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Kim J, Kim JW, Lee KK, Lee K, Ku BK, Kim HY. Laboratory investigation of causes of bovine abortion and stillbirth in the Republic of Korea, 2014-2020. J Vet Diagn Invest 2024; 36:428-437. [PMID: 38711295 PMCID: PMC11110765 DOI: 10.1177/10406387241239919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024] Open
Abstract
Bovine abortion is a critical problem in the cattle industry. Identifying causes of abortion is key to establishing appropriate herd management and prevention strategies. We used pathology examinations, detection of etiologic agents, and serology to determine the cause of bovine abortions in Korea. We analyzed 360 abortion and stillbirth cases submitted to the Animal and Plant Quarantine Agency from December 2014 to January 2020. The putative cause of abortion was identified in 140 of 360 (38.9%) cases; 124 of the 140 (88.6%) cases were attributed to infections. The most common etiologic agents detected were bovine viral diarrhea virus (65 of 360; 18.1%), Coxiella burnetii (19 of 360; 5.3%), Leptospira spp. (13 of 360; 3.6%), Listeria monocytogenes (9 of 360; 2.5%), and Neospora caninum (8 of 360; 2.2%). Minor abortifacient pathogens included Brucella abortus (2 of 360; 0.6%), bovine alphaherpesvirus 1 (2 of 360; 0.6%), Akabane virus (2 of 360, 0.6%), and bovine ephemeral fever virus (1 of 360; 0.3%). Non-infectious conditions included congenital anomalies (7 of 360; 1.9%), goiter (7 of 360; 1.9%), and vitamin A deficiency (2 of 360; 0.6%). Our diagnostic rate in cases with placenta submitted (42 of 86; 48.8%) was significantly higher than in cases without placenta (98 of 274; 35.8%), which highlights the value of submitting placentas. Our results confirm the status of the large variety of causative agents associated with abortions in cattle in Korea.
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Affiliation(s)
- Jongho Kim
- Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
- Veterinary Pathology Laboratory, College of Veterinary Medicine, Jeonbuk National University, Iksan, Republic of Korea
| | - Jong Wan Kim
- Research Planning Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Kyoung-Ki Lee
- Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Kyunghyun Lee
- Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Bok-Kyung Ku
- Animal Disease Diagnostic Division , Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Ha-Young Kim
- Bacterial Disease Division , Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
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Wang L, Li X, Li L, Cao L, Zhao Z, Huang T, Li J, Zhang X, Cao S, Zhang N, Wang X, Gong P. Establishment of an ultrasensitive and visual detection platform for Neospora caninum based-on the RPA-CRISPR/Cas12a system. Talanta 2024; 269:125413. [PMID: 38042139 DOI: 10.1016/j.talanta.2023.125413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 11/09/2023] [Accepted: 11/14/2023] [Indexed: 12/04/2023]
Abstract
Neospora caninum is a protozoan parasite that causes neosporosis in cattle, and leads to a high rate of abortion and severe financial losses. Rapid and accurate detection is particularly important for preventing and controlling neosporosis. In our research, a highly effective diagnostic technique based on the RPA-CRISPR/Cas system was created to successfully identify N. caninum against the Nc5 gene, fluorescent reporter system and the lateral flow strip (LFS) biosensor were exploited to display results. The specificity and sensitivity of the PRA-CRISPR/Cas12a assay were evaluated. We discovered that it was highly specific and did not react with any other pathogens. The limit of detection (LOD) for this technology was as low as one parasite per milliliter when employing the fluorescent reporter system, and was approximately ten parasites per milliliter based on the LFS biosensor and under blue or UV light. Meanwhile, the placental tissue samples were detected by our RPA-CRISPR/Cas12a detection platform were completely consistent with that of the nested PCR assay (59.4 %, 19/32). The canine feces were detected by our RPA-CRISPR/Cas12a detection platform were completely consistent with that of the nested PCR assay (8.6 %, 6/70). The RPA-CRISPR/Cas12a detection procedure was successfully finished in within 90 min and offers advantages of high sensitivity and specificity, speed and low cost. The technique was better suitable for extensive neosporosis screening in non-laboratory and resource-constrained locations. This study provided a new strategy for more rapid and portable identification of N. caninum.
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Affiliation(s)
- Li Wang
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
| | - Xin Li
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
| | - Lu Li
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
| | - Lili Cao
- Jilin Academy of Animal Husbandry and Veterinary Medicine, Changchun, 130062, China.
| | - Zhiteng Zhao
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
| | - Taojun Huang
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
| | - Jianhua Li
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
| | - Xichen Zhang
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
| | - Songgao Cao
- Pingdu People's Hospital, Qingdao, 266700, China.
