scholarly journals A metapopulation model for highly pathogenic avian influenza: implications for compartmentalization as a control measure

2013 ◽  
Vol 142 (9) ◽  
pp. 1813-1825 ◽  
Author(s):  
S. NICKBAKHSH ◽  
L. MATTHEWS ◽  
S. W. J. REID ◽  
R. R. KAO
Keyword(s):  
Avian Influenza ◽  
Highly Pathogenic Avian Influenza ◽  
Control Measure ◽  
Effective Control ◽  
Poultry Industry ◽  
Long Distance ◽  
Highly Pathogenic ◽  
Economic Implications ◽  
Pathogenic Avian Influenza ◽  
Network Links

SUMMARYAlthough the compartmentalization of poultry industry components has substantial economic implications, and is therefore a concept with huge significance to poultry industries worldwide, the current requirements for compartment status are generic to all OIE member countries. We examined the consequences for potential outbreaks of highly pathogenic avian influenza in the British poultry industry using a metapopulation modelling framework. This framework was used to assess the effectiveness of compartmentalization relative to zoning control, utilizing empirical data to inform the structure of potential epidemiological contacts within the British poultry industry via network links and spatial proximity. Conditions were identified where, despite the efficient isolation of poultry compartments through the removal of network-mediated links, spatially mediated airborne spread enabled spillover of infection with nearby premises making compartmentalization a more ‘risky’ option than zoning control. However, when zoning control did not effectively inhibit long-distance network links, compartmentalization became a relatively more effective control measure than zoning. With better knowledge of likely distance ranges for airborne spread, our approach could help define an appropriate minimum inter-farm distance to provide more specific guidelines for compartmentalization in Great Britain.

scholarly journals Detection of mortality clusters associated with highly pathogenic avian influenza in poultry: a theoretical analysis

2008 ◽  
Vol 5 (29) ◽  
pp. 1409-1419 ◽  
Author(s):  
Nicholas J Savill ◽  
Suzanne G St. Rose ◽  
Mark E.J Woolhouse
Keyword(s):  
Avian Influenza ◽  
Highly Pathogenic Avian Influenza ◽  
Effective Control ◽  
False Alarms ◽  
Flock Size ◽  
Detection Thresholds ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Background Mortality ◽  
Time To Detection

Rapid detection of infectious disease outbreaks is often crucial for their effective control. One example is highly pathogenic avian influenza (HPAI) such as H5N1 in commercial poultry flocks. There are no quantitative data, however, on how quickly the effects of HPAI infection in poultry flocks can be detected. Here, we study, using an individual-based mathematical model, time to detection in chicken flocks. Detection is triggered when mortality, food or water intake or egg production in layers pass recommended thresholds suggested from the experience of past HPAI outbreaks. We suggest a new threshold for caged flocks—the cage mortality detection threshold—as a more sensitive threshold than current ones. Time to detection is shown to depend nonlinearly on R 0 and is particularly sensitive for R 0 <10. It also depends logarithmically on flock size and number of birds per cage. We also examine how many false alarms occur in uninfected flocks when we vary detection thresholds owing to background mortality. The false alarm rate is shown to be sensitive to detection thresholds, dependent on flock size and background mortality and independent of the length of the production cycle. We suggest that current detection thresholds appear sufficient to rapidly detect the effects of a high R 0 HPAI strain such as H7N7 over a wide range of flock sizes. Time to detection of the effects of a low R 0 HPAI strain such as H5N1 can be significantly improved, particularly for large flocks, by lowering detection thresholds, and this can be accomplished without causing excessive false alarms in uninfected flocks. The results are discussed in terms of optimizing the design of disease surveillance programmes in general.

scholarly journals EVALUASI KEBERLANJUTAN PENERAPAN LANGKAH-LANGKAH BIOSEKURITI PADA PETERNAKAN AYAM BROILER DI DESA SELANBAWAK, KECAMATAN MARGA, KABUPATEN TABANAN

2018 ◽  
Vol 21 (2) ◽  
pp. 76
Author(s):  
SARINI N. P. ◽  
N. N. SURYANI ◽  
NI PUTU MARIANI ◽  
A. A. OKA ◽  
M. DEWANTARI
Keyword(s):  
Avian Influenza ◽  
Infectious Diseases ◽  
Highly Pathogenic Avian Influenza ◽  
Negative Impact ◽  
Poultry Industry ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Poultry Farms ◽  
The Government

