Issue No62
1Q2015 /
SWINE BIBLIOGRAPHICAL BULLETIN
/ Page 1 / 9F. Joisel
G. BallyCONTENTS
BACTERIOLOGY
Mycoplasma hyopneumoniae……………………………………………………………………………………………………….2
Clostridium perfringens & difficile...... 2
Escherichia coli...... 2
VIROLOGY
African Swine Fever...... 3
Porcine astrovirus (PAstV)...... 3
Porcine epidemic diarrhoea...... 4
Postweaningmultisystemicwasting syndrome(PMWS) –Circovirus...... 5
Porcinereproductive andrespiratory syndrome (PRRS)...... 6
Swine influenza...... 8
MISCELLANEOUS
Diagnosis...... 8
Immunity...... 8
Management...... 9
BACTERIOLOGY
Mycoplasma hyopneumoniae
Polmonite enzootica e lesioni al macello: studio preliminare sulla correlazione fra punteggio Madec, percentuale di tessuto polmonare colpito e perdita economica- Enzootic pneumonia and lung lesions at slaughter: preliminary study on the correlation between Madec score, percentage of lung tissue affected and economic loss
F. SALVINI, G. GUADAGNINI, F. PAOLETTI, M. BRESAOLA, F. OTTOLINI, M.V. GIBELLINI, C. MAZZONI, A. SCOLLO, A. AMORICO
Proceedings of the SIPAS’s Annual Meeting, 2015, pp. 107-119
The study was conducted on pigs slaughtered in Italy. At slaughter, lung lesions were assessed (percentage of lung damaged) and a Madec score attributed. Economic losses were also evaluated. The results confirmed a positive correlation between lung lesions, Madec score and economic losses.
Turn tocontents
Clostridium difficile
Clostridium perfringens and difficile: Proper diagnosis, prevention, and control
P. ARRUDA, K. SCHWARTZ, B. WILBERTS, D. MADSON
Proceedings of the AASV’s Annual Meeting, 2015, Seminar, n°7 pp. 11-13
The authors review the pathogenesis and the diagnostic aspects of some Clostridia spp. infections, namely C. perfringens type A, type C and C. difficile, which cause enteric disease in baby piglets and thus result in a decreased weight or even mortality. The diagnostic methods used to detect these pathogens arereviewed, mainly histopathology, ELISA targeting Toxin A and C and PCR. Commercial vaccines do exist for C. perfringens but not for C. difficile.
Turn tocontents
Escherichia coli
Urinary tract infections in sows
A.DE QUATREBARBES, T.C. YAN
Asian Pork Magazine, 2015, Volume76, no1, pp.70‑76
The purpose of this study, conducted in three Malaysian farms, was to investigate the prevalence of urinary tract infections in sows and determine the causative pathogens and potential impact on health and performances. Urine samples were collected from gestating sows and analysed for the presence of bacteria. The results showed a relatively high prevalence of E. coli and a correlation between infection and the number of stillborn piglets. Nitrite strips could easily be used in farms to detect bacterial infection, after which treatments could be implemented to avoid the development of urinary tract infections.
Turn to contents
VIROLOGY
African Swine Fever (ASF)
An Update on the Epidemiology and Pathology ofAfrican Swine Fever
J. M. SANCHEZ-VIZCAINO, L. MUR, J. C. GOMEZ-VILLAMANDOS, ET L. CARRASCO
Journal of Comparative Pathology, 2015, volume152, no1, pp.9‑21
In this paper, the authors review the information available on African Swine Fever (ASF) infection, in order to provide the reader with the elements needed for an early detection of the virus. Indeed, early detection is critical as no treatment or vaccine is available to control this disease. To achieve this, one has first to be aware of the routes of introduction of the virus, which spread in the African continent before being introduced into Europe via Georgia. Clinical signs of the different forms of the disease (peracute, acute, subacute and chronic), though varying and possibly limited to fever and some haemorrhagic lymph nodes, should be identified at the earliest, in order to control the spread of the disease, and differential diagnoses should be discarded. The diagnosis of ASFV infectioncan be confirmed by virological (virus isolation, haemadsorption tests, PCR and direct immunofluorescence) and serological (ELISA, immunoblotting test, immunoperoxidase test) detection.
