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Malone CJ, Oksanen A, Mukaratirwa S, Sharma R, Jenkins E. From wildlife to humans: The global distribution of Trichinella species and genotypes in wildlife and wildlife-associated human trichinellosis. Int J Parasitol Parasites Wildl 2024; 24:100934. [PMID: 38651034 PMCID: PMC11033181 DOI: 10.1016/j.ijppaw.2024.100934] [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: 02/28/2024] [Revised: 04/02/2024] [Accepted: 04/02/2024] [Indexed: 04/25/2024]
Abstract
Zoonotic nematodes of the genus Trichinella are foodborne parasites that have a global distribution in wild carnivores and omnivores, with spillover and spillback into domestic livestock and people, with concomitant trade and health consequences. Historically, most human cases were linked to domestic pigs infected with Trichinella spiralis, but under current high biosecurity swine production in many countries, wildlife have become a more important source of human trichinellosis. The aim of this review is to update the global distribution of Trichinella species and genotypes reported in wildlife, as well as reported human outbreaks from the consumption of wildlife. Using several online databases and by "snowballing" references, hundreds of reports of Trichinella spp. in wildlife published between January 1991 and December 2023 provide an important update to the host and geographic range for each of the recognized 13 species/genotypes, grouped by continent. Surveillance effort was highest in Europe and North America, while Africa, Asia, Oceania, Central and South America have had limited surveillance, in some instances with human cases serving as sentinels of transmission in a region. Dozens of human outbreaks are described, with wild boars (Sus scrofa) being the most frequently implicated wildlife species in human outbreaks globally. Bears are an important source of infection in North America, for wildlife tourism, and importation of bear meat has also been implicated in multicountry outbreaks. The largest study limitation was the dearth of molecular identification of larvae in both wildlife surveillance studies and human outbreaks, particulary in under-studied regions. We highlight the need for enhanced molecular epidemiological approaches to outbreaks of this important foodborne parasite, and emphasize the need for a One Health approach to manage Trichinella spp. which transmit among terrestrial and marine wildlife (including migratory birds), pigs, horses, and people, often across large geographic scales and borders.
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Affiliation(s)
- Cody J. Malone
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Antti Oksanen
- Finnish Food Authority, (FINPAR), Elektroniikkatie 3, FI-90590, Oulu, Finland
| | - Samson Mukaratirwa
- One Health Center for Zoonoses and Tropical Veterinary Medicine, Ross University School of Veterinary Medicine, Basseterre, Saint Kitts and Nevis
- School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Rajnish Sharma
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- Centre for One Health, College of Veterinary Science, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - Emily Jenkins
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Marin AM, Popovici DC, Marucci G, Cherchi S, Mederle N. First Identification of Trichinella pseudospiralis in a Golden Jackal ( Canis aureus) in Romania. Pathogens 2023; 13:32. [PMID: 38251339 PMCID: PMC10818659 DOI: 10.3390/pathogens13010032] [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: 12/10/2023] [Revised: 12/26/2023] [Accepted: 12/27/2023] [Indexed: 01/23/2024] Open
Abstract
Trichinella spp. are etiological zoonotic agents that spread throughout the world and affect mammals, birds, and reptiles. Within this genus, Trichinella pseudospiralis is the only recognized non-encapsulated species known to infect mammals and birds. This species has been reported in the majority of European countries, and the real epidemiological scenario of this species remains to be defined because its detection in mammals is much lower than that of the capsulated species. The aim of this study was to examine the presence of Trichinella larvae isolated from the muscles of a jackal from the hunting fund of 36 Murfatlar, Constanta County, Romania. The muscle samples were examined by artificial digestion, and the larvae were identified at the species level by multiplex PCR. The presence of larvae belonging to T. pseudospiralis, a species more frequently reported in carnivorous birds, was observed. This study describes the first identification of T. pseudospiralis in a jackal. The results suggest that there is an urgent need to investigate which species of mammals and/or birds act as reservoirs for this zoonotic nematode in Romania.
