Limited Outbreak of Highly Pathogenic Influenza A(H5N1) in Herring Gull Colony, Canada, 2022.

In summer 2022, highly pathogenic influenza A(H5N1) virus reached the herring gull (Larus argentatus subspecies smithsonianus) breeding colony on Kent Island, New Brunswick, Canada. Real-time monitoring revealed a self-limiting outbreak with low mortality. Proactive seabird surveillance is crucial for monitoring such limited outbreaks, protecting seabirds, and tracing zoonotic transmission routes.

Highly Pathogenic Avian Influenza A(H5N1) Virus in a Harbor Porpoise, Sweden.

We found highly pathogenic avian influenza A(H5N1) virus clade 2.3.4.4b associated with meningoencephalitis in a stranded harbor porpoise (Phocoena phocoena). The virus was closely related to strains responsible for a concurrent avian influenza outbreak in wild birds. This case highlights the potential risk for virus spillover to mammalian hosts.

Mass Mortality Caused by Highly Pathogenic Influenza A(H5N1) Virus in Sandwich Terns, the Netherlands, 2022.

We collected data on mass mortality in Sandwich terns (Thalasseus sandvicensis) during the 2022 breeding season in the Netherlands. Mortality was associated with at least 2 variants of highly pathogenic avian influenza A(H5N1) virus clade 2.3.4.4b. We report on carcass removal efforts relative to survival in colonies. Mitigation strategies urgently require structured research.

Concomitant NA and NS deletion on avian Influenza H3N1 virus associated with hen mortality in France in 2019.

An H3N1 avian influenza virus was detected in a laying hens farm in May 2019 which had experienced 25% mortality in Northern France. The complete sequencing of this virus showed that all segment sequences belonged to the Eurasian lineage and were phylogenetically very close to many of the Belgian H3N1 viruses detected in 2019. The French virus presented two genetic particularities with NA and NS deletions that could be related to virus adaptation from wild to domestic birds and could increase virulence, respectively. Molecular data of H3N1 viruses suggest that these two deletions occurred at two different times.

Improving siRNA design targeting nucleoprotein gene as antiviral against the Indonesian H5N1 virus.

BACKGROUND: Small interfering RNA technology has been considered a prospective alternative antiviral treatment using gene silencing against influenza viruses with high mutations rates. On the other hand, there are no reports on its effectiveness against the highly pathogenic avian influenza H5N1 virus isolated from Indonesia. OBJECTIVES: The main objective of this study was to improve the siRNA design based on the nucleoprotein gene (siRNA-NP) for the Indonesian H5N1 virus. METHODS: The effectiveness of these siRNA-NPs (NP672, NP1433, and NP1469) was analyzed in vitro in Marbin-Darby canine kidney cells. RESULTS: The siRNA-NP672 caused the largest decrease in viral production and gene expression at 24, 48, and 72 h post-infection compared to the other siRNA-NPs. Moreover, three serial passages of the H5N1 virus in the presence of siRNA-NP672 did not induce any mutations within the nucleoprotein gene. CONCLUSIONS: These findings suggest that siRNA-NP672 can provide better protection against the Indonesian strain of the H5N1 virus.

Highly Pathogenic Avian Influenza A(H5N1) Virus in Wild Red Foxes, the Netherlands, 2021.

We detected infection with highly pathogenic avian influenza A(H5N1) virus clade 2.3.4.4b in 2 red fox (Vulpes vulpes) cubs found in the wild with neurologic signs in the Netherlands. The virus is related to avian influenza viruses found in wild birds in the same area.

Novel Clade 2.3.4.4b Highly Pathogenic Avian Influenza A H5N8 and H5N5 Viruses in Denmark, 2020.

