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Travel Medicine and Infectious Disease 2023Avian influenza viruses are members of the Orthomyxoviridae family, considered highly pathogenic (HPAI). They result from genetic variations from their low virulence... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Avian influenza viruses are members of the Orthomyxoviridae family, considered highly pathogenic (HPAI). They result from genetic variations from their low virulence predecessors. HPAI is a global problem. Large outbreaks of HAPI have significant health and economic impacts.
OBJECTIVE
The objective of this study was to assess the prevalence of the H5N8 Influenza virus in birds, as well as to assess its variability according to the countries and years.
METHODS
A systematic review of the literature was carried out in six databases (Web of Sciences, Scopus, PubMed, SciELO, Lilacs and Google Scholar) to evaluate the proportion of birds infected with the H5N8 Influenza virus, by molecular and immunological techniques. A meta-analysis was performed using a random-effects model to calculate the pooled prevalence, 95% confidence intervals (95%CI). A 2-tailed 5% alpha level was used for hypothesis testing. Measures of heterogeneity were estimated and reported, including the Cochrane Q statistic, the I index, and the tau-squared test. In addition, bird species performed subgroup analyzes.
RESULTS
152 data groups were analyzed, a combined prevalence of 1.6% (95% CI 1.3-1.9%) was found for molecular studies, and the ELISA study yielded a seroprevalence of 66.7%; those results of molecular detection varied by year, from 0.2% in 2014 to 52.6% in 2020 and 96.9% in 2015.
CONCLUSION
The combined prevalence was substantial because large outbreaks have caused severe economic repercussions. In addition, it is considered a serious concern for public health due to its possible zoonotic activity.
Topics: Humans; Animals; Influenza A Virus, H5N8 Subtype; Influenza in Birds; Seroepidemiologic Studies; Animals, Wild; Birds; Disease Outbreaks; Influenza, Human; Phylogeny
PubMed: 36336273
DOI: 10.1016/j.tmaid.2022.102490 -
IJID Regions Jun 2023Population factors such as urbanization, socio-economic, and environmental factors are driving forces for emerging/re-emerging zoonotic diseases in Cameroon. To inform... (Review)
Review
INTRODUCTION
Population factors such as urbanization, socio-economic, and environmental factors are driving forces for emerging/re-emerging zoonotic diseases in Cameroon. To inform preparedness and prioritization efforts, this study mapped out epidemiological data (including prevalence) of zoonotic diseases occurring in Cameroon between 2000 and 2022 by demographic factors.
METHODS
Following the PRISMA guidelines, a protocol was registered in the PROSPERO database (CRD42022333059). Independent reviewers searched the PubMed, Embase, CINAHL, Cochrane, and Scopus databases on May 30, 2022 for relevant articles; duplicates were removed, and the titles, abstracts, and full texts were screened to identify eligible articles.
RESULTS
Out of 4142 articles identified, 64 eligible articles were retrieved in the database search and an additional 12 from the cited literature ( = 76). Thirty-five unique zoonoses (viral, bacterial, and parasitic) were indexed, including Cameroon priority zoonoses: anthrax, bovine tuberculosis, Ebola and Marburg virus disease, highly pathogenic avian influenza, and rabies. The number of studies varied by region, ranging from 12 in the Far North to 32 in the Centre Region. The most reported were as follows: brucellosis (random-effects pooled estimate proportion (effect size), ES 0.05%, 95% confidence interval (CI) 0.03-0.07; = 6), dengue (ES 0.13%, 95% CI 0.06-0.22; = 12), avian and swine influenza virus (ES 0.10%, 95% CI 0.04-0.20; = 8), and toxoplasmosis (ES 0.49%, 95% CI 0.35-0.63; = 11), although values were greater than 75%, thus there was high inter-study heterogeneity ( < 0.01).
CONCLUSIONS
This understanding of the distribution of emerging and re-emerging zoonotic threats in Cameroon is vital to effective preventive and resource prioritization measures.
PubMed: 37009575
DOI: 10.1016/j.ijregi.2022.12.001 -
The Journal of International Medical... Jan 2020H7N9 avian influenza virus (AIV) caused human infections in 2013 in China. Phylogenetic analyses indicate that H7N9 AIV is a novel reassortant strain with pandemic...
H7N9 avian influenza virus (AIV) caused human infections in 2013 in China. Phylogenetic analyses indicate that H7N9 AIV is a novel reassortant strain with pandemic potential. We conducted a systemic review regarding virus-induced pathogenesis, vaccine development, and diagnosis of H7N9 AIV infection in humans. We followed PRISMA guidelines and searched PubMed, Web of Science, and Google Scholar to identify relevant articles published between January 2013 and December 2018. Pathogenesis data indicated that H7N9 AIV belongs to low pathogenic avian influenza, which is mostly asymptomatic in avian species; however, H7N9 induces high mortality in humans. Sporadic human infections have recently been reported, caused by highly pathogenic avian influenza viruses detected in poultry. H7N9 AIVs resistant to adamantine and oseltamivir cause severe human infection by rapidly inducing progressive acute community-acquired pneumonia, multiorgan dysfunction, and cytokine dysregulation; however, mechanisms via which the virus induces severe syndromes remain unclear. An H7N9 AIV vaccine is lacking; designs under evaluation include synthesized peptide, baculovirus-insect system, and virus-like particle vaccines. Molecular diagnosis of H7N9 AIVs is suggested over conventional assays, for biosafety reasons. Several advanced or modified diagnostic assays are under investigation and development. We summarized virus-induced pathogenesis, vaccine development, and current diagnostic assays in H7N9 AIVs.
