1
|
Milton AAP, Das S, Ghatak S, Srinivas K, Priya GB, Angappan M, Prasad MCB, Wahlang L, Sailo B, Lalhruaipuii L, Singh M, Garam GB, Sen A. Seroepidemological investigation of Toxoplasma gondii and Trichinella spp. in pigs reared by tribal communities and small-holder livestock farmers in Northeastern India. PLoS One 2024; 19:e0298357. [PMID: 38377066 PMCID: PMC10878514 DOI: 10.1371/journal.pone.0298357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 01/22/2024] [Indexed: 02/22/2024] Open
Abstract
Toxoplasma gondii and Trichinella spp. are critical tissue-dwelling foodborne zoonotic parasites associated with pork consumption and pig rearing. Despite being a major pig-rearing region in the country, Northeastern India has not undergone any investigation regarding the presence of T. gondii and Trichinella spp. in pigs. Therefore, this study aims to determine the seroprevalence of T. gondii and Trichinella spp. and identify associated risk factors in pigs reared by tribal communities and small-holder livestock farmers in the northeastern region of India. In a cross-sectional serological survey, 400 pigs from 400 households across five northeastern states of India underwent testing for the seroprevalence of porcine toxoplasmosis and trichinellosis. Serum samples (80 from each state) were analyzed using commercially available ELISA assays. Data on backyard farm characteristics and various management aspects were collected, and risk factors linked with prevalence were analyzed through univariate and multivariate logistic regression analysis. The findings revealed that the apparent and true prevalence of anti-T. gondii antibodies were 45% (40.12-49.88, 95% CI) and 45.7% (40.7-50.69, 95% CI), respectively. As for anti- Trichinella antibodies, both the apparent and true prevalence were 0.75% (-0.1-1.6, 95% CI). The univariate and multivariate analyses indicated that age above 24 months (OR 7.20, 95% CI 2.45-23.71), exposure to cats (OR = 5.87, 95% CI 2.55-14.05), and farms operating for breeding purposes (OR = 5.60, 95% CI 3.01-11.04) were significant risk factors associated with the seroprevalence of T. gondii. This study marks the initial documentation of the seroprevalence of T. gondii and Trichinella spp. in pigs reared by tribal communities in Northeastern India. The results emphasize the significance of these parasites as foodborne zoonotic threats in the region, potentially posing substantial public health risks, especially within tribal and rural communities. The insights derived from this research could be valuable in formulating targeted preventive and control strategies against T. gondii and Trichinella spp. in pigs, not only in this region but also in areas with similar rearing practices.
Collapse
Affiliation(s)
- A. A. P. Milton
- ICAR Research Complex for NEH Region, Umiam, Meghalaya, India
| | - Samir Das
- ICAR Research Complex for NEH Region, Umiam, Meghalaya, India
| | - S. Ghatak
- ICAR Research Complex for NEH Region, Umiam, Meghalaya, India
| | - K. Srinivas
- ICAR Research Complex for NEH Region, Umiam, Meghalaya, India
| | - G. Bhuvana Priya
- College of Agriculture, Central Agricultural University (Imphal), Kyrdemkulai, Meghalaya, India
| | - M. Angappan
- ICAR Research Complex for NEH Region, Umiam, Meghalaya, India
| | - M. C. B. Prasad
- ICAR Research Complex for NEH Region, Umiam, Meghalaya, India
| | - L. Wahlang
- ICAR Research Complex for NEH Region, Umiam, Meghalaya, India
| | - Blessa Sailo
- ICAR Research Complex for NEH Region, Umiam, Meghalaya, India
| | | | - Mahak Singh
- ICAR Research Complex for NEH Region, Umiam, Meghalaya, India
| | - G. B. Garam
- Department of Animal Husbandry, Veterinary & Dairy Development, Nirjuli, Arunachal Pradesh, India
| | - A. Sen
- ICAR Research Complex for NEH Region, Umiam, Meghalaya, India
| |
Collapse
|
2
|
Papatsiros VG, Athanasiou LV, Kostoulas P, Giannakopoulos A, Tzika E, Billinis C. Toxoplasma gondii Infection in Swine: Implications for Public Health. Foodborne Pathog Dis 2021; 18:823-840. [PMID: 34491108 DOI: 10.1089/fpd.2021.0039] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Toxoplasmosis, due to Toxoplasma gondii, is a parasitic disease with global importance. Among livestock, chronic T. gondii infection has been reported in higher rates in pigs and small ruminants, but with subclinical infections in case commonly encountered in pigs. Seroprevalence in the global pig population ranges according to the age or species of pigs, geographical distribution, production programs, and systems. Generally, T. gondii infections are noticed in low prevalence rates in conventional pig farms with high hygiene standards. In contrast, higher prevalence is common on free-ranging farms, outdoor or backyard small pig fams, as well as in farmed or hunted wild boars. The T. gondii average worldwide seroprevalence in pigs is reported to be 13% in Europe, 21% in Africa, 25% in North America, 21% in Asia, and 23% in South America. Human toxoplasmosis outbreaks have been correlated with the consumption of raw or undercooked meat, especially from infected pigs or wild boars, as well as of contaminated drinking water. The risk of infection in processed pork products is lower compared with fresh pork, as meat processing can reduce or inactivate T. gondii tissue cysts. Hence, the prevalence of T. gondii in the pig population may be a useful indicator of the risk of human toxoplasmosis associated with the consumption of pork products. The lack of obligatory screening methods at farm level for the detection of antibodies in farmed animals or the viable T. gondii in carcasses at slaughterhouse level increases the risk of contaminated pork or meat products. For this reason, the application of biosecurity and surveillance programs at farm level is very important to prevent a T. gondii infection.