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Affiliation(s)
- Ana-Maria Marin
- Faculty of Veterinary Medicine, University of Life Sciences “King Michael I”, 300645 Timisoara, Romania; (A.-M.M.); (N.M.)
| | | | - Gianluca Marucci
- Department of Infectious Diseases, Istituto Superiore di Sanità, 00161 Rome, Italy; (G.M.); (S.C.)
| | - Simona Cherchi
- Department of Infectious Diseases, Istituto Superiore di Sanità, 00161 Rome, Italy; (G.M.); (S.C.)
| | - Narcisa Mederle
- Faculty of Veterinary Medicine, University of Life Sciences “King Michael I”, 300645 Timisoara, Romania; (A.-M.M.); (N.M.)
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Reichard MV, Sanders TL, Prentiss NL, Cotey SR, Koch RW, Fairbanks WS, Interisano M, La Rosa G, Pozio E. Detection of Trichinella murrelli and Trichinella pseudospiralis in bobcats (Lynx rufus) from Oklahoma. VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2021; 25:100609. [PMID: 34474802 DOI: 10.1016/j.vprsr.2021.100609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 06/28/2021] [Accepted: 07/11/2021] [Indexed: 10/20/2022]
Abstract
Trichinella spp. infect wild carnivores throughout the world. We determined the prevalence and mean infection intensity of Trichinella spp. in bobcats (Lynx rufus) from 41 counties in Oklahoma (USA). Tongues from 306 bobcats were examined using artificial tissue digestion. The prevalence (95% confidence interval) of Trichinella spp. was 5.9% (3.7%-9.2%) in which 18 of the 301 bobcats were infected. Bobcats infected with Trichinella spp. were detected in 10 of the 41 (24.4%; 13.7%-39.5%) counties sampled. Although variable, a statistically significant difference was not detected in the prevalence of Trichinella spp. among counties where bobcats were collected. The mean (standard deviation) and median (range) infection intensity of Trichinella sp. larvae were 30.9 (39.8) and 9.6 (0.6-119.9) larvae per gram of tissue examined. Genotyping results demonstrated that 17 bobcats were infected with T. murrelliand one bobcat was infected with T. pseudospiralis. This is the first report of T. pseudospiralis in bobcats and in Oklahoma. These data suggest the bobcat, as an obligate carnivore, is likely an important host in maintaining T. murrelli sylvatic cycles in Oklahoma.
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Affiliation(s)
- Mason V Reichard
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK, USA.
| | - Tiana L Sanders
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK, USA
| | - Natasha L Prentiss
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK, USA
| | - Stacy R Cotey
- College of Forest Resources and Environmental Science, Michigan Tech University, Houghton, MI, USA
| | - Ryan W Koch
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK, USA
| | - W Sue Fairbanks
- Department of Natural Resource Ecology and Management, Division of Agricultural Science and Natural Resources, Oklahoma State University, Stillwater, OK, USA
| | - Maria Interisano
- Department of Infectious Diseases, Unit of Foodborne and Neglected Parasitic Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Giuseppe La Rosa
- Department of Infectious Diseases, Unit of Foodborne and Neglected Parasitic Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Edoardo Pozio
- Department of Infectious Diseases, Unit of Foodborne and Neglected Parasitic Diseases, Istituto Superiore di Sanità, Rome, Italy
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Sharma R, Thompson P, Elkin B, Mulders R, Branigan M, Pongracz J, Wagner B, Scandrett B, Hoberg E, Rosenthal B, Jenkins E. Trichinella pseudospiralis in a wolverine (Gulo gulo) from the Canadian North. Int J Parasitol Parasites Wildl 2019; 9:274-280. [PMID: 31289720 PMCID: PMC6593184 DOI: 10.1016/j.ijppaw.2019.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 06/12/2019] [Accepted: 06/12/2019] [Indexed: 11/28/2022]
Abstract