Topics: Animals; Birds; Drug Resistance, Viral; Host-Pathogen Interactions; Humans; Influenza A Virus, H7N9 Subtype; Influenza Vaccines; Influenza in Birds; Influenza, Human
PubMed: 31068040
DOI: 10.1177/0300060519845488 -
One Health (Amsterdam, Netherlands) Dec 2016Live poultry markets (LPMs) pose a threat to public health by promoting the amplification and dissemination of avian influenza viruses (AIVs) and by providing the ideal...
BACKGROUND
Live poultry markets (LPMs) pose a threat to public health by promoting the amplification and dissemination of avian influenza viruses (AIVs) and by providing the ideal setting for zoonotic influenza transmission.
OBJECTIVE
This review assessed the impact of different interventions implemented in LPMs to control the emergence of zoonotic influenza.
METHODS
Publications were identified through a systematic literature search in the PubMed, MEDLINE and Web of Science databases. Eligible studies assessed the impact of different interventions, such as temporary market closure or a ban on holding poultry overnight, in reducing i) AIV-detection rates in birds and the market environment or ii) influenza incidence in humans. Unpublished literature, reviews, editorials, cross-sectional studies, theoretical models and publications in languages other than English were excluded. Relevant findings were extracted and critically evaluated. For the comparative analysis of findings across studies, standardized outcome measures were computed as i) the relative risk reduction (RRR) of AIV-detection in LPMs and ii) incidence rate ratios (IRRs) of H7N9-incidence in humans.
RESULTS
A total of 16 publications were identified and reviewed. Collectively, the data suggest that AIV-circulation can be significantly reduced in the LPM-environment and among market-birds through (i) temporary LPM closure, (ii) periodic rest days (iii) market depopulation overnight and (iv) improved hygiene and disinfection. Overall, the findings indicate that the length of stay of poultry in the market is a critical control point to interrupt the AIV-replication cycle within LPMs. In addition, temporary LPM closure was associated with a significant reduction of the incidence of zoonotic influenza. The interpretation of these findings is limited by variations in the implementation of interventions. In addition, some of the included studies were of ecologic nature or lacked an inferential framework, which might have lead to cosiderable confounding and bias.
CONCLUSIONS
The evidence collected in this review endorses permanent LPM-closure as a long-term objective to reduce the zoonotic risk of avian influenza, although its economic and socio-political implications favour less drastic interventions, e.g. weekly rest days, for implementation in the short-term.
PubMed: 27213177
DOI: 10.1016/j.onehlt.2016.03.002 -
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 -
European Review For Medical and... Oct 2012Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome that is often fatal despite treatment. It is caused by a dysregulation in natural killer T-cell function,... (Review)
Review
BACKGROUND
Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome that is often fatal despite treatment. It is caused by a dysregulation in natural killer T-cell function, resulting in activation and proliferation of histiocytes with uncontrolled hemophagocytosis and cytokines overproduction. The syndrome is characterized by fever, hepatosplenomegaly, cytopenias, liver dysfunction, and hyperferritinemia. HLH can be either primary, with a genetic aetiology, or secondary, associated with malignancies, autoimmune diseases, or infections.
AIM
To focus on secondary HLH complicating zoonotic diseases.
MATERIALS AND METHODS
PubMed search of human cases of HLH occurring during zoonotic diseases was performed combining the terms (haemophagocytic or haemophagocytosis or hemophagocytosis or hemophagocytic or erythrophagocytosis or macrophage activation syndrome) with each one of the etiological agents of zoonoses.
RESULTS
Among bacterial diseases, most papers reported cases occurring during brucellosis, rickettsial diseases and Q fever. Regarding viral diseases, most of the cases were reported in patients with avian influenza A subtype H5N1. Among the protozoan zoonoses, most of the cases were reported in patients with visceral leishmaniasis. Regarding zoonotic fungi, most of the cases were reported in AIDS patient with histoplasmosis. No cases of secondary HLH were reported in patient with zoonotic helminthes.
CONCLUSIONS
Zoonotic diseases are an important cause of HLH. Secondary HLH can delay the correct diagnosis of the zoonotic disease, and can contribute to an adverse outcome.
