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Musse SL, Nielsen GB, Stege H, Weber NR, Houe H. Productivity parameters, antimicrobial consumption, and prevalence of enteric pathogens before and after intramuscular vaccination against Lawsonia intracellularis in naturally infected Danish weaner and finisher pig herds. Prev Vet Med 2023; 217:105973. [PMID: 37451064 DOI: 10.1016/j.prevetmed.2023.105973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/18/2023]
Abstract
In Danish pig production, gastro-intestinal diseases account for most of the antimicrobials (AM) used in growing pigs. Diarrhoea is most frequently caused by Lawsonia intracellularis (LI), Brachyspira pilosicoli (BP), E coli fimbria type F4 (F4) and E. coli fimbria type F18 (F18). With a new LI vaccine available from 2019, it was relevant to investigate the effect of this vaccine in a Danish field study including both weaner and finisher sites. The aim was to evaluate the efficacy of Porcilis® Lawsonia Vet. in naturally LI-infected pig herds by comparing of productivity parameters, AM consumption and dynamics of enteric pathogens over two 6-months periods before and after LI vaccination. Further, faecal sock samples were collected from each site before and after vaccination and analysed by qPCR for excretion levels of LI, BP, F18 and F4. In total, 28 weaner and 41 finisher sites were included in the study. Vaccination reduced Feed Conversion Ratio by 0.12 Feed Unit/kg (p = 0.029) and 0.08 Feed Unit/kg (p = 0.005) in weaners and finishers, respectively. Increased Average Daily Weight Gain of 45.6 gr./day (p < 0.001) was found in the finishers. Mortality risk fell by 8.8% in weaners (RR = 0.912; p < 0.001). AM prescriptions for oral group treatments were reduced by 38.8% active compound/kg pig produced (p = 0.005) or 33.3% Weighted Animal Daily Doses per 100 animals per day in finishers (p = 0.004). LI prevalence was reduced in weaners and finishers (both p < 0.001) and BP prevalence was reduced in finishers (p = 0.043). Mean excretion levels of LI and BP decreased at weaner sites (-1.32 and -1.02 log(10) copies/gr faeces, respectively; both p < 0.001) and at finisher sites (-1.04 and -1.16 log(10) copies/gr faeces, respectively; both p < 0.001). Prevalence and excretion levels of F18 and F4 were unaffected by LI vaccination. In conclusion, vaccination against LI using Porcilis® Lawsonia Vet. improved productivity parameters, cut AM consumption, and reduced prevalence and excretion levels of LI and BP in naturally LI-infected pig herds.
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Affiliation(s)
- Susanne Leth Musse
- MSD Animal Health Nordic, Havneholmen 25, DK - 1561 København V, Denmark; University of Copenhagen, Department of Veterinary and Animal Sciences, Section for Animal Welfare and Disease Control, Grønnegårdsvej 8, DK -1870 Frederiksberg C, Denmark.
| | | | - Helle Stege
- University of Copenhagen, Department of Veterinary and Animal Sciences, Section for Production, Nutrition and Health, Grønnegårdsvej 2, DK - 1870 Frederiksberg C, Denmark
| | - Nicolai Rosager Weber
- Danish Agriculture & Food Council, Axelborg, Axeltorv 3, DK - 1609 København V, Denmark
| | - Hans Houe
- University of Copenhagen, Department of Veterinary and Animal Sciences, Section for Animal Welfare and Disease Control, Grønnegårdsvej 8, DK -1870 Frederiksberg C, Denmark
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Veyna-Salazar NP, Cantó-Alarcón GJ, Olvera-Ramírez AM, Ruiz-López FJ, Bernal-Reynaga R, Bárcenas-Reyes I, Durán-Aguilar M. Occurrence of Giardia duodenalis in Cats from Queretaro and the Risk to Public Health. Animals (Basel) 2023; 13:ani13061098. [PMID: 36978639 PMCID: PMC10044519 DOI: 10.3390/ani13061098] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/17/2023] [Accepted: 03/18/2023] [Indexed: 03/22/2023] Open
Abstract
Giardia is a protozoan that affects humans as well as a wide range of domestic species. It is distributed worldwide, and the highest frequency is seen in developing countries. Due to the potential for domestic cats to be carriers of this parasite and subsequently transmit the infection to humans, it is important to know the risk of transmission. For this reason, the objective of this study was to determine the frequency of this parasite in the cat population of the city of Santiago de Queretaro, Mexico, and identify the assemblages present to determine the role this host plays in public health, this being the first study of its type to be performed in the country. This was a cross-sectional study during which 200 fecal samples were collected from cats of both sexes and varying ages and strata of origin. The samples were analyzed by microscopy following the flotation technique, having obtained a general frequency of 25%. Giardia cysts were found at higher frequency in pasty stools. The assemblages found were zoonotic, specifically assemblage A, which suggests that the cat poses an important risk for the dissemination of the parasite to humans, making it an important public health problem.
