53 research outputs found

    The Analysis of Internal Parasites in Mosquitofish Throughout Texas

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    Mosquitofish (Gambusia affinis) are a species of small fish commonly found in many different freshwater environments throughout Texas. However, the ecology of these environments varies as each habitat is unique with differing communities. Parasites are often overlooked in these environments and can lend clues to ecological relationships between organisms within the parasite’s life cycle. This study will examine the parasites within the internal organs and eyes of female mosquitofish obtained from three different freshwater lakes throughout Texas and compare the parasitic species found in each location. From the data collected we can learn more about organismal interactions in these environments

    Trade patterns facilitating highly pathogenic avian influenza virus dissemination in the free-grazing layer duck system in Vietnam

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    Highly pathogenic avian influenza (HPAI) viruses continue to threaten smallholder poultry producers in several South‐east Asian countries, including Vietnam. In particular, the free‐grazing duck system has been repeatedly highlighted as a major risk factor for HPAI outbreaks. Free‐grazing ducks, which scavenge on rice paddies after the harvest, account for a large proportion of the duck population in Vietnam and the wider South‐east Asian region. However, the structure and dynamics of the free‐grazing duck production from farm to consumption has not been described for Vietnam. In this study, we used a value chain approach to provide a complete picture of the actors involved in the production and marketing of free‐grazing duck eggs and spent layer ducks, as well as to investigate the governance structure of this food system. Group interviews and key informant interviews were conducted in two provinces located in the Mekong River Delta (MRD) and the Red River Delta (RRD). The results presented here highlight similarities and differences in farming and trade practices between the two provinces. The trade of spent layer ducks involved large volumes of live ducks being sent to China and Cambodia for consumption, generating a substantial risk of transboundary spread of pathogens, including HPAI viruses. We describe the major role of “duck yards”, which act as hubs in the northbound trade of spent layer ducks. These yards should be considered as essential links in the value chain of spent layer ducks when considering HPAI surveillance and control. The veterinary authorities are only marginally involved in the value chain activities, and their influence could be strengthened by increasing surveillance activities for instance in duck yards. Last, we discuss the dynamics of the duck value chain and further implications for future HPAI management policies

    A large-scale study of a poultry trading network in Bangladesh: implications for control and surveillance of avian influenza viruses

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    Since its first report in 2007, avian influenza (AI) has been endemic in Bangladesh. While live poultry marketing is widespread throughout the country and known to influence AI dissemination and persistence, trading patterns have not been described. The aim of this study is to assess poultry trading practices and features of the poultry trading networks which could promote AI spread, and their potential implications for disease control and surveillance. Data on poultry trading practices was collected from 849 poultry traders during a cross-sectional survey in 138 live bird markets (LBMs) across 17 different districts of Bangladesh. The quantity and origins of traded poultry were assessed for each poultry type in surveyed LBMs. The network of contacts between farms and LBMs resulting from commercial movements of live poultry was constructed to assess its connectivity and to identify the key premises influencing it

    Extensive Mammalian Ancestry of Pandemic (H1N1) 2009 Virus

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    We demonstrate that the novel pandemic influenza (H1N1) viruses have human virus–like receptor specificity and can no longer replicate in aquatic waterfowl, their historic natural reservoir. The biological properties of these viruses are consistent with those of their phylogenetic progenitors, indicating longstanding adaptation to mammals

    Optimising the detectability of H5N1 and H5N6 highly pathogenic avian influenza viruses in Vietnamese live-bird markets

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    Live bird markets (LBMs) are major targets for avian influenza virus (AIV) surveillance programmes. While sampling the LBM environment has become a widely used alternative to the labour-intensive sampling of live poultry, the design of surveillance programmes and the interpretation of their results are compromised by the lack of knowledge about the effectiveness of these sampling strategies. We used latent class models and a unique empirical dataset collated in Vietnamese LBMs to estimate the sensitivity and specificity of five different sample types for detecting AIVs subtypes H5N1 and H5N6: oropharyngeal duck samples, solid and liquid wastes, poultry drinking water and faeces. Results suggest that the sensitivity of environmental samples for detecting H5N1 viruses is equivalent to that of oropharyngeal duck samples; however, taking oropharyngeal duck samples was estimated to be more effective in detecting H5N6 viruses than taking any of the four environmental samples. This study also stressed that the specificity of the current surveillance strategy in LBMs was not optimal leading to some false positive LBMs. Using simulations, we identified 42 sampling strategies more parsimonious than the current strategy and expected to be highly sensitive for both viruses at the LBM level. All of these strategies involved the collection of both environmental and oropharyngeal duck samples

