% and 31.01% of individual nasal swabs and oral fluids, respectively. H1N2 was detected most often, with sporadic detection of H1N1 and H3N2. Whole-genome sequences of IAV isolated from suckling piglets revealed an H1 hemagglutinin (HA) from the 1B.2.2.2 clade and N2 neuraminidase (NA) from the 2002A clade. The internal gene constellation of the endemic H1N2 was TTTTPT with a pandemic lineage matrix. The HA gene had 97.59% and 97.52% nucleotide and amino acid identities, respectively, to the H1 1B.2.2.2 used in the farm-specific vaccine. A similar H1 1B.2.2.2 was detected in the downstream nursery. These data demonstrate the low frequency of IAV detection in suckling piglets and downstream nurseries from farms with endemic infections in spite of using farm-specific IAV vaccines in sows.

Asunto(s)

Granjas , Virus de la Influenza A , Vacunas contra la Influenza , Infecciones por Orthomyxoviridae , Filogenia , Enfermedades de los Porcinos , Animales , Porcinos , Enfermedades de los Porcinos/virología , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/prevención & control , Infecciones por Orthomyxoviridae/veterinaria , Infecciones por Orthomyxoviridae/virología , Infecciones por Orthomyxoviridae/epidemiología , Virus de la Influenza A/genética , Virus de la Influenza A/inmunología , Virus de la Influenza A/aislamiento & purificación , Virus de la Influenza A/clasificación , Vacunas contra la Influenza/inmunología , Vacunas contra la Influenza/administración & dosificación , Animales Lactantes , Vacunación/veterinaria , Enfermedades Endémicas/veterinaria , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/inmunología , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , ARN Viral/genética , Subtipo H3N2 del Virus de la Influenza A/genética , Subtipo H3N2 del Virus de la Influenza A/inmunología , Subtipo H3N2 del Virus de la Influenza A/aislamiento & purificación , Subtipo H1N2 del Virus de la Influenza A/genética , Subtipo H1N2 del Virus de la Influenza A/aislamiento & purificación , Subtipo H1N2 del Virus de la Influenza A/inmunología , Genoma Viral

RESUMEN

Novel H1N2 and H3N2 swine influenza A viruses (IAVs) have recently been identified in Chile. The objective of this study was to evaluate their zoonotic potential. We perform phylogenetic analyses to determine the genetic origin and evolution of these viruses, and a serological analysis to determine the level of cross-protective antibodies in the human population. Eight genotypes were identified, all with pandemic H1N1 2009-like internal genes. H1N1 and H1N2 were the subtypes more commonly detected. Swine H1N2 and H3N2 IAVs had hemagglutinin and neuraminidase lineages genetically divergent from IAVs reported worldwide, including human vaccine strains. These genes originated from human seasonal viruses were introduced into the swine population since the mid-1980s. Serological data indicate that the general population is susceptible to the H3N2 virus and that elderly and young children also lack protective antibodies against the H1N2 strains, suggesting that these viruses could be potential zoonotic threats. Continuous IAV surveillance and monitoring of the swine and human populations is strongly recommended.IMPORTANCEIn the global context, where swine serve as crucial intermediate hosts for influenza A viruses (IAVs), this study addresses the pressing concern of the zoonotic potential of novel reassortant strains. Conducted on a large scale in Chile, it presents a comprehensive account of swine influenza A virus diversity, covering 93.8% of the country's industrialized swine farms. The findings reveal eight distinct swine IAV genotypes, all carrying a complete internal gene cassette of pandemic H1N1 2009 origin, emphasizing potential increased replication and transmission fitness. Genetic divergence of H1N2 and H3N2 IAVs from globally reported strains raises alarms, with evidence suggesting introductions from human seasonal viruses since the mid-1980s. A detailed serological analysis underscores the zoonotic threat, indicating susceptibility in the general population to swine H3N2 and a lack of protective antibodies in vulnerable demographics. These data highlight the importance of continuous surveillance, providing crucial insights for global health organizations.