Collapse
Affiliation(s)
- Vasileios G Papatsiros
- Clinic of Medicine, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, Karditsa, Greece
| | - Labrini V Athanasiou
- Clinic of Medicine, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, Karditsa, Greece
| | - Polychronis Kostoulas
- Laboratory of Epidemiology & Artificial Intelligence, Faculty of Public Health, School of Health Sciences, University of Thessaly, Karditsa, Greece
| | - Alexios Giannakopoulos
- Department of Microbiology & Parasitology, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, Karditsa, Greece
| | - Eleni Tzika
- Farm Animal Clinic, Faculty of Veterinary Medicine, School of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Charalambos Billinis
- Department of Microbiology & Parasitology, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, Karditsa, Greece
| |
Collapse
|
3
|
Olsen A, Alban L, Denwood M, Houe H, Birk Jensen T, Vedel Nielsen H. A longitudinal study of Toxoplasma gondii seroconversion on four large Danish sow farms. Vet Parasitol 2021; 295:109460. [PMID: 34029851 DOI: 10.1016/j.vetpar.2021.109460] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 11/26/2022]
Abstract
Serological tests are routinely used to detect Toxoplasma gondii specific IgG antibodies in serum. Serological surveys of T. gondii show a medium to high prevalence in Danish indoor sows at the time of slaughter. However, little is known about when sows acquire T. gondii, and for how long they remain seropositive. Our focus was on quantifying the incidence rates in different age-cohorts and on investigating the T. gondii IgG antibody dynamics in sows. Four large Danish sow farms were longitudinally surveyed for 1 year. A total of 320 animals from 6, 12, 18, and 24-months age-cohorts were sampled at 5-week intervals. In total, 2989 plasma samples were tested using commercial enzyme linked immunosorbent assay (ELISA). The incidence rate in each of the four age-cohorts was calculated, and a time-to-event analysis was applied to the interval censored data to investigate the relationship between age and probability of T. gondii seroconversion. In the initial ELISA testing, eight sows tested positive for T. gondii at first survey, of which seven remained seropositive throughout the follow-up period. Additionally, 16 sows seroconverted, but only five of these remained seropositive. Weekly incidence rates in the 6, 12, 18, and 24-month age-cohorts were 0.0017 (95% CI = 0.0008 - 0.0037), 0.0009 (95% CI = 0.0003 - 0.0027), 0.0003 (95% CI = 0.0000 - 0.0018), and 0.0023 (95% CI = 0.0010 - 0.0051), respectively. Time-to-event analysis suggested that the incidence rate increased with age but could not conclude this definitively. The retesting of a subsample of the sows (n = 200) with the same ELISA and with modified direct agglutination test (MAT), and western blot (WB) assays suggested that 12 out of the 24 initial ELISA seropositive sows may have been false positive. These 12 sows also showed fluctuating antibody dynamics in ELISA. Hence, the unstable antibody dynamics in ELISA may pose a challenge for serological surveys of T. gondii in sows.
Collapse
Affiliation(s)
- Abbey Olsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Grønnegårdsvej 8, DK-1870, Frederiksberg C, Denmark; Department of Food Safety, Veterinary Issues & Risk Analysis, Danish Agriculture & Food Council, Axelborg, Axeltorv 3, DK-1609, Copenhagen, Denmark.
| | - Lis Alban
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Grønnegårdsvej 8, DK-1870, Frederiksberg C, Denmark; Department of Food Safety, Veterinary Issues & Risk Analysis, Danish Agriculture & Food Council, Axelborg, Axeltorv 3, DK-1609, Copenhagen, Denmark.
| | - Matthew Denwood
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Grønnegårdsvej 8, DK-1870, Frederiksberg C, Denmark.
| | - Hans Houe
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Grønnegårdsvej 8, DK-1870, Frederiksberg C, Denmark.
| | | | - Henrik Vedel Nielsen
- Laboratory of Parasitology, Department of Bacteria, Parasites & Fungi, Infectious Disease Preparedness, Statens Serum Institut, Artillerivej 5, DK-2300, Copenhagen S, Denmark.
