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Fredericks J, Hill DE, Zarlenga DS, Fournet VM, Hawkins-Cooper DS, Urban JF, Kramer M. *Inactivation of encysted muscle larvae of Trichinella spiralis in pigs using Mebendazole. Vet Parasitol 2024; 327:110140. [PMID: 38330532 DOI: 10.1016/j.vetpar.2024.110140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/19/2024] [Accepted: 01/23/2024] [Indexed: 02/10/2024]
Abstract
We evaluated the effect of 4 anthelmintic treatments on the viability of Trichinella spiralis encysted muscle larvae (ML) 55 days post infection (PI) in experimentally infected pigs. Muscle larvae were isolated from pig muscle by artificial digestion after oral treatment of pigs with Levamisole (8 mg/kg, daily for 5 days) and Mebendazole (50 mg/kg, daily for 5 days); Doramectin (0.3 mg/kg, single IM injection), and Moxidectin (0.5 mg/kg, single pour on). Isolated larvae from treated pigs were orally inoculated into mice to assess viability of ML from each treatment. Only Mebendazole treatment of pigs significantly reduced ML viability in mice. The effect of timing of the effective Mebendazole treatment on ML from a longer term infection was then examined in a second experiment. Analysis revealed that Mebendazole treatment of pigs with 250 mg/kg over 3 days (83 mg/kg/day) or 5 days (50 mg/kg/day) reduced numbers of ML recovered from pig tissues compared to untreated, infected controls, and rendered ML non-infective to mice; Mebendazole treatment of pigs with 250 mg/kg in a single dose was not effective in reducing ML numbers recovered from pigs or in impacting ML infectivity to mice. An examination of the lowest effective dose of Mebendazole on encysted ML was determined in a third experiment. Mebendazole of pigs with 5, 50, or 100 mg/kg over 3 days demonstrated that 5 or 50 mg/kg over 3 days insufficient to reduce infectivity in recovered ML, while 100 mg/kg (and 83 g from experiment 2) over 3 days significantly reduces infectivity of ML. This procedure provides a means to evaluate the efficacy of various anthelmintic treatments on the viability of Trichinella spiralis ML in pig tissues, and identified Mebendazole, at 83-100 mg/kg administered over a 3-5 day period as an anthelmintic which renders encysted Trichinella spiralis ML from pig tissues non-infective. As risk from Trichinella significantly impacts acceptance of pork from pasture-raised pigs, these data provide a method, especially for producers of these high-risk pigs, to eliminate the potential of Trichinella transmission from infected pork.
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Affiliation(s)
- Jorrell Fredericks
- USDA, ARS, Northeast Area, Animal Parasitic Diseases Laboratory, BARC-East, Beltsville, MD 20705 USA.
| | - Dolores E Hill
- USDA, ARS, Northeast Area, Animal Parasitic Diseases Laboratory, BARC-East, Beltsville, MD 20705 USA
| | - Dante S Zarlenga
- USDA, ARS, Northeast Area, Animal Parasitic Diseases Laboratory, BARC-East, Beltsville, MD 20705 USA
| | - Valsin M Fournet
- USDA, ARS, Northeast Area, Animal Parasitic Diseases Laboratory, BARC-East, Beltsville, MD 20705 USA
| | - Diane S Hawkins-Cooper
- USDA, ARS, Northeast Area, Animal Parasitic Diseases Laboratory, BARC-East, Beltsville, MD 20705 USA
| | - Joseph F Urban
- USDA, ARS, Beltsville Human Nutrition Center, Diet, Genomics, and Immunology Laboratory, BARC-East, Beltsville, MD 20705 USA
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Seroprevalence of Taenia solium and Trichinella spiralis among Humans and Pigs in Ghana. BIOMED RESEARCH INTERNATIONAL 2021; 2021:1031965. [PMID: 34660777 PMCID: PMC8519675 DOI: 10.1155/2021/1031965] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 08/25/2021] [Indexed: 11/30/2022]
Abstract