| | - Nan Zhang
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
| | - Xiaocen Wang
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
| | - Pengtao Gong
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
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Jilo Tache K, Getachew Y, Negussie H. Seroepidemiology of Neospora caninum in Cattle of Pastoral Production System in Teltelle District of Borana Zone, Southern Ethiopia. Vet Med (Auckl) 2022; 13:247-256. [PMID: 36128200 PMCID: PMC9482781 DOI: 10.2147/vmrr.s377408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 09/05/2022] [Indexed: 12/01/2022]
Abstract
Background Neosporosis is a major cause of abortion in smallholder dairy farms in Ethiopia. However, its status and impact in pastoral cattle production settings were uncovered. This study was performed with the aims of estimating the seroprevalence and associated potential risk factors for Neospora caninum in Boran cattle in Teltelle district of Borana zone, Ethiopia. Methods 180 blood samples were collected from 48 randomly selected pastoral herds using a multistage sampling technique and subjected to an indirect enzyme-linked immunosorbent assay (ELISA) test to detect antibodies specific to N. caninum. A questionnaire survey was also used to identify the potential risk factors of N. caninum in the study area. Evaluation of the associated risk factors was conducted using a multivariable logistic regression model. Results Antibodies against N. caninum exposure were detected in 5% of cattle (95% CI: 1.816–8.184) from 180 animals tested. Similarly, the seroprevalence of N. caninum in herds with at least one positive animal was 14.6% (95% CI: 4.598–24.567) from 48 herds examined. A multivariable logistic regression model identified the following as significant risk factors: a history of abortion (AOR = 23; 95% CI: 2.354–188.702; P = 0.006), dystocia (AOR = 11; 95% CI = 22.275–55.860; P = 0.003), wells water sources (AOR = 9; 95% CI: 1.599–47.568; P = 0.012), and dogs fed with raw animal products (AOR = 6; 95% CI: 11.213–27.222; P = 0.028). Conclusion This study revealed the first serological evidence of N. caninum exposure in cattle reared under pastoral production system. Our findings suggest N. caninum is likely to be an important cause of abortion and dystocia in cattle in Ethiopia. Management practices, such as provision of hygienic water and restriction of dogs fed with raw animal products, are likely to reduce the risk of infection. Thus, maximizing community awareness about these disease management practices is suggested.
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Affiliation(s)
- Kula Jilo Tache
- School of Veterinary Medicine, Borena University, Borena, Yabelo, Ethiopia
| | - Yitbarek Getachew
- Department of Clinical Studies, College of Veterinary Medicine and Agriculture, Addis Ababa University, Bishoftu, Ethiopia
| | - Haileleul Negussie
- Department of Clinical Studies, College of Veterinary Medicine and Agriculture, Addis Ababa University, Bishoftu, Ethiopia
- Correspondence: Haileleul Negussie, Department of Clinical Studies, College of Veterinary Medicine and Agriculture, Addis Ababa University, P. O. Box; 34, Bishoftu, Ethiopia, Email
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Macedo CABD, Macedo MFSBD, Miura AC, Taroda A, Cardim ST, Innes EA, Katzer F, Cantón GJ, Chianini F, Headley SA, Garcia JL. Occurrence of abortions induced by Neospora caninum in dairy cattle from Santa Catarina, southern Brazil. REVISTA BRASILEIRA DE PARASITOLOGIA VETERINARIA 2017; 26:292-298. [PMID: 28977243 DOI: 10.1590/s1984-29612017051] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 08/21/2017] [Indexed: 11/22/2022]
Abstract
Abstract The aim of the present study was to investigate the occurrence of N. caninum associated with abortions of dairy cattle from Santa Catarina state, southern Brazil by using enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC), and polymerase chain reaction (PCR). Blood from dairy cows that aborted along with intrathoracic fluid and tissue samples (brain, heart, liver, and lung) from their fetuses were collected and used for serology; PCR, histopathological, and immunohistochemistry (IHC) evaluations were also conducted. Twenty-one cows (51.2%) out of 41, and eight fetuses (26.7%) out of 30 were ELISA (HerdCheck, IDEXX) positive for N. caninum. Dams > 36 months of age had a higher risk of being serum positive than younger animals. PCR and IHC revealed that 38.8% (14/36) and 25.0% (9/36) of the fetuses were positive for N. caninum, respectively for each of the tests. Seropositive cows had a higher frequency of fetuses that were also positive by either intrathoracic fluid, PCR, or IHC. In summary, the present study observed a high frequency of N. caninum in abortions from dairy cows from southern Brazil, with a higher N. caninum prevalence found in cows that were older than 36 months. In addition, serology, PCR, and IHC should be used all together for better diagnosis of neosporosis in cattle.