| |
Collapse
|
4
|
Olsen A, Sandberg M, Houe H, Nielsen HV, Denwood M, Jensen TB, Alban L. Seroprevalence of Toxoplasma gondii infection in sows and finishers from conventional and organic herds in Denmark: Implications for potential future serological surveillance. Prev Vet Med 2020; 185:105149. [PMID: 33127169 DOI: 10.1016/j.prevetmed.2020.105149] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/10/2020] [Accepted: 09/02/2020] [Indexed: 11/28/2022]
Abstract
Pigs are one of several host species for Toxoplasma gondii parasites, and consumption of infected pork may lead to toxoplasmosis in humans. We estimated seroprevalence in sows and finishers from conventional and organic herds in Denmark and discussed the strategies for reducing the risk from pork. We collected 447 blood samples from 59 herds, and additional meat-juice samples from 212 of the same pigs. Using a T. gondii IgG commercial ELISA test, we found 2% (95% CI = 0.4%-5%) apparent seroprevalence of T. gondii in conventional finishers, 11% (95% CI = 6%-17%) in organic finishers, 19% (95% CI = 11%-30%) in conventional sows and 60% (95% CI = 47%-72%) in organic sows. The odds of an animal testing positive for T. gondii was 16 times higher (95% CI = 4.6-74.3) in organic compared to conventional herds. The odds were 22 times higher (95% CI = 6.5-88.3) if the animal was a sow compared to a finisher. Meat-juice ELISA values were significantly correlated with plasma results (P < 0.001), but on average 64% of the blood-plasma ELISA values. Lowering the recommended cut-off from 20 to 13 percent positive values of the positive control for meat-juice ELISA, resulted in the meat-juice ELISA identifying 93% of the plasma positives as positive and 99% of the plasma negatives as negative. The time taken to detect one or more infected pigs from a T. gondii positive herd at slaughter was estimated using abattoir data on pigs (17,195,996) and batches (165,569) delivered to Danish abattoirs in 2018. The time to detection was affected by the seroprevalence, frequency at which the pigs were delivered, the number of samples tested per batch delivery and the batch sizes. Time to detection was long in conventional finisher herds due to low prevalence, and in sow herds because of intermittent delivery of a low number of sows. In organic finisher herds, time to detection was short due to medium prevalence and frequent delivery of a high number of finishers. Conventional finisher herds may be classified as low-risk, organic finisher herds as medium-risk, and conventional and organic sow herds as high-risk herds. Risk-mitigation strategies at processing plants (freezing or curing) or at the consumer level (heat treatment) for meat originating from high-risk herds, surveillance of medium-risk herds, and auditing for controlled housing (high biosecurity) in low-risk herds may be cost-effective alternatives to serological surveillance of all Danish pig herds.
Collapse
Affiliation(s)
- Abbey Olsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Grønnegaardsvej 8, DK-1870, Frederiksberg C, Denmark; Department of Food Safety, Veterinary Issues & Risk Analysis, Danish Agriculture & Food Council, Axelborg, Axeltorv 3, DK-1609, Copenhagen, Denmark.
| | - Marianne Sandberg
- Department of Food Safety, Veterinary Issues & Risk Analysis, Danish Agriculture & Food Council, Axelborg, Axeltorv 3, DK-1609, Copenhagen, Denmark
| | - Hans Houe
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Grønnegaardsvej 8, DK-1870, Frederiksberg C, Denmark
| | - Henrik Vedel Nielsen
- Laboratory of Parasitology, Department of Bacteria, Parasites & Fungi, Infectious Disease Preparedness, Statens Serum Institut, Artillerivej 5, DK-2300, Copenhagen S, Denmark
| | - Matt Denwood
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Grønnegaardsvej 8, DK-1870, Frederiksberg C, Denmark
| | | | - Lis Alban
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Grønnegaardsvej 8, DK-1870, Frederiksberg C, Denmark; Department of Food Safety, Veterinary Issues & Risk Analysis, Danish Agriculture & Food Council, Axelborg, Axeltorv 3, DK-1609, Copenhagen, Denmark
| |
Collapse
|
5
|
Dubey JP, Cerqueira-Cézar CK, Murata FHA, Kwok OCH, Hill D, Yang Y, Su C. All about Toxoplasma gondii infections in pigs: 2009-2020. Vet Parasitol 2020; 288:109185. [PMID: 33271424 DOI: 10.1016/j.vetpar.2020.109185] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Toxoplasma gondii infections are common in humans and animals worldwide. Toxoplasma gondii infection in pigs continues to be of public health concern. Pigs are important for the economy of many countries, particularly, USA, China, and European countries. Among the many food animals, pigs are considered the most important for T. gondii transmission in USA and China because viable parasites have rarely been isolated from beef or indoor raised chickens. Besides public health issues, T. gondii causes outbreaks of clinical toxoplasmosis in pigs in China, associated with a unique genotype of T. gondii (ToxoDB genotype #9 or Chinese 1), rarely found in other countries. The safety of ready to eat pork products with respect to T. gondii infection is a matter of recent debate. Here, we review in detail seroprevalence, prevalence of viable and nonviable T. gondii, epidemiology, risk assessment, diagnosis, and curing of pork products containing T. gondii for the past decade. This review will be of interest to biologists, parasitologists, veterinarians, and public health workers.