The entry of Avian Influenza (AI) to Indonesia in 2003 gave a tremendously negative impact on poultrybusinesses. Biosecurity is one of the government efforts to protect the spread of infectious diseases to the farms.It gets a good response from all the stakeholders in the poultry industry. Although there are no Avian Influenzaoutbreaks anymore, control to the Highly Pathogenic Avian Influenza (HPAI) is still becoming a main priority incontrolling diseases in the poultry farms. This research was conducted to evaluate the sustainability of biosecurityimplementation in the broiler farms and mentored requirement to prevent AI outbreaks from occurring again.A survey was used to gain information on broiler famers at Selanbawak Village. The samples in this study wereall the farmers who were involved in the ACIAR project AH/2006/169. They had been trained and supervised toimplement biosecurity measures in their farms. The data obtained were descriptive-qualitatively analyzed usingpercentage approach based on the biosecurity implementation criteria. It was found that the biosecurity measuresimplemented by those farmers had not been maintained. Most of the farms were untidy; and rubbishes and busheswere scattered around the farms. The footbath was not properly used as sanitary equipment, and even some wereburied with cement.

scholarly journals Avian influenza human death reported in the Netherlands

2003 ◽  
Vol 7 (17) ◽  
Author(s):  
J Crofts
Keyword(s):  
The Netherlands ◽  
Avian Influenza ◽  
Highly Pathogenic Avian Influenza ◽  
Poultry Industry ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Human Death

A human fatality has been reported from the outbreak of highly pathogenic avian influenza (HPAI) A H7N7, which has been ongoing in the Netherlands since the end of February and which has caused a standstill to that country’s poultry industry.

scholarly journals Highly Pathogenic Avian Influenza Virus H5N1 Infection in a Long-Distance Migrant Shorebird under Migratory and Non-Migratory States

PLoS ONE ◽  
2011 ◽  
Vol 6 (11) ◽  
pp. e27814 ◽  
Author(s):  
Leslie A. Reperant ◽  
Marco W. G. van de Bildt ◽  
Geert van Amerongen ◽  
Debbie M. Buehler ◽  
Albert D. M. E. Osterhaus ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Highly Pathogenic Avian Influenza ◽  
Long Distance ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Virus H5n1 ◽  
Avian Influenza Virus H5n1 ◽  
Pathogenic Avian Influenza Virus

scholarly journals Genetic evolution and transmission dynamics of clade 2.3.2.1a highly pathogenic avian influenza A/H5N1 viruses in Bangladesh

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Jung-Hoon Kwon ◽  
Dong-Hun Lee ◽  
Miria Ferreira Criado ◽  
Lindsay Killmaster ◽  
Md Zulfekar Ali ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Avian Influenza ◽  
Influenza A ◽  
Highly Pathogenic Avian Influenza ◽  
Influenza Viruses ◽  
Effective Control ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
History Of ◽  
Genetic Sequences

Abstract Asian lineage A/H5N1 highly pathogenic avian influenza viruses (HPAIVs) have been responsible for continuous outbreaks in Bangladesh since 2007. Although clades 2.2.2 and 2.3.4.2 HPAIVs have disappeared since poultry vaccination was introduced in 2012, clade 2.3.2.1a viruses have continued to be detected in Bangladesh. In this study, we identified A/H9N2 (n = 15), A/H5N1 (n = 19), and A/H5N1-A/H9N2 (n = 18) mixed viruses from live bird markets, chicken farms, and wild house crows (Corvus splendens) in Bangladesh from 2016 to 2018. We analyzed the genetic sequences of the H5 HPAIVs, to better understand the evolutionary history of clade 2.3.2.1a viruses in Bangladesh. Although seven HA genetic subgroups (B1–B7) and six genotypes (G1, G1.1, G1.2, G2, G2.1, and G2.2) have been identified in Bangladesh, only subgroup B7 and genotypes G2, G2.1, and G2.2 were detected after 2016. The replacement of G1 genotype by G2 in Bangladesh was possibly due to vaccination and viral competition in duck populations. Initially, genetic diversity decreased after introduction of vaccination in 2012, but in 2015, genetic diversity increased and was associated with the emergence of genotype G2. Our phylodynamic analysis suggests that domestic Anseriformes, including ducks and geese, may have played a major role in persistence, spread, evolution, and genotype replacement of clade 2.3.2.1a HPAIVs in Bangladesh. Thus, improvements in biosecurity and monitoring of domestic Anseriformes are needed for more effective control of HPAI in Bangladesh.

scholarly journals Wild Ducks as Long-Distance Vectors of Highly Pathogenic Avian Influenza Virus (H5N1)

2008 ◽  
Vol 14 (4) ◽  
pp. 600-607 ◽  
Author(s):  
Juthatip Keawcharoen ◽  
Debby van Riel ◽  
Geert van Amerongen ◽  
Theo Bestebroer ◽  
Walter E. Beyer ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Highly Pathogenic Avian Influenza ◽  
Long Distance ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Virus H5n1 ◽  
Avian Influenza Virus H5n1 ◽  
Pathogenic Avian Influenza Virus
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