Quantified degree of poultry exposure differs for human cases of avian influenza H5N1 and H7N9

Bethmont, Anna; Bui, Chau Minh; Gardner, Lauren; Sarkar, Sahotra; Chughtai, Abrar Ahmad; MacIntyre, C. Raina

doi:10.1017/s0950268816001035

Cited by 6 publications

(8 citation statements)

References 26 publications

(44 reference statements)

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“…In 2013 a new subtype H7N9 emerged in humans in China and the human case count by December 2016 was over 795, with over 314 deaths [2]. Differences in the epidemiology of H7N9 and H5N1 have previously been described: human H5N1 cases report higher severity of disease [3] and higher levels of contact with sick or dead birds [4]; H7N9 is asymptomatic in birds [5] and found at lower prevalence rates in poultry [6]; and the spatial distribution of H5N1 within a comparable time frame is considerably greater than that of H7N9 [3]. This study aimed to improve upon our current understanding of the spreading mechanisms behind H7N9 and H5N1, provide a geographic risk profile for each of the two virus subtypes across all of mainland China, and highlight the regions at greatest risk of experiencing AIV transmission.Implementing effective AIV control measures in China to prevent spread among domestic poultry population, and transmission to humans, is a recognized challenge.…”

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confidence: 99%

Influenza A H5N1 and H7N9 in China: A spatial risk analysis

et al. 2017

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BackgroundZoonotic avian influenza poses a major risk to China, and other parts of the world. H5N1 has remained endemic in China and globally for nearly two decades, and in 2013, a novel zoonotic influenza A subtype H7N9 emerged in China. This study aimed to improve upon our current understanding of the spreading mechanisms of H7N9 and H5N1 by generating spatial risk profiles for each of the two virus subtypes across mainland China.Methods and findingsIn this study, we (i) developed a refined data set of H5N1 and H7N9 locations with consideration of animal/animal environment case data, as well as spatial accuracy and precision; (ii) used this data set along with environmental variables to build species distribution models (SDMs) for each virus subtype in high resolution spatial units of 1km2 cells using Maxent; (iii) developed a risk modelling framework which integrated the results from the SDMs with human and chicken population variables, which was done to quantify the risk of zoonotic transmission; and (iv) identified areas at high risk of H5N1 and H7N9 transmission. We produced high performing SDMs (6 of 8 models with AUC > 0.9) for both H5N1 and H7N9. In all our SDMs, H7N9 consistently showed higher AUC results compared to H5N1, suggesting H7N9 suitability could be better explained by environmental variables. For both subtypes, high risk areas were primarily located in south-eastern China, with H5N1 distributions found to be more diffuse and extending more inland compared to H7N9.ConclusionsWe provide projections of our risk models to public health policy makers so that specific high risk areas can be targeted for control measures. We recommend comparing H5N1 and H7N9 prevalence rates and survivability in the natural environment to better understand the role of animal and environmental transmission in human infections.

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confidence: 99%

Influenza A H5N1 and H7N9 in China: A spatial risk analysis

et al. 2017

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“…Human cases of AIV infection have typically in the past been exposed to virus via infected poultry on farms or markets, however in recent years, and particularly in China, occurrence of human infection have largely been in association with visiting live bird markets (LBMs) rather than close contact with poultry [7]. However, exposure details are missing for a large proportion of cases (see Additional file 1: Table S1 and [3, 7]).…”

Section: Resultsmentioning

confidence: 99%

“…However, exposure details are missing for a large proportion of cases (see Additional file 1: Table S1 and [3, 7]). We have shown that a history of close poultry contact is far more common for human H5N1 cases than H7N9 cases [7]. In the latter case, a history of incidental poultry contact (such as walking through LBMs) is more common [7].…”

Section: Resultsmentioning

confidence: 99%

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An overview of the epidemiology and emergence of influenza A infection in humans over time

et al. 2017

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In recent years multiple novel influenza A strains have emerged in humans. We reviewed publically available data to summarise epidemiological characteristics of distinct avian influenza viruses known to cause human infection and describe changes over time. Most recently identified zoonotic strains have emerged in China (H7N9, H5N6, H10N8) – these strains have occurred mostly in association with visiting a live bird market. Most zoonotic AIVs and swine influenza variants typically cause mild infections in humans however severe illness and fatalities are associated with zoonotic H5N6, H10N8, H7N9 and H5N1 serotypes, and the H1N1 1918 Spanish Influenza. The changing landscape of avian influenza globally indicates a need to reassess the risk of a pandemic influenza outbreak of zoonotic origin.Electronic supplementary materialThe online version of this article (doi:10.1186/s13690-017-0182-z) contains supplementary material, which is available to authorized users.

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“…10,11 The leading cause of death in infected patients is diffuse alveolar damage and hemorrhage in the lungs, which is caused by overactive inflammatory responses. 12,13 Overproduction of inflammatory cytokines in H5N1-infected mice and humans, referred to as a cytokine storm, has been identified as the main cause of death associated with this virus. 14,15 Vaccination remains the most effective preventive measure against influenza viruses.…”

Section: Introductionmentioning

confidence: 99%

<p>Pre-Treatment with Zirconia Nanoparticles Reduces Inflammation Induced by the Pathogenic H5N1 Influenza Virus</p>

Huo¹,

Xiao²,

Xiao³

et al. 2020

IJN

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Background: New approaches are urgently needed to fight influenza viral infection. Previous research has shown that zirconia nanoparticles can be used as anticancer materials, but their antiviral activity has not been reported. Here, we investigated the antiviral effect of zirconia (ZrO 2 ) nanoparticles (NPs) against a highly pathogenic avian influenza virus. Materials and Methods: In this study, the antiviral effects of ZrO 2 on H5N1 virus were assessed in vivo, and the molecular mechanism responsible for this protection was investigated. Results: Mice treated with 200 nm positively-charged NPs at a dose of 100 mg/kg showed higher survival rates and smaller reductions in weight. 200 nm ZrO 2 activated mature dendritic cells and initially promoted the expression of cytokines associated with the antiviral response and innate immunity. In the lungs of H5N1-infected mice, ZrO 2 treatment led to less pathological lung injury, significant reduction in influenza A virus replication, and overexpression of pro-inflammatory cytokines. Conclusion: This antiviral study using zirconia NPs shows protection of mice against highly pathogenic avian influenza virus and suggests strong application potential for this method, introducing a new tool against a wide range of microbial infections.

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Quantified degree of poultry exposure differs for human cases of avian influenza H5N1 and H7N9

Cited by 6 publications

References 26 publications

Influenza A H5N1 and H7N9 in China: A spatial risk analysis

Influenza A H5N1 and H7N9 in China: A spatial risk analysis

An overview of the epidemiology and emergence of influenza A infection in humans over time

<p>Pre-Treatment with Zirconia Nanoparticles Reduces Inflammation Induced by the Pathogenic H5N1 Influenza Virus</p>

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