Collapse
Affiliation(s)
- Jitender P Dubey
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD 20705-2350, USA.
| | - Camila K Cerqueira-Cézar
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD 20705-2350, USA
| | - Fernando H A Murata
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD 20705-2350, USA
| | - Oliver C H Kwok
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD 20705-2350, USA
| | - Dolores Hill
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD 20705-2350, USA
| | - Yurong Yang
- Laboratory of Veterinary Pathology, College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou 450002, PR China
| | - Chunlei Su
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996-0845, USA
| |
Collapse
|
6
|
|
7
|
Sroka J, Karamon J, Wójcik-Fatla A, Piotrowska W, Dutkiewicz J, Bilska-Zając E, Zając V, Kochanowski M, Dąbrowska J, Cencek T. Toxoplasma gondii infection in slaughtered pigs and cattle in Poland: seroprevalence, molecular detection and characterization of parasites in meat. Parasit Vectors 2020; 13:223. [PMID: 32366276 PMCID: PMC7199313 DOI: 10.1186/s13071-020-04106-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Accepted: 04/27/2020] [Indexed: 12/17/2022] Open
Abstract
Background Toxoplasma gondii infection may pose a severe medical problem especially in a congenital form and as an acquired infection in immunocompromised persons. Raw and undercooked meat of slaughtered animals is regarded as an important source of parasite infection; however, data concerning this issue in Poland are still insufficient. The aim of this study was to estimate the prevalence of T. gondii infection in pigs and cattle slaughtered for human consumption in Poland using serological and molecular methods. Methods Sera of 3111 pigs and 2411 cattle from 16 regions (voivodeships) of the country were examined for the presence of anti-T. gondii IgG using the direct agglutination test (DAT). Pepsin-digested samples of diaphragm and heart of seropositive animals were examined for the presence of T. gondii DNA (B1 gene) by nested PCR and real-time PCR, while non-digested samples were only examined by nested PCR. The B1 gene DNA samples were genotyped at 11 genetic markers using multilocus nested PCR-RFLP (Mn-PCR-RFLP) and sequencing. Results Seropositive DAT results were found in 11.9% of pigs and 13.0% of cattle. The highest seroprevalence was found in pigs from Podkarpackie (32.6%) and in cattle from Mazowieckie (44.6%). Data analysis showed that cattle > 5–10 years-old, as well as cattle and pigs from small farms, and pigs from farms with open production systems, had higher odds of testing seropositive (P < 0.05). Among the examined tissue samples, positive PCR results were found in samples from 12.2% and 10.2% of seropositive pigs and cattle, respectively. Among the samples successfully genotyped by Mn-PCR-RFLP and sequenced, four samples were identified as T. gondii type II and one sample as type I. Conclusions The presence of T. gondii antibodies in a substantial proportion of examined pigs and cattle as well as the detection of parasite DNA in their tissues highlight a potential health risk to the consumers in Poland.![]()
Collapse
Affiliation(s)
- Jacek Sroka
- Department of Parasitology and Invasive Diseases, National Veterinary Research Institute, Puławy, Poland.
| | - Jacek Karamon
- Department of Parasitology and Invasive Diseases, National Veterinary Research Institute, Puławy, Poland
| | - Angelina Wójcik-Fatla
- Department of Health Biohazards and Parasitology, Institute of Rural Health, Lublin, Poland
| | - Weronika Piotrowska
- Department of Parasitology and Invasive Diseases, National Veterinary Research Institute, Puławy, Poland
| | - Jacek Dutkiewicz
- Department of Health Biohazards and Parasitology, Institute of Rural Health, Lublin, Poland
| | - Ewa Bilska-Zając
- Department of Parasitology and Invasive Diseases, National Veterinary Research Institute, Puławy, Poland
| | - Violetta Zając
- Department of Health Biohazards and Parasitology, Institute of Rural Health, Lublin, Poland
| | - Maciej Kochanowski
- Department of Parasitology and Invasive Diseases, National Veterinary Research Institute, Puławy, Poland
| | - Joanna Dąbrowska
- Department of Parasitology and Invasive Diseases, National Veterinary Research Institute, Puławy, Poland
| | - Tomasz Cencek
- Department of Parasitology and Invasive Diseases, National Veterinary Research Institute, Puławy, Poland
| |
Collapse
|
8
|
Su R, Jiang N, Lu Y, Jian F, Wang H, Zhang G, Zhang L, Yang Y. Low prevalence of viable Toxoplasma gondii in swine from slaughter houses in the central of China. Parasitol Int 2020; 76:102090. [PMID: 32092465 DOI: 10.1016/j.parint.2020.102090] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/07/2020] [Accepted: 02/19/2020] [Indexed: 01/03/2023]
Abstract
BACKGROUND Toxoplasma gondii is widely distributed and can infect many species of warm-blooded animals, including swine. This study aimed to evaluate the prevalence of T. gondii in swines from the central of China. A total of 2798 samples, including 305 hearts, 2086 diaphragms, and 407 sera were collected from different swine in Henan Province, China. The modified agglutination test was used to detect antibodies against T. gondii in sera from jugular vein blood and heart blood (cut-off: 1:25), diaphragm juice (cut-off: 1:10). T. gondii DNA was screened from the digestive fluids of all diaphragm tissue samples and seropositive hearts, and attempt to isolate viable T. gondii strain by bioassay in mice. RESULTS A total of 9.94% (278/2798) swine tested positive for T. gondii antibodies. Region, but not gender, was associated with T. gondi seropositivity in swine. T. gondii nucleic acid was not found in the tissue digestive fluids (2090 swines). Three groups of mice showed T. gondii antibodies after having been bioassayed with diaphragm samples (n = 81, which came from 2090 swine). No viable T. gondii strain was isolated from muscle of swine. CONCLUSIONS This is the first large-scale survey T. gondi infection in swine from the central of China. Overall, the prevalence of viable T. gondii in swine was low. Nevertheless, T. gondii infection is present in swine from the central of China. Consumers may acquire T. gondii infection from ingestion of raw or undercooked pork.