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Affiliation(s)
- Nerina P. Veyna-Salazar
- Doctorado en Ciencias Biológicas, Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Avenida de las Ciencias S/N Juriquilla, Delegación Santa Rosa Jáuregui, Querétaro 76230, Mexico
| | - Germinal J. Cantó-Alarcón
- Cuerpo Académico Mejoramiento Animal Integral, Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Avenida de las Ciencias S/N Juriquilla, Delegación Santa Rosa Jáuregui, Querétaro 76230, Mexico
| | - Andrea M. Olvera-Ramírez
- Cuerpo Académico Salud Animal y Microbiología Ambiental, Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Avenida de las Ciencias S/N Juriquilla, Delegación Santa Rosa Jauregui, Querétaro 76230, Mexico
| | - Felipe J. Ruiz-López
- Centro Nacional de Investigación en Fisiología y Mejoramiento Animal, INIFAP-SAGARPA, México. Km1. Carr. Ajuchitlán-Colón Ajuchitlán, Querétaro 76280, Mexico
| | - Rodolfo Bernal-Reynaga
- Cuerpo Académico de Salud Pública, Unidad de Investigaciones en Salud Pública “Dra. Kaethe Willms”, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Sinaloa, Ave. de las Américas y Blvd. Universitarios, Ciudad Universitaria, Culiacán 80100, Mexico
| | - Isabel Bárcenas-Reyes
- Cuerpo Académico Mejoramiento Animal Integral, Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Avenida de las Ciencias S/N Juriquilla, Delegación Santa Rosa Jáuregui, Querétaro 76230, Mexico
| | - Marina Durán-Aguilar
- Cuerpo Académico Mejoramiento Animal Integral, Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Avenida de las Ciencias S/N Juriquilla, Delegación Santa Rosa Jáuregui, Querétaro 76230, Mexico
- Correspondence: ; Tel.: +52-442-350-7485
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Musse SL, Nielsen GB, Stege H, Weber NR, Houe H. Prevalences and excretion levels of Lawsonia intracellularis, Brachyspira pilosicoli and Escherichia coli F4 and F18 in fecal sock samples from Danish weaner and finisher pig batches and the association with diarrhea. Porcine Health Manag 2022; 8:44. [PMID: 36307895 PMCID: PMC9617295 DOI: 10.1186/s40813-022-00290-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 10/14/2022] [Indexed: 11/20/2022] Open
Abstract
Background Bacterial enteritis in growing pigs is a matter of concern in Danish pig production challenging herd health as well as production economy, and antimicrobial usage. The aim of this observational study using fecal sock samples was to determine the prevalence and excretion level of Lawsonia intracellularis (LI), Brachyspira pilosicoli (BP), Escherichia coli F4 (F4) and F18 (F18) and to investigate associations between prevalence or excretion levels of the bacteria and diarrhea. The study was performed in the late weaner and the early finisher period in herds with a history of diarrhea. Every weaner and finisher herd contributed with one sample each. Results In total, 47 weaner and 59 finisher herds were sampled. The overall prevalence and excretion levels (median and range in log(10) copies/gram of feces) were for LI 84.0% (median 6.2; range 3.0–7.7), for BP 45.2% (median 5.6; range 3.0–6.6), for F18 20.8% (median 5.7; range 4.7–7.7), and for F4 4.7% (median 5.5; range 5.2–6.0). In both diarrheic and non-diarrheic samples, the most prevalent bacteria were either LI alone or LI and BP in combination. In general, no association was found between increasing total bacterial excretion levels and diarrhea, but prevalence (p = 0.04) and excretion (p < 0.01) level of F18 was found to be significantly higher in diarrheic samples. Further, a significant association was found between low LI excretion level and lack of diarrhea in weaner herds (p = 0.03). A significant positive correlation was found between excretion levels of LI and BP in diarrheic weaner herd samples (p = 0.02). Conclusion Enteric pathogens were prevalent in a wide range of bacterial excretion levels in both diarrheic and non-diarrheic samples. Especially LI and BP were frequently found and with a positive correlation between excretion levels. Even in the absence of diarrhea, high prevalence and excretion levels of LI and BP were detected, thus making the status of diarrhea an insufficient tool for assessing the severity of their infections.