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Affiliation(s)
| | | | | | | | | | | | | | - German Jose Cantón
- Moredun Research Institute, United Kingdom; Instituto Nacional de Tecnología Agropecuaria, Argentina
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Gondim LSQ, Jesus RF, Ribeiro-Andrade M, Silva JCR, Siqueira DB, Marvulo MFV, Aléssio FM, Mauffrey JF, Julião FS, Savani ESMM, Soares RM, Gondim LFP. Sarcocystis neurona and Neospora caninum in Brazilian opossums (Didelphis spp.): Molecular investigation and in vitro isolation of Sarcocystis spp. Vet Parasitol 2017; 243:192-198. [PMID: 28807293 DOI: 10.1016/j.vetpar.2017.07.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 06/12/2017] [Accepted: 07/04/2017] [Indexed: 11/19/2022]
Abstract
Sarcocystis neurona and Neospora spp. are protozoan parasites that induce neurological diseases in horses and other animal species. Opossums (Didelphis albiventris and Didelphis virginiana) are definitive hosts of S. neurona, which is the major cause of equine protozoal myeloencephalitis (EPM). Neospora caninum causes abortion in cattle and infects a wide range of animal species, while N. hughesi is known to induce neurologic disease in equids. The aims of this study were to investigate S. neurona and N. caninum in tissues from opossums in the northeastern Brazil, and to isolate Brazilian strains of Sarcocystis spp. from wild opossums for comparison with previously isolated strains. Carcasses of 39 opossums from Bahia state were available for molecular identification of Sarcocystis spp. and N. caninum in their tissues, and for sporocyst detection by intestinal scraping. In addition, Sarcocystis-like sporocysts from nine additional opossums, obtained in São Paulo state, were tested. Sarcocystis DNA was found in 16 (41%) of the 39 opossums' carcasses; N. caninum DNA was detected in tissues from three opossums. The sporocysts from the nine additional opossums from São Paulo state were tested by bioassay and induced infection in nine budgerigars, but in none of the gamma-interferon knockout mice. In vitro isolation was successful using tissues from all nine budgerigars. The isolated strains were maintained in CV-1 and Vero cells. Three of nine isolates presented contamination in cell culture and were discarded. Analysis of six isolates based on five loci showed that these parasites were genetically different from each other and also distinct from S. neurona, S. falcatula, S. lindsayi, and S. speeri. In conclusion, opossums in the studied regions were infected with N. caninum and Sarcocystis spp. and represent a potential source of infection to other animals. This is the first report of N. caninum infection in tissues from black-eared opossum (D. aurita or D. marsupialis) and white-eared opossum (D. albiventris). Brazilian opossums are probably infected by different Sarcocystis spp. distinct from S. neurona and S. falcatula, or present a high level of genetic recombination.
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Affiliation(s)
- Leane S Q Gondim
- Departamento de Anatomia, Patologia e Clínicas, Universidade Federal da Bahia, Escola de Medicina Veterinária e Zootecnia, Avenida Adhemar de Barros, 500, Ondina, Salvador 40170-110, Bahia, Brazil
| | - Rogério F Jesus
- Departamento de Anatomia, Patologia e Clínicas, Universidade Federal da Bahia, Escola de Medicina Veterinária e Zootecnia, Avenida Adhemar de Barros, 500, Ondina, Salvador 40170-110, Bahia, Brazil
| | - Müller Ribeiro-Andrade
- Departamento de Anatomia, Patologia e Clínicas, Universidade Federal da Bahia, Escola de Medicina Veterinária e Zootecnia, Avenida Adhemar de Barros, 500, Ondina, Salvador 40170-110, Bahia, Brazil
| | - Jean C R Silva
- Departamento de Medicina Veterinária, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, s/n, Dois Irmãos, Recife 52171-900, Pernambuco, Brazil; Instituto Brasileiro para Medicina da Conservação - Tríade, Rua Silveira Lobo 32, Caixa Postal 38, Casa Forte, Recife 532061-030, Pernambuco, Brazil
| | - Daniel B Siqueira
- Instituto Brasileiro para Medicina da Conservação - Tríade, Rua Silveira Lobo 32, Caixa Postal 38, Casa Forte, Recife 532061-030, Pernambuco, Brazil
| | - Maria F V Marvulo
- Faculdade Max Planck, Rodovia João Ceccon 60, Altos da Bela Vista, Indaiatuba 13331-400, São Paulo, Brazil; Instituto Brasileiro para Medicina da Conservação - Tríade, Rua Silveira Lobo 32, Caixa Postal 38, Casa Forte, Recife 532061-030, Pernambuco, Brazil
| | - Felipe M Aléssio
- Instituto de Ciências Biológicas da Universidade de Pernambuco, Rua Arnóbio Marques, 310, Santo Amaro, Recife 50100-130, Pernambuco, Brazil; Laboratoire Population Environnement Développement, IRD Aix-Marseille Université, Centre St Charles, Case 10 3, place Victor Hugo 13331 Marseille, Cedex 03 France
| | - Jean-François Mauffrey
- Laboratoire Population Environnement Développement, IRD Aix-Marseille Université, Centre St Charles, Case 10 3, place Victor Hugo 13331 Marseille, Cedex 03 France
| | - Fred S Julião
- Instituto Federal Baiano, Campus Santa Inês, Salvador, Bahia, Brazil
| | | | - Rodrigo M Soares
- Departamento de Medicina Veterinária Preventiva e Saúde Animal (VPS), Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, Av. Prof. Dr. Orlando Marques de Paiva, 87-Cidade Universitária, São Paulo, SP, 05508 270, Brazil
| | - Luís F P Gondim
- Departamento de Anatomia, Patologia e Clínicas, Universidade Federal da Bahia, Escola de Medicina Veterinária e Zootecnia, Avenida Adhemar de Barros, 500, Ondina, Salvador 40170-110, Bahia, Brazil.
