Finding PRRSV in sow herds: Family oral fluids vs. serum samples from due-to-wean pigs.

The aim of this study was to compare the detection of porcine reproductive and respiratory syndrome virus (PRRSV) in due-to-wean litters in commercial swine breeding herds using family oral fluids (FOF) vs. individual piglet serum samples. FOF and piglet serum samples were collected in 199 due-to-wean litters on six farms containing 2177 piglets. All samples were individually tested for PRRSV RNA by RT-rtPCR. A litter was considered PRRSV-positive when PRRSV RNA was detected in ≥ 1 piglet serum sample or the FOF sample. Mixed effect logistic regression with farm as a random effect was used 1) to evaluate the probability of obtaining a PRRSV RNA positive FOF as a function of the proportion of viremic piglets in a litter and 2) the effect of litter size and parity on the probability that a litter would test PRRSV RNA positive in FOF. A Bayesian prevalence estimation under misclassification (BayesPEM) analysis was used to calculate the PRRSV prevalence and 95 % credible interval given the condition that all samples (FOF and serum) tested negative. In total, 34 of 199 litters (17.1 %) contained ≥ 1 viremic piglet(s), and 28 of 199 litters (14.1 %) were FOF positive. When all piglet serum samples within a litter tested negative, 1 of 165 FOF (0.6 %) tested PRRSV RNA positive. The probability of a PCR-positive FOF sample from litters with 10 %, 20 %, 30 %, 40 %, and 50 % within-litter PRRSV prevalence was 3.5 %, 35.1 %, 88.8 %, 99.2 %, and >99.9 %, respectively. The odds of a PCR-positive FOF in a first parity litter were 3.36 times (95 % CI: 2.10-5.38) that of a parity ≥ 2 litter. The odds of a positive FOF result in a litter with ≤ 11 piglets were 9.90 times (95 % CI: 4.62-21.22) that of a litter with > 11 piglets. FOF was shown to be an efficacious sample type for PRRSV detection in farrowing rooms. A risk-based approach for litter selection combined with FOF collection can be used to improve on-farm PRRSV detection with a limited sample size, compared to sampling multiple individual pigs. Finally, the BayesPEM analysis showed that PRRSV may still be present in breeding herds when all samples (serum and FOF) test PRRSV RNA negative, i.e., negative surveillance results should be interpreted with caution.

Collecting oral fluid samples from due-to-wean litters.

Oral fluids are a common diagnostic sample in group-housed nursery, grow-finish, and adult swine. Although oral fluids from due-to-wean litters could be a valuable tool in monitoring pathogens and predicting the health status of pig populations post-weaning, it is generally not done because of inconsistent success in sample collection. The objective of this study was to determine the optimum procedure for collecting oral fluid samples from due-to-wean litters. Successful collection of oral fluids from due-to-wean litters using "Litter Oral Fluid" (LOF) or "Family Oral Fluid" (FOF) sampling techniques were compared in 4 phases involving 920 attempts to collect oral fluids. Phase 1 testing showed that prior exposure to a rope improved the success rates of both LOF (33.4%) and FOF (16.4%) techniques. Phase 2 determined that longer access to the rope (4 h vs 30 min) did not improve the success rate for either LOF or FOF. Phase 3 evaluated the effect of attractants and found that one (Baby Pig Restart®) improved the success rate when used with the FOF technique. Phase 4 compared the success rates of "optimized LOF" (litters previously trained) vs "optimized FOF" (litter previously trained and rope treated with Baby Pig Restart®) vs standard FOF. No difference was found between the FOF-based techniques, but both were superior to the "optimized LOF" technique. Thus, FOF-based procedures provided a significantly higher probability of collecting oral fluids from due-to-wean litters (mean success rate 84.9%, range 70% to 92%) when compared to LOF-based methods (mean success rate 24.1%, range 16.5% to 32.2%).

Systematic Epidemiological Investigations of Cases of Senecavirus A in US Swine Breeding Herds.

