Browsing by Author "Ariyama, Naomi"

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    Avian orthoavulavirus 1 (Newcastle Disease virus) antibodies in five penguin species, Antarctic peninsula and Southern Patagonia
    (2021) Ariyama, Naomi; Tapia, Rodrigo; Godoy, Claudia; Aguero, Belen; Valdes, Valentina; Berrios, Felipe; Garcia Borboroglu, Pablo; Putz, Klemens; Alegria, Raul; Barriga, Gonzalo P.; Medina, Rafael; Neira, Victor
    Avian orthoavulavirus 1 (AOaV-1) causes Newcastle disease, one of the most important and contagious infections in poultry, where migratory birds can play a key role as a reservoir. Seven hundred and seven serum samples were collected from five penguin species (King, Magellanic, Gentoo, Chinstrap and Adelie penguins) in the Antarctic and Sub-Antarctic zones. Using a competitive ELISA to detect antibodies against AOaV-1, we identified positive individuals in all penguin species. The Magellanic penguin showed the highest seropositivity rate (30.3%), suggesting it could be a natural reservoir of this virus. At the Antarctic zones, Chinstrap penguin showed the highest occurrence (7.5%). Interesting, positive sera was only obtained in Sub-Antarctic and Northern zones at the Antarctic peninsula, no seroreactivity was observed in Southern locations. Further studies are needed to establish the role of these penguin species in the epidemiology of the AOaV-1 and determine the effects of this virus in these populations.
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    Emergence and rapid dissemination of highly pathogenic avian influenza virus H5N1 clade 2.3.4.4b in wild birds, Chile.
    (SPRINGER INTERNATIONAL PUBLISHING AG, 2023) Ariyama, Naomi; Pardo-Roa, Catalina; Munoz, Gabriela; Aguayo, Carolina; Avila, Claudia; Mathieu, Christian; Brito, Barbara; Medina, Rafael; Johow, Magdalena; Neira, Victor
    In December 2022, HPAI H5N1 clade 2.3.4.4b emerged in Chile. We detected the virus in 93 wild bird samples and sequenced the whole genome of nine Chilean strains from pelicans and gulls. Phylogenetic analysis suggests at least two different HPAI viral clusters in South America.
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    First report and genetic characterization of Seneca Valley virus (SVV) in Chile
    (SPRINGER INTERNATIONAL PUBLISHING AG, 2022) Bennett, Benjamin; Urzua-Encina, Constanza; Pardo-Roa, Catalina; Ariyama, Naomi; Lecocq, Claudio; Rivera, Carlos; Badia, Catalina; Suarez, Paulina; Agredo, Michel; Aguayo, Carolina; Avila, Claudia; Araya, Hugo; Perez, Patricio; Berrios, Felipe; Aguero, Belen; Mendieta, Vanessa; Pituco, Edviges Maristela; de Almeida, Iassudara Garcia; Medina, Rafael; Brito, Barbara; Johow, Magdalena; Neira Ramirez, Victor
    Seneca Valley virus (SVV) is a non-enveloped RNA virus and the only member of the Senecavirus A (SVA) species, in the Senecavirus genus, Picornaviridae family. SVV infection causes vesicular lesions in the oral cavity, snout and hooves of pigs. This infection is clinically indistinguishable from trade-restrictions-related diseases such as foot-and-mouth disease. Other clinical manifestations include diarrhoea, anorexia, lethargy, neurological signs and mortality in piglets during their first week of age. Before this study, Chile was considered free of vesicular diseases of swine, including SVV. In April 2022, a suspected case of vesicular disease in a swine farm was reported in Chile. The SVV was confirmed and other vesicular diseases were ruled out. An epidemiological investigation and phylogenetic analyses were performed to identify the origin and extent of the outbreak. Three hundred ninety-five samples from 44 swine farms were collected, including faeces (208), oral fluid (28), processing fluid (14), fresh semen (61), environmental samples (80) and tissue from lesions (4) for real-time RT-PCR detection. Until June 2022, the SVV has been detected in 16 out of 44 farms, all epidemiologically related to the index farm. The closest phylogenetic relationship of the Chilean SVV strain is with viruses collected from swine in California in 2017. The direct cause of the SVV introduction has not yet been identified; however, the phylogenetic analyses suggest the USA as the most likely source. Since the virus remains active in the environment, transmission by fomites such as contaminated feed cannot be discarded. Further studies are needed to determine the risk of the introduction of novel SVV and other transboundary swine pathogens to Chile.
