Survey of Canine Monogenetic Diseases with Established Molecular Bases

The development of a dog breed often involves selection, which intentionally propagates valued genetic traits. Unfortunately, untoward traits can be collaterally propagated during this process. For the purpose of identifying trends in canine genetic diseases, we examined 36 randomly chosen canine pathologies involving single gene mutations. For each disease we provide a brief summary of breed predilection, clinical signs, the underlying genetic mutation, and the availability of a commercial diagnostic test. The following trends were noted in this non-exhaustive list of diseases. First, these genetic diseases primarily involve the ophthalmic (28%) and nervous systems (28%). Second, no single breed was over-represented in these genetic diseases. Third, the majority (89%) of the mutations involve coding regions of the respective genes. Fourth, most (78%) mutations were autosomal recessive. Fifth, nucleotide substitutions were the most common mutation (42%). Finally, genetic testing is available for 89% of these diseases. This review encapsulates canine pathologies associated with single genetic defects, thus providing a resource for practitioners and researchers

Recommendations for pen-based oral-fluid collection in growing pigs

Sampling guidelines were developed by observing pigs during oral-fluid sample collection in commercial herds. Pigs with previous oral-fluid collection experience (“trained”) should be allowed 20 minutes access to the rope. Pigs with no prior experience (“untrained”) should be allowed 60 minutes. One collection is enough to train pigs

Detection of porcine reproductive and respiratory syndrome virus (PRRSV)-specific IgM-IgA in oral fluid samples reveals PRRSV infection in the presence of maternal antibody

The ontogeny of PRRSV antibody in oral fluids has been described using isotype-specific ELISAs. Mirroring the serum response, IgM appears in oral fluid by 7 days post inoculation (DPI), IgA after 7 DPI, and IgG by 9 to 10 DPI. Commercial PRRSV ELISAs target the detection of IgG because the higher concentration of IgG relative to other isotypes provides the best diagnostic discrimination. Oral fluids are increasingly used for PRRSV surveillance in commercial herds, but in younger pigs, a positive ELISA result may be due either to maternal antibody or to antibody produced by the pigs in response to infection. To address this issue, a combined IgM-IgA PRRSV oral fluid ELISA was developed and evaluated for its capacity to detect pig-derived PRRSV antibody in the presence of maternal antibody. Two longitudinal studies were conducted. In Study 1 (modified-live PRRS vaccinated pigs), testing of individual pig oral fluid samples by isotype-specific ELISAs demonstrated that the combined IgM-IgA PRRSV ELISA provided better discrimination than individual IgM or IgA ELISAs. In Study 2 (field data), testing of pen-based oral fluid samples confirmed the findings in Study 1 and established that the IgM-IgA ELISA was able to detect antibody produced by pigs in response to wild-type PRRSV infection, despite the presence of maternal IgG. Overall, the combined PRRSV IgM-IgA oral fluid ELISA described in this study is a potential tool for PRRSV surveillance, particularly in populations of growing pigs originating from PRRSV-positive or vaccinated breeding herds

The italian quaternary volcanism

The peninsular and insular Italy are punctuated by Quaternary volcanoes and their rocks constitute an important aliquot of the Italian Quaternary sedimentary successions. Also away from volcanoes themselves, volcanic ash layers are a common and frequent feature of the Quaternary records, which provide us with potential relevant stratigraphic and chronological markers at service of a wide array of the Quaternary science issues. In this paper, a broad representation of the Italian volcano logical community has joined to provide an updated comprehensive state of art of the Italian Quaternary volcanism. The eruptive history, style and dynamics and, in some cases, the hazard assessment of about thirty Quaternary volcanoes, from the north ernmost Mt. Amiata, in Tuscany, to the southernmost Pantelleria and Linosa, in Sicily Channel, are here reviewed in the light of the substantial improving of the methodological approaches and the overall knowledge achieved in the last decades in the vol canological field study. We hope that the present review can represent a useful and agile document summarising the knowledege on the Italian volcanism at the service of the Quaternary community operating in central Mediterranean area