Asunto(s)

Subtipo H1N1 del Virus de la Influenza A , Virus de la Influenza A , Gripe Humana , Infecciones por Orthomyxoviridae , Enfermedades de los Porcinos , Niño , Humanos , Animales , Porcinos , Preescolar , Anciano , Virus de la Influenza A/genética , Subtipo H3N2 del Virus de la Influenza A/genética , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/veterinaria , Subtipo H1N1 del Virus de la Influenza A/genética , Filogenia , Chile/epidemiología , Virus Reordenados/genética , Enfermedades de los Porcinos/epidemiología , Gripe Humana/epidemiología

RESUMEN

We describe the evolution of the outbreak of Highly Pathogenic Avian Influenza (HPAI) A(H5N1) in sea lions (Otaria flavescens) of South America. At least 24,000 sea lions died in Peru, Chile, Argentina, Uruguay, and Brazil between January-October 2023. The most plausible route of infection is cohabiting with or foraging on infected birds. However, we urge a detailed evaluation of the sea lions actual source of infection given that the concomitant massive wild bird mortalities registered in the Pacific Ocean did not occur in the Atlantic Ocean.

Asunto(s)

Subtipo H5N1 del Virus de la Influenza A , Leones Marinos , Animales , América del Sur/epidemiología , Brotes de Enfermedades , Gripe Aviar/mortalidad , Gripe Aviar/epidemiología , Gripe Aviar/virología , Océano Atlántico , Océano Pacífico , Infecciones por Orthomyxoviridae/veterinaria , Infecciones por Orthomyxoviridae/mortalidad , Infecciones por Orthomyxoviridae/virología , Infecciones por Orthomyxoviridae/epidemiología , Aves/virología

RESUMEN

Clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) viruses have caused large outbreaks within avian populations on five continents, with concurrent spillover into a variety of mammalian species. Mutations associated with mammalian adaptation have been sporadically identified in avian isolates, and more frequently among mammalian isolates following infection. Reports of human infection with A(H5N1) viruses following contact with infected wildlife have been reported on multiple continents, highlighting the need for pandemic risk assessment of these viruses. In this study, the pathogenicity and transmissibility of A/Chile/25945/2023 HPAI A(H5N1) virus, a novel reassortant with four gene segments (PB1, PB2, NP, MP) from North American lineage, isolated from a severe human case in Chile, was evaluated in vitro and using the ferret model. This virus possessed a high capacity to cause fatal disease, characterized by high morbidity and extrapulmonary spread in virus-inoculated ferrets. The virus was capable of transmission to naïve contacts in a direct contact setting, with contact animals similarly exhibiting severe disease, but did not exhibit productive transmission in respiratory droplet or fomite transmission models. Our results indicate that the virus would need to acquire an airborne transmissible phenotype in mammals to potentially cause a pandemic. Nonetheless, this work warrants continuous monitoring of mammalian adaptations in avian viruses, especially in strains isolated from humans, to aid pandemic preparedness efforts.

Asunto(s)

Hurones , Subtipo H5N1 del Virus de la Influenza A , Gripe Humana , Infecciones por Orthomyxoviridae , Animales , Hurones/virología , Humanos , Chile , Gripe Humana/virología , Gripe Humana/transmisión , Infecciones por Orthomyxoviridae/virología , Infecciones por Orthomyxoviridae/transmisión , Infecciones por Orthomyxoviridae/veterinaria , Subtipo H5N1 del Virus de la Influenza A/genética , Subtipo H5N1 del Virus de la Influenza A/patogenicidad , Subtipo H5N1 del Virus de la Influenza A/aislamiento & purificación , Subtipo H5N1 del Virus de la Influenza A/clasificación , Subtipo H5N1 del Virus de la Influenza A/fisiología , Virus Reordenados/genética , Virus Reordenados/aislamiento & purificación , Virus Reordenados/patogenicidad , Virus Reordenados/clasificación , Filogenia , Gripe Aviar/virología , Gripe Aviar/transmisión

RESUMEN

AIMS: This study aimed to identify exposure to human, swine, and avian influenza A virus subtypes in rural companion and hunting dogs, backyard pigs, and feral pigs. METHODS AND RESULTS: The study took place in a region of southeastern Mexico where the sampled individuals were part of backyard production systems in which different domestic and wild species coexist and interact with humans. We collected blood samples from pigs and dogs at each of the sites. We used a nucleoprotein enzyme-linked immunosorbent assay to determine the exposure of individuals to influenza A virus. Haemagglutination inhibition was performed on the positive samples to determine the subtypes to which they were exposed. For data analysis, a binomial logistic regression model was generated to determine the predictor variables for the seropositivity of the individuals in the study. We identified 11 positive individuals: three backyard pigs, four companion dogs, and four hunting dogs. The pigs tested positive for H1N1 and H1N2. The dogs were positive for H1N1, H1N2, and H3N2. The model showed that dogs in contact with backyard chickens are more likely to be seropositive for influenza A viruses. CONCLUSIONS: We demonstrated the essential role hunting dogs could play as intermediate hosts and potential mixing vessel hosts when exposed to human and swine-origin viral subtypes. These results are relevant because these dogs interact with domestic hosts and humans in backyard systems, which are risk scenarios in the transmission of influenza A viruses. Therefore, it is of utmost importance to implement epidemiological surveillance of influenza A viruses in backyard animals, particularly in key animals in the transmission of these viruses, such as dogs and pigs.