Turn to contents
Porcine Astrovirus (PAstV)
Astrovirus as a possible cause of congenital tremor type AII in piglets?
A.-L. BLOMSTRÖM, C. LEY, M. JACOBSON
Acta Veterinaria Scandinavica, 2014, Volume56, no1, pp.82
The purpose of this study, conducted in a Swedish organic farm where piglets showed signs of congenital tremor, was to determine the presence of astrovirus (AstV) and PCV2 and correlate them with brain lesions and clinical signs. The study was conducted on 6 piglets (among which 3 were used as controls) that were euthanised for brain tissue examination and analyses (DNA and RNA extraction, nested pan-AstV PCR, sequencing). The brains of piglets presenting signs of congenital tremors showed mild to moderate vacuolar changes in the white matter. The analyses conducted confirmed the presence of AstV in all piglets (including controls) and of PCV2 in one control and one diseased piglet. These findings therefore cannot confirm therole of PCV2 or AstV alone in the occurrence of congenital tremor in piglets.
Turn tocontents
Porcine epidemic diarrhoea
Previous infection of sows with a “mild” strain of PED virus confers protection against infection with a “severe” strain
D. GOEDE, C. DVORAK, M. MURTAUGH, J. NEREM, P. YESKE, K. ROSSOW, R.B. MORRISON
Proceedings of the AASV’s Annual Meeting, 2015, pp. 55-58
The purpose of this study, conducted in two sow farms, was to investigate the cross-protective immune efficacy of mild strains of PEDV against severe PEDV strains and the duration of the immunity they confer, if any. Sows from the first farm had experienced a previous infection with PEDV, while sows from the second farm had not. Sows and their piglets were challenged with a virulent PEDV strain. Colostrum and milk samples were collected, as well as sow and piglet faeces, and tested for PEDV. Small intestine samples from euthanised piglets were examined by means of an IHC. The results confirmed the protective effect of a previous PEDV infection, up to 7 months after exposure. A reduced morbidity, mortality and faecal shedding could be observed in challenged animals.
Turn to contents
Review of porcine epidemic diarrhea virus exposure techniques
M.B. TURNER
Proceedings of the AASV’s Annual Meeting, 2015, pp. 417-420
The author here reports the results of a survey given to US veterinarians in order to get a better idea of how they were handling PEDV infection, and which methods they used to eliminate the infection from the herds. The results are based on 44 surveys completed, representing a total of 702 breeding herds.
Turn to contents
PED: Dealing with endemic herds
L. DUFRESNE
Proceedings of the AASV’s Annual Meeting, 2015, pp. 425-427
The author here provides tips to control PEDV infection in a herd, in order to avoid that it becomes chronic or, if this is the case, to improve immunity in the herd, reduce infection pressure, particularly in the farrowing unit, and implement strict cleaning and disinfection strategies. Exposing gilts to PEDV can also ensure the herd will remain stable and piglets will not get infected.
Turn to contents
Use of oral fluids in PEDV surveillance
M. ROTOLO, L. GIMENEZ-LIROLA, S. ABATE, M. HOOGLAND, C. WANG, D. BAUM, P. GAUGER, K. HARMON, R. MAIN, A. RAMIREZ, J. ZIMMERMAN
Proceedings of the AASV’s Annual Meeting, 2015, pp. 15-2
The authors here show the results of oral fluid sampling analyses conducted at the Iowa State University Veterinary Diagnostic Laboratory, which confirm the efficacy of such method for the detection and surveillance of PEDV circulation in swine herds.