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Affiliation(s)
- Susanne Leth Musse
- MSD Animal Health Nordics, Havneholmen 25, 1561, Copenhagen, Denmark. .,Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 8, 1870, Frederiksberg, Denmark.
| | | | - Helle Stege
- Section for Production, Nutrition and Health, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 2, 1870, Frederiksberg, Denmark
| | - Nicolai Rosager Weber
- Danish Agriculture and Food Council, Axelborg, Axeltorv 3, 1609, Copenhagen, Denmark
| | - Hans Houe
- Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 8, 1870, Frederiksberg, Denmark
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Ly A, Dhand NK, Sergeant ESG, Marsh I, Plain KM. Determining an optimal pool size for testing beef herds for Johne's disease in Australia. PLoS One 2019; 14:e0225524. [PMID: 31747440 PMCID: PMC6867630 DOI: 10.1371/journal.pone.0225524] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 11/06/2019] [Indexed: 12/21/2022] Open
Abstract
Bovine Johne's disease (JD) is a chronic debilitating disease affecting cattle breeds worldwide. Pooled faecal samples are routinely tested by culture to detect Mycobacterium avium subsp. paratuberculosis (Mptb) infection. More recently, a direct high throughput molecular test has been introduced in Australia for the detection of Mptb in faeces to circumvent the long culture times, however, the optimal pool size for beef cattle faeces is not known. This study aimed to determine the optimal pool size to achieve the highest test sensitivity and specificity for beef cattle. Individual archived faecal samples with low, medium and high quantities of Mptb (n = 30) were pooled with faecal samples from confirmed JD negative animals to create pool sizes of 5, 10, 15 and 20, to assess the diagnostic sensitivity relative to individual faecal qPCR. Samples from JD-free cattle (n = 10) were similarly evaluated for diagnostic specificity. Overall, 160 pools were created, with Mptb DNA extracted using magnetic bead isolation method prior to Mptb-specific IS900 quantitative PCR (qPCR). The pool size of 10 yielded the highest sensitivity 73% (95% CI: 54-88%), regardless of the quantity of Mptb DNA present in the faeces. There was no significant differences between the four different pool sizes for positive pool detection, however, there was statistical significance between low, medium and high quantities of Mptb. Diagnostic specificity was determined to be 100%. The increase in pool size greater than 10 increased the chances of PCR inhibition, which was successfully relieved with the process of DNA dilution. The results of this study demonstrate that the pool size of 10 performed optimally in the direct faecal qPCR. The results from this study can be applied in future simulation modelling studies to provide suggestions on the cost-effective testing for JD in beef cattle.