Collapse
Affiliation(s)
- Ruijing Su
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Nan Jiang
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Yaoyao Lu
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Fuchun Jian
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Haiyan Wang
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Gaiping Zhang
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Longxian Zhang
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China.
| | - Yurong Yang
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China.
| |
Collapse
|
9
|
Paştiu AI, Cozma-Petruț A, Mercier A, Balea A, Galal L, Mircean V, Pusta DL, Bogdan L, Györke A. Prevalence and genetic characterization of Toxoplasma gondii in naturally infected backyard pigs intended for familial consumption in Romania. Parasit Vectors 2019; 12:586. [PMID: 31842955 PMCID: PMC6915976 DOI: 10.1186/s13071-019-3842-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 12/08/2019] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Foodborne toxoplasmosis in humans can be due to the exposure to tissue cysts of Toxoplasma gondii through the consumption of meat, including pork, of infected animals. Traditional Romanian food habits include pork as the preferred meat, while backyard pig rearing remains a common practice in many rural areas of Romania. The aims of the present study were to estimate the prevalence of T. gondii infection in naturally infected backyard pigs slaughtered for familial consumption and to genetically characterize the T. gondii strains obtained. METHODS Paired blood and heart samples were collected from 94 backyard pigs, home slaughtered for private consumption. Serum samples were analyzed using the immunofluorescence antibody test (IFAT) for anti-T. gondii antibody detection. Heart samples were screened by polymerase chain reaction (PCR) targeting the 529-bp repeat region (REP529) for T. gondii detection. In addition, heart samples from IFAT positive animals were bioassayed in mice. The T. gondii isolates were genotyped by the analysis of 15 microsatellite markers. RESULTS The results showed that almost half of the pigs investigated were T. gondii seropositive (46.8%, 95% confidence interval (CI): 36.4-57.4%) and in more than a quarter of the pigs (26.6%, 95% CI: 18.0-36.7%), the parasite was detected by PCR. Three (3/44) T. gondii strains were isolated from hearts of seropositive pigs and they all belonged to genotype II. CONCLUSIONS The present study showed the presence of T. gondii infection in backyard pigs in Romania, which suggests that consumption of pork from animals reared and slaughtered at home may pose a potential threat to human health and should be given attention. In addition, to our knowledge, this is the first study to provide data concerning T. gondii strains circulating in pigs from Romania.
Collapse
Affiliation(s)
- Anamaria Ioana Paştiu
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, 3-5 Calea Mănăştur Street, 400372 Cluj-Napoca, Cluj Romania
- Department of Genetics and Hereditary Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, 3-5 Calea Mănăştur Street, 400372 Cluj-Napoca, Cluj Romania
| | - Anamaria Cozma-Petruț
- Department of Bromatology, Hygiene, Nutrition, Faculty of Pharmacy, “Iuliu Haţieganu” University of Medicine and Pharmacy, 6 Pasteur Street, 400349 Cluj-Napoca, Cluj Romania
| | - Aurélien Mercier
- INSERM UMR_S 1094, Neuroépidémiologie Tropicale, Laboratoire de Parasitologie-Mycologie, Faculté de Médecine, Université de Limoges, Limoges, France
- Centre National de Référence Toxoplasmose/Toxoplasma Biological Resource Center, CHU Limoges, 2 Martin Luther King Street, 87042 Limoges, France
| | - Anamaria Balea
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, 3-5 Calea Mănăştur Street, 400372 Cluj-Napoca, Cluj Romania
| | - Lokman Galal
- INSERM UMR_S 1094, Neuroépidémiologie Tropicale, Laboratoire de Parasitologie-Mycologie, Faculté de Médecine, Université de Limoges, Limoges, France
- Centre National de Référence Toxoplasmose/Toxoplasma Biological Resource Center, CHU Limoges, 2 Martin Luther King Street, 87042 Limoges, France
| | - Viorica Mircean
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, 3-5 Calea Mănăştur Street, 400372 Cluj-Napoca, Cluj Romania
| | - Dana Liana Pusta
- Department of Genetics and Hereditary Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, 3-5 Calea Mănăştur Street, 400372 Cluj-Napoca, Cluj Romania
| | - Liviu Bogdan
- Department of Reproduction, Obstetrics and Pathology of Animal Reproduction, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine, 3-5 Calea Mănăştur Street, 400372 Cluj-Napoca, Cluj Romania
| | - Adriana Györke
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, 3-5 Calea Mănăştur Street, 400372 Cluj-Napoca, Cluj Romania
| |
Collapse
|
10
|
Cubas-Atienzar AI, Hide G, Smith JE. Mat Seroprevalence Infers Low Rates of Toxoplasma gondii in Domestic Pigs from Yucatan, Mexico. J Parasitol 2019. [DOI: 10.1645/18-188] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Ana Isabel Cubas-Atienzar
- Biomedical Research Center, School of Environment and Life Sciences, University of Salford, Salford M5 4WT, U.K
| | - Geoff Hide
- Biomedical Research Center, School of Environment and Life Sciences, University of Salford, Salford M5 4WT, U.K