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Agerholm JS. Coxiella burnetii associated reproductive disorders in domestic animals--a critical review. Acta Vet Scand 2013; 55:13. [PMID: 23419216 PMCID: PMC3577508 DOI: 10.1186/1751-0147-55-13] [Citation(s) in RCA: 184] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 01/21/2013] [Indexed: 12/01/2022] Open
Abstract
The bacterium Coxiella burnetii has been detected in the fetal membranes, birth fluids and vaginal mucus, as well as in the milk and other excretions of several domestic mammals. The finding of C. burnetii in association with abortion, parturition and in the postpartum period has led to the hypothesis that C. burnetii causes a range of reproductive diseases. This review critically evaluates the scientific basis for this hypothesis in domestic mammals.The review demonstrates a solid evidence for the association between C. burnetii infection and sporadic cases of abortion, premature delivery, stillbirth and weak offspring in cattle, sheep and goats. C. burnetii induced in-herd epidemics of this complete expression of reproductive failure have been reported for sheep and goats, but not for cattle. The single entities occur only as part of the complex and not as single events such as generally increased stillbirth rate. Studies show that C. burnetii initially infects the placenta and that subsequent spread to the fetus may occur either haematogenous or by the amniotic-oral route. The consequences for the equine, porcine, canine and feline conceptus remains to the elucidated but that infection of the conceptus may occur is documented for most species. There is no solid evidence to support a hypothesis of C. burnetii causing disorders such as subfertility, endometritis/metritis, or retained fetal membranes in any kind of domestic animal species.There is a strong need to validate non-pathology based methods such as polymerase chain reaction for their use in diagnostic and research in relation to establishing C. burnetii as the cause of abortion and to adapt an appropriate study design and include adequate control animals when linking epidemiological findings to C. burnetii or when evaluating effects of vaccination in production herds.
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Affiliation(s)
- Jørgen S Agerholm
- Section for Veterinary Reproduction and Obstetrics, Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 68, DK-1870, Frederiksberg C, Denmark.
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Bishop S, King J, Windsor P, Reichel MP, Ellis J, Slapeta J. The first report of ovine cerebral neosporosis and evaluation of Neospora caninum prevalence in sheep in New South Wales. Vet Parasitol 2010; 170:137-42. [PMID: 20189309 DOI: 10.1016/j.vetpar.2010.01.030] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Revised: 01/15/2010] [Accepted: 01/20/2010] [Indexed: 11/27/2022]
Abstract
Presence of Neospora caninum DNA was detected in the brain and spinal cord of an adult Merino sheep suspected of dying with acute non-suppurative meningoencephalitis and mild to moderate non-suppurative myelitis. The most severe neurological lesions were found in the midbrain at the rostral coliculi with moderate to severe multifocal vasculitis and gliosis. As this was the first known occurrence of cerebral disease in sheep in Australia caused by N. caninum, we surveyed sera from five sheep properties in New South Wales (NSW) to obtain information on the likely prevalence of N. caninum infection in NSW sheep flocks. Serology using a commercial indirect enzyme-linked immunosorbent assay (ELISA) revealed no N. caninum antibody-positive sheep (n=184). However an observed prevalence for N. caninum antibodies using a commercially available competitive ELISA was 2.2% (5/232). We conclude that although the diagnosis of fatal ovine cerebral neosporosis is of importance to our surveillance program for transmissible spongiform encephalopathy (TSE) exclusion, sheep in NSW are not commonly infected with N. caninum and this species likely plays only a minor role in the life cycle of this parasite in Australia.
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Affiliation(s)
- Stephanie Bishop
- Faculty of Veterinary Science, University of Sydney, New South Wales 2006, Australia
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Seroprevalence of Neospora caninum in dairy cattle ranches with high abortion rate: Special emphasis to serologic co-existence with Toxoplasma gondii, Brucella abortus and Listeria monocytogenes. Vet Parasitol 2009; 164:306-10. [DOI: 10.1016/j.vetpar.2009.06.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Revised: 05/28/2009] [Accepted: 06/02/2009] [Indexed: 11/19/2022]
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Pescador CA, Corbellini LG, Oliveira EC, Raymundo DL, Driemeier D. Histopathological and immunohistochemical aspects of Neospora caninum diagnosis in bovine aborted fetuses. Vet Parasitol 2007; 150:159-63. [PMID: 17904290 DOI: 10.1016/j.vetpar.2007.08.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 08/04/2007] [Accepted: 08/14/2007] [Indexed: 11/20/2022]
Abstract
Lesions suggestive of protozoal infection such as nonsuppurative myositis, nonsuppurative myocarditis, nonsuppurative pneumonia associated with focal cellular necrosis and multifocal necrotizing nonsuppurative encephalitis were observed in 89 (34%) out of 258 aborted bovine fetuses. Immunohistochemistry (IHC) revealed tachyzoites and cysts of Neospora caninum in 55 (61.8%) of these 89 fetuses. Several fetal variables were tested by multivariate logistic regression, in which increasing odds for positivity in IHC were associated with the presence of lesion in the lung (OR=12.11) and less autolytic brain tissue (brain consistency, OR=5.73). However, autolysis in the brain precluded presumptive diagnosis made by histopathology in 53% of the fetuses examined. These results indicate that, when fetal brain is autolyzed, the lung may be adequately used for the presumptive diagnosis of N. caninum infection. The results also confirmed that, even autolyzed, the brain is the most suitable organ for anti-N. caninum IHC.