Turn tocontents
PMWS-Circovirus
Phylogenetic analysis of 32 porcine circovirus type 2 isolates from Shandong, China
J. SHI, S. XU, F. FU, X. CONG, X. YUAN, Z. PENG, J. WU, W. SUN, Y. DU, J. LI, B. HUANG, ET J. WANG
Archives of Virology, 2014, volume160, no2, pp.465‑468
The authors conducted a phylogenetic analysis on 32 PCV2 isolates collected from Chinese pigs, from the Shandong Province, between 2005 and 2013. This study showed that the PCV2b/1C lineage was the most frequently detected in this region, and that it is genetically distant from the vaccine strains currently in use in this country.
Turn to contents
Influence of porcine circovirus type 2 vaccination on the probability and severity of pneumonia detected postmortem
J. RAITH, S. KUCHLING, C. SCHLEICHER, H. SCHOBESBERGER, ET J. KÖFER
Veterinary Record, 2015, Volume176, Issue5, pp.124‑124
The objective of the study was to determine whether PCV2 vaccination had an impact on lung health in pigs. To do so, the authors reviewed the recorded post-mortem findings of 247,505 Austrian fattening pigs. The authors compared PCV2 vaccination with pneumonia findings at slaughter (classified as mild, moderate or severe). This review showed that PCV2 vaccination had a positive impact on post-mortem pneumonia findings and pneumonia severity at slaughter, particularly in fattening farms (as compared to farrow-to-finish farms).
Turn to contents
Prevalence of porcine circovirus-2 DNA-positive ovarian and uterine tissues in gilts culled due to reproductive disturbance in Thailand
P. PEARODWONG, S. SRISUWATANASAGUL, K. TEANKUM, R. TANTILERTCHAROEN, P. TUMMARUK
Tropical Animal Health and Production, 2015, Volume 47, pp. 833-840
The objective of the study was to determine the prevalence of PCV2 DNA in 70 ovarian and 102 uterine tissue samples collected from 102 gilts from 4 swine herds, culled because of reproductive problems. Analyses were conducted to detect PCV2 and the reasons for culling and age at culling were also recorded. The results showed that PCV2 was more frequently detected in ovarian and uterine tissues of gilts culled due to abortion, abnormal vaginal discharge or anoestrus, than in tissues from gilts that did not suffer from reproductive problems. The age did not seem to have any impact on PCV2 detection.
Turn to contents
Vaccination of sows with CIRCOVAC® and piglet PCV2 vaccination gives a better chance of controlling PCV2 circulation in the pig flow
F. JOISEL, E. BORDIN, P.A. MARTINEZ, A.C. IANNI, O. MERDY, C. CHARREYRE
Proceedings of the AASV’s Annual Meeting, 2015, pp. 209-214
The authors here report the results of two studies conducted in two Brazilian farms, with the aim of assessing PCV2 vaccination. The experimental design was as follows:
-Study 1: sows vaccinated or not with CIRCOVAC®, before farrowing, and piglets vaccinated with a sub-unit vaccine.
-Study 2: sows vaccinated with CIRCOVAC® (for 4 years before the study started), piglets vaccinated with CIRCOVAC® at 3 weeks of age or at 6.5 weeks of age, or left unvaccinated.
Several variables were recorded, such as live born and weaned piglets, weight and mortality. The presence of PCV2 was also assessed. The results confirmed the very positive effect of CIRCOVAC® vaccination, with an improvement of performances (higher number of weaned piglets, better weight gain, both at weaning and at slaughter, reduced mortality, reduction of PCV2 circulation).
Turn to contents
PCV2: Tools to assess the subclinical impact
K. SCHWARTZ
Proceedings of the AASV’s Annual Meeting, 2015, pp. 487-491
The author suggests some methods to measure the subclinical impact of PCV2 vaccination, focussing on the importance of considering the context, the animals themselves (via clinical observations), adapting to the particular situation of the herd involved.