Species of Trichinella are a globally distributed assemblage of nematodes, often with distinct host ranges, which include people, domestic, and wild animals. Trichinella spp. are important in northern Canada, where dietary habits of people and methods of meat preparation (drying, smoking, fermenting as well as raw) increase the risk posed by these foodborne zoonotic parasites. Outbreaks in the arctic and subarctic regions of Canada and the United States are generally attributed to T. nativa (T2) or the T6 genotype, when genetic characterization is performed. We report the discovery of Trichinella pseudospiralis (T4), a non-encapsulated species, in a wolverine (Gulo gulo) from the Northwest Territories of Canada. This parasite has been previously reported elsewhere from both mammals and carnivorous birds, but our findings represent new host and geographic records for T. pseudospiralis. Multiplex PCR and sequencing of fragments of Cytochrome Oxidase Subunit I (COI) and D3 rDNA confirmed the identification. Phylogenetically, Canadian isolates linked with each other and others derived from Palearctic or Neotropical regions, but not elsewhere in the Nearctic (continental USA). We suggest that migratory birds might have played a role in the dispersal of this pathogen 1000's of km to northwestern Canada. Wolverines are not typically consumed by humans, and thus should not pose a direct food safety risk for trichinellosis. However, the current finding suggests that they may serve as an indicator of a broader distribution for T. pseudospiralis. Along with infection risk already recognized for T. nativa and Trichinella T6, our observations emphasize the need for further studies using molecular diagnostics and alternative methods to clarify if this is a solitary case, or if T. pseudospiralis and other freeze susceptible species of Trichinella (such as T. spiralis) circulate more broadly in wildlife in Canada, and elsewhere.
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Affiliation(s)
- Rajnish Sharma
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada
| | - Peter Thompson
- USDA-Agricultural Research Service, Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, 10300 Baltimore Avenue, Beltsville, MD, 20705, USA
| | - Brett Elkin
- Environment and Natural Resources, Government of the Northwest Territories, 600, 5102-50th Avenue, Yellowknife, NT, X1A 3S8, Canada
| | - Robert Mulders
- Environment and Natural Resources, Government of the Northwest Territories, 600, 5102-50th Avenue, Yellowknife, NT, X1A 3S8, Canada
| | - Marsha Branigan
- Environment and Natural Resources, Government of the Northwest Territories, P.O. Box 2749, Shell Lake, Inuvik, NT, X0E 0T0, Canada
| | - Jodie Pongracz
- Environment and Natural Resources, Government of the Northwest Territories, P.O. Box 2749, Shell Lake, Inuvik, NT, X0E 0T0, Canada
| | - Brent Wagner
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada
| | - Brad Scandrett
- Centre for Food-borne and Animal Parasitology, Canadian Food Inspection Agency, Saskatoon Laboratory, 116 Veterinary Road, Saskatoon, Saskatchewan, S7N 2R3, Canada
| | - Eric Hoberg
- Museum of Southwestern Biology and Department of Biology, University of New Mexico, Albuquerque, NM, 87131-0001, USA
| | - Benjamin Rosenthal
- USDA-Agricultural Research Service, Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, 10300 Baltimore Avenue, Beltsville, MD, 20705, USA
| | - Emily Jenkins
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada
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de Almeida M, Bishop H, Nascimento FS, Mathison B, Bradbury RS, da Silva A. Multiplex TaqMan qPCR assay for specific identification of encapsulated Trichinella species prevalent in North America. Mem Inst Oswaldo Cruz 2018; 113:e180305. [PMID: 30379199 PMCID: PMC6204614 DOI: 10.1590/0074-02760180305] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 09/18/2018] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Human trichinellosis is a foodborne parasitic zoonotic disease caused by ingestion of raw or undercooked meat infected with nematode larvae of the genus Trichinella. In the USA, sporadic cases and outbreaks caused by the consumption of wild game meat infected with Trichinella have been reported. The current methods for diagnosis such as serology and microscopy are not specific, may result in false negative results, and cannot differentiate encapsulated Trichinella larvae to species level. The molecular protocols currently available for the differentiation of all encapsulate Trichinella species prevalent in North America have some limitations such as the inability to identify and resolve the presence of several Trichinella species in a single test. OBJECTIVES/METHODS In this study we developed and evaluated a multiplex TaqMan quantitative real-time polymerase chain reaction (qPCR) assay, which can simultaneously detect, identify