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Affiliation(s)
- C A Pescador
- Faculdade de Medicina Veterinária, Departamento de Patologia Clínica Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Cx. Postal 15094, CEP91540-000, Porto Alegre, Rio Grande do Sul, Brazil
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Gibney EH, Kipar A, Rosbottom A, Guy CS, Smith RF, Hetzel U, Trees AJ, Williams DJL. The extent of parasite-associated necrosis in the placenta and foetal tissues of cattle following Neospora caninum infection in early and late gestation correlates with foetal death. Int J Parasitol 2007; 38:579-88. [PMID: 18021783 DOI: 10.1016/j.ijpara.2007.09.015] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 08/31/2007] [Accepted: 09/04/2007] [Indexed: 11/19/2022]
Abstract
The protozoan parasite Neospora caninum is the most frequently diagnosed abortifacient in the UK and a leading cause of abortion worldwide but the mechanisms leading to abortion are not fully understood. The distribution of parasites and the histopathological changes in the placenta and foetus were compared in 12 cows following experimental infection of cattle with N. caninum in early (n=6) and late (n=6) gestation, by PCR, immunohistology, light microscopy and transmission electron microscopy. Twelve uninfected pregnant cattle were used as controls. Infection in early gestation led to foetal death. In the placentae of cattle immediately following foetal death, N. caninum DNA was detected and there was evidence of widespread parasite dissemination. This was associated with extensive focal epithelial necrosis, serum leakage and moderate maternal interstitial mononuclear cell infiltration. In the foetuses, parasites were evident in all tissues examined and were associated with necrosis. In the placenta of cattle infected in late gestation, N. caninum DNA was detected sporadically but parasites were not evident immunohistologically. Small foci of necrosis were seen associated with mild interstitial mononuclear cell infiltration. Detection of N. caninum DNA in the foetuses was sporadic and parasites were demonstrated immunohistologically in brain and spinal cord only, with an associated mononuclear cell infiltration. This data is consistent with uncontrolled parasite spread in an immunologically immature foetus and could, via multiparenchymal necrosis of foetal tissues or the widespread necrosis and inflammation observed in the placenta, be the cause of Neospora-associated abortions.
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Affiliation(s)
- E Helen Gibney
- Veterinary Parasitology, Liverpool School of Tropical Medicine/Faculty of Veterinary Science, Pembroke Place, Liverpool L3 5QA, UK
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Ramamoorthy S, Duncan R, Lindsay DS, Sriranganathan N. Optimization of the use of C57BL/6 mice as a laboratory animal model for Neospora caninum vaccine studies. Vet Parasitol 2007; 145:253-9. [PMID: 17306460 DOI: 10.1016/j.vetpar.2006.12.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Revised: 10/22/2006] [Accepted: 12/07/2006] [Indexed: 11/20/2022]
Abstract
The development and testing of vaccines for Neospora caninum in mice require challenge studies to demonstrate a reduction in clinical signs or prevention of vertical transmission of the parasite after vaccination. Genetic susceptibility to N. caninum varies with the strain of mice. In this study, C57BL/6 mice were evaluated as a model for Neospora vaccine studies. A lethal challenge model was developed and the LD(50) was determined to be 1.5 x 10(7)N. caninum tachyzoites/mouse, delivered intraperitoneally. Brain lesions encountered in sections from sub-lethally challenged mice were scored on the basis of severity and total number of lesions to develop a histopathological scoring system for vaccine efficacy. A vertical transmission model for N. caninum vaccine studies was developed by studying mice that were infected either 2 weeks prior to mating or between days 12 and 14 of pregnancy. It was found that infection prior to mating reduced the average number of pups per litter. DNA extracted from fetal tissue was examined by a N. caninum specific polymerase chain reaction (PCR). The rate of vertical transmission was 0, 100 and 90.5% for the uninfected controls, mice infected during pregnancy and mice infected before mating, respectively. This study demonstrates that the C57BL/6 strain of mice is a good model for N. caninum vaccine studies because it is possible to establish a clear-cut lethal challenge model in C57BL/6 mice and they transmit the disease to their offspring efficiently.
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Affiliation(s)
- S Ramamoorthy
- Department of Biomedical Sciences and Pathobiology, Virginia Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute & State University, 1410 Prices Fork Road, CMMID, Blacksburg, VA 24061, USA
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Angelo MD, Galuppo A, Zerio N, Melo G, Pituco E, Okuda L. ESTUDO MORFOLÓGICO DE EMBRIÕES BOVINOS FERTILIZADOS IN VITRO EXPOSTOS EXPERIMENTALMENTE À NEOSPORA CANINUM. ARQUIVOS DO INSTITUTO BIOLÓGICO 2006. [DOI: 10.1590/1808-1657v73p2112006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
RESUMO Durante a última década, a infecção por Neospora caninum tem emergido como uma importante doença reprodutiva em bovinos e, em vários países, tem sido diagnosticada como principal causa de aborto. Tendo em vista a importância dessa doença esse trabalho teve como objetivo avaliar morfologicamente embriões bovinos produzidos in vitro infectados experimentalmente por N. caninum. Os embriões foram produzidos in vitro a partir de oócitos colhidos de ovários de bovinos provenientes de abatedouro. Foram separados em grupo controle, mantido somente com meio HTF e grupo infectado com 10 mL de N. caninum. Os embriões foram avaliados após 48 e 96h em microscópio óptico invertido. Os embriões do grupo controle não apresentaram alterações morfológicas. No grupo infectado foi verificado o aparecimento de grânulos escuros no citoplasma, bloqueio da clivagem e ruptura da zona pelúcida (ZP). Em alguns casos, observou-se estruturas semelhantes a taquizoitos de N. caninum no interior da ZP. Esses resultados sugerem que, de alguma maneira há a interação do patógeno com o embrião, talvez em um processo inicial de ligação com a ZP, promovendo posteriormente sua entrada. Esses estudos tornam-se relevantes quando se leva em consideração a possível transmissão da N. caninum por técnicas conceptivas artificiais.