Turn to contents
Impact dela vaccination des porcelets vis-à-vis du PCV2 sur les performances des porcs en croissance dans un contexte d’infection subclinique
I. CORREGE, G. PERREUL, B. BOIVENT, O. MERDY, T. VILA, A. HEMONIC
Journées de Recherche Porcine, 2015, Volume 47,pp. 265-270
The objective of the study was to investigate the impact of piglet PCV2vaccination (CIRCOVAC®), in a herd where sows were vaccinated and where pig growth performance were already high despite subclinical PCV2 infection. A total of 168 piglets, born to vaccinated sows, were included in the study and assigned to two groups (vaccinated or not). FCR, average daily weight gain and weight at slaughter were recorded. The results showed a significant improvement in the FCR in vaccinated pigs. This suggests that the use of both sow and piglet vaccination, even in the absence of actual PCV2clinical signs,help to optimise the technical and economical results of the herd.
Turn tocontents
Porcine reproductive and respiratory syndrome (PRRS)
Temporal and spatial dynamics of porcine reproductive and respiratory syndrome virus infection in the United States
S.J.P. TOUSIGNANT, A.M. PEREZ, J.F. LOWE, P.E. YESKE, R.B. MORRISON
American Journal of Veterinary Research, 2015, Volume76, no1, pp.70‑76
The objective of this study, conducted on 371 sow herds in the US during a 4-year period, was to determine the temporal and spatial dynamics of PRRSV infection. New infections, along with their characteristics (time of the year, area) were recorded for each herd. The findings confirmed the repeatability of PRRSV infections at the temporal and spatial levels. The PRRSV infection pattern is therefore very similar each year, which supports the need for PRRSV control or elimination at the regional level.
Turn tocontents
Diagnosis of the Lelystad strain of Porcine reproductive and respiratory syndrome virus infection in individually housed pigs: comparison between serum and oral fluid samples for viral nucleic acid and antibody detection
I. DECORTE, W. V. CAMPE, L. MOSTIN, A. B. CAY, ET N. D. REGGE
Journal of Veterinary Diagnostic Investigation, 2015, volume27, no1, pp.47‑54.
The objective of the study as to investigate the efficacy of oral fluid sampling vs. serum sampling, for the detection of PRRSV via ELISAs and qRT-PCR, over a 6-week period following infection. The study was conducted on a total of 16 individually housed piglets, aged about 8 weeks, which were assigned to two groups (challenge/control). Pigs in the challenge group were infected with Lelystad virus, the type 1 prototype PRRSV strain, while pigs in the second group were kept as controls. Oral fluid and serum sampling were done on a regular basis throughout the study and up to 42 days after infection. Samples were analysed by ELISA and qRT-PCR for PRRSV. The results showed a good agreement between oral fluid and serum sampling at every time point during the study, when analysed via ELISA, confirming the efficacy of oral fluid sampling in the detection of PRRSV. The results showed a variation of the detection rates of PRRSV depending on the moment the analyses were conducted after infection.
Turn to contents
Variation of porcine reproductive and respiratory syndrome virus open reading frame 5 diagnostic sequencing
A.M. STRICKER, D.D. POLSON, M.P. MURTAUGH, J. CHRISTOPHER-HENNINGS
Journal of Swine Health and Production, 2015, Volume23, Issue 1, pp.18-27
The objective of this study was to investigate the variation of the PRRSV ORF5 sequencing. In this regard, PRRSV-positive blood samples were sent off to three diagnostic laboratories, at three different occasions, for analysis. The results did not show any significant variation in this sequencing process, the median variation being one base difference (0.2%), which suggests a correct reliability of the process within and among laboratories.
Turn to contents
PRSS diagnostic trends: What changed with PRRS behavior?