Since late 2020, outbreaks of H5 highly pathogenic avian influenza (HPAI) viruses belonging to clade 2.3.4.4b have emerged in Europe. To investigate the evolutionary history of these viruses, we performed genetic characterization on the first HPAI viruses found in Denmark during the autumn of 2020. H5N8 viruses from 14 wild birds and poultry, as well as one H5N5 virus from a wild bird, were characterized by whole genome sequencing and phylogenetic analysis. The Danish H5N8 viruses were found to be genetically similar to each other and to contemporary European clade 2.3.4.4b H5N8 viruses, while the Danish H5N5 virus was shown to be a unique genotype from the H5N5 viruses that circulated at the same time in Russia, Germany, and Belgium. Genetic analyses of one of the H5N8 viruses revealed the presence of a substitution (PB2-M64T) that is highly conserved in human seasonal influenza A viruses. Our analyses showed that the late 2020 clade 2.3.4.4b HPAI H5N8 viruses were most likely new incursions introduced by migrating birds to overwintering sites in Europe, rather than the result of continued circulation of H5N8 viruses from previous introductions to Europe in 2016/2017 and early 2020.

H7N6 low pathogenic avian influenza outbreak in commercial turkey farms in Chile caused by a native South American Lineage.

In December 2016, low pathogenic avian influenza (LPAI) caused by an H7N6 subtype was confirmed in a grow-out turkey farm located in Valparaiso Region, Chile. Depopulation of exposed animals, zoning, animal movement control and active surveillance were implemented to contain the outbreak. Two weeks later, a second grow-out turkey farm located 70 km north of the first site was also infected by H7N6 LPAI, which subsequently spilled over to one backyard poultry flock. The virus involved in the outbreak shared a close genetic relationship with Chilean aquatic birds' viruses collected in previous years. The A/turkey/Chile/2017(H7N6) LPAI virus belonged to a native South American lineage. Based on the H7 and most of the internal genes' phylogenies, these viruses were also closely related to the ones that caused a highly pathogenic avian influenza outbreak in Chile in 2002. Results from this study help to understand the regional dynamics of influenza outbreaks, highlighting the importance of local native viruses circulating in the natural reservoir hosts.

Novel Reassortant Avian Influenza A(H9N2) Virus Isolate in Migratory Waterfowl in Hubei Province, China.

In December 2017, an influenza A(H9N2) virus (B51) was isolated from migratory waterfowl in Hubei Province, China. Phylogenetic analysis demonstrated that B51 is a novel reassortant influenza virus containing segments from human H7N4 virus and North American wild bird influenza viruses. This suggest that B51 has undergone multiple reassortment events.

Evaluation of potential risk of transmission of avian influenza A viruses at live bird markets in response to unusual crow die-offs in Bangladesh.

In response to unusual crow die-offs from avian influenza A(H5N1) virus infection during January-February 2017 in Dhaka, Bangladesh, a One Health team assessed potential infection risks in live bird markets (LBMs). Evidence of aerosolized avian influenza A viruses was detected in LBMs and in the respiratory tracts of market workers, indicating exposure and potential for infection. This study highlighted the importance of surveillance platforms with a coordinated One Health strategy to investigate and mitigate zoonotic risk.

Evolution of highly pathogenic H7N3 avian influenza viruses in Mexico.

Highly pathogenic H7N3 influenza A viruses have persisted in poultry in Mexico since 2012, diversifying into multiple lineages that have spread to three Mexican states, as of 2016. The H7N3 viruses segregate into three distinct clades that are geographically structured. All 2016 viruses are resistant to adamantane antiviral drugs and have an extended 24-nucleotide insertion at the HA cleavage site that was acquired from host 28S ribosomal RNA.

Seasonal Influenza and Avian Influenza A(H5N1) Virus Surveillance among Inpatients and Outpatients, East Jakarta, Indonesia, 2011-2014.

During October 2011-September 2014, we screened respiratory specimens for seasonal and avian influenza A(H5N1) virus infections among outpatients with influenza-like illness and inpatients with severe acute respiratory infection (SARI) in East Jakarta, an Indonesia district with high incidence of H5N1 virus infection among poultry. In total, 31% (1,875/6,008) of influenza-like illness case-patients and 15% (571/3,811) of SARI case-patients tested positive for influenza virus. Influenza A(H1N1)pdm09, influenza A(H3N2), and influenza B virus infections were detected in all 3 years, and the epidemic season extended from November through May. Although 28% (2,810/10,135) of case-patients reported exposure to poultry, only 1 SARI case-patient with an H5N1 virus infection was detected. Therefore, targeted screening among case-patients with high-risk poultry exposures (e.g., a recent visit to a live bird market or close proximity to sick or dead poultry) may be a more efficient routine surveillance strategy for H5N1 virus in these types of settings.

