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The Journal of Infectious Diseases Aug 2022The extent of human infections with avian influenza A(H7N9) virus, including mild and asymptomatic infections, is uncertain. (Meta-Analysis)
Meta-Analysis
BACKGROUND
The extent of human infections with avian influenza A(H7N9) virus, including mild and asymptomatic infections, is uncertain.
METHODS
We performed a systematic review and meta-analysis of serosurveys for avian influenza A(H7N9) virus infections in humans published during 2013-2020. Three seropositive definitions were assessed to estimate pooled seroprevalence, seroconversion rate, and seroincidence by types of exposures. We applied a scoring system to assess the quality of included studies.
RESULTS
Of 31 included studies, pooled seroprevalence of A(H7N9) virus antibodies from all participants was 0.02%, with poultry workers, close contacts, and general populations having seroprevalence of 0.1%, 0.2%, and 0.02%, respectively, based on the World Health Organization (WHO)-recommended definition. Although most infections were asymptomatic, evidence of infection was highest in poultry workers (5% seroconversion, 19.1% seroincidence per 100 person-years). Use of different virus clades did not significantly affect seroprevalence estimates. Most serological studies were of low to moderate quality and did not follow standardized seroepidemiological protocols or WHO-recommended laboratory methods.
CONCLUSIONS
Human infections with avian influenza A(H7N9) virus have been uncommon, especially for general populations. Workers with occupational exposures to poultry and close contacts of A(H7N9) human cases had low risks of infection.
Topics: Animals; Birds; China; Humans; Influenza A Virus, H7N9 Subtype; Influenza in Birds; Influenza, Human; Poultry; Seroepidemiologic Studies
PubMed: 33119755
DOI: 10.1093/infdis/jiaa679 -
Viruses Sep 2020In the recent past, sub-Saharan Africa has not escaped the devastating effects of avian influenza virus (AIV) in poultry and wild birds. This systematic review describes... (Meta-Analysis)
Meta-Analysis
In the recent past, sub-Saharan Africa has not escaped the devastating effects of avian influenza virus (AIV) in poultry and wild birds. This systematic review describes the prevalence, spatiotemporal distribution, and virus subtypes detected in domestic and wild birds for the past two decades (2000-2019). We collected data from three electronic databases, PubMed, SpringerLink electronic journals and African Journals Online, using the Preferred Reporting Items for Systematic reviews and Meta-Analyses protocol. A total of 1656 articles were reviewed, from which 68 were selected. An overall prevalence of 3.0% AIV in birds was observed. The prevalence varied between regions and ranged from 1.1% to 7.1%. The Kruskal-Wallis and Wilcoxon signed-rank sum test showed no significant difference in the prevalence of AIV across regions, χ(3) = 5.237, = 0.1553 and seasons, T = 820, z = -1.244, = 0.2136. Nineteen hemagglutinin/neuraminidase subtype combinations were detected during the reviewed period, with southern Africa recording more diverse AIV subtypes than other regions. The most detected subtype was H5N1, followed by H9N2, H5N2, H5N8 and H6N2. Whilst these predominant subtypes were mostly detected in domestic poultry, H1N6, H3N6, H4N6, H4N8, H9N1 and H11N9 were exclusively detected in wild birds. Meanwhile, H5N1, H5N2 and H5N8 were detected in both wild and domestic birds suggesting circulation of these subtypes among wild and domestic birds. Our findings provide critical information on the eco-epidemiology of AIVs that can be used to improve surveillance strategies for the prevention and control of avian influenza in sub-Saharan Africa.
Topics: Africa, Southern; Animals; Animals, Wild; Birds; Influenza A virus; Influenza in Birds; Phylogeny; Poultry; Poultry Diseases
PubMed: 32906666
DOI: 10.3390/v12090993 -
Planta Medica Oct 2020Viruses have a high mutation rate, and, thus, there is a continual emergence of new antiviral-resistant strains. Therefore, it becomes imperative to explore and develop...