Topics: Animals; Comorbidity; Humans; Lymphohistiocytosis, Hemophagocytic; Zoonoses
PubMed: 23104648
DOI: No ID Found -
Influenza and Other Respiratory Viruses Sep 2013Highly pathogenic avian influenza A H5N1 viruses remain a significant health threat to humans given the continued rare occurrence of human cases with a high case... (Review)
Review
Highly pathogenic avian influenza A H5N1 viruses remain a significant health threat to humans given the continued rare occurrence of human cases with a high case fatality rate. This brief literature review summarizes available evidence of risk factors for H5N1 infection in humans and updates a recent systematic review published in early 2011. Several epidemiologic studies have been published to evaluate the risk factors for H5N1 infection in humans, including contact with poultry and poultry products and non-poultry-related contact such as from H5N1-contaminated water. While most H5N1 cases are attributed to exposure to sick poultry, it is unclear how many may be due to human-to-human transmission. The collective results of published literature suggest that transmission risk of H5N1 from poultry to humans may be highest among individuals who may have been in contact with the highest potential concentrations of virus shed by poultry. This suggests that there may be a threshold of virus concentration needed for effective transmission and that circulating H5N1 strains have not yet mutated to transmit readily from either poultry to human or from human to human. However, the mode of potential transmission can be quite varied throughout different countries and by study with exposures ranging from visiting a wet market, preparing infected poultry for consumption, to swimming or bathing in ponds frequented by poultry. Several important data gaps remain in the understanding of the epidemiology of H5N1 in humans and limit our ability to interpret the results of the available H5N1 seroepidemiologic studies.
Topics: Animals; Humans; Influenza A Virus, H5N1 Subtype; Influenza in Birds; Influenza, Human; Poultry; Risk Factors; Virus Shedding; Zoonoses
PubMed: 24034480
DOI: 10.1111/irv.12077 -
Applied and Environmental Microbiology Feb 2011Understanding factors that influence persistence of influenza virus in an environment without host animals is critical to appropriate decision-making for issues such as... (Meta-Analysis)
Meta-Analysis Review
Understanding factors that influence persistence of influenza virus in an environment without host animals is critical to appropriate decision-making for issues such as quarantine downtimes, setback distances, and eradication programs in livestock production systems. This systematic review identifies literature describing persistence of influenza virus in environmental samples, i.e., air, water, soil, feces, and fomites. An electronic search of PubMed, CAB, AGRICOLA, Biosis, and Compendex was performed, and citation relevance was determined according to the aim of the review. Quality assessment of relevant studies was performed using criteria from experts in virology, disease ecology, and environmental science. A total of 9,760 abstracts were evaluated, and 40 appeared to report the persistence of influenza virus in environmental samples. Evaluation of full texts revealed that 19 of the 40 studies were suitable for review, as they described virus concentration measured at multiple sampling times, with viruses detectable at least twice. Seven studies reported persistence in air (six published before 1970), seven in water (five published after 1990), two in feces, and three on surfaces. All three fomite and five air studies addressed human influenza virus, and all water and feces studies pertained to avian influenza virus. Outcome measurements were transformed to half-lives, and resultant multivariate mixed linear regression models identified influenza virus surviving longer in water than in air. Temperature was a significant predictor of persistence over all matrices. Salinity and pH were significant predictors of persistence in water conditions. An assessment of the methodological quality review of the included studies revealed significant gaps in reporting critical aspects of study design.
Topics: Air Microbiology; Animals; Environmental Monitoring; Feces; Fomites; Humans; Orthomyxoviridae; Soil Microbiology; Water Microbiology
PubMed: 21148699
DOI: 10.1128/AEM.02733-09 -
BMC Veterinary Research Dec 2012Poultry represents an important sector in animal production, with backyard flocks representing a huge majority, especially in the developing countries. In these... (Review)
Review
BACKGROUND
Poultry represents an important sector in animal production, with backyard flocks representing a huge majority, especially in the developing countries. In these countries, villagers raise poultry to meet household food demands and as additional sources of incomes. Backyard production methods imply low biosecurity measures and high risk of infectious diseases, such as Newcastle disease or zoonosis such as Highly Pathogenic Avian Influenza (HPAI).We reviewed literature on biosecurity practices for prevention of infectious diseases, and published recommendations for backyard poultry and assessed evidence of their impact and feasibility, particularly in developing countries. Documents were sourced from the Food and Agriculture Organization (FAO) website, and from Pubmed and Google databases.
RESULTS
A total of 62 peer-reviewed and non-referred documents were found, most of which were published recently (after 2004) and focused on HPAI/H5N1-related biosecurity measures (64%). Recommendations addressed measures for flock management, feed and water management, poultry trade and stock change, poultry health management and the risk to humans. Only one general guideline was found for backyard poultry-related biosecurity; the other documents were drawn up for specific developing settings and only engaged their authors (e.g. consultants). These national guidelines written by consultants generated recommendations regarding measures derived from the highest standards of commercial poultry production. Although biosecurity principles of isolation and containment are described in most documents, only a few documents were found on the impact of measures in family poultry settings and none gave any evidence of their feasibility and effectiveness for backyard poultry.
CONCLUSIONS
Given the persistent threat posed by HPAI/H5N1 to humans in developing countries, our findings highlight the importance of encouraging applied research toward identifying sustained and adapted biosecurity measures for smallholder poultry flocks in low-income countries.
Topics: Animal Husbandry; Animals; Developing Countries; Poultry; Poultry Diseases
PubMed: 23216706
DOI: 10.1186/1746-6148-8-240 -
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