and differentiate all species of encapsulated Trichinella occurring in North America i.e., T. nativa, T. spiralis, T. murrelli and Trichinella T6, even in cases of multiple infection in a single sample. We investigated two human biopsies and 35 wild animal meat samples considered as having a high likelihood of harboring Trichinella larvae obtained from the United States during 2009-2017. FINDINGS Using the multiplex assay describe here, 22 (59%) samples that tested positive contained Trichinella spp., were identified as: T. nativa (n = 7, including a human biopsy), T. spiralis (n = 9, including a human biopsy), T. murrelli (n = 3), Trichinella T6 (n = 1). Results also included two rare mixed infection cases in bears, a T. nativa/T. spiralis from Alaska and a T. spiralis/Trichinella T6 from California. The species identifications were confirmed using a conventional PCR targeting the rRNA ITS1-ITS2 region, followed by DNA sequencing analysis. The estimated limit of detection (LOD) was approximately seven larvae per gram of meat. MAIN CONCLUSIONS Differentiation of Trichinella spp. is needed to improve efforts on identification of case, optimize food safety control and better understand the geographic distribution of Trichinella species. The Trichinella qPCR multiplex proved to be a robust, easy to perform assay and is presented as an improved technique for identification of all known encapsulated species occurring in North America continent.
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Affiliation(s)
- Marcos de Almeida
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Center for Global Health, Atlanta, GA, USA
| | - Henry Bishop
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Center for Global Health, Atlanta, GA, USA
| | - Fernanda S Nascimento
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Center for Global Health, Atlanta, GA, USA
| | - Blaine Mathison
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Center for Global Health, Atlanta, GA, USA
| | - Richard S Bradbury
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Center for Global Health, Atlanta, GA, USA
| | - Alexandre da Silva
- US Food and Drug Administration Center for Food Safety and Applied Nutrition, Office of Applied Nutrition and Safety Assessment, Laurel, MD, USA
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Pozio E. Trichinella pseudospiralis an elusive nematode. Vet Parasitol 2016; 231:97-101. [PMID: 27113211 DOI: 10.1016/j.vetpar.2016.03.021] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/18/2016] [Accepted: 03/26/2016] [Indexed: 11/16/2022]
Abstract
Trichinella pseudospiralis is one of the three species whose larvae do not encapsulate after muscle cell differentiation, and the only one infecting both mammals and birds. More than 40 years after its discovery, the epidemiology remains, at least in part, still enigmatic. The aim of this work was to reconsider the current knowledge on the T. pseudospiralis epidemiology by collecting the information available in the literature and in the website of the International Trichinella Reference Center. Over the last decade, there was an increasing number of reports of T. pseudospiralis due to the increased use of the digestion tests. T. pseudospiralis was detected in 18 mammalian species (3 species of Dasyuridae; 2 species of Muridae; 4 species of Canidae; 3 species of Felidae; 2 species of Mustelidae; 1 species of Procyonidae; 1 species of Ursidae; and swine) including humans, and 8 avian species (3 species of Accipitridae; 1 species of Cathartidae; 1 species of Corvidae; 1 species of Tytonidae; 2 species of Strigidae) for a total of 249 isolates from Asia, America, Australia, and Europe. In the European Union, T. pseudospiralis has been documented in 19 out of 28 countries. The zoonotic role of this parasite was documented in 128 persons with trichinellosis. The number of mammals tested for Trichinella spp. by digestion has been much higher than that of birds, thus the role played by birds in the epidemiology of T. pseudospiralis still needs to be elaborated in more detail. The results may suggest that T. pseudospiralis, allowing to make up for the lower prevalence than that of the encapsulated species in the host populations, uses a wider host range.
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Affiliation(s)
- Edoardo Pozio
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy.