Viruses have a high mutation rate, and, thus, there is a continual emergence of new antiviral-resistant strains. Therefore, it becomes imperative to explore and develop new antiviral compounds continually. The search for pharmacological substances of plant origin that are effective against animal viruses, which have a high mortality rate or cause large economic losses, has garnered interest in the last few decades. This systematic review compiles 130 plant species that exhibit antiviral activity on 37 different virus species causing serious diseases in animals. The kind of extract, fraction, or compound exhibiting the antiviral activity and the design of the trial were particularly considered for review. The literature revealed details regarding plant species exhibiting antiviral activities against pathogenic animal virus species of the following families-, and that cause infections, among others, in poultry, cattle, pigs, horses, shrimps, and fish. Overall, 30 plant species exhibited activity against various influenza viruses, most of them causing avian influenza. Furthermore, 30 plant species were noted to be active against Newcastle disease virus. In addition, regarding the pathogens most frequently investigated, this review provides a compilation of 20 plant species active against bovine herpesvirus, 16 against fowlpox virus, 12 against white spot syndrome virus in marine shrimps, and 10 against suide herpesvirus. Nevertheless, some plant extracts, particularly their compounds, are promising candidates for the development of new antiviral remedies, which are urgently required.
Topics: Animal Diseases; Animals; Antiviral Agents; Cattle; Horses; Orthomyxoviridae; Plant Extracts; Plants, Medicinal; Swine; Veterinary Medicine
PubMed: 32777833
DOI: 10.1055/a-1224-6115 -
Animal Health Research Reviews Jun 2020Automated systems for high-input data collection and data storage have led to exponential growth in the availability of information. Such datasets and the tools applied...
Automated systems for high-input data collection and data storage have led to exponential growth in the availability of information. Such datasets and the tools applied to them have been referred to as 'big data'. Starting with a systematic review of the terms 'informatics, bioinformatics and big data' in animal health this special issue of AHRR illustrates some big-data applications with papers on how the use of various omics methods may be used to facilitate the development of improved diagnostics, therapeutics, and vaccines for foodborne pathogens in poultry and on how a better understanding of rumen microbiota could lead to improved feed absorption while minimizing methane production. Other papers in this issue cover the use of big data modeling in dairy cattle for more effective disease interventions and machine learning tools for livestock breeding. The final two reviews describe the use of big data in better vector-borne pathogen forecasts with canine seroprevalence maps and modeling approaches to understand the transmission of avian influenza virus. Although a lot of technical and ethical issues remain with the use of big data, these reviews illustrate the tremendous potential that big-data systems have to revolutionize animal health research.
Topics: Animals; Big Data; Research; Veterinary Medicine
PubMed: 32684189
DOI: 10.1017/S1466252319000215 -
Transboundary and Emerging Diseases Jan 2021This literature review provides an overview of use of environmental samples (ES) such as faeces, water, air, mud and swabs of surfaces in avian influenza (AI)...
This literature review provides an overview of use of environmental samples (ES) such as faeces, water, air, mud and swabs of surfaces in avian influenza (AI) surveillance programs, focussing on effectiveness, advantages and gaps in knowledge. ES have been used effectively for AI surveillance since the 1970s. Results from ES have enhanced understanding of the biology of AI viruses in wild birds and in markets, of links between human and avian influenza, provided early warning of viral incursions, allowed assessment of effectiveness of control and preventive measures, and assisted epidemiological studies in outbreaks, both avian and human. Variation exists in the methods and protocols used, and no internationally recognized guidelines exist on the use of ES and data management. Few studies have performed direct comparisons of ES versus live bird samples (LBS). Results reported so far demonstrate reliance on ES will not be sufficient to detect virus in all cases when it is present, especially when the prevalence of infection/contamination is low. Multiple sample types should be collected. In live bird markets, ES from processing/selling areas are more likely to test positive than samples from bird holding areas. When compared to LBS, ES is considered a cost-effective, simple, rapid, flexible, convenient and acceptable way of achieving surveillance objectives. As a non-invasive technique, it can minimize effects on animal welfare and trade in markets and reduce impacts on wild bird communities. Some limitations of environmental sampling methods have been identified, such as the loss of species-specific or information on the source of virus, and taxonomic-level analyses, unless additional methods are applied. Some studies employing ES have not provided detailed methods. In others, where ES and LBS are collected from the same site, positive results have not been assigned to specific sample types. These gaps should be remedied in future studies.
Topics: Animals; Animals, Wild; Birds; Environmental Monitoring; Epidemiological Monitoring; Influenza A virus; Influenza in Birds; Prevalence; Sampling Studies
PubMed: 32652790
DOI: 10.1111/tbed.13633 -
The Journal of Antibiotics Sep 2020Ivermectin proposes many potentials effects to treat a range of diseases, with its antimicrobial, antiviral, and anti-cancer properties as a wonder drug. It is highly...