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Affiliation(s)
- Anna Ly
- Faculty of Science, Sydney School of Veterinary Science, The University of Sydney, Camden, NSW, Australia
| | - Navneet K. Dhand
- Faculty of Science, Sydney School of Veterinary Science, The University of Sydney, Camden, NSW, Australia
| | | | - Ian Marsh
- Elizabeth Macarthur Agricultural Institute, NSW Department of Primary Industries, Menangle, Australia
| | - Karren M. Plain
- Faculty of Science, Sydney School of Veterinary Science, The University of Sydney, Camden, NSW, Australia
- * E-mail:
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Papaiakovou M, Wright J, Pilotte N, Chooneea D, Schär F, Truscott JE, Dunn JC, Gardiner I, Walson JL, Williams SA, Littlewood DTJ. Pooling as a strategy for the timely diagnosis of soil-transmitted helminths in stool: value and reproducibility. Parasit Vectors 2019; 12:443. [PMID: 31522691 PMCID: PMC6745781 DOI: 10.1186/s13071-019-3693-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 08/30/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The strategy of pooling stool specimens has been extensively used in the field of parasitology in order to facilitate the screening of large numbers of samples whilst minimizing the prohibitive cost of single sample analysis. The aim of this study was to develop a standardized reproducible pooling protocol for stool samples, validated between two different laboratories, without jeopardizing the sensitivity of the quantitative polymerase chain reaction (qPCR) assays employed for the detection of soil-transmitted helminths (STHs). Two distinct experimental phases were recruited. First, the sensitivity and specificity of the established protocol was assessed by real-time PCR for each one of the STHs. Secondly, agreement and reproducibility of the protocol between the two different laboratories were tested. The need for multiple stool sampling to avoid false negative results was also assessed. Finally, a cost exercise was conducted which included labour cost in low- and high-wage settings, consumable cost, prevalence of a single STH species, and a simple distribution pattern of the positive samples in pools to estimate time and money savings suggested by the strategy. RESULTS The sensitivity of the pooling method was variable among the STH species but consistent between the two laboratories. Estimates of specificity indicate a 'pooling approach' can yield a low frequency of 'missed' infections. There were no significant differences regarding the execution of the protocol and the subsequent STH detection between the two laboratories, which suggests in most cases the protocol is reproducible by adequately trained staff. Finally, given the high degree of agreement, there appears to be little or no need for multiple sampling of either individuals or pools. CONCLUSIONS Our results suggest that the pooling protocol developed herein is a robust and efficient strategy for the detection of STHs in 'pools-of-five'. There is notable complexity of the pool preparation to ensure even distribution of helminth DNA throughout. Therefore, at a given setting, cost of labour among other logistical and epidemiological factors, is the more concerning and determining factor when choosing pooling strategies, rather than losing sensitivity and/or specificity of the molecular assay or the method.
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Affiliation(s)
- Marina Papaiakovou
- Department of Life Sciences, Natural History Museum, London, UK.
- Department of Biological Sciences, Smith College, Northampton, MA, USA.
| | - James Wright
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK
- The Hospital for Sick Children, Toronto, ON, Canada
| | - Nils Pilotte
- Department of Biological Sciences, Smith College, Northampton, MA, USA
- Molecular and Cellular Biology Programme, University of Massachusetts, Amherst, MA, USA
| | - Darren Chooneea
- Core Research Laboratories, Natural History Museum, London, UK
| | | | - James E Truscott
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK
| | - Julia C Dunn
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK
| | | | - Judd L Walson
- DeWorm3, Natural History Museum, London, UK