Asunto(s)

Enfermedades de los Perros , Subtipo H1N1 del Virus de la Influenza A , Virus de la Influenza A , Gripe Humana , Infecciones por Orthomyxoviridae , Enfermedades de los Porcinos , Animales , Humanos , Perros , Porcinos , Subtipo H3N2 del Virus de la Influenza A , Perros de Trabajo , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/veterinaria , México/epidemiología , Pollos , Anticuerpos Antivirales , Sus scrofa

RESUMEN

The piscine orthomyxovirus called infectious salmon anemia virus (ISAV) is one of the most important emerging pathogens affecting the salmon industry worldwide. The first reverse genetics system for ISAV, which allows the generation of recombinant ISA virus (rISAV), is an important tool for the characterization and study of this virus. The plasmid-based reverse genetics system for ISAV includes the use of a novel fish promoter, the Atlantic salmon internal transcribed spacer region 1 (ITS-1). The salmon, viral, and mammalian genetic elements included in the pSS-URG vectors allow the expression of the eight viral RNA segments. In addition to four cytomegalovirus (CMV)-based vectors that express the four proteins of the ISAV ribonucleoprotein complex, the eight pSS-URG vectors allowed the generation of infectious rISAV in salmon cells.

Asunto(s)

Enfermedades de los Peces , Isavirus , Infecciones por Orthomyxoviridae , Orthomyxoviridae , Animales , Isavirus/genética , ADN Complementario/genética , Línea Celular , Orthomyxoviridae/genética , ARN Viral/genética , Infecciones por Orthomyxoviridae/veterinaria , Salmón/genética , Mamíferos/genética

RESUMEN

Swine influenza is a respiratory disease that affects the pork industry and is a public health threat. It is caused by type A influenza virus (FLUAV), which continuously undergoes genetic and antigenic variations. A large amount of information regarding FLUAV in pigs is available worldwide, but it is limited in Latin America. The HA sequences of H1 subtype FLUAV-positive samples obtained from pigs in Colombia between 2008-2021 were analyzed using sequence-based antigenic cartography and N-Glycosylation analyses. Of the 12 predicted global antigenic groups, Colombia contained five: four corresponding to pandemic strains and one to the classical swine H1N1 clade. Circulation of these clusters was observed in some regions during specific years. Ca2 was the immunodominant epitope among Colombian viruses. The counts of N-Glycosylation motifs were associated with the antigenic cluster ranging from three to five. The results show for the first time the existence of antigenic diversity of FLUAV in Colombia and highlight the impact of spatial and temporal factors on this diversity. This study provides information about FLUAV variability in pigs under natural conditions in the absence of vaccination and emphasizes the need for surveillance of its phylogenetic and antigenic characteristics.

Asunto(s)

Subtipo H1N1 del Virus de la Influenza A , Gripe Humana , Infecciones por Orthomyxoviridae , Enfermedades de los Porcinos , Porcinos , Animales , Humanos , Colombia/epidemiología , Filogenia , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/veterinaria , Variación Antigénica , Enfermedades de los Porcinos/epidemiología

