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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 -
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 -
PloS One 2012The World Health Organization has identified studies of the role of host genetics on susceptibility to severe influenza as a priority. A systematic review was conducted... (Review)
Review
BACKGROUND
The World Health Organization has identified studies of the role of host genetics on susceptibility to severe influenza as a priority. A systematic review was conducted to summarize the current state of evidence on the role of host genetics in susceptibility to influenza (PROSPERO registration number: CRD42011001380).
METHODS AND FINDINGS
PubMed, Web of Science, the Cochrane Library, and OpenSIGLE were searched using a pre-defined strategy for all entries up to the date of the search. Two reviewers independently screened the title and abstract of 1,371 unique articles, and 72 full text publications were selected for inclusion. Mouse models clearly demonstrate that host genetics plays a critical role in susceptibility to a range of human and avian influenza viruses. The Mx genes encoding interferon inducible proteins are the best studied but their relevance to susceptibility in humans is unknown. Although the MxA gene should be considered a candidate gene for further study in humans, over 100 other candidate genes have been proposed. There are however no data associating any of these candidate genes to susceptibility in humans, with the only published study in humans being under-powered. One genealogy study presents moderate evidence of a heritable component to the risk of influenza-associated death, and while the marked familial aggregation of H5N1 cases is suggestive of host genetic factors, this remains unproven.
CONCLUSION
The fundamental question "Is susceptibility to severe influenza in humans heritable?" remains unanswered. Not because of a lack of genotyping or analytic tools, nor because of insufficient severe influenza cases, but because of the absence of a coordinated effort to define and assemble cohorts of cases. The recent pandemic and the ongoing epizootic of H5N1 both represent rapidly closing windows of opportunity to increase understanding of the pathogenesis of severe influenza through multi-national host genetic studies.
Topics: ABO Blood-Group System; Animals; Birds; Disease Models, Animal; Family; GTP-Binding Proteins; Genetic Predisposition to Disease; HLA Antigens; Host-Pathogen Interactions; Humans; Influenza in Birds; Influenza, Human; Mice; Mice, Inbred Strains; Myxovirus Resistance Proteins; Species Specificity
PubMed: 22438897
DOI: 10.1371/journal.pone.0033180 -
Animal Health Research Reviews Dec 2011East and Southeast Asia are important pig- and poultry-producing areas, where the majority of production takes place on small-scale farms with low biosecurity levels.... (Review)
Review
East and Southeast Asia are important pig- and poultry-producing areas, where the majority of production takes place on small-scale farms with low biosecurity levels. This systematic review synthesizes data on swine influenza virology, serology and epidemiology in East and Southeast Asia. A total of 77 research articles, literature reviews and conference papers were selected and analyzed from 510 references retrieved from PubMed and ISI Web of KnowledgeSM. The number of published articles increased in the last 3 years, which may be attributed to improvement in monitoring and/or a better promotion of surveillance data. Nevertheless, large inequalities in surveillance and research among countries are underlined. Virological results represent the largest part of published data, while the serological and epidemiological features of swine influenza in East and Southeast Asia remain poorly described. The literature shows that there have been several emergences of swine influenza in the region, and also considerable evidence of multiple introductions of North American and avian-like European strains. Furthermore, several avian-origin strains are isolated from pigs, including H5 and H9 subtypes. However, their low seroprevalence in swine also shows that pigs remain poorly infected by these subtypes. We conclude that sero-epidemioligical investigations have been neglected, and that they may help to improve virological surveillance. Inter- and intra-continental surveillance of gene flows will benefit the region. Greater investment is needed in swine influenza surveillance, to improve our knowledge of circulating strains as well as the epidemiology and disease burden in the region.
Topics: Animals; Asia, Southeastern; Humans; Influenza A virus; Influenza, Human; Risk Factors; Sentinel Surveillance; Swine; Zoonoses
PubMed: 22123276
DOI: 10.1017/S1466252311000181 -
PloS One Jan 2011The threat posed by highly pathogenic avian influenza A H5N1 viruses to humans remains significant, given the continued occurrence of sporadic human cases (499 human... (Review)
Review
BACKGROUND
The threat posed by highly pathogenic avian influenza A H5N1 viruses to humans remains significant, given the continued occurrence of sporadic human cases (499 human cases in 15 countries) with a high case fatality rate (approximately 60%), the endemicity in poultry populations in several countries, and the potential for reassortment with the newly emerging 2009 H1N1 pandemic strain. Therefore, we review risk factors for H5N1 infection in humans.
METHODS AND FINDINGS
Several epidemiologic studies have evaluated the risk factors associated with increased risk of H5N1 infection among humans who were exposed to H5N1 viruses. Our review shows that most H5N1 cases are attributed to exposure to sick poultry. Most cases are sporadic, while occasional limited human-to-human transmission occurs. The most commonly identified factors associated with H5N1 virus infection included exposure through contact with infected blood or bodily fluids of infected poultry via food preparation practices; touching and caring for infected poultry; [corrected] exposure to H5N1 via swimming or bathing in potentially virus laden ponds; and exposure to H5N1 at live bird markets.