In this study, the seroprevalence of the intestinal worms Taenia solium and Trichinella spiralis in humans and pigs was assessed. A cross-sectional serological study design was performed. Blood samples were collected from 322 humans and 245 pigs used in the study. These were tested for markers of antibodies for Taenia solium and Trichinella spp. Demographic data such as sex, age, education, pig farming practices, and water source used were also obtained. An overall seroprevalence of 3.1% was recorded for Taenia solium in humans. There was also a statistical association between pig management system employed by pig farmers and seropositivity to Taenia solium (p = 0.005). Factors such as mode of waste disposal (p = 0.003) and water source used statistically correlated with Taenia solium seroprevalence among humans. For the pig samples, a Taenia solium seroprevalence of 24.9% was recorded. All the pig samples which tested positive for Taenia solium were reared on the free-ranged system. This study also recorded a seroprevalence of 0.31% for Trichinella spp. for humans and a seroprevalence of 4.5% for Trichinella spp. for pigs. Again, all the samples that showed serological evidence of Trichinella spp. among pigs came from those pigs which were raised on the free-ranged system. Proper pig management practice is a very important tool for controlling these intestinal parasites in both humans and animals. This study recommends public health education among the general public and good pig farming practices.
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Hu D, Cheng TY, Morris P, Zimmerman J, Wang C. Active regional surveillance for early detection of exotic/emerging pathogens of swine: A comparison of statistical methods for farm selection. Prev Vet Med 2020; 187:105233. [PMID: 33373958 DOI: 10.1016/j.prevetmed.2020.105233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 09/28/2020] [Accepted: 12/08/2020] [Indexed: 11/19/2022]
Abstract
In this study, five spatially balanced sampling methods, i.e., generalized random-tessellation stratified (GRTS), local pivotal method (LPM), spatially correlated Poisson sampling (SCPS), local cube method (LCUBE), and balanced acceptance sampling (BAS) were compared to simple random sampling (SRS) based on a livestock disease transmission model on a hypothetical region (195 km × 300 km) populated with 6000 farms in terms of the probability of detection by sample size. Given a fixed sample size, four of the five spatially balanced sampling methods provided better performance than SRS, i.e., higher probabilities of detecting at least one infected farms over a range of regional prevalence evaluated (1%-5%). That is, for any given probability of detection, spatially balanced methods required testing fewer farms than SRS. In an era of pandemics, active regional surveillance for early detection of emerging pathogens becomes urgent, yet shrinking budgets impose intractable constraints. The better performance and higher efficiency of spatially balanced sampling methods suggests a potential improvement in regional livestock disease surveillances and a partial solution to the challenge of affordable surveillance.
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Affiliation(s)
- Dapeng Hu
- Department of Statistics, College of Liberal Arts and Sciences, Iowa State University, Ames, IA, United States
| | - Ting-Yu Cheng
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Paul Morris
- Department of Statistics, College of Liberal Arts and Sciences, Iowa State University, Ames, IA, United States
| | - Jeffrey Zimmerman
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Chong Wang
- Department of Statistics, College of Liberal Arts and Sciences, Iowa State University, Ames, IA, United States; Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States.