Surveillance in contemporary livestock production systems

The objectives of this research were to explore the use of swine oral fluids, a type of aggregate sample, in infectious disease surveillance. In Chapter 2, the uses and surveillance applications of aggregate samples are reviewed. As reported in the refereed literature, bulk tank milk samples from ovine, bovine, and caprine herds have been tested to determine disease status and herd immunity. Likewise, swine producers and veterinarians have used oral fluid testing for disease detection and the evaluation of herd immunity. In Chapter 3, sampling guidelines for oral fluid surveillance in commercial swine herds are presented. These guidelines are the result of field-based research in which oral fluids were collected weekly from 3 barns on one wean-to-finish farm for 9 weeks and tested for porcine reproductive and respiratory syndrome virus (PRRSV) RNA. Results were modeled using a piecewise exponential survival model to provide estimates of the probability of detection by disease prevalence, sample size, and diagnostic assay performance. Notably, this study showed that fixed spatial sampling was as good, if not better, than simple random sampling and that probability of detection on a swine farm improved significantly when multiple barns on the farm were sampled. In Chapter 4, a combined IgM-IgA PRRSV oral fluid ELISA was evaluated for its ability to detect pig-derived antibody produced in response to infection in the presence of maternal antibody. Two studies were performed. In Study 1 (experimental conditions), oral fluid samples were collected daily from 12 PRRSV-negative pigs from days post vaccination (DPV) -7 to DPV 42. Pigs were vaccinated using a modified-live PRRS vaccine on DPV 0. In Study 2 (field conditions), oral fluids were collected weekly from 3 wean-to-finish sites, each with 3 barns, for a total of 9 samplings. Testing of oral fluids from both studies by IgG, IgM, IgA, and IgM-IgA ELISAs showed that the IgM-IgA ELISA was able to detect pig-derived IgM and IgA in the face of circulating maternal antibody and that the combined IgM-IgA assay provided better performance than detection of either IgM or IgA alone.</p

A latent spatial piecewise exponential model for interval-censored disease surveillance data with time-varying covariates and misclassification

Understanding the dynamics of disease spread is critical to achieving effective animal disease surveillance. A major challenge in modeling disease spread is the fact that the true disease status cannot be known with certainty due to the imperfect diagnostic sensitivity and specificity of the tests used to generate the disease surveillance data. Other challenges in modeling such data include interval censoring, relating disease spread to distance between units, and incorporating time-varying covariates, which are the unobserved disease statuses. We propose a latent spatial piecewise exponential model (PEX) with misclassification of events to address the challenges in modeling such disease surveillance data. Specifically, a piecewise exponential model is used to describe the latent disease process, with spatial distance and timevarying covariates incorporated for disease spread. The observed surveillance data with imperfect diagnostic tests are then modeled using a binary misclassification process given the latent disease statuses from the PEX model. Model parameters are estimated through a Bayesian approach utilizing non-informative priors. A simulation study is performed to evaluate the model performance and the results are compared with a candidate model where no misclassification is considered. For further illustration, we discuss an application of this model to a porcine reproductive and respiratory syndrome virus (PRRSV) surveillance data collected from commercial swine farms.This article is published as Sun, Yaxuan, Chong Wang, William Q. Meeker, Max Morris, Marisa L. Rotolo, and Jeffery Zimmerman. "A latent spatial piecewise exponential model for interval-censored disease surveillance data with time-varying covariates and misclassification." Statistics and Its Interface 12, no. 1 (2019): 11-19. DOI: 10.4310/SII.2019.v12.n1.a2. Posted with permission.</p

Serological and Molecular Detection of Senecavirus A Associated with an Outbreak of Swine Idiopathic Vesicular Disease and Neonatal Mortality