RESUMEN

Commercial swine farms provide unique systems for interspecies transmission of influenza A viruses (FLUAVs) at the animal-human interface. Bidirectional transmission of FLUAVs between pigs and humans plays a significant role in the generation of novel strains that become established in the new host population. Active FLUAV surveillance was conducted for 2 years on a commercial pig farm in Southern Guatemala with no history of FLUAV vaccination. Nasal swabs (n = 2,094) from fattening pigs (6 to 24 weeks old) with respiratory signs were collected weekly from May 2016 to February 2018. Swabs were screened for FLUAV by real-time reverse transcriptase PCR (RRT-PCR), and full virus genomes of FLUAV-positive swabs were sequenced by next-generation sequencing (NGS). FLUAV prevalence was 12.0% (95% confidence interval [CI], 10.6% to 13.4%) with two distinct periods of high infection. All samples were identified as FLUAVs of the H1N1 subtype within the H1 swine clade 1A.3.3.2 and whose ancestors are the human origin 2009 H1N1 influenza pandemic virus (H1N1 pdm09). Compared to the prototypic reference segment sequence, 10 amino acid signatures were observed on relevant antigenic sites on the hemagglutinin. The Guatemalan swine-origin FLUAVs show independent evolution from other H1N1 pdm09 FLUAVs circulating in Central America. The zoonotic risk of these viruses remains unknown but strongly calls for continued FLUAV surveillance in pigs in Guatemala. IMPORTANCE Despite increased surveillance efforts, the epidemiology of FLUAVs circulating in swine in Latin America remains understudied. For instance, the 2009 H1N1 influenza pandemic strain (H1N1 pdm09) emerged in Mexico, but its circulation remained undetected in pigs. In Central America, Guatemala is the country with the largest swine industry. We found a unique group of H1N1 pdm09 sequences that suggests independent evolution from similar viruses circulating in Central America. These viruses may represent the establishment of a novel genetic lineage with the potential to reassort with other cocirculating viruses and whose zoonotic risk remains to be determined.

Asunto(s)

Subtipo H1N1 del Virus de la Influenza A , Virus de la Influenza A , Gripe Humana , Infecciones por Orthomyxoviridae , Enfermedades de los Porcinos , Porcinos , Humanos , Animales , Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/genética , Gripe Humana/epidemiología , Granjas , Guatemala/epidemiología , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/veterinaria , Enfermedades de los Porcinos/epidemiología , Filogenia

RESUMEN

Due to their documented epidemiological relevance as hosts for influenza A viruses (IAV), humans, poultry and pigs in backyard production systems (BPS) within wetlands could be key to the emergence of novel IAV variants able to transmit between humans or animals. To better understand the circulation of IAV at the human-animal interface of BPS within wetlands, we studied IAV in backyard duck flocks and pig herds in the Pacific Coast of Guatemala. From April 2013 to October 2014, we estimated the monthly IAV per cent seropositive and viral positive flocks and herds in two resource-limited communities. We detected antibodies in sera against the IAV nucleoprotein through ELISA. We also detected IAV viral RNA in respiratory (ducks and pigs) and cloacal (ducks) swabs through rRT-PCR directed at the matrix gene. We attempted viral isolation in eggs or MDCK cells followed by sequencing from swabs positive for IAV. During our study period, IAV seropositivity in duck flocks was 38%, and viral positivity was 23% (n = 86 BPS sampled). IAV seropositivity in pig herds was 42%, and viral positivity was 20% (n = 90 BPS sampled). Both flocks and herds had detectable antibodies against IAV mostly year-round, and IAV was detected in several months. We isolated an H3N2 virus from one pig sampled at the end of 2013. Standard nucleotide BLAST searches indicate that the isolated virus was similar to seasonal viruses circulating in humans, suggesting human-to-pig transmission. Our data show concurrent circulation of IAV in multiple species of poultry and pigs that were commingled in rudimentary conditions in proximity to humans, but no significant risk factors could be identified.

Asunto(s)

Virus de la Influenza A , Infecciones por Orthomyxoviridae , Enfermedades de los Porcinos , Animales , Patos , Guatemala/epidemiología , Humanos , Subtipo H3N2 del Virus de la Influenza A/genética , Nucleoproteínas , Nucleótidos , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/veterinaria , Óvulo , Aves de Corral , ARN Viral/genética , Porcinos