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Alban L, Petersen JV. Ensuring a negligible risk of Trichinella in pig farming from a control perspective. Vet Parasitol 2016; 231:137-144. [DOI: 10.1016/j.vetpar.2016.07.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Revised: 07/06/2016] [Accepted: 07/09/2016] [Indexed: 11/24/2022]
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General Principles for the welfare of animals in production systems: The underlying science and its application. Vet J 2013; 198:19-27. [DOI: 10.1016/j.tvjl.2013.06.028] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 06/24/2013] [Accepted: 06/28/2013] [Indexed: 11/23/2022]
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Baer AA, Miller MJ, Dilger AC. Pathogens of Interest to the Pork Industry: A Review of Research on Interventions to Assure Food Safety. Compr Rev Food Sci Food Saf 2013. [DOI: 10.1111/1541-4337.12001] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Arica A. Baer
- Dept. of Animal Science, Univ. of Illinois Urbana-Champaign; 1503 S
| | - Michael J. Miller
- Dept. of Food Science and Human Nutrition; Div. of Nutritional Sciences; 905 S.; Goodwin Ave.; Urbana; IL 61801; U.S.A
| | - Anna C. Dilger
- Dept. of Animal Science, Univ. of Illinois Urbana-Champaign; 1503 S
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Takumi K, Franssen F, Fonville M, Grasset A, Vallée I, Boireau P, Teunis P, van der Giessen J. Within-host dynamics of Trichinella spiralis predict persistent parasite transmission in rat populations. Int J Parasitol 2010; 40:1317-24. [DOI: 10.1016/j.ijpara.2010.03.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 03/25/2010] [Accepted: 03/25/2010] [Indexed: 11/15/2022]
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Evaluation of fermentation, drying, and/or high pressure processing on viability of Listeria monocytogenes, Escherichia coli O157:H7, Salmonella spp., and Trichinella spiralis in raw pork and Genoa salami. Int J Food Microbiol 2010; 140:61-75. [DOI: 10.1016/j.ijfoodmicro.2010.02.008] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 02/03/2010] [Accepted: 02/09/2010] [Indexed: 11/21/2022]
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Richardson EKB, Cogger N, Pomroy WE, Potter MA, Morris RS. Quantitative risk assessment for the annual risk of exposure to Trichinella spiralis in imported chilled pork meat from New Zealand to Singapore. N Z Vet J 2009; 57:269-77. [PMID: 19802040 DOI: 10.1080/00480169.2009.58620] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AIMS To determine the annual likelihood of exposure to an infectious dose of Trichinella spiralis from consuming imported pork meat from New Zealand to Singapore. METHODS Input values specific for chilled pork meat imported into Singapore from New Zealand were used in a quantitative risk-assessment model. The model, designed to allow any combination of importing and exporting countries, was divided into two components, viz the release assessment, and the exposure assessment that assessed the annual risk of exposure to the consumer (ARC). The former estimated the likelihood that a contaminated fresh meat product from New Zealand would arrive at Singapore's border, and took into consideration the prevalence of disease on different types of farms. The latter determined the likelihood over a year that a person in Singapore would consume one or more servings of imported fresh meat from New Zealand that contained a burden of greater than or equal to one larva(e) of T. spiralis per gram after preparation for consumption. RESULTS The ARC for offal was 2.41 x 10(-7), which was below the pre-selected safety threshold of 1.00 x 10(-6). The ARC for lean meat was 2.39 x 10(-5), which was above the acceptable safety threshold. CONCLUSIONS The study demonstrated that continued routine testing at slaughter is unnecessary for pig offal produced commercially, and provided a model with which to further assess management of the risk of exposure to T. spiralis in lean meat. CLINICAL RELEVANCE The potential of Trichinella species to cause disease in humans is a public health concern, and has created adverse effects on the international trade of fresh lean meat without regard to the surveillance measures employed by particular pork-producing countries.
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Affiliation(s)
- E K B Richardson
- Epicentre, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand.
