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- W75279286 abstract "In late 2003 and early 2004, outbreaks of highly pathogenic avian influenza (HPAI) H5N1 occurred in domestic poultry across East Asia and Southeast Asia. Since May 2005, infection spread to wild birds and domestic poultry in Central and South Asia, Europe, Middle East and Africa. The rapid geographical spread of H5N1, the direct transmission of an avian virus to humans, the death and destruction of hundreds of millions of poultry with disease endemnicity in many areas, the perpetuation of virus in apparently healthy ducks and paradoxically, its unusual virulence for waterfowl and mammals, and the constant viral evolution, highlighted the challenges the global community faced. This thesis addresses issues related to the diagnosis, epidemiology and control of H5N1 through research evaluating tools for rapid virus detection, field epidemiology studies and improved methods of vaccination in ducks as a disease control option. In particular, Chapter Two evaluates rapid antigen tests for H5N1 HPAI diagnosis in the field; Chapter Three identifies H5N1 infection in healthy village poultry in Bali and the possible role played by village poultry traders on H5N1 virus transmission; Chapter Four identifies risks for spread of viruses from live poultry markets in Bali; Chapter Five analyses the phylogenetic relationship of H5N1 viruses circulating in the village study sites during the 2006-2007 study period in Bali; and Chapter Six evaluates a recombinant baculovirus-expressed H5 vaccine against virulent H5N1 HPAI virus challenge in ducks for purpose of disease control.Chapter Two describes a laboratory evaluation of five influenza antigen detection tests to estimate their diagnostic sensitivity. The evaluation was performed using close to 300 H5N1 positive swab samples that had been collected from field cases in Hong Kong. The results showed that the overall sensitivities of these tests ranged from 36.3% to 51.4% (95% confidence interval ranging from 31.0% to 57.0%). Analysis of test sensitivity indicated that these antigen detection tests could be used for rapid and preliminary flock investigations of H5N1 outbreaks in sick and dead birds but should not be used for surveillance testing of clinically healthy birds. These tests offer a valuable role in disease investigation for example in rural village communities without immediate access to reference facilities. For the surveillance studies in villages (Chapter 3) and markets (Chapter 4) in Bali the evaluation studies of the rapid tests showed they were not suitable for detection of H5N1 infections in nonoutbreak situations and consequently were not used for this purpose.Chapters Three and Four describe field studies that were carried out to investigate the epidemiology of H5N1 in poultry in Bali, Indonesia. The surveillance recovered H5N1 HPAI virus at a low isolation rate (0.09% in chickens and 0.13% in ducks) in apparently healthy village poultry. A casecontrol study of village household flocks was performed. Using logistic regression analysis, the study identified risk factors that could influence the occurrence of H5N1 HPAI: the sale of poultry to collectors (p<0.01), a poultry production system with access to backyard roaming birds (p<0.05) and purchase of live poultry (chickens) (p<0.1). To further investigate the H5N1 epidemiology, characteristics of live bird markets were studied through a questionnaire survey of market sellers. The survey found that live bird markets aggregate birds of different species, from different sources and locations, to be kept in close proximity, and this lack of biosecurity can contribute to H5N1 persistence and dissemination. Separately, molecular analysis of isolates from the surveillance showed the continuing evolution of H5N1 virus from 2004 till 2007. Isolates from the surveillance of apparently healthy birds shared close phylogenetic relationship with poultry viruses from outbreak cases (under subclade 2.1) and also contained the characteristic HPAI molecular pathotypes. Based on this finding, further research is needed to ascertain if asymptomatic chickens and ducks are H5N1 HPAI carriers and can become a transmission risk for poultry and humans.Finally, as ducks were a source of H5N1 infection for other poultry in rural, endemic areas, Chapter Six describes a laboratory challenge study that was performed to investigate the efficacy of a recombinant baculovirus-expressed H5 vaccine. The study showed that the vaccine conferred protection from disease and mortality in ducks following challenge from an H5N1 HPAI virus. Vaccination in ducks resulted in elimination of respiratory virus shedding compared to unvaccinated control birds. The use of vaccines as a control strategy to break flock transmission and reduce the threat of ducks acting as a virus reservoir for other poultry is discussed. In addition, recombinant vaccine technologies offer a feasible method of production for affected developing countries without needing high biocontainment facilities or the expensive infrastructure required for producing vaccines via chicken embryos." @default.
- W75279286 created "2016-06-24" @default.
- W75279286 creator A5057466735 @default.