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Zamora MJ, Alvarez M, Olmedo J, Blanco MC, Pozio E. Trichinella pseudospiralis in the Iberian peninsula. Vet Parasitol 2015; 210:255-9. [PMID: 25913596 DOI: 10.1016/j.vetpar.2015.04.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 03/31/2015] [Accepted: 04/02/2015] [Indexed: 11/16/2022]
Abstract
Nematode worms of the genus Trichinella are zoonotic parasites circulating in most continents, including Europe. In Spain, Trichinella spiralis and Trichinella britovi are highly prevalent in wildlife but seldom in domestic pigs. In Portugal, only T. britovi was documented in wild carnivores. In the period 2006-2013 in Spain, 384 (0.0001%) pigs and 1399 (0.20%) wild boars (Sus scrofa) were positive for Trichinella spp. larvae, which were identified as T. spiralis or T. britovi. In 2014, Trichinella pseudospiralis larvae were isolated from a wild boar hunted in the Gerona province, Cataluña region, North-East of Spain, near the border to France. This is the first report of T. pseudospiralis in the Iberian peninsula, which suggests a broad distribution area of this zoonotic nematode in Europe. Since larvae of this Trichinella species do not encapsulate in the host muscles, they can be detected only by artificial digestion of muscle samples. T. pseudospiralis is the only Trichinella species infecting both mammals and birds. Birds can spread this pathogen over great distances including islands triggering new foci of infections in areas previously considered at low risk for this pathogen.
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Affiliation(s)
- M J Zamora
- Servicio de Microbiología Alimentaria, Centro Nacional de Alimentación, Agencia Española de Consumo, Seguridad Alimentaria y Nutrición, Ctra. Pozuelo a Majadahonda, Km 5,100, 28220 Majadahonda, Madrid, Spain
| | - M Alvarez
- Servicio de Microbiología Alimentaria, Centro Nacional de Alimentación, Agencia Española de Consumo, Seguridad Alimentaria y Nutrición, Ctra. Pozuelo a Majadahonda, Km 5,100, 28220 Majadahonda, Madrid, Spain
| | - J Olmedo
- Servicio de Microbiología Alimentaria, Centro Nacional de Alimentación, Agencia Española de Consumo, Seguridad Alimentaria y Nutrición, Ctra. Pozuelo a Majadahonda, Km 5,100, 28220 Majadahonda, Madrid, Spain
| | - M C Blanco
- Servicio de Microbiología Alimentaria, Centro Nacional de Alimentación, Agencia Española de Consumo, Seguridad Alimentaria y Nutrición, Ctra. Pozuelo a Majadahonda, Km 5,100, 28220 Majadahonda, Madrid, Spain
| | - E Pozio
- Department of Infectious Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, Viale Regia Elena, 299, 00161 Rome, Italy.
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Hill DE, Dubey JP, Baroch JA, Swafford SR, Fournet VF, Hawkins-Cooper D, Pyburn DG, Schmit BS, Gamble HR, Pedersen K, Ferreira LR, Verma SK, Ying Y, Kwok OCH, Feidas H, Theodoropoulos G. Surveillance of feral swine for Trichinella spp. and Toxoplasma gondii in the USA and host-related factors associated with infection. Vet Parasitol 2014; 205:653-65. [PMID: 25182211 DOI: 10.1016/j.vetpar.2014.07.026] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 07/23/2014] [Accepted: 07/25/2014] [Indexed: 11/26/2022]
Abstract
Trichinella spp. and Toxoplasma gondii are important zoonotic parasites that infect warm blooded animals and humans worldwide. Among domesticated food animals, pigs are the main host for Trichinella spiralis. Pigs, chickens, sheep, and goats are known to be infected with T. gondii at varying rates, depending on husbandry. Infections in wildlife with these parasites are generally higher than in domesticated species. Feral swine act as reservoirs of infection in the sylvatic ecosystem for Trichinella spp. and T. gondii, acting as sources of infection for peridomestic carnivores whose home ranges overlap with domestic pigs. Feral swine can have direct contact with non-biosecure domestic pigs, presenting opportunity for direct disease transmission through cannibalistic behavior. Determination of the prevalence of Trichinella spp. and T. gondii infection in feral swine is needed to understand the risk of transmission of these parasites to domestic pigs. A cross-sectional serological survey was conducted between 2006 and 2010 to estimate the antibody prevalence of Trichinella spp. and T. gondii and risk factors associated with infection in feral swine in the USA. Serum samples were tested from 3247 feral pigs from 32 states; results are reported from 26 states. Maximum entropy ecological niche modeling and spatial scan statistic were utilized to predict the geographic range and to examine clusters of infection of Trichinella spp. and T. gondii in feral pigs. The seroprevalence of antibodies to Trichinella spp. and T. gondii was 3.0% and 17.7%, respectively. Species distribution modeling indicated that the most probable distribution areas for both parasites was similar, concentrated primarily in the South and the Midwest regions of the USA. A follow up survey conducted during 2012-2013 revealed that 2.9% of 984 sampled feral swine were seropositive for Trichinella spp., and 28.4% were seropositive for T. gondii. Three hundred and thirty (330) tongues were collected from the 984 sampled animals during 2012-2013; 1.81% were tissue positive for T. spiralis muscle larvae; no other genotypes were found. The potential exists for introduction of these pathogens into domestic herds of non-biosecure domestic pigs as a result of increasing overlap of the range of feral pigs with non-biosecure domestic pigs production facilities in the USA.