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Akkoc N, Kuruuzum Z, Akar S, Yuce A, Onen F, Yapar N, Ozgenc O, Turk M, Ozdemir D, Avci M, Guruz Y, Oral AM, Pozio E. A large-scale outbreak of trichinellosis caused by Trichinella britovi in Turkey. Zoonoses Public Health 2008; 56:65-70. [PMID: 18705658 DOI: 10.1111/j.1863-2378.2008.01158.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
An outbreak of trichinellosis occurred in Izmir, Turkey, between January and March 2004. The outbreak was caused by the consumption of raw meat balls made of beef deceptively mixed with pork infected with Trichinella britovi. A total of 1098 people who had consumed this food either in 14 restaurants or from the street vendors located in three different neighbourhoods, consulted six different healthcare centres with a wide range of clinical signs and symptoms. Of them, 418 (38.1%) patients fulfilled the criteria for the diagnosis of acute trichinellosis. The most commonly observed signs and symptoms were myalgia (89.2%), arthralgia (69.9%) and eyelid (67%) and facial oedema (65.8%). High levels of creatinine kinase (69.3%) and lactate dehydrogenase (93.8%) with leucocytosis (>10 000/mm(3), 58.9%) and eosinophilia (>1000/mm(3), 60.5%) were the most prominent laboratory findings. All, but 13 of these patients were treated with mebendazole or albendazole. Based on the physicians' assessments of disease severity, 78 (19%) patients were additionally given prednisolone in whom a significantly more rapid recovery of clinical signs and symptoms (e.g. fever, myalgia, facial and eyelid oedema) was observed, with a rapid improvement in leucocytosis, eosinophilia and muscle enzymes, compared with those, who had not received corticosteroids (P < 0.05). Beef illegally mixed with pork of unknown origin, by a wholesale butcher who had sold this product to restaurants and street vendors at a lower price than the prevailing market price of beef, was the cause of this large-scale outbreak in a country with a predominantly Muslim population.
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Affiliation(s)
- N Akkoc
- Department of Internal Medicine, Division of Rheumatology, Dokuz Eylul University School of Medicine, Izmir, Turkey
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Towards a risk-based surveillance for Trichinella spp. in Danish pig production. Prev Vet Med 2008; 87:340-57. [PMID: 18649961 DOI: 10.1016/j.prevetmed.2008.05.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Revised: 05/16/2008] [Accepted: 05/27/2008] [Indexed: 11/24/2022]
Abstract
Increasing demands for cost-effectiveness in surveillance for human health hazards from animal origins can be met by introducing risk-based principles. This e.g. implies targeting subpopulations with higher risk of infection compared to the whole population. Furthermore, historical data from surveillance can be collated and used to assess future risk of infection. To demonstrate the effectiveness of combining these two approaches, we used a model called "Discounting historical evidence". It depends mainly on the annual risk of introduction (PIntro) and the surveillance system sensitivity (SSe) (ability to detect infection if present). The model implies simulations that reiterate for a number of years. For each year the output is updated with the confidence on absence in infection. Trichinella spiralis infection in pigs is used as an example. In Denmark, more than 20 million pigs are tested annually. Despite more than 70 years of testing no pigs have been found positive for Trichinella. Hence, PIntro is low. SSe can be estimated from the maximum number of infected carcasses expected under the specified design prevalence, and the sensitivity of the test applied. According to our assessment, the current prevalence of Trichinella in Danish pigs is less than one case per million, which we interpret as negligible risk. Based on this, a risk-based surveillance programme for Trichinella is designed that targets all out-door reared pigs as well as all sows and boars (current total 610,000 slaughtered annually). These subpopulations are judged to have higher risk of getting Trichinella. Again, SSe and PIntro are estimated and the model results show that risk-based surveillance can be applied without jeopardizing human health. Finally, we incorporate wildlife surveys and test quality assurance in the programme. The results of the simulation model were included in an application to the European Commission concerning Denmark's status as a region with negligible risk of Trichinella. In July 2007, the European Commission granted status as "negligible risk" to Danish pigs and pork.