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Staubli D, Sager H, Haerdi C, Haessig M, Gottstein B. Precolostral serology in calves born from Neospora-seropositive mothers. Parasitol Res 2006; 99:398-404. [PMID: 16572335 DOI: 10.1007/s00436-006-0170-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2006] [Accepted: 02/10/2006] [Indexed: 11/29/2022]
Abstract
The present study was designed to exploratively determine (a) how many healthy calves, born from seropositive mothers, were also precolostrally seropositive; (b) how many precolostrally negative calves became postcolostrally positive; and (c) in these calves, how the IgG1/IgG2 situation developed pre- and postcolostrally. All calves were born from mothers that were determined to be seropositive in a conventional Neospora caninum-ELISA and by immunoblotting. When the diagnostic performance of the conventional ELISA was compared with that of immunoblotting and an IgG1/IgG2-ELISA in the calves, the latter two exhibited a higher sensitivity: From a total of 15 precolostral calf sera, 7 were positive in the conventional ELISA (diagnostic sensitivity 47%) compared to 15 that were positive by immunoblotting (diagnostic sensitivity 100%) and 12 that were positive by the IgG1/IgG2-ELISA (diagnostic sensitivity 80%). With regard to IgG1/IgG2 findings in the dams, IgG2 appeared as the dominant subclass in the humoral immune response of adult cattle, while in calves, IgG1 appeared as the main prenatally/precolostrally reactive antibody isotype. Provided that precolostral seropositivity reflects postnatal persistent infection with N. caninum, we then postulate that, basically, all of our study calves born form N. caninum-seropositive mothers were prenatally infected with the parasite, and may, thus, all become members of the next transmitting generation.
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Affiliation(s)
- Daniela Staubli
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Laenggass-Strasse 122, CH-3012, Bern, Switzerland
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Sager H, Moret CS, Müller N, Staubli D, Esposito M, Schares G, Hässig M, Stärk K, Gottstein B. Incidence of Neospora caninum and other intestinal protozoan parasites in populations of Swiss dogs. Vet Parasitol 2006; 139:84-92. [PMID: 16564131 DOI: 10.1016/j.vetpar.2006.02.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2005] [Revised: 02/14/2006] [Accepted: 02/21/2006] [Indexed: 11/23/2022]
Abstract
The protozoan parasite Neospora caninum is one of the most important abortifacient organisms in cattle worldwide. The dog is known to act as definitive host although its potential role as infection source for bovines still remains unelucidated. The aim of the present study was to compile initial epidemiological data on the prevalence and incidence of N. caninum in Swiss dogs acting as definitive hosts. Thus, 249 Swiss dogs were investigated coproscopically in monthly intervals over a period of 1 year. A total of 3289 fecal samples was tested by the flotation technique. Among these, 202 were shown to contain Sarcocystis sp. (6.1%), 149 Cystoisospora sp. (=Isospora sp.; 4.5%) and 25 Hammondia/Neospora-like oocysts (HNlO) (0.7%). All but one sample containing HNlO were from different dogs; one dog shed HNlO at two subsequent time points. Calculation of the yearly incidence for HNlO resulted in the surprisingly high value of 9.2%. Farm dogs exhibited a higher incidence for HNlO than urban family dogs. Thirteen out of the 25 HNlO-samples showed sporulation after 5 days incubation at room temperature. HNlO were further differentiated by species-specific PCR. However, all HNlO-samples were negative for N. caninum, Hammondia heydorni and Toxoplasma gondii. One reason may be the low oocyst density found in most fecal samples, which did not permit us to carry out PCR under optimal conditions. Three out of the 25 HNlO-cases contained enough oocysts to allow further enrichment and purification by the flotation technique. Subsequently, twenty to fifty sporulated HNlO-oocysts were orally administered to Meriones unguiculatus. All gerbils were seronegative for N. caninum at 5 weeks p.i. A N. caninum-seroprevalence of 7.8% was determined by ELISA upon 1132 serum samples collected from dogs randomly selected by veterinarians among their clinical patients.
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Affiliation(s)
- H Sager
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, CH-3001-Bern, Switzerland.