Ivermectin proposes many potentials effects to treat a range of diseases, with its antimicrobial, antiviral, and anti-cancer properties as a wonder drug. It is highly effective against many microorganisms including some viruses. In this comprehensive systematic review, antiviral effects of ivermectin are summarized including in vitro and in vivo studies over the past 50 years. Several studies reported antiviral effects of ivermectin on RNA viruses such as Zika, dengue, yellow fever, West Nile, Hendra, Newcastle, Venezuelan equine encephalitis, chikungunya, Semliki Forest, Sindbis, Avian influenza A, Porcine Reproductive and Respiratory Syndrome, Human immunodeficiency virus type 1, and severe acute respiratory syndrome coronavirus 2. Furthermore, there are some studies showing antiviral effects of ivermectin against DNA viruses such as Equine herpes type 1, BK polyomavirus, pseudorabies, porcine circovirus 2, and bovine herpesvirus 1. Ivermectin plays a role in several biological mechanisms, therefore it could serve as a potential candidate in the treatment of a wide range of viruses including COVID-19 as well as other types of positive-sense single-stranded RNA viruses. In vivo studies of animal models revealed a broad range of antiviral effects of ivermectin, however, clinical trials are necessary to appraise the potential efficacy of ivermectin in clinical setting.
Topics: Animals; Antiviral Agents; Betacoronavirus; Cell Line; DNA Viruses; Disease Models, Animal; Global Health; Humans; Ivermectin; Molecular Structure; RNA Viruses; SARS-CoV-2
PubMed: 32533071
DOI: 10.1038/s41429-020-0336-z -
Pathogens (Basel, Switzerland) May 2020The global anxiety and a significant threat to public health due to the current COVID-19 pandemic reiterate the need for active surveillance for the zoonotic virus... (Review)
Review
The global anxiety and a significant threat to public health due to the current COVID-19 pandemic reiterate the need for active surveillance for the zoonotic virus diseases of pandemic potential. Influenza virus due to its wide host range and zoonotic potential poses such a significant threat to public health. Swine serve as a "mixing vessel" for influenza virus reassortment and evolution which as a result may facilitate the emergence of new strains or subtypes of zoonotic potential. In this context, the currently available scientific data hold a high significance to unravel influenza virus epidemiology and evolution. With this objective, the current systematic review summarizes the original research articles and case reports of all the four types of influenza viruses reported in swine populations worldwide. A total of 281 articles were found eligible through screening of PubMed and Google Scholar databases and hence were included in this systematic review. The highest number of research articles ( = 107) were reported from Asia, followed by Americas ( = 97), Europe ( = 55), Africa ( = 18), and Australia ( = 4). The H1N1, H1N2, H3N2, and A(H1N1)pdm09 viruses were the most common influenza A virus subtypes reported in swine in most countries across the globe, however, few strains of influenza B, C, and D viruses were also reported in certain countries. Multiple reports of the avian influenza virus strains documented in the last two decades in swine in China, the United States, Canada, South Korea, Nigeria, and Egypt provided the evidence of interspecies transmission of influenza viruses from birds to swine. Inter-species transmission of equine influenza virus H3N8 from horse to swine in China expanded the genetic diversity of swine influenza viruses. Additionally, numerous reports of the double and triple-reassortant strains which emerged due to reassortments among avian, human, and swine strains within swine further increased the genetic diversity of swine influenza viruses. These findings are alarming hence active surveillance should be in place to prevent future influenza pandemics.
PubMed: 32397138
DOI: 10.3390/pathogens9050355 -
Pathogens (Basel, Switzerland) Apr 2020Emerging and re-emerging viral diseases are of great public health concern. The recent emergence of Severe Acute Respiratory Syndrome (SARS) related coronavirus...