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Gebreyes WA, Bahnson PB, Funk JA, McKean J, Patchanee P. Seroprevalence of Trichinella, Toxoplasma, and Salmonella in Antimicrobial-Free and Conventional Swine Production Systems. Foodborne Pathog Dis 2008; 5:199-203. [DOI: 10.1089/fpd.2007.0071] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Wondwossen A. Gebreyes
- College of Veterinary Medicine, Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, Ohio
| | - Peter B. Bahnson
- School of Veterinary Medicine, Department of Medical Sciences, University of Wisconsin—Madison, Madison, Wisconsin
| | - Julie A. Funk
- College of Veterinary Medicine, Department of Clinical Sciences, Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, Iowa
| | - James McKean
- College of Veterinary Medicine, Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, Iowa
| | - Prapas Patchanee
- College of Veterinary Medicine, Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, Ohio
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Hill DE, Benedetto SMC, Coss C, McCrary JL, Fournet VM, Dubey JP. Effects of time and temperature on the viability of Toxoplasma gondii tissue cysts in enhanced pork loin. J Food Prot 2006; 69:1961-5. [PMID: 16924924 DOI: 10.4315/0362-028x-69.8.1961] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Enhanced or pumped pork products represent a significant proportion (40 to 50%) of the commercially available pork cuts available to consumers at the retail level. In a previous study, pork loins containing viable Toxoplasma gondii tissue cysts were pumped with solutions containing 2% sodium chloride or 1.4% or higher potassium or sodium lactate and stored at 4 degrees C for 7 days. This treatment prevented transmission of T. gondii to cats. In the present study, enhanced pork loins were stored for 0, 8, 16, 24, 32, or 40 h at 4 degrees C and then fed to T. gondii-seronegative cats to determine how quickly the loss of tissue cyst viability occurred. In a second experiment, pork loins collected from pigs experimentally infected with T. gondii were stored at temperatures found in retail meat cases and then fed to T. gondii-seronegative cats to determine the effect of typical meat case storage temperatures on tissue cyst viability. In both experiments, cat feces were examined for 14 days after the infected meat meal to assess oocyst shedding. The results indicate that solutions containing 2% sodium chloride or 1.4% potassium or sodium lactate are effective within 8 h of injection for killing T. gondii tissue cysts in pork loins and that storage at meat case temperatures at or below 0 degrees C (32 degrees F) for 7 days also killed T. gondii tissue cysts in pork loins.
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Affiliation(s)
- D E Hill
- U.S. Department of Agriculture, Agricultural Research Service, Animal and Natural Resources Institute, Animal Parasitic Diseases Laboratory, BARC-East, Beltsville, Maryland 20705, USA.
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Pozio E, Zarlenga DS. Recent advances on the taxonomy, systematics and epidemiology of Trichinella. Int J Parasitol 2006; 35:1191-204. [PMID: 16153648 DOI: 10.1016/j.ijpara.2005.07.012] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Revised: 06/22/2005] [Accepted: 07/15/2005] [Indexed: 11/18/2022]
Abstract
Since Owen first described Trichinella as a human pathogen in 1835, the number of organisms comprising this genus has grown dramatically. Where it was once thought to be a monospecific group, this genus is now comprised of eight species and three additional genotypic variants that have yet to be taxonomically defined. Along with the growth in the genus and description of the parasites has come a concomitant increase in our understanding of the epidemiology and geographical distribution of these organisms. Recent expansion of the non-encapsulated group to include three species biologically defined by their unique host ranges encompassing mammals, birds and reptiles, has raised substantial questions as to the term, 'Trichinella-free' as it applies to geographical localities. A true appreciation of the adaptability of this genus to host and environmental selection factors, as well as its dissemination to the far reaches of the world can best be appreciated by reviewing what we know and what we hope to know about this ancient and elusive parasite. The review herein consolidates our current understanding of the taxonomy, epidemiology, and phylogeny of the genus Trichinella, and identifies areas where data are lacking and our knowledge requires additional clarification.
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Affiliation(s)
- E Pozio
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy.
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Pyburn DG, Gamble HR, Wagstrom EA, Anderson LA, Miller LE. Trichinae certification in the United States pork industry. Vet Parasitol 2005; 132:179-83. [PMID: 15993000 DOI: 10.1016/j.vetpar.2005.05.051] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Control of Trichinella infection in U.S. pork has traditionally been accomplished by inspection of individual carcasses at slaughter or by post-slaughter processing to inactivate parasites. We propose that an alternative to individual carcass testing or processing can be used when pigs are raised in production systems where risk of exposure to Trichinella spiralis has been mitigated. Declines in prevalence of this parasite in U.S. domestic swine during the last 30 years, coupled with improvements in pork production systems, now allow Trichinella control to be shifted to the farm through implementation of specific pork production practices. Knowledge of risk factors for exposure of swine to T. spiralis was used to develop an objective audit of risk that can be applied to pork production sites. In a pilot study, 461 production site audits were performed by trained veterinary practitioners. The on-farm audit included aspects of farm management, bio-security, feed and feed storage, rodent control programs and general hygiene. Of the 461 production site audits, 450 audits (97.6%) indicated compliance with the required good production practices. These sites are eligible for certification under the U.S. Trichinae Certification Program and will be audited regularly to maintain that status. The described trichinae certification mechanism will establish a process for ensuring the Trichinella safety of swine, and ultimately food products derived from swine, at the production level.
