Divergent Pathogenesis and Transmission of Highly Pathogenic Avian Influenza A(H5N1) in Swine.

Highly pathogenic avian influenza (HPAI) viruses have potential to cross species barriers and cause pandemics. Since 2022, HPAI A(H5N1) belonging to the goose/Guangdong 2.3.4.4b hemagglutinin phylogenetic clade have infected poultry, wild birds, and mammals across North America. Continued circulation in birds and infection of multiple mammalian species with strains possessing adaptation mutations increase the risk for infection and subsequent reassortment with influenza A viruses endemic in swine. We assessed the susceptibility of swine to avian and mammalian HPAI H5N1 clade 2.3.4.4b strains using a pathogenesis and transmission model. All strains replicated in the lung of pigs and caused lesions consistent with influenza A infection. However, viral replication in the nasal cavity and transmission was only observed with mammalian isolates. Mammalian adaptation and reassortment may increase the risk for incursion and transmission of HPAI viruses in feral, backyard, or commercial swine.

Dual Gene Detection of H5N1 Avian Influenza Virus Based on Dual RT-RPA.

The H5N1 avian influenza virus seriously affects the health of poultry and humans. Once infected, the mortality rate is very high. Therefore, accurate and timely detection of the H5N1 avian influenza virus is beneficial for controlling its spread. This article establishes a dual gene detection method based on dual RPA for simultaneously detecting the HA and M2 genes of H5N1 avian influenza virus, for the detection of H5N1 avian influenza virus. Design specific primers for the conserved regions of the HA and M2 genes. The sensitivity of the dual RT-RPA detection method for HA and M2 genes is 1 × 10-7 ng/µL. The optimal primer ratio is 1:1, the optimal reaction temperature is 40 °C, and the optimal reaction time is 20 min. Dual RT-RPA was used to detect 72 samples, and compared with RT-qPCR detection, the Kappa value was 1 (p value < 0.05), and the clinical sample detection sensitivity and specificity were both 100%. The dual RT-RPA method is used for the first time to simultaneously detect two genes of the H5N1 avian influenza virus. As an accurate and convenient diagnostic tool, it can be used to diagnose the H5N1 avian influenza virus.

Advances in Detection Techniques for the H5N1 Avian Influenza Virus.

Avian influenza is caused by avian influenza virus infection; the H5N1 avian influenza virus is a highly pathogenic subtype, affecting poultry and human health. Since the discovery of the highly pathogenic subtype of the H5N1 avian influenza virus, it has caused enormous losses to the poultry farming industry. It was recently found that the H5N1 avian influenza virus tends to spread among mammals. Therefore, early rapid detection methods are highly significant for effectively preventing the spread of H5N1. This paper discusses the detection technologies used in the detection of the H5N1 avian influenza virus, including serological detection technology, immunological detection technology, molecular biology detection technology, genetic detection technology, and biosensors. Comparisons of these detection technologies were analyzed, aiming to provide some recommendations for the detection of the H5N1 avian influenza virus.

Preventive, safety and control measures against Avian Influenza A(H5N1) in occupationally exposed groups: A scoping review.

Introduction: During the outbreak of avian influenza, A (H5N1) (IA) in wild and domestic birds recorded in January 2023, the epidemiological alert has been extended due to its potential contagion to humans, particularly in those exposed occupational groups. Objective: to identify the primary occupational risk groups, as well as the preventive, safety, and control measures against IA intended or implemented in these positions. Material and methods: A systematic search was conducted in Pubmed, Scopus, Web of science, Scielo and literature databases. Scientific articles, normative documents, and technical reports identifying vulnerable occupational groups and preventive measures against IA were included. Two authors conducted a full-text review, extracting information independently, and findings were summarized narratively. Results: A total of 5518 documents were identified, and 30 reports were included. 20% of the reports were published in 2023, 13/30 were affiliated to a university institution. Occupationally exposed groups were identified both directly and indirectly. 63.3% of reports identified breeders, poultry farmers and sellers as the most concerning occupational group, while 60% identified biosecurity practices (use of PPE, handwashing) as the primary measure against IA, followed by strategies such as education (training and capacity-building). Conclusion: Occupational groups of interest were identified, primarily those involved in sales, commerce, and the handling of bird waste with potential exposure to IA. Furthermore, the maintenance of biosecurity measures, cleaning-disinfection practices, and educational strategies in workplace settings are recommended.