RESUMEN

Infectious salmon anemia virus (ISAV) is the etiological agent of infectious salmon anemia. It belongs to the genus isavirus, one of the genera of the Orthomyxoviridae family, as does Influenzavirus A. The ISAV genome comprises eight negative-sense single-stranded RNA segments that code for at least 10 proteins. Although some ISAV strains can reach 100% mortality rates, the factors that determine isavirus infectivity remain unknown. However, some studies suggest that segments 5 and 6 are responsible for the different degrees of virulence and infectivity among ISAV subtypes, unlike the influenza A virus, where most segments are involved in the virus infectivity. In this work, synthetic reassortant viruses for the eight segments of ISAV were generated by reverse genetics, combining a highly virulent virus, ISAV 752_09 (HPR7b), and an avirulent strain, SK779/06 (HPR0). We characterized the rescued viruses and their capacity to replicate and infect different cell lines, produce plaques in ASK cells, and their ability to induce and modulate the cellular immune response in vitro. Our results show that the majority of ISAV segments are involved in at least one of the analyzed characteristics, segment 5 being one of the most important, allowing HPR0 viruses, among other things, to produce plaques and replicate in CHSE-214 cells. We determined that segments 5 and 6 participate in different stages of the viral cycle, and their compatibility is critical for viral infection. Additionally, we demonstrated that segment 2 can modulate the cellular immune response. Our results indicate a high degree of genetic compatibility between the genomic segments of HPR7b and HPR0, representing a latent risk of reassortant that would give rise to a new virus with an unknown phenotype.

Asunto(s)

Enfermedades de los Peces , Isavirus , Infecciones por Orthomyxoviridae , Salmo salar , Animales , Isavirus/genética , Infecciones por Orthomyxoviridae/veterinaria , Filogenia , Salmo salar/genética , Análisis de Secuencia de ADN

RESUMEN

A specialized and fine-tuned immune response of bats upon infection with viruses is believed to provide the basis for a "friendly" coexistence with these pathogens, which are often lethal for humans and other mammals. First insights into the immunity of bats suggest that bats have evolved to possess their own strategies to cope with viral infections. Yet, the molecular details for this innocuous coexistence remain poorly described and bat infection models are the key to unveiling these secrets. In Jamaican fruit bats (Artibeus jamaicensis), a New World bat species, infection experiments with its (putative) natural viral pathogens Tacaribe virus (TCRV), rabies virus (RABV), and the bat influenza A virus (IAV) H18N11, have contributed to an accurate, though still incomplete, representation of the bat-imposed immunity. Surprisingly, though many aspects of their innate and adaptive immune responses differ from that of the human immune response, such as a contraction of the IFN locus and reduction in the number of immunoglobulin subclasses, variations could also be observed between Jamaican fruit bats and other bat species.

Asunto(s)

Quirópteros/inmunología , Quirópteros/virología , Viroma , Virosis/veterinaria , Inmunidad Adaptativa , Animales , Infecciones por Arenaviridae/inmunología , Infecciones por Arenaviridae/veterinaria , Infecciones por Arenaviridae/virología , Arenavirus del Nuevo Mundo/aislamiento & purificación , Inmunidad Innata , Virus de la Influenza A/aislamiento & purificación , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/veterinaria , Rabia/inmunología , Rabia/veterinaria , Rabia/virología , Virus de la Rabia/aislamiento & purificación , Virosis/inmunología

RESUMEN

There are different opinions around the World regarding the zoonotic capability of H3N8 equine influenza viruses. In this report, we have tried to summarize the findings of different research and review articles from Chinese, English, and Mongolian Scientific Literature reporting the evidence for equine influenza virus infections in human beings. Different search engines i.e. CNKI, PubMed, ProQuest, Chongqing Database, Mongol Med, and Web of Knowledge yielded 926 articles, of which 32 articles met the inclusion criteria for this review. Analyzing the epidemiological and Phylogenetic data from these articles, we found a considerable experimental and observational evidence of H3N8 equine influenza viruses infecting human being in different parts of the World in the past. Recently published articles from Pakistan and China have highlighted the emerging threat and capability of equine influenza viruses for an epidemic in human beings in future. In this review article we have summarized the salient scientific reports published on the epidemiology of equine influenza viruses and their zoonotic aspect. Additionally, several recent developments in the start of 21st century, including the transmission and establishment of equine influenza viruses in different animal species i.e. camels and dogs, and presumed encephalopathy associated to influenza viruses in horses, have documented the unpredictable nature of equine influenza viruses. In sum up, several reports has highlighted the unpredictable nature of H3N8 EIVs highlighting the need of continuous surveillance for H3N8 in equines and humans in contact with them for novel and threatening mutations.

Asunto(s)

Enfermedades de los Caballos/epidemiología , Subtipo H3N8 del Virus de la Influenza A , Infecciones por Orthomyxoviridae , Animales , China , Enfermedades de los Caballos/transmisión , Caballos , Humanos , Subtipo H3N8 del Virus de la Influenza A/genética , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/transmisión , Infecciones por Orthomyxoviridae/veterinaria , Pakistán , Filogenia , Zoonosis