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Affiliation(s)
- David G Pyburn
- USDA APHIS VS, 210 Walnut Street, Suite 891 Des Moines, IA 50309, USA.
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Sukura A, Nareaho A, Mikkonen T, Niemi M, Oivanen L. Trichinella nativa and T. spiralis induce distinguishable histopathologic and humoral responses in the raccoon dog (Nyctereutes procyonoides). Vet Pathol 2002; 39:257-65. [PMID: 12009064 DOI: 10.1354/vp.39-2-257] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Three experimental groups of six male raccoon dogs (Nyctereutes procyonoides) each were formed by placing one of three littermates from six litters into each group. One group was inoculated with pig-origin Trichinella spiralis, the second was inoculated with raccoon dog-origin T. nativa, and the third served as a control group. The infective dose was 1,000 larvae/kg of body weight. Every third week, biopsies from M. triceps brachii were taken, and serum samples were collected for up to 12 weeks postinfection. In the early phase of the infection, cysts of both parasites were elongated cylinders that later became more spherical. However, at the end of the experiment, the cysts of T. nativa were more rounded than those of T. spiralis (mean length/width = 2.5 versus 1.5 in T. spiralis versus T. nativa, respectively). Both species accumulated a collagen-rich capsule around the nurse cell, but the capsule was thicker in T. nativa. In both parasites, the total surface area of the sagittal section of the cyst was equal. Inflammation was more intense around T. nativa cysts. Specific antibodies were recognizable 2 weeks after infection by both enzyme-linked immunosorbent assay (ELISA) and western blot. In western blots, serum from both T. nativa- and T. spiralis-infected animals recognized the same components, but reaction with the homologous antigen was stronger. The same pattern was also seen in the ELISA. Immunoreactive epitopes were localized only in internal organs and cuticula of larvae in muscle.
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Affiliation(s)
- A Sukura
- Department of Basic Veterinary Science, Faculty of Veterinary Medicine, University of Helsinki, Finland
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Abstract
Trichinella spp. are some of the most widespread parasites infecting people and other mammals all over the world, regardless of climate. This paper attempts to describe the present status of trichinellosis worldwide and to determine if and why trichinellosis is emerging or re-emerging. The global prevalence of the disease is difficult to evaluate but as many as 11 million people may be infected. More than 10000 cases of human trichinellosis were reported by the International Commission on Trichinellosis from 1995 to June 1997 and about 10000 porcine infections were reported by the Office International des Epizooties in 1998. The disease is particularly worrisome in the Balkans, Russia, the Baltic republics, in some parts of China and Argentina. Horsemeat-related outbreaks have been reported in France and Italy and have involved about 3000 patients in the past 25 years. The emergence of trichinellosis in some countries is explained by a better knowledge of the disease (formerly often misdiagnosed as influenza), modifications of consumer habits, re-forestation in Europe and increase of wild game, importation of meats from countries where trichinellosis is endemic and failure of veterinary control due to human error or to social upheavals. This disease linked to meat-consumption which is theoretically easy to prevent by adequate cooking, freezing and veterinary controls, should deserve the attention of all persons involved in public health and it could be eradicated at least from domestic pigs.
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Affiliation(s)
- J Dupouy-Camet
- Parasitology Department, Cochin Hospital, R. Descartes University, 27 rue du Faubourg St Jacques, 75014, Paris, France.
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