- Department of Global Health, University of Washington, Seattle, WA, USA
| | - Steven A Williams
- Department of Biological Sciences, Smith College, Northampton, MA, USA
- Molecular and Cellular Biology Programme, University of Massachusetts, Amherst, MA, USA
| | - D Timothy J Littlewood
- Department of Life Sciences, Natural History Museum, London, UK
- DeWorm3, Natural History Museum, London, UK
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Weber NR, Pedersen KS, Hansen CF, Denwood M, Hjulsager CK, Nielsen JP. Batch medication of intestinal infections in nursery pigs-A randomised clinical trial on the efficacy of treatment strategy, type of antibiotic and bacterial load on average daily weight gain. Prev Vet Med 2017; 137:69-76. [PMID: 28107883 DOI: 10.1016/j.prevetmed.2016.12.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 12/28/2016] [Accepted: 12/28/2016] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Previous research projects have demonstrated the need for better diagnostic tools to support decisions on medication strategies for infections caused by Escherichia coli F4 (F4) and F18 (F18), Lawsonia intracellularis (LI) and Brachyspira pilosicoli (PILO). This study was carried out as a randomised clinical trial in three Danish pig herds and included 1047 nursery pigs, distributed over 10 batches and 78 pens. The objectives of this study were: (1) to assess the effect of four 5-day treatment strategies (initiated at clinical outbreak of diarrhoea or at fixed time points 14, 21, or 28days after weaning) on average daily weight gain (ADG); (2) to compare the effect of treatment with doxycycline or tylosine on diarrhoea prevalence, pathogenic bacterial load, and ADG; (3) to evaluate PCR testing of faecal pen floor samples as a diagnostic tool for determining the optimal time of treatment. RESULTS (1) The four treatment strategies had a significant overall effect on ADG (p=0.01). Pigs starting treatment 14days after weaning had a significantly higher ADG (42 g) compared to pigs treated on day 28 (p=0.01). (2) When measured 2days after treatment, doxycycline treatment resulted in fewer LI-positive pens (p=0.004), lower excretion levels of LI (p=0.013), and fewer pens with a high level of LI (p=0.031) compared to pens treated with tylosine. There was no significant difference in F4, F18 and PILO levels after treatment with the two antibiotic compounds. There was a significant difference (p=0.04) of mean diarrhoea prevalence on day 21 of the study between pens treated with tylosine (0.254, 95% CI: 0.184-0.324), and doxycycline (0.167, 95% CI: 0.124-0.210). The type of antibiotic compound was not found to have a significant effect on ADG (p=0.209). (3) Pigs starting treatment on day 14 in pens where F4, F18, LI or PILO were detected by qPCR on the pen floor had a statistically significant increase in ADG (66g) compared to pigs treated on day 14 in pens where no enteric pathogens were detected (p=0.04). CONCLUSIONS The results of this study showed that the highest ADG was achieved when treatment was initiated 14days after weaning in pens where intestinal pathogens were detected. Doxycycline was more effective in reducing diarrhoea and LI excretion levels than treatment with tylosine.
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Affiliation(s)
- Nicolai Rosager Weber
- University of Copenhagen, Faculty of Health and Medical Sciences, Department of Large Animal Sciences, Grønnegårdsvej 2, 1870 Frederiksberg C, Denmark.
| | - Ken Steen Pedersen
- University of Copenhagen, Faculty of Health and Medical Sciences, Department of Large Animal Sciences, Grønnegårdsvej 2, 1870 Frederiksberg C, Denmark; Øvet A/S, Køberupvej 33, 4700 Næstved, Denmark.
| | - Christian Fink Hansen
- University of Copenhagen, Faculty of Health and Medical Sciences, Department of Large Animal Sciences, Grønnegårdsvej 2, 1870 Frederiksberg C, Denmark.
| | - Matthew Denwood
- University of Copenhagen, Faculty of Health and Medical Sciences, Department of Large Animal Sciences, Grønnegårdsvej 2, 1870 Frederiksberg C, Denmark.
| | | | - Jens Peter Nielsen
- University of Copenhagen, Faculty of Health and Medical Sciences, Department of Large Animal Sciences, Grønnegårdsvej 2, 1870 Frederiksberg C, Denmark.