Epidemiological investigations were conducted on a case series of six Senecavirus A (SVA)-affected breeding herds in the United States to determine potential routes of introduction and enhance the swine industry's knowledge of SVA's clinical presentation and spread. Each SVA-affected herd was evaluated using a standard form to ensure that all relevant data were collected. The form was used to guide a detailed discussion about the clinical presentation of SVA and risk events that occurred in the 4 weeks prior to the first observation of clinical signs with the herd veterinarian and farm personnel. Each event was then subjectively assigned a risk level of low, medium or high likelihood for SVA introduction by the investigation team. The clinical presentation of SVA varied by case. All SVA-affected herds (six of six) reported increases in pre-weaning mortality and sow anorexia. Vesicular lesions were observed in four of six herds, and mild-to-moderate neonatal diarrhoea was observed in three of six herds. No gross anatomic or histologic lesions were observed in neonatal pigs that tested positive for SVA via PCR. Multiple potential routes of introduction were identified. Events subjectively rated as high risk for SVA introduction were on-farm employee entry (six of six), carcass disposal (four of six), cull sow removal (three of six) and breeding replacement entry (two of six). Non-swine domestic animals, rodents, other visitors, repairs outside swine barns, feed delivery, weaned pig removal and semen entry were assigned a high risk level in one of six herds. Cases occurred in breeding herds of all sizes with variable biosecurity in both swine dense and swine sparse areas.

Neonatal Mortality, Vesicular Lesions and Lameness Associated with Senecavirus A in a U.S. Sow Farm.

A 300-sow farrow-to-finish swine operation in the United States experienced a sudden and severe increase in mortality in neonatal piglets with high morbidity followed by vesicular lesions on the snout and feet of adult females and males. Affected live piglets were submitted for diagnostic investigation. Samples tested polymerase chain reaction (PCR) negative for foot-and-mouth disease virus, porcine delta coronavirus, porcine epidemic diarrhoea virus, porcine rotavirus types A, B and C, transmissible gastroenteritis virus, and porcine reproductive and respiratory syndrome virus. Senecavirus A (SV-A) formerly known as Seneca Valley virus was detected by real-time reverse-transcription polymerase chain reaction (rRT-PCR) from serum, skin and faeces of piglets and from serum and faeces of sows. SV-A was isolated in cell culture from piglet samples. SV-A VP1 gene region sequencing from piglet tissues was also successful. A biosecurity and disease entry evaluation was conducted and identified potential biosecurity risks factors for the entry of new pathogens into the operation. This is the first case report in the United States associating SV-A with a clinical course of severe but transient neonatal morbidity and mortality followed by vesicular lesions in breeding stock animals. Veterinarians and animal caretakers must remain vigilant for vesicular foreign animal diseases and report suspicious clinical signs and lesions to state animal health authorities for diagnostic testing and further investigation.

Mind the gap: the minimal detectable separation distance between two objects during active electrolocation.

In a food-rewarded two-alternative forced-choice procedure, it was determined how well the weakly electric elephantnose fish Gnathonemus petersii can sense gaps between two objects, some of which were placed in front of complex backgrounds. The results show that at close distances, G. petersii is able to detect gaps between two small metal cubes (2 cm × 2 cm × 2 cm) down to a width of c. 1·5 mm. When larger objects (3 cm × 3 cm × 3 cm) were used, gaps with a width of 2-3 mm could still be detected. Discrimination performance was better (c. 1 mm gap size) when the objects were placed in front of a moving background consisting of plastic stripes or plant leaves, indicating that movement in the environment plays an important role for object identification. In addition, the smallest gap size that could be detected at increasing distances was determined. A linear relationship between object distance and gap size existed. Minimal detectable gap sizes increased from c. 1·5 mm at a distance of 1 cm, to 20 mm at a distance of 7 cm. Measurements and simulations of the electric stimuli occurring during gap detection revealed that the electric images of two close objects influence each other and superimpose. A large gap of 20 mm between two objects induced two clearly separated peaks in the electric image, while a 2 mm gap caused just a slight indentation in the image. Therefore, the fusion of electric images limits spatial resolution during active electrolocation. Relative movements either between the fish and the objects or between object and background might improve spatial resolution by accentuating the fine details of the electric images.