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Affiliation(s)
- D E Hill
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD, 20705-2350, USA.
| | - J P Dubey
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD, 20705-2350, USA
| | - J A Baroch
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, 4101 LaPorte Ave, Fort Collins, CO 80521, USA
| | - S R Swafford
- United States Fish and Wildlife Service, 595 Yazoo Refuge Road, MS 38748-9729, USA
| | - V F Fournet
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD, 20705-2350, USA
| | - D Hawkins-Cooper
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD, 20705-2350, USA
| | - D G Pyburn
- National Pork Board, 1776 NW 114th St., Clive, IA 50325, USA
| | - B S Schmit
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, 4101 LaPorte Ave, Fort Collins, CO 80521, USA
| | - H R Gamble
- National Academy of Sciences, 500 5th Street N.W., Washington, D.C., 20001, USA
| | - K Pedersen
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, 4101 LaPorte Ave, Fort Collins, CO 80521, USA
| | - L R Ferreira
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD, 20705-2350, USA
| | - S K Verma
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD, 20705-2350, USA
| | - Y Ying
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD, 20705-2350, USA
| | - O C H Kwok
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD, 20705-2350, USA
| | - H Feidas
- Department of Meteorology and Climatology, School of Geology, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - G Theodoropoulos
- Department of Anatomy and Physiology of Farm Animals, Agricultural University of Athens, 75 Iera Odos, Votanikos, Athens 11855, Greece
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Gajadhar AA, Forbes LB. A 10-year wildlife survey of 15 species of Canadian carnivores identifies new hosts or geographic locations for Trichinella genotypes T2, T4, T5, and T6. Vet Parasitol 2010; 168:78-83. [DOI: 10.1016/j.vetpar.2009.10.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2009] [Revised: 10/14/2009] [Accepted: 10/15/2009] [Indexed: 10/20/2022]
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Meng XJ, Lindsay DS, Sriranganathan N. Wild boars as sources for infectious diseases in livestock and humans. Philos Trans R Soc Lond B Biol Sci 2009; 364:2697-707. [PMID: 19687039 DOI: 10.1098/rstb.2009.0086] [Citation(s) in RCA: 284] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Wild boars (Sus scrofa) are indigenous in many countries in the world. These free-living swine are known reservoirs for a number of viruses, bacteria and parasites that are transmissible to domestic animals and humans. Changes of human habitation to suburban areas, increased use of lands for agricultural purposes, increased hunting activities and consumption of wild boar meat have increased the chances of exposure of wild boars to domestic animals and humans. Wild boars can act as reservoirs for many important infectious diseases in domestic animals, such as classical swine fever, brucellosis and trichinellosis, and in humans, diseases such as hepatitis E, tuberculosis, leptospirosis and trichinellosis. For examples, wild boars are reservoirs for hepatitis E virus, and cluster cases of hepatitis E have been reported in Japan of humans who consumed wild boar meat. In Canada, an outbreak of trichinellosis was linked to the consumption of wild boar meat. The incidence of tuberculosis owing to Mycobacterium bovis has increased in wild boars, thus posing a potential concern for infections in livestock and humans. It has also been documented that six hunters contracted Brucella suis infections from wild swine in Florida. This article discusses the prevalence and risk of infectious agents in wild boars and their potential transmission to livestock and humans.