| | - Judith Elisabeth Smith
- Biomedical Research Center, School of Environment and Life Sciences, University of Salford, Salford M5 4WT, U.K
| |
Collapse
|
11
|
Stelzer S, Basso W, Benavides Silván J, Ortega-Mora L, Maksimov P, Gethmann J, Conraths F, Schares G. Toxoplasma gondii infection and toxoplasmosis in farm animals: Risk factors and economic impact. Food Waterborne Parasitol 2019; 15:e00037. [PMID: 32095611 PMCID: PMC7033994 DOI: 10.1016/j.fawpar.2019.e00037] [Citation(s) in RCA: 180] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/25/2019] [Accepted: 01/30/2019] [Indexed: 12/23/2022] Open
Abstract
The protozoan parasite Toxoplasma gondii is a zoonotic parasite that can be transmitted from animals to humans. Felids, including domestic cats, are definitive hosts that can shed oocysts with their feces. In addition to infections that occur by accidental oral uptake of food or water contaminated with oocysts, it is assumed that a large proportion of affected humans may have become infected by consuming meat or other animal products that contained infective parasitic stages of T. gondii. Since farm animals represent a direct source of infection for humans, but also a possible reservoir for the parasite, it is important to control T. gondii infections in livestock. Moreover, T. gondii may also be pathogenic to livestock where it could be responsible for considerable economic losses in some regions and particular farming systems, e.g. in areas where the small ruminant industry is relevant. This review aims to summarize actual knowledge on the prevalence and effects of infections with T. gondii in the most important livestock species and on the effects of toxoplasmosis on livestock. It also provides an overview on potential risk factors favoring infections of livestock with T. gondii. Knowledge on potential risk factors is prerequisite to implement effective biosecurity measures on farms to prevent T. gondii infections. Risk factors identified by many studies are cat-related, but also those associated with a potential contamination of fodder or water, and with access to a potentially contaminated environment. Published information on the costs T. gondii infections cause in livestock production, is scarce. The most recent peer reviewed reports from Great Britain and Uruguay suggest annual cost of about 5-15 million US $ per country. Since these estimates are outdated, future studies are needed to estimate the present costs due to toxoplasmosis in livestock. Further, the fact that T. gondii infections in livestock may affect human health needs to be considered and the respective costs should also be estimated, but this is beyond the scope of this article.
Collapse
Affiliation(s)
- S. Stelzer
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493 Greifswald - Insel Riems, Germany
| | - W. Basso
- Institute of Parasitology, University of Bern, Länggassstrasse 122, 3012 Bern, Switzerland
| | - J. Benavides Silván
- Instituto de Ganadería de Montaña (CSIC-Universidad de León) Grulleros, 24346 León, Spain
| | - L.M. Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - P. Maksimov
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493 Greifswald - Insel Riems, Germany
| | - J. Gethmann
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493 Greifswald - Insel Riems, Germany
| | - F.J. Conraths
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493 Greifswald - Insel Riems, Germany
| | - G. Schares
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493 Greifswald - Insel Riems, Germany
| |
Collapse
|
12
|
First Report on Toxoplasma gondii Seroprevalence in Free-Ranging Pigs in Northeastern China. Acta Parasitol 2019; 64:295-299. [PMID: 30941667 DOI: 10.2478/s11686-019-00045-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 02/13/2019] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Toxoplasma gondii is the pathogen of toxoplasmosis, which affects a wide range of animal species and humans. MATERIALS AND METHODS In the present study, a serological investigation was undertaken to determine the seroprevalence of T. gondii infection in free-ranging pigs in northeastern China. A total of 806 serum samples were collected from free-ranging pigs in 6 cities in Liaoning, Jilin, and Heilongjiang Provinces. RESULTS Among them, 163 serum samples (20.22%) were detected T. gondii positive by indirect hemagglutination test (IHA). In each administrative district, the prevalence ranges from 12.99 to 22.22%. It was found that sample collection year and season were associated with T. gondii infection. Samples collected in 2015 and 2016 had had higher positive rate compared to those collected in 2017. Samples collected in summer and autumn also have higher positive rate than those in winter. CONCLUSION This is the first report on T. gondii seroprevalence in free-ranging pigs in northeastern China, which adds the epidemiological data of T. gondii infection in free-ranging pigs in China. These results indicated that free-ranging pigs in Liaoning, Jilin, and Heilongjiang Provinces are exposed to T. gondii, which is a significant threat to local pig industry as well as public health. It is necessary to take relevant comprehensive measures to prevent and control T. gondii infection in free-ranging pigs in these regions.