[Terminology for classifying the porcine reproductive and respiratory syndrome virus (PRRSV) status of swine herds]. / Terminologie zur Klassifizierung des PRRSV-Status von Schweineherden.

Standardized terminology for the porcine reproductive and respiratory syndrome virus (PRRSV) status of swine herds is necessary to facilitate communication between veterinarians, swine producers, genetic companies, and other industry participants. It is also required for implementation of regional and national efforts towards PRRSV control and elimination. The purpose of this paper is to provide a herd classification system for describing the PRRSV status of herds, based upon a set of definitions reflecting the biology and ecology of PRRSV. The herd classification system was developed by a definitions committee formed jointly by the American Association of Swine Veterinarians (AASV) and the United States Department of Agriculture PRRS-Coordinated Agricultural Project, and was approved by the AASV Board of Directors on March 9, 2010. The committee included veterinarians from private practice and industry, researchers, and representatives from AASV and the National Pork Board. Breeding herds, with or without growing pigs on the same premises, are categorized as Positive Unstable (Category I), Positive Stable (Category II), Provisional Negative (Category III), or Negative (Category IV) on the basis of herd shedding and exposure status. Growing-pig herds are categorized as Positive or Negative. Recommended testing procedures and decision rules for herd classification are detailed.

Plasmid-mediated growth hormone-releasing hormone efficacy in reducing disease associated with Mycoplasma hyopneumoniae and porcine reproductive and respiratory syndrome virus infection.

The purpose of this study was to determine the effects of plasmid-mediated growth hormone releasing hormone (GHRH) supplementation on the clinical outcomes of pigs vaccinated against and challenged with either Mycoplasma hyopneumonia (M. hyo) and/or with porcine reproductive and respiratory syndrome (PRRS) virus. Before the first vaccination, pigs received a single i.m. injection of 0.625 mg of a porcine GHRH-expressing plasmid followed by electroporation of the injection site. Pigs were vaccinated at 2-wk intervals, challenged with either M. hyo and/or PRRS virus 2-wk after the second vaccination, and necropsied at 17 and 36 d after challenge. Clinical parameters associated with M. hyo challenge were improved with the GHRH treatment. Average daily gain between challenge and necropsy was improved (P = 0.04). Respiratory scores for M. hyo-challenged pigs tended to be lower in GHRH-treated animals compared to controls, and coughing scores were improved by the treatment (P = 0.01). Macroscopic lesions associated with M. hyo infection pneumonia were fewer in the group that received the GHRH-expressing plasmid. No differences between treatment groups in the macroscopic pneumonia associated with PRRS virus were observed. No differences in serum antibodies to M. hyo or PRRS virus were observed with GHRH treatment. Nevertheless, IgG in the bronchioalveolar lavage was increased by the GHRH treatment in M. hyo-challenged animals (P < 0.03). The results of this study suggest that GHRH supplementation before vaccination may enhance the protection against M. hyo-induced pneumonia and that a single dose of GHRH-expressing plasmid was sufficient to elicit an improved clinical outcome in this disease challenge model.

Development, pharmacology and clinical experience with clomiphene citrate.

This review describes the development and pharmacology of clomiphene and those specific characteristics of both drug and patients which determine its clinical efficacy. The studies reviewed describe clinical observation of patient characteristics (age, additional infertility diagnosis, semen quality), vaginal ultrasound observations of ovaries (number and size of pre-ovulatory follicles) and endometrial lining (thickness, pattern) in 2841 clomiphene cycles in patients who required intrauterine insemination (IUI) because of poor sperm quality or an unsatisfactory postcoital test. They show that (i) conception in clomiphene cycles is related to the number and size of pre-ovulatory follicles, endometrial thickness, patient age, pelvic adhesions, type of anovulatory disorder and semen quality; (ii) pregnancy rates per clomiphene-IUI cycle are constant through at least six cycles; (iii) multiple births cannot be prevented by withholding human chorionic gonadotrophin or advising against coitus when multiple pre-ovulation follicles are present unless all follicles down to 10-12 mm diameter are counted. We also reviewed pregnancy outcome (number of gestational sacs, babies, preclinical and clinical abortion, ectopic pregnancy and birth sex) in 1744 clomiphene pregnancies from our clinic. We found that (i) preclinical and clinical abortions are increased only slightly by clomiphene use, compared to spontaneous pregnancy; (ii) clinical abortions are decreased in patients with polycystic ovaries and luteal insufficiency who use clomiphene; (iii) conception and preclinical abortions are related to endometrial thickness prior to ovulation; (iv) ectopic pregnancies are not increased by clomiphene and (v) the ratio of male births is not altered by clomiphene, except possibly in timed insemination cycles. These studies repudiate many misconceptions regarding clomiphene. They also show that clinical outcome may be improved by pre-ovulation ultrasound monitoring of ovarian and endometrial response.