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Affiliation(s)
- X J Meng
- Center for Molecular Medicine and Infectious Diseases, Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, CRC-Integrated Life Sciences Building, Blacksburg, VA 24061-0913, USA.
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11
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Hill DE, Forbes L, Zarlenga DS, Urban JF, Gajadhar AA, Gamble HR. Survival of North American genotypes of Trichinella in frozen pork. J Food Prot 2009; 72:2565-70. [PMID: 20003740 DOI: 10.4315/0362-028x-72.12.2565] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
North American genotypes of Trichinella spiralis (T-1), Trichinella nativa (T-2), Trichinella pseudospiralis (T-4), Trichinella murrelli (T-5), and Trichinella T-6 were examined for susceptibility to freezing in pork using time-temperature combinations that have been proven to inactivate T. spiralis. Infections were established in 3-month-old pigs of mixed sex and breed by oral inoculation of 10,000 muscle larvae (ML) (all genotypes, rodent-derived ML), 20,000 ML (T-1, T-4, and T-5; cat-derived ML), or 30,000 ML (T-2 and T-6; cat-derived ML). Pigs were euthanized 60 days postinoculation. Muscles from the tongue, masseter muscles, diaphragm, triceps, hams, neck, rump, and loins were ground, pooled, and mixed to ensure even distribution of larvae. Samples (20 g) containing each Trichinella species, genotype, and source combination were placed in heat-sealable pouches, transferred to a constant temperature refrigerant bath, and maintained according to defined time and temperature combinations. Larvae recovered from cold-treated pork samples were inoculated into mice to determine infectivity. Results indicated that the time-temperature combinations known to render pork safe for T. spiralis are sufficient to inactivate T. nativa and T-6 (the freeze-resistant isolates), T. murrelli (the most common sylvatic species in the United States excluding Alaska), and T. pseudospiralis (a species that lacks a muscle nurse cell). These data close a gap in knowledge about the effectiveness of freezing for inactivating these parasites in pork and should alleviate concern about the safety of frozen pork products from the United States.
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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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12
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13
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Analysis of cytochrome c-oxidase (COI) gene of mitochondrial DNA from the Trichinella spp. in China. Parasitol Res 2008; 103:1355-9. [DOI: 10.1007/s00436-008-1141-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Accepted: 07/17/2008] [Indexed: 11/26/2022]
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14
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Abstract
The etiological agents of human trichinellosis show virtually worldwide distribution in domestic and/or wild animals, with the exception of Antarctica, where the presence of the parasite has not been reported. This global distribution of Trichinella and varying cultural eating habits represent the main factors favouring human infections in industrialised and non-industrialised countries. Human trichinellosis has been documented in 55 (27.8%) countries around the world. In several of these countries, however, trichinellosis affects only ethnic minorities and tourists because the native inhabitants do not consume uncooked meat or meat of some animal species. Trichinella sp. infection has been documented in domestic animals (mainly pigs) and in wildlife of 43 (21.9%) and 66 (33.3%) countries, respectively. Of the 198 countries of the world, approximately 40 (20%) are small islands far from the major continents, or city-states where Trichinella sp. cannot circulate among animals for lack of local fauna (both domestic and wild). Finally, information on the occurrence of Trichinella sp. infection in domestic and/or wildlife is still lacking for 92 countries.
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Affiliation(s)
- Edoardo Pozio
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy.