Collapse
|
13
|
Foroutan M, Fakhri Y, Riahi SM, Ebrahimpour S, Namroodi S, Taghipour A, Spotin A, Gamble HR, Rostami A. The global seroprevalence of Toxoplasma gondii in pigs: A systematic review and meta-analysis. Vet Parasitol 2019; 269:42-52. [PMID: 31079827 DOI: 10.1016/j.vetpar.2019.04.012] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 03/26/2019] [Accepted: 04/26/2019] [Indexed: 01/29/2023]
Abstract
Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, is an important disease with worldwide distribution. Infection can occur from ingesting raw or undercooked infected meat, and among food animal species, pork is known to be one of the main sources of meat-borne infection. Here, we present results of the first systematic review and meta-analysis on the global T. gondii seroprevalence in pigs. PubMed/MEDLINE, Scopus, and EMBASE databases were comprehensively searched for relevant studies published between January 1, 1990 and October 25, 2018. We used a random effects model to calculate pooled seroprevalence estimates with 95% confidence intervals (CI) and analyzed data from five continents. We also conducted subgroup and meta-regression analyses to evaluate the effects of geographical and climate variables on pooled seroprevalence rates. Among 1542 publications identified, 148 studies containing 150 datasets were included in the meta-analysis, and comprised 148,092 pigs from 47 countries. The pooled global T. gondii seroprevalence in pigs was estimated to be 19% (95%CI, 17-22%; 23,696/148,092), with the lowest seroprevalence in Europe (13%; 10-15%) and highest seroprevalence in Africa (25%; 17-34%) and North America (25%; 19-33%). The seropositivity rates in Asia and South America regions were (21%, 16-26%) and (23%; 17-30%), respectively. A significantly higher T. gondii seroprevalence was associated with higher mean annual temperature and lower geographical latitude. The presence of cats on farms was identified as a potential risk factor for T. gondii seropositivity (OR, 1.41; 95%CI, 1.00-2.02). Our findings highlight the importance of pigs as a possible source of human T. gondii infections.
Collapse
Affiliation(s)
- Masoud Foroutan
- Abadan School of Medical Sciences, Abadan, Iran; Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Yadolah Fakhri
- Department of Environmental Health Engineering, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Seyed Mohammad Riahi
- Social Determinants of Health Research Center, Department of Epidemiology and Biostatistics, Faculty of Health, Birjand University of Medical Sciences, Birjand, Iran
| | - Soheil Ebrahimpour
- Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
| | - Somayeh Namroodi
- Department of Environmental sciences, Faculty of Fisheries and Environmental sciences, Gorgan University of Agricultural Sciences & Natural Resources, Gorgan, Iran
| | - Ali Taghipour
- Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Adel Spotin
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - H Ray Gamble
- National Academy of Sciences, Washington, DC, USA
| | - Ali Rostami
- Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran; mmunoregulation Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran.
| |
Collapse
|
14
|
Tagel M, Lassen B, Viltrop A, Jokelainen P. Large-Scale Epidemiological Study on Toxoplasma gondii Seroprevalence and Risk Factors in Sheep in Estonia: Age, Farm Location, and Breed Associated with Seropositivity. Vector Borne Zoonotic Dis 2019; 19:421-429. [PMID: 30835644 DOI: 10.1089/vbz.2018.2343] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Toxoplasma gondii is a zoonotic parasite of major veterinary and public health importance. The parasite is common in many host species in Estonia, however, information about the seroprevalence in the local sheep population is lacking. We estimated T. gondii seroprevalence and evaluated a limited selection of possible risk factors for T. gondii seropositivity in sheep raised in Estonia. Sera from 1599 sheep from 122 flocks, collected during 2012-2013, were diluted to 1:40 and screened for the presence of anti-T. gondii immunoglobulin G antibodies using a commercial direct agglutination test. The cutoff titer for seropositivity was 40. A total of 667 of the 1599 sheep were T. gondii seropositive, yielding an apparent seroprevalence estimate of 41.71% (95% confidence interval 39.31-44.14). At least one seropositive sheep was detected on the majority (88.53%) of the farms. T. gondii seroprevalence was significantly lower in lambs (age <12 months) than in adults (age ≥12 months) (11.11% and 42.16%, respectively). The seroprevalence increased steeply with age in the first years of life. A multivariable random-effects logistic regression model identified being an adult (odds ratio [OR] 9.55) and being from a farm located on the islands (OR 2.51) as risk factors for T. gondii seropositivity, while being of Texel breed appeared as a protective factor (OR 0.34) when compared with the Estonian Blackhead breed. Exposure to T. gondii was widespread among the investigated sheep. Undercooked meat and unpasteurized milk from sheep from Estonia should be considered possible sources of T. gondii infections to other hosts, including humans.