[Genetic characteristic of hemagglutinin of avian influenza A (H7N9) virus in Guizhou Province in 2017].

The number of H7N9 bird flu cases was high and the situation was grim in guizhou province in 2017. To understand the molecular characteristics of the hemagglutinin gene (HA) and the risk of human infection with avian influenza virus A(H7N9) in Guizhou Province, 2017. Homology, genetic evolution and pivotal sites related to receptor binding regions, pathogenicity and potential glycosylation of 14 avian influenza viruses A(H7N9) were analyzed by a series of bioinformation softwares. It was cleared that there was 95.9%-100% similarity among 14 strains in nucleotide of the HA gene, and there were 96.8%-97.8% and 96.8%-97.9% similarities with vaccine strains A/Shanghai/2/2013 and A/Anhui/1/2013 recommended by WHO, respectively. Phylogenetic analysis showed that 14 HA genes were directly evolved in the Yangtze River Delta evolution branch, but they could be derived from five diffenrent strains. Then 13 of 14 strains cleavage site sequences of HA protein revealed they were low pathogenic avian influenza viruses, while A/Guizhou-Weining/CSY01/2017 was high pathogenic avian influenza virus. Mutation G186V at the receptor binding sites in the HA was found in all 14 strains, and mutation Q226L in 13 strains besides A/Guizhou-Weining/CSY01/2017. All five potential glycosylation motifs in the HA were conservative.

Estimating Risk to Responders Exposed to Avian Influenza A H5 and H7 Viruses in Poultry, United States, 2014-2017.

In the United States, outbreaks of avian influenza H5 and H7 virus infections in poultry have raised concern about the risk for infections in humans. We reviewed the data collected during 2014-2017 and found no human infections among 4,555 exposed responders who were wearing protection.

Genetic characteristic of hemagglutinin of avian influenza A (H7N9) virus in Guizhou Province in 2017 / 中华预防医学杂志

The number of H7N9 bird flu cases was high and the situation was grim in guizhou province in 2017. To understand the molecular characteristics of the hemagglutinin gene (HA) and the risk of human infection with avian influenza virus A(H7N9) in Guizhou Province, 2017. Homology, genetic evolution and pivotal sites related to receptor binding regions, pathogenicity and potential glycosylation of 14 avian influenza viruses A(H7N9) were analyzed by a series of bioinformation softwares. It was cleared that there was 95.9%-100% similarity among 14 strains in nucleotide of the HA gene, and there were 96.8%-97.8% and 96.8%-97.9% similarities with vaccine strains A/Shanghai/2/2013 and A/Anhui/1/2013 recommended by WHO, respectively. Phylogenetic analysis showed that 14 HA genes were directly evolved in the Yangtze River Delta evolution branch, but they could be derived from five diffenrent strains. Then 13 of 14 strains cleavage site sequences of HA protein revealed they were low pathogenic avian influenza viruses, while A/Guizhou-Weining/CSY01/2017 was high pathogenic avian influenza virus. Mutation G186V at the receptor binding sites in the HA was found in all 14 strains, and mutation Q226L in 13 strains besides A/Guizhou-Weining/CSY01/2017. All five potential glycosylation motifs in the HA were conservative.