Cytochrome P450 mediated reactions studied in genetically engineered V79 Chinese hamster cells.

V79 Chinese hamster cells genetically engineered for stable expression of rat and human CYP have been shown to serve as analytical tools for studying metabolism related problems in toxicology and pharmacology. Here, the application of rat and human CYP1A1 and CYP1A2 is demonstrated for comparative studies on the oxidation of polycyclic aromatic hydrocarbons, such as phenanthrene, benz[a]anthracene, and benzo[a]pyrene. Live cells were cultivated for 2 days in the presence of these chemicals. Thereafter, the supernatant medium was checked for metabolites by gas chromatography and mass spectrometry. Marked cytochromes P450 and species dependent differences in the metabolite profiles were observed. Most important was the finding, that human cytochrome P450 1A1 almost exclusively oxidized benzo[a]pyrene in the 7,8,9,10-position, yielding the ultimate carcinogen 7,8-dihydroxy-9,10-epoxy-7,8,9, 10-tetrahydrobenzo[a]pyrene whereas the rat cytochrome P450 1A1 oxidized benzo[]pyrene in the 4,5-position and 7,8,9,10-position. The importance of this finding is underlined by results from cytotoxicity studies. Benzo[a]pyrene was twice as cytotoxic in the human cytochrome P450 1A1 than in the rat cytochrome P450 1A1 expressing V79 cells. Species and cytochrome P450 specific metabolite profiles were also observed for phenanthrene and benz[a]anthracene.

Development of a scanning, solar-blind, water Raman lidar.

The need for an instrument capable of measuring water-vapor fluxes over mixed canopy and large areas has long been recognized. Such a device would greatly enhance the study of evapotranspiration processes and has great practical value for water management. To address this problem, a scanning water Raman lidar has been designed and constructed. Analytical methods have also been developed to take advantage of the type of information that this lidar can generate. The lidar is able to measure the absolute water content and calculate the evaporative flux quickly over relatively large areas. This capability provides new opportunities for the study of microscale atmospheric processes. The variogram data indicate that the spatial sampling size must be of the order of 10 m if fluxes and scalars are to be properly represented. Examples of data are presented.

Evaluation of Klippel-Trenaunay syndrome with radionuclide total body angiography. A case report.

A 21-year-old Italian woman with extensive Klippel-Trenaunay syndrome (KTS) developed recurrent pulmonary embolism in spite of the insertion of a Greenfield filter in the inferior vena cava. Clinical and radiologic diagnostic tests failed to demonstrate the pathway of the emboli. Radionuclide venography and intravenous radionuclide total body arteriography were performed. These radionuclide procedures helped to evaluate the extent of KTS and to detect the route of the emboli. This is the first case of KTS studied with intravenous total body arteriography reported in the literature.

Triarylpyridylethanols and triarylpyridylethylenes. Chemistry and antifertility effects.

Triarylpyridylethanols were prepared by condensing the corresponding diaryl ketones and diarylmethanes. The ethylenes were obtained by the acid-catalyzed elimination of H2O from the ethanols. In the absence of electron-donating substituents, acid treatment of the carbinols resulted in predominant cleavage to starting ketone. The compounds were tested for their antifertility effects in pregnant hamsters. The most active compound was carbinol 3, which, at 30 mg/kg, prevented all of the treated animals from maintaining their pregnancies.