We performed a longitudinal field study in a swine breeding herd that presented with an outbreak of vesicular disease (VD) that was associated with an increase in neonatal mortality. Initially, a USDA Foreign Animal Disease (FAD) investigation confirmed the presence of Senecavirus A (SVA) and ruled out the presence of exotic agents that produce vesicular lesions, e.g., foot-and-mouth disease virus and others. Subsequently, serum samples, tonsil swabs, and feces were collected from sows (n = 22) and their piglets (n = 33) beginning 1 week after the onset of the clinical outbreak and weekly for 6 weeks. The presence of SVA RNA was evaluated in all specimens collected by reverse transcriptase quantitative PCR (RT-qPCR) targeting a conserved region of the 5′ untranslated region (5′-UTR). The serological response (IgG) to SVA was evaluated by the weekly testing of sow and piglet serum samples on a SVA VP1 recombinant protein (rVP1) indirect enzyme-linked immunosorbent assay (ELISA). The rVP1 ELISA detected seroconversion against SVA in clinically affected and non-clinically affected sows at early stages of the outbreak as well as maternal SVA antibodies in offspring. Overall, the absence of vesicles (gross lesions) in SVA-infected animals and the variability of RT-qPCR results among specimen type demonstrated that a diagnostic algorithm based on the combination of clinical observations, RT-qPCR in multiple diagnostic specimens, and serology are essential to ensure an accurate diagnosis of SVA.This article is published as Gimenez-Lirola, Luis Gabriel, Chris Rademacher, Daniel Linhares, Karen Harmon, Marisa Rotolo, Yaxuan Sun, David H. Baum, Jeffrey Zimmerman, and Pablo Piñeyro. "Serological and molecular detection of Senecavirus A associated with an outbreak of swine idiopathic vesicular disease and neonatal mortality." Journal of clinical microbiology 54, no. 8 (2016): 2082-2089. doi: 10.1128/JCM.00710-16. Posted with permission.</p

Sampling guidelines for oral fluid-based surveys of group-housed animals

Formulas and software for calculating sample size for surveys based on individual animal samples are readily available. However, sample size formulas are not available for oral fluids and other aggregate samples that are increasingly used in production settings. Therefore, the objective of this study was to develop sampling guidelines for oral fluid-based porcine reproductive and respiratory syndrome virus (PRRSV) surveys in commercial swine farms. Oral fluid samples were collected in 9 weekly samplings from all pens in 3 barns on one production site beginning shortly after placement of weaned pigs. Samples (n = 972) were tested by real-time reverse-transcription PCR (RT-rtPCR) and the binary results analyzed using a piecewise exponential survival model for interval-censored, time-to-event data with misclassification. Thereafter, simulation studies were used to study the barn-level probability of PRRSV detection as a function of sample size, sample allocation (simple random sampling vs fixed spatial sampling), assay diagnostic sensitivity and specificity, and pen-level prevalence. These studies provided estimates of the probability of detection by sample size and within-barn prevalence. Detection using fixed spatial sampling was as good as, or better than, simple random sampling. Sampling multiple barns on a site increased the probability of detection with the number of barns sampled. These results are relevant to PRRSV control or elimination projects at the herd, regional, or national levels, but the results are also broadly applicable to contagious pathogens of swine for which oral fluid tests of equivalent performance are available.This article is published as Rotolo, Marisa L., Yaxuan Sun, Chong Wang, Luis Giménez-Lirola, David H. Baum, Phillip C. Gauger, Karen M. Harmon, Marlin Hoogland, Rodger Main, and Jeffrey J. Zimmerman. "Sampling guidelines for oral fluid-based surveys of group-housed animals." Veterinary microbiology 209 (2017): 20-29. doi: 10.1016/j.vetmic.2017.02.004.</p

Survey of Canine Monogenetic Diseases with Established Molecular Bases

The development of a dog breed often involves selection, which intentionally propagates valued genetic traits. Unfortunately, untoward traits can be collaterally propagated during this process. For the purpose of identifying trends in canine genetic diseases, we examined 36 randomly chosen canine pathologies involving single gene mutations. For each disease we provide a brief summary of breed predilection, clinical signs, the underlying genetic mutation, and the availability of a commercial diagnostic test. The following trends were noted in this non-exhaustive list of diseases. First, these genetic diseases primarily involve the ophthalmic (28%) and nervous systems (28%). Second, no single breed was over-represented in these genetic diseases. Third, the majority (89%) of the mutations involve coding regions of the respective genes. Fourth, most (78%) mutations were autosomal recessive. Fifth, nucleotide substitutions were the most common mutation (42%). Finally, genetic testing is available for 89% of these diseases. This review encapsulates canine pathologies associated with single genetic defects, thus providing a resource for practitioners and researchers.This article is from Austin J Vet Sci & Anim Husb. 2014;1(1): 7. Posted with permission.</p