Publications by authors named "Halvorson D"

Article Synopsis
  • The complexity of influenza A virus infections in birds creates challenges for effectively vaccinating poultry.
  • Vaccines can help prevent infections from specific IAV strains and are used in strategies to control outbreaks and maintain poultry production.
  • However, vaccination against highly pathogenic avian influenza is regulated and requires special permission due to its impact on international trade.
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Tech-check-tech (TCT) programs in pharmacies are beneficial in facilitating a transition from fee for service dispensing tasks to advanced patient care, but they are underutilized. To describe the design, implementation, and evaluation of a transferable TCT program in several North Dakota pharmacies, with the goal of facilitating future efforts in other states. We developed a universal TCT implementation toolkit, recruited 6 pharmacies to implement it, developed an educational program for the pharmacies, and worked with the pharmacies over a year to assess success of the program.

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Understanding the amount of virus shed at the flock level by birds infected with low pathogenicity avian influenza virus (LPAIV) over time can help inform the type and timing of activities performed in response to a confirmed LPAIV-positive premises. To this end, we developed a mathematical model which allows us to estimate viral shedding by 10,000 turkey toms raised in commercial turkey production in the United States, and infected by H7 LPAIV strains. We simulated the amount of virus shed orally and from the cloaca over time, as well as the amount of virus in manure.

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Artificial insemination is a routine practice for turkeys that can introduce pathogens into breeder flocks in a variety of ways. In this manuscript, a risk analysis on the potential transmission of highly pathogenic avian influenza (HPAI) to naïve hens through artificial insemination is presented. A case of HPAI on a stud farm where the potential transmission of the virus to susceptible hens in the 2015 H5N2 HPAI outbreak in Minnesota is described along with documentation of known and potential transmission pathways from the case.

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Movement and land application of manure is a known risk factor for secondary spread of avian influenza viruses. During an outbreak of highly pathogenic avian influenza (HPAI), movement of untreated (i.e.

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Avian infection studies with influenza A are an important means of assessing host susceptibility, viral pathogenesis, host responses to infection, mechanisms of transmission, viral pathotype, and viral evolution. Complex systems and natural settings may also be explored with carefully designed infection studies. In this chapter, we explore the elements of infection studies, general guidelines for choosing a virus to use, host selection, and many aspects of study design.

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We have examined a variety of sampling strategies for detecting pathogens in turkey flocks undergoing infections with low pathogenicity avian influenza virus (LPAIV). We found that viral RNA was widely distributed in the barn environment of turkey flocks undergoing an active LPAIV infection and was in both water and drinker biofilm samples. Viral RNA was concentrated in drinker biofilm and sediment and was detectable using real-time reverse-transcription polymerase chain reaction (RRT-PCR) and by virus isolation.

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Article Synopsis
  • * Different levels of real-time testing were assessed to estimate the likelihood of detecting infections and the proportion of infectious birds that remain undetected at the time of movement.
  • * Results indicate that RRT-PCR testing is most effective shortly after exposure, while serology testing is more beneficial later on, suggesting these findings apply beyond U.S. flocks as well.
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Outbreaks involving avian influenza viruses are often devastating to the poultry industry economically and otherwise. Disease surveillance is critically important because it facilitates timely detection and generates confidence that infected birds are not moved during business continuity intended to mitigate associated economic losses. The possibility of using an abnormal increase in daily mortality to levels that exceed predetermined thresholds as a trigger to initiate further diagnostic investigations for highly pathogenic avian influenza (HPAI) virus infection in the flock is explored.

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Respiratory secretions, feces, feathers, and eggs of avian influenza-infected hens provide ample sources of virus which heavily contaminate barn and farm environments during a disease outbreak. Environmental sampling surveys were conducted in the Midwestern United States on affected farms during the 2015 H5N2 highly pathogenic avian influenza (HPAI) outbreak to assess the degree of viral contamination. A total of 930 samples were obtained from various sites inside and outside layer barns housing infected birds and tested with real-time reverse transcriptase PCR.

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Background: Avian influenza (AI) is an infectious viral disease that affects several species and has zoonotic potential. Due to its associated health and economic repercussions, minimizing AI outbreaks is important. However, most control measures are generic and mostly target pathways important for the conventional poultry farms producing chickens, turkeys, and eggs and may not target other pathways that may be specific to the upland game bird sector.