    Influenza A virus survival in water is influenced by the origin species of the host cell

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    Background: Influenza A viruses have an envelope made of a lipid bilayer and two surface glycoproteins, the hemagglutinin and the neuraminidase. The structure of the virus is directly dependent on the genetic makeup of the viral genome except the glycosylation moieties and the composition of the lipid bilayer. They both depend on the host cell and are in direct contact with the environment, such as air or water. Virus survival is important for virus transmission from contaminated waters in the case of wild aquatic birds or from contaminated surface or air for humans. Objective: The objective of this study was to check whether the origin species of the host cell has an influence on influenza A virus survival. Method: The persistence in water at 35°C of viruses grown on either mammalian cells or avian cells and belonging to two different subtypes H1N1 and H5N1 was compared. Results: Both H5N1 and H1N1 viruses remained infectious for periods of time as long as 19-25 days, respectively. However, within the same subtype, viruses grown on mammalian cells were more stable in water at 35°C than their counterparts grown on avian cells, even for viruses sharing the same genetic background. Conclusions: This difference in virus stability outside the host is probably connected to the nature of the lipid bilayer taken from the cell or to the carbohydrate side chains of the virus surface glycoproteins. Moreover, the long-lasting survival time might have a critical role in the ecology of influenza viruses, especially for avian viruses

    Prevalence of avian influenza A(H5) and A(H9) in live bird markets in Bangladesh

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    We conducted a cross-sectional study in live bird markets (LBMs) in Dhaka and Chittagong, Bangladesh, to estimate the prevalence of avian influenza A(H5) and A(H9) viruses in different types of poultry and environmental areas by using Bayesian hierarchical logistic regression models. We detected these viruses in nearly all LBMs. Prevalence of A(H5) virus was higher in waterfowl than in chickens, whereas prevalence of A(H9) virus was higher in chickens than in waterfowl and, among chicken types, in industrial broilers than in cross-breeds and indigenous breeds. LBMs with >1 wholesaler were more frequently contaminated by A(H5) virus than retail-only LBMs. Prevalence of A(H9) virus in poultry and level of environmental contamination were also higher in LBMs with >1 wholesaler. We found a high level of circulation of both avian influenza viruses in surveyed LBMs. Prevalence was influenced by type of poultry, environmental site, and trading patterns because our study included previously collected data

    Use of ELISA to test seroprevalence of Toxoplasma gondii in cats of Tom Green County

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    The purpose of this study was to investigate the seroprevalence of Toxoplasma gondii in cats Tom Green County. We coordinated with four different veterinary offices in the county to collect the remains of blood samples taken in their practices for clinical tests. Using an ELISA, we tested the blood samples to determine if they had IgG antibodies against T. gondii, thus suggesting that they were or are currently infected. We found that 90% of the cats were positive for IgG antibodies to T. gondii, but there were no significant P-values for the seroprevalence of cats based on the animal’s sex, age, gender, and location in the county. This study is significant because 90% is higher than the seroprevalence we most commonly found in the literature of 30%-60%. In addition to this, Tom Green County is located in a dry region of west Texas which makes it harder for oocysts to survive in the environment and should result in a lower seroprevalence.Head of the River Ranch Travel Grant ASU Undergraduate Faculty Mentored semester long research gran

    An inquiry in the prevalence of Dirofilaria immitis in domestic and stray dogs in Tom Green County through ELISA

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    The objective of this project is to determine the risk of exposure to Dirofilaria immitis in dogs in Tom Green County by measuring antibody titers against the parasite. Host factors will be examined to determine if gender, age, geographical area are correlated with antibody titers. The results will help better determine if dog heartworm medications should be used in this area.Head of the River Ranch travel grant and ASU Undergraduate Faculty Mentored Semester long research gran
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