Collapse
Affiliation(s)
- Maarja Tagel
- 1 Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Tartu, Estonia
| | - Brian Lassen
- 1 Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Tartu, Estonia.,2 Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Arvo Viltrop
- 1 Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Tartu, Estonia
| | - Pikka Jokelainen
- 1 Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Tartu, Estonia.,3 Laboratory of Parasitology, Department of Bacteria, Parasites & Fungi, Infectious Disease Preparedness, Statens Serum Institut, Copenhagen, Denmark.,4 Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| |
Collapse
|
15
|
Olsen A, Berg R, Tagel M, Must K, Deksne G, Enemark HL, Alban L, Johansen MV, Nielsen HV, Sandberg M, Lundén A, Stensvold CR, Pires SM, Jokelainen P. Seroprevalence of Toxoplasma gondii in domestic pigs, sheep, cattle, wild boars, and moose in the Nordic-Baltic region: A systematic review and meta-analysis. Parasite Epidemiol Control 2019; 5:e00100. [PMID: 30906889 PMCID: PMC6411595 DOI: 10.1016/j.parepi.2019.e00100] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/01/2019] [Accepted: 03/01/2019] [Indexed: 12/13/2022] Open
Abstract
Background Toxoplasma gondii is an important foodborne zoonotic parasite. Meat of infected animals is presumed to constitute a major source of human infection and may be a driver of geographical variation in the prevalence of anti-T. gondii antibodies in humans, which is substantial in the Nordic-Baltic region in northern Europe. However, data on seroprevalence of T. gondii in different animal species used for human consumption are scattered. Methods We conducted a systematic review of seroprevalence studies and meta-analysis to estimate the seroprevalence of T. gondii in five animal species that are raised or hunted for human consumption in the Nordic-Baltic region: domestic pigs (Sus scrofa domesticus), sheep (Ovis aries), cattle (Bos taurus), wild boars (Sus scrofa), and moose (Alces alces). We searched for studies that were conducted between January 1990 and June 2018, and reported in articles, theses, conference abstracts and proceedings, and manuscripts. Subgroup analyses were performed to identify variables influencing the seroprevalence. Findings From a total of 271 studies identified in the systematic review, 32 were included in the meta-analysis. These comprised of 13 studies on domestic pigs, six on sheep, three on cattle, six on wild boars, and four on moose. The estimated pooled seroprevalence of T. gondii was 6% in domestic pigs (CI95%: 3–10%), 23% in sheep (CI95%: 12–36%), 7% in cattle (CI95%: 1–21%), 33% in wild boars (CI95%: 26–41%), and 16% in moose (CI95%: 10–23%). High heterogeneity was observed in the seroprevalence data within each species. In all host species except wild boars, the pooled seroprevalence estimates were significantly higher in animals >1 year of age than in younger animals. Not all studies provided information on animal age, sensitivity and specificity of the serological method employed, and the cut-off values used for defining an animal seropositive. Conclusions A substantial proportion of animals raised or hunted for human consumption in the region had tested positive for T. gondii. This indicates widespread exposure to T. gondii among animals raised or hunted for human consumption in the region. Large variations were observed in the seroprevalence estimates between the studies in the region; however, studies were too few to identify spatial patterns at country-level.
Collapse
Affiliation(s)
- Abbey Olsen
- Section for Parasitology and Aquatic Pathobiology, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 100, DK-1870 Frederiksberg C, Denmark.,Department of Food Safety, Veterinary Issues & Risk Analysis, Danish Agriculture & Food Council, Axelborg, Axeltorv 3, DK-1609 Copenhagen, Denmark
| | - Rebecca Berg
- Section for Organismal Biology, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg, Denmark
| | - Maarja Tagel
- Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 62, 51006 Tartu, Estonia
| | - Kärt Must
- Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 62, 51006 Tartu, Estonia
| | - Gunita Deksne
- Department of Parasitology, Institute of Food Safety, Animal Health and Environment "BIOR", Lejupes Str. 3, LV-1076 Riga, Latvia.,Department of Zoology and Animal Ecology, Faculty of Biology, University of Latvia, Jelgavas Str. 1, LV-1004 Riga, Latvia
| | - Heidi Larsen Enemark
- Norwegian Veterinary Institute, Department of Animal Health and Food Safety, P.O. Box 750, Sentrum, NO-0106 Oslo, Norway
| | - Lis Alban
- Department of Food Safety, Veterinary Issues & Risk Analysis, Danish Agriculture & Food Council, Axelborg, Axeltorv 3, DK-1609 Copenhagen, Denmark
| | - Maria Vang Johansen
- Section for Parasitology and Aquatic Pathobiology, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 100, DK-1870 Frederiksberg C, Denmark
| | - Henrik Vedel Nielsen
- Laboratory of Parasitology, Department of Bacteria, Parasites & Fungi, Infectious Disease Preparedness, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark
| | - Marianne Sandberg
- Department of Food Safety, Veterinary Issues & Risk Analysis, Danish Agriculture & Food Council, Axelborg, Axeltorv 3, DK-1609 Copenhagen, Denmark
| | - Anna Lundén
- National Veterinary Institute, Department of Microbiology, SE-751 89 Uppsala, Sweden
| | - Christen Rune Stensvold
- Laboratory of Parasitology, Department of Bacteria, Parasites & Fungi, Infectious Disease Preparedness, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark
| | - Sara M Pires
- National Food Institute, Technical University of Denmark, Kemitorvet 201, 2800 Kgs. Lyngby, Denmark
| | - Pikka Jokelainen
- Laboratory of Parasitology, Department of Bacteria, Parasites & Fungi, Infectious Disease Preparedness, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark.,Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 62, 51006 Tartu, Estonia.,Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, 00014 Helsinki, Finland
| |
Collapse
|