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Better control of highly pathogenic avian influenza (HPAI) outbreaks requires deeper understanding of within-flock virus transmission dynamics. For such fatal diseases, daily mortality provides a proxy for disease incidence. We used the daily mortality data collected during the 2015 H5N2 HPAI outbreak in Minnesota turkey flocks to estimate the within-flock transmission rate parameter (β).

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Producing a smaller yield of higher-value birds compared to conventional poultry production, the U.S. commercial upland game bird industry deals primarily in the sale of live birds for recreational hunting.

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The spatial spread of highly pathogenic avian influenza (HPAI) H5N2 during the 2015 outbreak in the U.S. state of Minnesota was analyzed through the estimation of a spatial transmission kernel, which quantifies the infection hazard an infectious premises poses to an uninfected premises some given distance away.

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Unlabelled: IntroductionForeign animal disease (FAD) outbreaks can have devastating impacts, but they occur infrequently in any specific sector anywhere in the United States (US). Training to proactively discuss implementation of control and prevention strategies are beneficial in that they provide stakeholders with the practical information and educational experience they will need to respond effectively to an FAD. Such proactive approaches are the mission of the Secure Food System (SFS; University of Minnesota; St.

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Background: Timely diagnosis of influenza A virus infections is critical for outbreak control. Due to their rapidity and other logistical advantages, lateral flow immunoassays can support influenza A virus surveillance programs and here, their field performance was proactively assessed. The performance of real-time polymerase chain reaction and two lateral flow immunoassay kits (FluDETECT and VetScan) in detecting low pathogenicity influenza A virus in oropharyngeal swab samples from experimentally inoculated broiler chickens was evaluated and at a flock-level, different testing scenarios were analyzed.

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Recent experiences with avian influenza outbreaks in poultry in the United States have tested biosecurity protocols and outbreak management strategies. During an outbreak, regulatory officials managing the emergency response need to make timely decisions in order to achieve disease control and eradication goals while simultaneously decreasing the unintended consequences of the response. To move susceptible animals or animal products out of a disease Control Area via a secure food supply continuity of business (COB) permit without the risk of expanding a disease outbreak, premises must be designated as Monitored Premises (MP) by regulatory officials.

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Garbage management represents a potential pathway of HPAI-virus infection for commercial poultry operations as multiple poultry premises may share a common trash collection service provider, trash collection site (e.g., shared dumpster for multiple premises) or disposal site (e.

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Risk management decisions associated with live poultry movement during a highly pathogenic avian influenza (HPAI) outbreak should be carefully considered. Live turkey movements may pose a risk for disease spread. On the other hand, interruptions in scheduled movements can disrupt business continuity.

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Subtype H3 influenza A viruses (IAVs) are abundant in wild waterfowl and also infect humans, pigs, horses, dogs, and seals. In Minnesota, turkeys are important and frequent hosts of IAV from wild waterfowl and from pigs. Over 48 yr of surveillance history, 11 hemagglutinin (HA) subtypes of IAV from waterfowl, as well as two HA subtypes from swine, H1 and H3, have infected turkeys in Minnesota.

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The regulatory response to an outbreak of highly pathogenic avian influenza (HPAI) in the United States may involve quarantine and stop movement orders that have the potential to disrupt continuity of operations in the U.S. turkey industry--particularly in the event that an uninfected breeder flock is located within an HPAI Control Area.

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Avian infection studies with influenza A virus are an important means of assessing host susceptibility, viral pathogenesis, host responses to infection, mechanisms of transmission, and viral pathotype. Complex systems and natural settings may also be explored with carefully designed infection studies. In this chapter, we explore the elements of infection studies, general guidelines for choosing a virus to use, host selection, and many aspects of study design.

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A highly pathogenic avian influenza (HPAI) outbreak in the United States will initiate a federal emergency response effort that will consist of disease control and eradication efforts, including quarantine and movement control measures. These movement control measures will not only apply to live animals but also to animal products. However, with current egg industry "just-in-time" production practices, limited storage is available to hold eggs.

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Early detection of highly pathogenic avian influenza (HPAI) infection in commercial poultry flocks is a critical component of outbreak control. Reducing the time to detect HPAI infection can reduce the risk of disease transmission to other flocks. The timeliness of different types of detection triggers could be dependent on clinical signs that are first observed in a flock, signs that might vary due to HPAI virus strain characteristics.

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