Cien años después, recordando cómo BMJ y JAMA comunicaron la pandemia de gripe de 1918-1919 / One hundred years later, recalling how BMJ and JAMA reported the 1918-1919 influenza pandemic

RESUMEN La pandemia de gripa que en 1918-1919 asoló el planeta, es sin duda el evento de enfermedad masivo de mayor virulencia y letalidad que la especie humana ha sorteado a lo largo de la historia. Este ensayo se centró en evaluar, a partir de lo publicado en la literatura médica de dos de las más importantes revistas de la época, (BMJ) The British Medical Journal y (JAMA)The Journal of the American Medical Association, la interpretación que desde la medicina se hizo de este fenómeno y de la respuesta que en términos de tecnología diagnóstica y terapéutica se dio por parte de los médicos. Se encontró que el arsenal de conocimientos, diagnóstico y terapéutica de la época ofrecía muy pocas herramientas para abordar el manejo clínico y frenar los contagios y mortalidad. No obstante, las dificultades que debieron sortear los clínicos y autoridades sanitarias de la época se constituyeron en un sólido aliciente para que en poco tiempo se avanzara significativamente en la comprensión y manejo de las enfermedades infecciosas, particularmente de etiología viral.

ABSTRACT The influenza pandemic that ravaged the planet in 1918-1919 is, undoubtedly, the most virulent and lethal infectious disease that the human species has ever overcome. This essay was to evaluate the medical interpretation of this phenomenon and the response given by doctors in terms of diagnostic and therapeutic technology based on the data published in the medical literature of two of the most important journals of the time, BMJ (The British Medical Journal) and JAMA (The Journal of the American Medical Association). It was found that the arsenal of knowledge, diagnosis and therapeutics of the time offered very few tools to address clinical management and curb contagion and mortality. However, the difficulties that clinicians and health authorities had to overcome were a solid incentive to make significant progress in the understanding and management of infectious diseases, particularly of viral etiology, in a short period of time.

A pandemia de gripe que devastou o planeta em 1918-1919 é, sem dúvida, o evento de doença maciça mais virulento e letal que a espécie humana passou ao longo da história. Este ensaio teve como objetivo avaliar, a partir do que foi publicado na literatura médica de duas das mais importantes revistas da época, (BMJ) The British Medical Journal e (JAMA) The Journal of American Medical Association,a interpretação que a medicina fez desse fenômeno e a resposta que os médicos deram em termos de tecnologia diagnóstica e terapêutica. Verificou-se que o arsenal de conhecimento, diagnóstico e terapia da época oferecia pouquíssimas ferramentas para abordar o manejo clínico e impedir infecções e mortalidade. No entanto, as dificuldades que os médicos e as autoridades de saúde da época tiveram que superar foram um sólido incentivo para que, em pouco tempo, fossem feitos progressos significativos no entendimento e tratamento de doenças infecciosas, particularmente de etiologia viral.(AU)

[Comparison of epidemiological characteristics of human infection with avian influenza A (H5N1) virus in five countries of Asia and Africa].

Objective: To understand characteristics of demographic, seasonal and spatial distribution of H5N1 cases in major countries of Asia (Indonesia, Cambodia, Vietnam, China) and Africa (Egypt). Methods: Through searching public data resource and published papers, we collected cases information in five countries from May 1st, 1997 to November 6th, 2017, including general characteristics, diagnosis, onset and exposure history, etc. Different characteristics of survived and death cases in different countries were described and χ(2) test was used to compare the differences among death cases and odds ratio (OR) and 95%CI value was used to compare death risk in different countries. Results: A total of 856 cases were reported in five countries with Egypt had the most cases (44.3%). The highest number of cases were reported in 2015 (18.3%). 53% cases were reported from January to March, and 96.1% of cases had the history of poultry exposure. 64.2% (43 cases) cases in China had live poultry market exposure, but the sick/dead poultry exposure was the major exposure for cases in other four countries. 452 death cases were reported in five countries, and the fatality rate was 52.8%. With Egypt as the reference group, the highest death risk was seen in Indonesia (OR (95%CI): 11.52 (7.46-17.77)), followed by Cambodia (OR (95%CI): 4.27(2.37-7.69)) and China (OR (95%CI): 2.87 (1.73-4.74)). The age distribution of death cases among 5 countries was statistically significant, and the highest fatality rate was in 15-54 years group in Egypt (83.6%, 102 cases), while in Cambodia the highest fatality rate was in 0-14 years group (76.9%, 30 cases). The highest number of deaths were reported in 2006, and 48.3% were reported from January to March. There was difference in exposure routes among 5 countries (χ(2)=43.85, P=0.001), 63.2% (24 cases) of the death cases in China had live poultry market exposure. 92.9% (79 cases), 83.3% (40 cases) and 100.0% (38 cases) death cases in Indonesia, Vietnam and Camodia had sick/dead poultry exposure, respectively;and 81.6% (31 cases) of the death cases in Egypt had backyard poultry exposure. Conclusion: The geographical distribution, seasonal age, gender, exposure matter and outcome of H5N1 cases in five countries were different.