Influenza h5n1 nnext pandemic? / Influenza h5n1: próxima pandemia? / Influenza h5n1: pandemia próximo?

Since 1990 there have been cases of patients infected by influenza caused by Low Pathogenic Avian Influenza. However, since 1997, highly pathogenic viruses, such as A/H5N1, have caused an increase in the number of people infected via zoonotic transmission. Infected patients have constitutional and mainly respiratory symptoms, hematological disorders and liver dysfunction. About half of patients are under 20 years and about 90% under 40 years. In recent studies in mammals it seems that only few mutations in viral genome are necessary to confer the virus the ability to infect mammalian cells. In response to these studies, the Centers for Disease Control (CDC) propose continuous researches without alerting the health care system, because, at present, there is not a global threat. Moreover, in the future, this issue would take place as a major concern from the point of view of public health; it could be the next pandemic. Due to the high human mortality rate occurring in cases of patients infected with this virus, an outbreak or pandemic would require proper knowledge of the biology of the avian influenza virus, the determinants of pathogenicity, prevention through vaccination and possible new treatment regimens.

Desde 1990 se han reportado casos de pacientes infectados por influenza causadas por virus de baja patogenicidad, sin embargo, desde el año 1997, virus altamente patógenos como el A/H5N1 han provocado un aumento en el número de personas infectadas por transmisión zoonotica. Los pacientes infectados presentan síntomas constitucionales y respiratorios, trastornos hematológicos y disfunción hepática. Cerca de la mitad de casos son pacientes menores de 20 años, y aproximadamente el 90% son menores de 40 años. Recientes estudios en mamíferos indican que son necesarias algunas mutaciones en el genoma viral para que el virus tenga la capacidad de infectar células mamíferas. En respuesta a estos estudios el centro de control de enfermedades (por sus siglas en ingles Centers for Disease Control), ente regulador en la dinámica epidemiológica mundial propone continuar con las investigaciones sin alertar a los sistemas de salud, pues en este momento no constituye una amenaza mundial. Sin embargo, este aspecto toma lugar como una preocupación importante desde el punto de vista de la salud pública, por cuanto podría constituir la próxima pandemia. Debido a la alta mortalidad en humanos que se presenta en los casos de pacientes infectados con este virus, un brote o una pandemia exigirán por tanto un conocimiento apropiado de la biología del virus de la influenza aviar, los determinantes de su patogenicidad, la prevención mediante vacuna y los posibles esquemas de tratamiento.

Desde 1990 se têm reportado casos de pacientes infectados por influenza causadas por vírus de baixa patogenicidade, porém, desde o ano 1997, vírus altamente patógenos como o A/H5N1 têm provocado um aumento no número de pessoas infectadas por transmissão zoonótica. Os pacientes infectados apresentam sintomas constitucionais e respiratórios, transtornos hematológicos e disfunção hepática. Cerca dametade de casos são pacientes menores de 20 anos, e aproximadamente o 90% são menores de 40 anos. Recentes estudos em mamíferos indicam que são necessárias algumas mutações no genoma viral para que o vírustenha a capacidade de infectar células mamíferas. Em resposta a estes estudos o centro de controle de doenças (por suas siglas em inglês: Centers for Disease Controle), ente regulador na dinâmica epidemiológica mundial propõe continuar com as pesquisassem alertar aos sistemas de saúde, pois em este momento não constituiu maameaça mundial. Porém, este aspecto toma lugar como uma preocupação importante desde o ponto de vista dasaúde pública, já que poderia constituir a próxima pandemia. Devido à alta mortalidade em humanos que se apresenta nos casos de pacientes infectados com este vírus, um surto ou uma pandemia, exigirão por tanto um conhecimento apropriado da biologia do vírus da influenza aviar, os determinantes dasua patogenicidade, a prevenção mediante vacinae os possíveis esquemas de tratamento.