A. ROVIRA
Proceedings of the AASV’s Annual Meeting, 2015, pp. 509-511
In this paper, the authors try to explain the yearly variations of PRRSV infection and the reduced severity of the PRRSV outbreak observed in the US in the 2013-2014 winter period. One possible explanation could be the onset of PEDV infection in that country in 2013, which resulted in a strengthening of biosecurity measures and herd closures, which possibly also helped controlling PRRSV infection. Also, vaccination may have helped in reducing the occurrence of PRRSV infection by improving the immune status of US herds. Lastly, the weather during that winter, particularly cold, may have limited PRRSV transmission.
Turn to contents
Infections précoces par le virus du SDRP: importance des anticorps maternels – EarlyPRRS virus infections: importance of maternally derived antibodies
M. ANDRAUD, S. MAHE, F. EONO, P. RENSON, O. BOURRY, N. ROSE
Journées de Recherche Porcine, 2015, Volume 47,pp. 301-302
The authors here report the development of a mathematical model used to determine the protection conferred by maternally-derived antibodies against PRRSV infection in piglets. This method was based on the definition of 3 serological status (passively immune, fully susceptible or infected), on transitions between these statuses and on infection pressure. The use of this method allowed the authors to confirm the importance of maternally-derived antibodies for newborn piglets, until they lose this passive immunity.
Turn to contents
Swine influenza
Influenza A viruses in swine: diversity, diagnostics and interpretation
P.C. GAUGER, A.L. VINCENT, K.M. HARMON, J. ZHANG
Proceedings of the AASV’s Annual Meeting, 2015, pp. 493-501
The authors here review the wide range of influenza A viruses currently circulating in the United States and the role of the USDepartment of Agriculture IAV surveillance programme in the detection of possible new variants and in the understanding of the IAV infection. Detection and diagnostic methods (ante- or post-mortem) are also reviewed.
Turn to contents
MISCELLANEOUS
Does the presence of shoulder ulcers affect the behaviour of sows?
T. LARSEN, M. KAISER, ET M. S. HERSKIN
Research in Veterinary Science, 2015, volume98, pp.19‑24
The authors investigated the impact of shoulder ulcers in lactating sows on their behaviour, by monitoring 38 sows, assigned to an “ulcer” group and a control group (no lesions). Sows were monitored via an infrared video camera during 24 hours and assessed for the time spent lying, standing still, nursing, walking, being active, etc. The observations made showed that sows presenting shoulder ulcers tended to change posture more often, spent less time lying and nursing and more time standing still and rubbing their shoulders. These findings showed shoulder ulcers could have a negative impact on their nursing behaviours, due to the pain or discomfort felt.
Turn to contents
Polar versus non-polar mycotoxins
K. NAEHRER
Pig International, January/February 2015, pp. 28-30
The great diversity of mycotoxins, making them show diverse structures and properties, makes it difficult to counteract their negative effects on the animals. In this paper, the authors describes how mycotoxins can usually be classified, i.e. as polar or non-polar molecules, depending on whether or not they possess electrical poles. This feature makes them water or fat soluble and therefore has an impact on the way they can be eliminated. Usually, mycotoxin binders (adsorbent materials) are used to treat mycotoxin infection, but they may not be efficient against all types of mycotoxins, for which biotransformation (use of enzymes or microorganisms to convert mycotoxins into less toxic molecules) can be used.
Turn to contents
Diagnosis
Collection of oral fluid from individually housed sows
B. PEPIN, F. LIU, R. MAIN, A. RAMIREZ, J. ZIMMERMAN
Journal of Swine Health and Production, 2015, Volume23, Issue 1, pp.35-37
The objectives of the study were to investigate the efficacy of oral fluid sampling depending on sow parity and training effect, as well as the repeatability of the diagnosis obtained with this method. The study was conducted in two farms in which cotton ropes were placed so that sows could chew them. This was done on two consecutive days. Sow parity was recorded and analyses conducted on the samples collected (PRRSV detection), to assess repeatability. The results showed that oral fluid sampling worked better with younger sows. However, a “training” effect was observed in all sows (irrespective of their age) as they got used to interact with the rope after repeated exposure. Diagnostic repeatability was also confirmed in this study.