Emerging and re-emerging viral diseases are of great public health concern. The recent emergence of Severe Acute Respiratory Syndrome (SARS) related coronavirus (SARS-CoV-2) in December 2019 in China, which causes COVID-19 disease in humans, and its current spread to several countries, leading to the first pandemic in history to be caused by a coronavirus, highlights the significance of zoonotic viral diseases. Rift Valley fever, rabies, West Nile, chikungunya, dengue, yellow fever, Crimean-Congo hemorrhagic fever, Ebola, and influenza viruses among many other viruses have been reported from different African countries. The paucity of information, lack of knowledge, limited resources, and climate change, coupled with cultural traditions make the African continent a hotspot for vector-borne and zoonotic viral diseases, which may spread globally. Currently, there is no information available on the status of virus diseases in Africa. This systematic review highlights the available information about viral diseases, including zoonotic and vector-borne diseases, reported in Africa. The findings will help us understand the trend of emerging and re-emerging virus diseases within the African continent. The findings recommend active surveillance of viral diseases and strict implementation of One Health measures in Africa to improve human public health and reduce the possibility of potential pandemics due to zoonotic viruses.
PubMed: 32325980
DOI: 10.3390/pathogens9040301 -
Transboundary and Emerging Diseases Sep 2020Although the effective transmission of the H5N1 virus from humans to humans has yet to be further observed, humans are at increased risk of a pandemic caused by H5N1. In... (Review)
Review
Although the effective transmission of the H5N1 virus from humans to humans has yet to be further observed, humans are at increased risk of a pandemic caused by H5N1. In order to fully evaluate the seroprevalence and risk factor of highly pathogenic avian influenza A (H5N1) virus infection among in mainland China, we performed a systematic review and meta-analysis. In this review, we searched literature on the seroprevalence of H5N1 infection among humans in mainland China from 1 January 1997 to 20 October 2018 in English and Chinese databases, including PubMed, Google scholar, Cochrane library, Clinical Trial, VIP, CNKI and WanFang database. We made a selection according to the title and the abstract of paper, and then, we excluded duplicated literature, and data incomplete literature according to the exclusion criteria we formulated. Finally, we extracted how many humans have H5N1 infection from the obtained studies to establish the seroprevalence of H5N1 infection among humans in mainland China. A total of 56 studies (including data of 35,159 humans) were compliant with our criteria. In China, the overall seroprevalence of H5N1 infection among humans was 2.45% (862/35,159), while the seroprevalence of H5N1 infection among humans from central China was 7.32% (213/2,911), higher than those in other regions of China. The seroprevalence of H5N1 infection was associated with test method, sampling time and demographic characteristics of humans. However, there was no significant difference in the effect of gender on the seroprevalence of H5N1 among humans in China. The purpose of this review was to better understand the real infection rate of H5N1 virus among humans and evaluate the potential risk factors for the zoonotic spread of H5N1 virus to humans. Sufficient epidemiological data are important to explore and understand the prevalent status of AIVs throughout the country and to disease control.
PubMed: 32259345
DOI: 10.1111/tbed.13564 -
PloS One 2020Poultry production has significantly increased worldwide, along with the number of avian influenza (AI) outbreaks and the potential threat for human pandemic emergence.... (Meta-Analysis)
Meta-Analysis
Knowledge and remaining gaps on the role of animal and human movements in the poultry production and trade networks in the global spread of avian influenza viruses - A scoping review.
Poultry production has significantly increased worldwide, along with the number of avian influenza (AI) outbreaks and the potential threat for human pandemic emergence. The role of wild bird movements in this global spread has been extensively studied while the role of animal, human and fomite movement within commercial poultry production and trade networks remains poorly understood. The aim of this work is to better understand these roles in relation to the different routes of AI spread. A scoping literature review was conducted according to the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) using a search algorithm combining twelve domains linked to AI spread and animal/human movements within poultry production and trade networks. Only 28 out of 3,978 articles retrieved dealt especially with the role of animal, human and fomite movements in AI spread within the international trade network (4 articles), the national trade network (8 articles) and the production network (16 articles). While the role of animal movements in AI spread within national trade networks has been largely identified, human and fomite movements have been considered more at risk for AI spread within national production networks. However, the role of these movements has never been demonstrated with field data, and production networks have only been partially studied and never at international level. The complexity of poultry production networks and the limited access to production and trade data are important barriers to this knowledge. There is a need to study the role of animal and human movements within poultry production and trade networks in the global spread of AI in partnership with both public and private actors to fill this gap.
Topics: Animal Husbandry; Animals; Commerce; Humans; Influenza A virus; Influenza in Birds; Internationality; Poultry; Poultry Products
PubMed: 32196515
DOI: 10.1371/journal.pone.0230567