Limited pathogenicity and transmissibility of Korean highly pathogenic avian influenza H5N6 clade 2.3.4.4 in ferrets.

The pathogenicity and transmissibility of a reassortant clade 2.3.4.4 avian influenza A (H5N6) virus were evaluated in ferrets. Virus excretion was detected in the upper respiratory tract, but the ferrets did not show any clinical signs of infection. Transmission did not occur between cohoused or respiratory droplet-contact ferrets.

Changing Role of Wild Birds in the Epidemiology of Avian Influenza A Viruses.

Waterbirds are the main reservoir for low pathogenic avian influenza A viruses (LPAIV), from which occasional spillover to poultry occurs. When circulating among poultry, LPAIV may become highly pathogenic avian influenza A viruses (HPAIV). In recent years, the epidemiology of HPAIV viruses has changed drastically. HPAIV H5N1 are currently endemic among poultry in a number of countries. In addition, global spread of HPAIV H5Nx viruses has resulted in major outbreaks among wild birds and poultry worldwide. Using data collected during these outbreaks, the role of migratory birds as a vector became increasingly clear. Here we provide an overview of current data about various aspects of the changing role of wild birds in the epidemiology of avian influenza A viruses.

Comparison of epidemiological characteristics of human infection with avian influenza A (H5N1) virus in five countries of Asia and Africa / 中华预防医学杂志

Objective@#To understand characteristics of demographic, seasonal and spatial distribution of H5N1 cases in major countries of Asia (Indonesia, Cambodia, Vietnam, China) and Africa (Egypt).@*Methods@#Through searching public data resource and published papers, we collected cases information in five countries from May 1st, 1997 to November 6th, 2017, including general characteristics, diagnosis, onset and exposure history, etc. Different characteristics of survived and death cases in different countries were described and χ2 test was used to compare the differences among death cases and odds ratio (OR) and 95%CI value was used to compare death risk in different countries.@*Results@#A total of 856 cases were reported in five countries with Egypt had the most cases (44.3%). The highest number of cases were reported in 2015 (18.3%). 53% cases were reported from January to March, and 96.1% of cases had the history of poultry exposure. 64.2% (43 cases) cases in China had live poultry market exposure, but the sick/dead poultry exposure was the major exposure for cases in other four countries. 452 death cases were reported in five countries, and the fatality rate was 52.8%. With Egypt as the reference group, the highest death risk was seen in Indonesia (OR (95%CI): 11.52 (7.46-17.77)), followed by Cambodia (OR (95%CI): 4.27(2.37-7.69)) and China (OR (95%CI): 2.87 (1.73-4.74)). The age distribution of death cases among 5 countries was statistically significant, and the highest fatality rate was in 15-54 years group in Egypt (83.6%, 102 cases), while in Cambodia the highest fatality rate was in 0-14 years group (76.9%, 30 cases). The highest number of deaths were reported in 2006, and 48.3% were reported from January to March. There was difference in exposure routes among 5 countries (χ2=43.85, P=0.001), 63.2% (24 cases) of the death cases in China had live poultry market exposure. 92.9% (79 cases), 83.3% (40 cases) and 100.0% (38 cases) death cases in Indonesia, Vietnam and Camodia had sick/dead poultry exposure, respectively;and 81.6% (31 cases) of the death cases in Egypt had backyard poultry exposure.@*Conclusion@#The geographical distribution, seasonal age, gender, exposure matter and outcome of H5N1 cases in five countries were different.