CONCLUSIONS
Research has demonstrated that despite frequent and widespread contact with poultry, transmission of the H5N1 virus from poultry to humans is rare. Available research has identified several risk factors that may be associated with infection including close direct contact with poultry and transmission via the environment. However, several important data gaps remain that limit our understanding of the epidemiology of H5N1 in humans. Although infection in humans with H5N1 remains rare, human cases continue to be reported and H5N1 is now considered endemic among poultry in parts of Asia and in Egypt, providing opportunities for additional human infections and for the acquisition of virus mutations that may lead to more efficient spread among humans and other mammalian species. Collaboration between human and animal health sectors for surveillance, case investigation, virus sharing, and risk assessment is essential to monitor for potential changes in circulating H5N1 viruses and in the epidemiology of H5N1 in order to provide the best possible chance for effective mitigation of the impact of H5N1 in both poultry and humans.
DISCLAIMER
The opinions expressed in this article are those of the authors and do not necessarily reflect those of the institutions or organizations with which they are affiliated.
Topics: Animals; Birds; Disease Vectors; Humans; Influenza A Virus, H5N1 Subtype; Influenza in Birds; Influenza, Human; Poultry
PubMed: 21283678
DOI: 10.1371/journal.pone.0014582 -
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 -
JBI Library of Systematic Reviews 2010Emerging acute respiratory infectious diseases, such as Severe Acute Respiratory Syndrome (SARS) and the Avian Influenza A/H5N1 virus are contagious with high morbidity...
A comprehensive systematic review of healthcare workers' perceptions of risk from exposure to emerging acute respiratory infectious diseases and the perceived effectiveness of strategies used to facilitate healthy coping in acute hospital and community healthcare settings.
BACKGROUND
Emerging acute respiratory infectious diseases, such as Severe Acute Respiratory Syndrome (SARS) and the Avian Influenza A/H5N1 virus are contagious with high morbidity and mortality rates. Hence, health care workers, who are in close contact with affected patients, face many risks. There need to be a greater understanding of: individual HCWs' risk perceptions; adopted risk-mitigating strategies; and factors influencing both.
OBJECTIVES
This review aimed to establish the best evidence regarding health care worker's risk perceptions and workplace strategies towards emerging acute respiratory infectious diseases in acute hospital and community healthcare settings; and to make recommendations for practice and future research.
INCLUSION CRITERIA
Participants Studies that included male and female health care workers practising in acute and community health care settings were considered.Types of intervention (s)/Phenomena of interest This review considered studies that investigated: health care workers' risk perceptions; perceived meaning/effectiveness of the individual and workplace strategies implemented; and the factors influencing both.Types of outcomes This review focused on factors affecting: health care worker' risk perceptions; use of risk-mitigating strategies; and their perceived meaning and effectiveness.Types of studies Both qualitative and quantitative study designs published in the English language were including in the study.
SEARCH STRATEGY
Using a three-step search strategy, the following databases from 1997-2009 were accessed: CINAHL, PubMed, SCOPUS, ScienceDirect, Sociological Abstracts, PsycINFO, and Web of Science.
METHODOLOGICAL QUALITY
Two independent reviewers assessed each paper for methodological validity prior to inclusion in the review using standardised critical appraisal instruments from the Joanna Briggs Institute. Disagreements were resolved through discussion, or with a third reviewer.
DATA EXTRACTION
Information was extracted by two independent reviewers from each paper using the standardised data extraction tools from JBI.
DATA SYNTHESIS
The findings are presented in narrative form, as textual pooling and statistical pooling was not possible for the qualitative and quantitative papers respectively.
RESULTS
Ten quantitative studies and one qualitative study were included in the review. Findings indicated that although health care workers perceived personal and familial health risks and stigmatization from their exposure to emerging acute respiratory infectious diseases, the majority were accepting of these risks. Organizational implementation of infection control measures; avoidance of patients; and complying with personal protective equipment were identified as risk-mitigating strategies. Demographic, individual and organizational factors were found to influence their risk perceptions and their adoption of these strategies.
CONCLUSIONS
There is a nebulous relationship between health care workers' risk perceptions and how these perceptions affect their use of risk-mitigating strategies. Hence, future research needs to examine the nuances of this relationship, as well as the influencing factors involved. In this review, several key factors influencing health care workers' risk perceptions and risk-mitigating strategies were identified and these may form the implications for new practice.
IMPLICATIONS FOR PRACTICE
Institutions need to: empower health care workers through education and training; protect them with organizational safeguards; and offer incentives to encourage willingness to work, especially for those with high risk perceptions.
IMPLICATIONS FOR RESEARCH
Future research need to examine the: differences between HCWs' intentions to care during SARS and influenza outbreaks; relationship between intentions to care and actual care provided; difference between their intentions to care/resign and acceptance of risks; factors influencing their intentions to care; and factors influencing compliance to infection control measures.