- W75279286 date "2009-01-01" @default.
- W75279286 modified "2023-09-23" @default.
- W75279286 title "Studies on the diagnosis, epidemiology and control of highly pathogenic H5N1 avian influenza" @default.
- W75279286 cites W106693069 @default.
- W75279286 cites W1218206777 @default.
- W75279286 cites W124219067 @default.
- W75279286 cites W1423013293 @default.
- W75279286 cites W146939554 @default.
- W75279286 cites W1476555807 @default.
- W75279286 cites W1482835904 @default.
- W75279286 cites W1483247593 @default.
- W75279286 cites W1487246189 @default.
- W75279286 cites W1496584707 @default.
- W75279286 cites W1499021452 @default.
- W75279286 cites W150919312 @default.
- W75279286 cites W1511685887 @default.
- W75279286 cites W1523679951 @default.
- W75279286 cites W1541595517 @default.
- W75279286 cites W1544187918 @default.
- W75279286 cites W1547972448 @default.
- W75279286 cites W1576737979 @default.
- W75279286 cites W1585148692 @default.
- W75279286 cites W1598638042 @default.
- W75279286 cites W1603867145 @default.
- W75279286 cites W1680107044 @default.
- W75279286 cites W1783971409 @default.
- W75279286 cites W1788079220 @default.
- W75279286 cites W1790557066 @default.
- W75279286 cites W1831786936 @default.
- W75279286 cites W1840869898 @default.
- W75279286 cites W1848588145 @default.
- W75279286 cites W1857245299 @default.
- W75279286 cites W1858483607 @default.
- W75279286 cites W1869612517 @default.
- W75279286 cites W1944984183 @default.
- W75279286 cites W1963675143 @default.
- W75279286 cites W1965152132 @default.
- W75279286 cites W1966893415 @default.
- W75279286 cites W1969823991 @default.
- W75279286 cites W1969919797 @default.
- W75279286 cites W1971178088 @default.
- W75279286 cites W1971215391 @default.
- W75279286 cites W1974150316 @default.
- W75279286 cites W1974355337 @default.
- W75279286 cites W1977131262 @default.
- W75279286 cites W1977411933 @default.
- W75279286 cites W1977991935 @default.
- W75279286 cites W1980633123 @default.
- W75279286 cites W1984669065 @default.
- W75279286 cites W1985007657 @default.
- W75279286 cites W1989479873 @default.
- W75279286 cites W1989787535 @default.
- W75279286 cites W1991773511 @default.
- W75279286 cites W1995003146 @default.
- W75279286 cites W1997343899 @default.
- W75279286 cites W1997384263 @default.
- W75279286 cites W1998318793 @default.
- W75279286 cites W1998800643 @default.
- W75279286 cites W1999550241 @default.
- W75279286 cites W1999984759 @default.
- W75279286 cites W2000811678 @default.
- W75279286 cites W2002765150 @default.
- W75279286 cites W2004944283 @default.
- W75279286 cites W2007740214 @default.
- W75279286 cites W2009387306 @default.
- W75279286 cites W2011879952 @default.
- W75279286 cites W2011983340 @default.
- W75279286 cites W2013299153 @default.
- W75279286 cites W2015735227 @default.
- W75279286 cites W2018150492 @default.
- W75279286 cites W2019091605 @default.
- W75279286 cites W2019907079 @default.
- W75279286 cites W2021079566 @default.
- W75279286 cites W2022724574 @default.
- W75279286 cites W2023753903 @default.
- W75279286 cites W2024558881 @default.
- W75279286 cites W2024698606 @default.
- W75279286 cites W2024814955 @default.
- W75279286 cites W2024970913 @default.
- W75279286 cites W2027126312 @default.
- W75279286 cites W2027191952 @default.
- W75279286 cites W2028003442 @default.
- W75279286 cites W2029542216 @default.
- W75279286 cites W2029623617 @default.
- W75279286 cites W2030895743 @default.
- W75279286 cites W2030956523 @default.
- W75279286 cites W2031606762 @default.
- W75279286 cites W2031798676 @default.
- W75279286 cites W2034750026 @default.
- W75279286 cites W2036034407 @default.
- W75279286 cites W2036523776 @default.
- W75279286 cites W2038441364 @default.
- W75279286 cites W2039850897 @default.
- W75279286 cites W2040707465 @default.
- W75279286 cites W2041243542 @default.
- W75279286 cites W2042619170 @default.
- W75279286 cites W2042839347 @default.