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Innes EA, Wright S, Bartley P, Maley S, Macaldowie C, Esteban-Redondo I, Buxton D. The host–parasite relationship in bovine neosporosis. Vet Immunol Immunopathol 2005; 108:29-36. [PMID: 16098610 DOI: 10.1016/j.vetimm.2005.07.004] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Infection with the protozoan parasite Neospora caninum is thought to be a major cause of reproductive failure in cattle worldwide. Cattle infected with the parasite are three to seven times more likely to abort compared to uninfected cattle. The parasite may be transmitted to cattle through the ingestion of oocysts that are shed in the faeces of acutely infected dogs (definitive host of N. caninum) or by congenital infection from mother to foetus via the placenta. Interestingly, transplacental transmission can occur over consecutive pregnancies and congenitally infected heifers can transmit the parasite to their own offspring. This repeated vertical transmission observed in naturally infected cattle suggests that cattle do not easily develop effective immunity to the parasite, presenting a significant challenge to the development of a control strategy based on vaccination. Neosporosis is a disease of pregnancy and studying the bovine maternal and foetal immune responses during pregnancy will help us to understand the change in the balance between the parasite and the host that may result in disease of the foetus. Studies in non-pregnant cattle and in murine models of infection have shown the importance of T-helper 1-type immune responses involving pro-inflammatory cytokines, such as IFNgamma and IL-12, in limiting intracellular multiplication of the parasite. During pregnancy, changes occur in the immune system allowing the mother to accept the foetal allograft. Research in other species has stressed the crucial role of T-helper 2-type cytokines at the materno-foetal interface in maintaining the pregnancy and regulating the potentially damaging effect of Th-1 responses. Studies in cattle have shown that cell proliferation and IFNgamma responses may be significantly down-regulated around mid-gestation. This may mean that cattle are less able to cope with N. caninum infection at this time and are more likely to transmit the parasite to the foetus. Another important factor is the gestational age and hence immuno-competence of the foetus at the time of infection. Early in gestation, N. caninum infection of the placenta and subsequently the foetus usually proves fatal, whereas infection occurring in mid to late pregnancy may result in the birth of a congenitally infected but otherwise healthy calf. Studies of foetal immune responses have shown that at 14 weeks of gestation, lymphocytes only respond to mitogen, while by 24 weeks (mid-gestation), they respond to antigen by proliferating and releasing IFNgamma. Clearly, there are several factors influencing the outcome of N. caninum infection in pregnancy: the timing, quantity and duration of parasitaemia, the effectiveness of the maternal immune response and the ability of the foetus to mount an immune response against the parasite. The challenge is to design a vaccine that will prevent foetal infection by N. caninum. This is likely to involve a fine balancing act with the immune system that will allow intervention in a manner that will tip the host-parasite balance in favour of the host without compromising the pregnancy.
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Affiliation(s)
- Elisabeth A Innes
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh EH26 OPZ, UK. lee.innes.@moredun.ac.uk
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Antony A, Williamson NB. Recent advances in understanding the epidemiology of Neospora caninum in cattle. N Z Vet J 2005; 49:42-7. [PMID: 16032161 DOI: 10.1080/00480169.2001.36201] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Neospora caninum is the most frequently diagnosed cause of cattle abortion in New Zealand and is an important pathogen worldwide. The parasite has been found in aborted bovine foetuses and in puppies with neurological disease. Recent developments have provided new insights into the epidemiology of the disease that are reviewed in this article. TRANSMISSION Transplacental infection is of major importance in the spread of N. caninum overseas. Most congenital infections result in the birth of apparently healthy calves. Seroepidemiological studies indicate introduced point-source infections are also likely, as do investigations of abortion outbreaks in cattle herds attributed to N. caninum. Horizontal transmission is an important determinant of the stability of infection prevalence in a herd. Two potential sources of horizontal transmission that have recently been reported are: via a canine definitive host and; cow-to-calf transmission through pooled colostrum or milk. Transmission parameters for the organism have been estimated using mathematical modeling, to explore the epidemiology and options for control of N. caninum infection in dairy cattle in the absence of precise epidemiological data. LIFE-CYCLE: Seroepidemiologic studies, combined with the knowledge that dogs can be a definitive host, provide evidence supporting a dog-cattle life-cycle. The importance of dogs in the epidemiology of bovine neosporosis is not yet clear. It is likely that N. caninum oocysts in dog faeces could serve as a source of infection for cattle and recent studies have shown that the canine and bovine isolatesflare the same organism. Infection of cattle orally exposed to oocysts has been demonstrated experimentally but not in nature. It is not known if other wild carnivores may serve as definitive hosts of N. caninum. CONCLUSION Despite active research for over a decade, very little is known about the mechanisms of transmission of N. caninum. Vertical transmission is well documented but horizontal spread and the pathogenesis of abortion from this disease need further investigation. It is evident that, even with a very high probability of vertical transmission, some form of horizontal transmission is required for the disease to persist in a herd.