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    Mass mortality event in South American sea lions (Otaria flavescens) correlated to highly pathogenic avian influenza (HPAI) H5N1 outbreak in Chile
    (2023) Ulloa, Mauricio; Fernandez, Antonio; Ariyama, Naomi; Colom-Rivero, Ana; Rivera, Carlos; Nunez, Paula; Sanhueza, Paola; Johow, Magdalena; Araya, Hugo; Torres, Juan Carlos; Gomez, Paola; Munoz, Gabriela; Aguero, Belen; Alegria, Raul; Medina, Rafael; Neira, Victor; Sierra, Eva
    In Chile, since January 2023, a sudden and pronounced increase in strandings and mortality has been observed among South American (SA) sea lions (Otaria flavescens), prompting significant concern. Simultaneously, an outbreak of highly pathogenic avian influenza H5N1 (HPAIV H5N1) in avian species has emerged since December 2022. To investigate the cause of this unexpected mortality, we conducted a comprehensive epidemiological and pathologic study. One hundred sixty-nine SA sea lions were sampled to ascertain their HPAIV H5N1 status, and long-term stranding trends from 2009 to 2023 were analyzed. In addition, two animals were necropsied. Remarkably, a significant surge in SA sea lion strandings was observed initiating in January 2023 and peaking in June 2023, with a count of 4,545 stranded and deceased animals. Notably, this surge in mortality correlates geographically with HPAIV outbreaks affecting wild birds. Among 168 sampled SA sea lions, 34 (20%) tested positive for Influenza A virus, and 21 confirmed for HPAIV H5N1 2.3.4.4b clade in tracheal/rectal swab pools. Clinical and pathological evaluations of the two necropsied stranded sea lions revealed prevalent neurological and respiratory signs, including disorientation, tremors, ataxia, and paralysis, as well as acute dyspnea, tachypnea, profuse nasal secretion, and abdominal breathing. The lesions identified in necropsied animals aligned with observed clinical signs. Detection of the virus via immunohistochemistry (IHC) and real-time PCR in the brain and lungs affirmed the findings. The findings provide evidence between the mass mortality occurrences in SA sea lions and HPAIV, strongly indicating a causal relationship. Further studies are needed to better understand the pathogenesis and transmission.
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    Ubiquitous influenza A virus in Chilean swine before the H1N1pdm09 introduction
    (2021) Mena, Juan; Ariyama, Naomi; Navarro, Camila; Quezada, Manuel; Brevis, Cristina; Rojas, Daniela; Medina, Rafael A.; Brito, Barbara; Ruiz, Alvaro; Neira, Victor
    Influenza A virus (IAV) was a neglected swine pathogen in South America before the 2009 H1N1 pandemic (A(H1N1)pdm2009). The A(H1N1)pdm2009 strain has widely spread among the Chilean swine population and co-circulates with endemic H1N2 and H3N2 viruses. The presence of IAV as a swine pathogen in Chilean swine before the 2009 pandemic is unknown. To understand the IAV in swine prior to 2009, aY retrospective study of samples from pigs affected with respiratory diseases was conducted. Ninety formalin-fixed and paraffin-embedded lung tissues belonging to 21 intensive pig production companies located in five different administrative regions of Chile, collected between 2005 and 2008, were evaluated. The tissues were tested by immunohistochemistry (IHC), identifying that 9 out of 21 farms (42.8%) and 31 out of 90 (34.4%) samples were IAV positive. Only three out of the 31 IHC-positive samples were positive upon RNA extraction and rtRT-PCR analysis. Partial nucleotide sequences were obtained from one sample and characterized as an H3N2 subtype closely related to a human seasonal H3N2 IAVs that circulated globally in the mid-90s. These results indicate that IAV was circulating in swine before 2009 and highlight the value of conducting retrospective studies through genomic strategies to analyse historical samples.