PubMed: 27819952
DOI: 10.11124/01938924-201008230-00001 -
Die Pharmazie Oct 2009Recently, the worldwide spread of A/H5N1 avian influenza with high virulence has highlighted the potential threat of a human influenza pandemic. The viral surface... (Review)
Review
Recently, the worldwide spread of A/H5N1 avian influenza with high virulence has highlighted the potential threat of a human influenza pandemic. The viral surface glycoprotein, neuraminidase (NA), has been found to be a potential target to control influenza virus. With an understanding of the enzyme mechanism, the X-ray crystallographic structures of NA and its substrate or inhibitors, and progress in computational chemistry, the information about NA binding sites and pharmacophore models is derived from existing inhibitors and will serve as design guidelines of more potent agents against NA. This article gives a systematic review of the recent advances in this area.
Topics: Animals; Antiviral Agents; Enzyme Inhibitors; Humans; Models, Chemical; Neuraminidase; Orthomyxoviridae; Quantitative Structure-Activity Relationship; X-Ray Diffraction
PubMed: 19947162
DOI: No ID Found -
The Cochrane Database of Systematic... Jul 2009Influenza is a highly infectious viral disease that is particularly common in the winter months. Oscillococcinum is a patented, commercially available homoeopathic... (Review)
Review
BACKGROUND
Influenza is a highly infectious viral disease that is particularly common in the winter months. Oscillococcinum is a patented, commercially available homoeopathic medicine. The rationale for its use in influenza comes from the homoeopathic principle of 'let like be cured by like'. This medicine is manufactured from wild duck heart and liver, which are said to be reservoirs for influenza viruses.
OBJECTIVES
To determine whether homoeopathic Oscillococcinum or similar medicines are more effective than placebo in the prevention and treatment of influenza and influenza-like syndromes.
SEARCH STRATEGY
We updated the electronic searches on the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2006); MEDLINE (January 1966 to February 2006) and EMBASE (1980 to February 2006). The manufacturers of Oscillococcinum were contacted for information.
SELECTION CRITERIA
Placebo-controlled trials of Oscillococcinum or homeopathically-prepared influenza virus, influenza vaccine or avian liver in the prevention and treatment of influenza and influenza-like syndromes.
DATA COLLECTION AND ANALYSIS
Two authors extracted data and assessed methodological quality independently.
MAIN RESULTS
Seven studies were included in the review, three prevention trials (number of participants (n) = 2265) and four treatment trials (n = 1194). Only two studies reported sufficient information to complete data extraction fully. There was no evidence that homoeopathic treatment can prevent influenza-like syndrome (relative risk (RR) 0.64, 95% confidence interval (CI) 0.28 to 1.43). Oscillococcinum treatment reduced the length of influenza illness by 0.28 days (95% CI 0.50 to 0.06). Oscillococcinum also increased the chances that a patient considered treatment to be effective (RR 1.08; 95% CI 1.17 to 1.00).
AUTHORS' CONCLUSIONS
Though promising, the data were not strong enough to make a general recommendation to use Oscillococcinum for first-line treatment of influenza and influenza-like syndromes. Further research is warranted but the required sample sizes are large. Current evidence does not support a preventative effect of Oscillococcinum-like homeopathic medicines in influenza and influenza-like syndromes.
Topics: Homeopathy; Humans; Influenza Vaccines; Influenza, Human; Syndrome
PubMed: 19588329
DOI: 10.1002/14651858.CD001957.pub4 -
The Lancet. Infectious Diseases Apr 2007Planning for the next influenza pandemic is occurring at many levels throughout the world, spurred on by the recent spread of H5N1 avian influenza in Asia, Europe, and... (Review)
Review
Planning for the next influenza pandemic is occurring at many levels throughout the world, spurred on by the recent spread of H5N1 avian influenza in Asia, Europe, and Africa. Central to these planning efforts in the health-care sector are strategies to minimise the transmission of influenza to health-care workers and patients. The infection control precautions necessary to prevent airborne, droplet, and contact transmission are quite different and will need to be decided on and planned before a pandemic occurs. Despite vast clinical experience in human beings, there continues to be much debate about how influenza is transmitted. We have done a systematic review of the English language experimental and epidemiological literature on this subject to better inform infection control planning efforts. We have found that the existing data are limited with respect to the identification of specific modes of transmission in the natural setting. However, we are able to conclude that transmission occurs at close range rather than over long distances, suggesting that airborne transmission, as traditionally defined, is unlikely to be of significance in most clinical settings. Further research is required to better define conditions under which the influenza virus may transmit via the airborne route.
Topics: Animals; Cross Infection; Disease Models, Animal; Disease Outbreaks; Disease Transmission, Infectious; Fomites; Humans; Influenza A Virus, H5N1 Subtype; Influenza, Human; Respiratory Protective Devices
PubMed: 17376383
DOI: 10.1016/S1473-3099(07)70029-4