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15
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Abstract
In this review, we describe the current knowledge on the systematics, ecology and epidemiology of Trichinella and trichinellosis, and the impact of recent research discoveries on the understanding of this zoonosis. The epidemiology of this zoonosis has experienced important changes over the past two decades, especially with regard to the importance of the sylvatic cycle and the sylvatic species. Outbreaks of trichinellosis due to Trichinella spiralis from domestic swine, while still frequent, increasingly are caused by other Trichinella spp. infecting hosts such as horses, dogs, wild boars, bears and walruses. The latter revelations have occurred as a result of a series of discoveries on the systematics of Trichinella spp., facilitated by new molecular tools. As a consequence, the genus is now composed of two clades, an encapsulated group (five species and three genotypes) and a non-encapsulated one (three species). This has sparked renewed investigations on the host range of these parasites and their epidemiological features. Most dramatic, perhaps, is the recognition that reptiles may also serve as hosts for certain species. This new knowledge base, in addition to having an important relevance for food safety policies and protection measures, is raising important questions on the phylogeny of Trichinella spp., the ecological characteristics of the species and their geographic histories. Answers to these questions may have great value for the understanding of the evolutionary biology for other parasitic helminths, and may increase the value of this genus as models for research on parasitism in general.
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Affiliation(s)
- Edoardo Pozio
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy
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16
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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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17
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Abstract
In recent years, studies on Trichinella have shown that the host range is wider than previously believed and new Trichinella species and genotypes have been described. Three classes of vertebrates are known to act as hosts, mammals, birds and reptiles, and infected vertebrates have been detected on all continents but Antarctica. Mammals represent the most important hosts and all Trichinella species are able to develop in this vertebrate class. Natural infections with Trichinella have been described in more than 150 mammalian species belonging to 12 orders (i.e., Marsupialia, Insectivora, Edentata, Chiroptera, Lagomorpha, Rodentia, Cetacea, Carnivora, Perissodactyla, Artiodactyla, Tylopoda and Primates). The epidemiology of the infection greatly varies by species relative to characteristics, such as diet, life span, distribution, behaviour, and relationships with humans. The non-encapsulated species Trichinella pseudospiralis, detected in both mammals (14 species) and birds (13 species), shows a cosmopolitan distribution with three distinguishable populations in the Palearctic, Nearctic and Australian regions. Two additional non-encapsulated species, Trichinella papuae, detected in wild pigs and saltwater crocodiles of Papua New Guinea, and Trichinella zimbabwensis, detected in farmed Nile crocodiles of Zimbabwe, can complete their life cycle in both mammals and reptiles. To the best of our knowledge, T. papuae and T. zimbabwensis are the only two parasites known to complete their entire life cycle independently of whether the host is warm-blooded or cold-blooded. This suggests that these two Trichinella species are capable of activating different physiological mechanisms, according to the specific vertebrate class hosting them.
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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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van der Giessen JWB, Fonville M, Briels I, Pozio E. Phylogenetic analysis of encapsulated and non-encapsulated Trichinella species by studying the 5S rDNA tandemly repeated intergenic region. Vet Parasitol 2005; 132:51-5. [PMID: 16076532 DOI: 10.1016/j.vetpar.2005.05.065] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The identification of sequence regions in the genomes of pathogens which can be useful to distinguish among species and genotypes, is of great importance for epidemiological, molecular, and phylogenetic studies. The 5S ribosomal DNA intergenic spacer region has been identified as a good target to distinguish among eight Trichinella species and genotypes. The recent discovery of two non-encapsulated species in this genus, Trichinella papuae and Trichinella zimbabwensis, which can infect both mammals and reptiles, has suggested analyzing their 5S rDNA. Amplification of the tandem repeats of the 5S rDNA intergenic region of encapsulated species of Trichinella shows a 751bp fragment, whereas the three non-encapsulated species show a fragment of 800bp with T. pseudospiralis showing an additional fragment of 522bp. Although the size of the 800bp PCR fragments of T. papuae and T. zimbabwensis are similar to that of T. pseudospiralis, there are differences in the 5S rDNA intergenic regions among the three non-encapsulated species. Phylogenetic analysis of the 5S rDNA intergenic regions shows a clustering together of the three non-encapsulated Trichinella species that is well separated from the encapsulated ones. In addition, a single PCR-based method allows distinguishing non-encapsulated and encapsulated species.
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Affiliation(s)
- J W B van der Giessen
- Microbiological Laboratory for Health Protection, National Institute of Public Health and the Environment (RIVM), P.O. Box 1, 3720 BA Bilthoven, The Netherlands.
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