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Why fly the extra mile? Using stress biomarkers to assess wintering habitat quality in migratory shorebirds. Oecologia 2016; 182:385-95. [DOI: 10.1007/s00442-016-3679-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 06/13/2016] [Indexed: 01/21/2023]
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Clasen J, Mellerup A, Olsen JE, Angen Ø, Folkesson A, Halasa T, Toft N, Birkegård AC. Determining the optimal number of individual samples to pool for quantification of average herd levels of antimicrobial resistance genes in Danish pig herds using high-throughput qPCR. Vet Microbiol 2016; 189:46-51. [DOI: 10.1016/j.vetmic.2016.04.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 04/19/2016] [Accepted: 04/21/2016] [Indexed: 01/17/2023]
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Larsen I, Nielsen SS, Olsen JE, Nielsen JP. The efficacy of oxytetracycline treatment at batch, pen and individual level on Lawsonia intracellularis infection in nursery pigs in a randomised clinical trial. Prev Vet Med 2016; 124:25-33. [DOI: 10.1016/j.prevetmed.2015.12.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 12/17/2015] [Accepted: 12/22/2015] [Indexed: 11/30/2022]
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Pedersen KS, Johansen M, Angen O, Jorsal SE, Nielsen JP, Jensen TK, Guedes R, Ståhl M, Bækbo P. Herd diagnosis of low pathogen diarrhoea in growing pigs - a pilot study. Ir Vet J 2014; 67:24. [PMID: 25392732 PMCID: PMC4228118 DOI: 10.1186/2046-0481-67-24] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 10/08/2014] [Indexed: 11/25/2022] Open
Abstract
Background The major indication for antibiotic use in Danish pigs is treatment of intestinal diseases post weaning. Clinical decisions on antibiotic batch medication are often based on inspection of diarrhoeic pools on the pen floor. In some of these treated diarrhoea outbreaks, intestinal pathogens can only be demonstrated in a small number of pigs within the treated group (low pathogen diarrhoea). Termination of antibiotic batch medication in herds suffering from such diarrhoea could potentially reduce the consumption of antibiotics in the pig industry. The objective of the present pilot study was to suggest criteria for herd diagnosis of low pathogen diarrhoea in growing pigs. Data previously collected from 20 Danish herds were used to create a case series of clinical diarrhoea outbreaks normally subjected to antibiotic treatment. In the present study, these diarrhoea outbreaks were classified as low pathogen (<15% of the pigs having bacterial intestinal disease) (n =5 outbreaks) or high pathogen (≥15% of the pigs having bacterial intestinal disease) (n =15 outbreaks). Based on the case series, different diagnostic procedures were explored, and criteria for herd diagnosis of low pathogen diarrhoea were suggested. The effect of sampling variation was explored by simulation. Results The diagnostic procedure with the highest combined herd-level sensitivity and specificity was qPCR testing of a pooled sample containing 20 randomly selected faecal samples. The criteria for a positive test result (high pathogen diarrhoea outbreak) were an average of 1.5 diarrhoeic faecal pools on the floor of each pen in the room under investigation and a pathogenic bacterial load ≥35,000 per gram in the faecal pool tested by qPCR. The bacterial load was the sum of Lawsonia intracellularis, Brachyspira pilosicoli and Escherichia coli F4 and F18 bacteria per gram faeces. The herd-diagnostic performance was (herd-level) diagnostic sensitivity =0.99, diagnostic specificity =0.80, positive predictive value =0.94 and negative predictive value =0.96. Conclusions The pilot study suggests criteria for herd diagnosis of low pathogen diarrhoea in growing pigs. The suggested criteria should now be evaluated, and the effect of terminating antibiotic batch medication in herds identified as suffering from low pathogen diarrhoea should be explored. Electronic supplementary material The online version of this article (doi:10.1186/2046-0481-67-24) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ken Steen Pedersen
- Pig Research Centre, Danish Agriculture & Food Council, Axelborg, Axeltorv 3, DK-1609 Copenhagen V, Denmark
| | - Markku Johansen
- Pig Research Centre, Danish Agriculture & Food Council, Axelborg, Axeltorv 3, DK-1609 Copenhagen V, Denmark
| | - Oystein Angen
- National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, 1790 Copenhagen V, Denmark
| | - Sven Erik Jorsal
- National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, 1790 Copenhagen V, Denmark
| | - Jens Peter Nielsen
- HERD - Centre for Herd-oriented Education, Research and Development, Department of Large Animal Sciences, University of Copenhagen, Groennegaardsvej 2, DK-1870 Frederiksberg C, Denmark
| | - Tim K Jensen
- National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, 1790 Copenhagen V, Denmark
| | - Roberto Guedes
- Department of Veterinary Clinics and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Belo Horizonte, MG 31.270-901 Brazil
| | - Marie Ståhl
- National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, 1790 Copenhagen V, Denmark
| | - Poul Bækbo
- Pig Research Centre, Danish Agriculture & Food Council, Axelborg, Axeltorv 3, DK-1609 Copenhagen V, Denmark
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