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Affiliation(s)
- A Antony
- Institute of Veterinary Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand
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Canada N, Carvalheira J, Meireles CS, Correia da Costa JM, Rocha A. Prevalence of Neospora caninum infection in dairy cows and its consequences for reproductive management. Theriogenology 2005; 62:1229-35. [PMID: 15325549 DOI: 10.1016/j.theriogenology.2004.01.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2003] [Revised: 12/03/2003] [Accepted: 01/15/2004] [Indexed: 11/28/2022]
Abstract
This study was carried out to determine the prevalence of neosporosis in an area of intensive dairy production, in Portugal. Sera samples were obtained in a random basis from 114 cows in 49 herds (group A), and from 1237 cows in 36 herds with a history of abortion outbreaks (group B). All sera samples were tested for neosporosis by direct agglutination test (DAT). Additionally, attempts to isolate Neospora caninum in 42 aborted bovine fetuses from 38 dairy herds (group C) were carried out, utilizing a bioassay with immuno-depressed Swiss Webster mice. Parasitological confirmation was done by indirect fluorescent antibody test (IFAT). The prevalence of neosporosis in the group A was 28%. Group B had a significantly (P < 0.001) higher prevalence (46%) and Neospora caninum was isolated in 36% of the aborted fetuses (group C). These results indicate that neosporosis, a disease only recently (2001) diagnosed in Portugal, has a high prevalence in the country, particularly in populations with a story of abortion. Thus, neosporosis should systematically be considered in the differential diagnosis of abortion. In the context of embryo transfers, the importance of selecting Neospora-free embryo recipients is discussed, as well as the pertinence of assessing the Neospora status of traded and imported cattle.
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Affiliation(s)
- Nuno Canada
- CECA, Center for the Study of Animal Sciences, Abel Salazar Institute of Biomedical Sciences, University of Porto, Campus Agrário de Vairão, R. Padre Armando Quintas, 4485-661 Vairão, Portugal.
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Macaldowie C, Maley SW, Wright S, Bartley P, Esteban-Redondo I, Buxton D, Innes EA. Placental pathology associated with fetal death in cattle inoculated with Neospora caninum by two different routes in early pregnancy. J Comp Pathol 2005; 131:142-56. [PMID: 15276854 DOI: 10.1016/j.jcpa.2004.02.005] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2003] [Accepted: 02/23/2004] [Indexed: 11/19/2022]
Abstract
Pregnant cattle were inoculated with N. caninum strain NC-1 tachyzoites intravenously (iv) (group 1, n = 8) or subcutaneously (sc) (group 2, n = 8) at 70 days' gestation. Control animals (group 3; n = 8) received uninfected Vero cells iv. Two animals from each group were killed at 14, 28, 42 and 56 days post-inoculation (dpi). Fetal mortality was 100% and 50%, respectively, in groups 1 and 2 from 28 dpi. In group 1 foci of degenerative fetal placental villi were observed at 14 dpi, with clusters of N. caninum tachyzoites in the affected mesenchyme. There was also inflammation of maternal septal tissues, with necrotic cell debris and serum exudate at the interstitium. At 28 dpi pregnancy had ended and the fetal cotyledons had become detached from the maternal caruncles. Immunohistochemically, particulate N. caninum antigen was detected in the cotyledons. At 42 and 56 dpi, fetal tissues had disappeared, the caruncles were greatly reduced in size, and the uterine epithelium had been largely restored. In group 2, lesions were either severe or absent ("all or nothing" response). In one animal carrying a dead fetus at 28 dpi, placentitis was much more severe than that seen in group 1 at 14 dpi. Lesions contained neutrophils, eosinophils and N. caninum antigen. In animals carrying dead fetuses at 42 and 56 dpi, fetal remains were found and the cotyledons contained N. caninum antigen. Antigen was also detected in fetal tissues. No significant pathological changes were detected in group 2 animals carrying live fetuses or any animal in group 3. Thus, N. caninum administered iv or sc in early pregnancy resulted in rapid fetal death, with parasite-associated lesions in the placenta and fetus. Of the two inoculation routes, the intravenous induced the more acute placental lesions and greater mortality.
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Affiliation(s)
- C Macaldowie
- Division of Virology, Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 OPZ, UK
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Hobson JC, Duffield TF, Kelton D, Lissemore K, Hietala SK, Leslie KE, McEwen B, Peregrine AS. Risk factors associated with Neospora caninum abortion in Ontario Holstein dairy herds. Vet Parasitol 2005; 127:177-88. [PMID: 15710518 DOI: 10.1016/j.vetpar.2004.09.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2004] [Indexed: 10/26/2022]
Abstract
The objective of this epidemiological study was to identify risk factors for Neospora caninum-related abortions in Ontario Holstein dairy herds. A total of 88 herds, consisting of 5080 cattle, and utilizing Dairy Herd Improvement (DHI) services, were divided into three groups. Case (n = 30) and first control (n = 31) herds were selected from 1998 and 1999 fetal abortion submissions to the Animal Health Laboratory, University of Guelph, that were histopathologically positive or negative, respectively, for N. caninum. A second control group (n = 27) was selected from multiple sources of herds sampled within the previous 4 years that had a low seroprevalence (<7%) to N. caninum. Between May and December 1999, all available cows on all farms, in parity one or greater, were blood sampled. The sera were then analyzed for antibody to N. caninum using a kinetic ELISA. A survey administered at the time of sampling recorded information on housing, animal species present, manure management, reproduction, biosecurity practices, wildlife observations, peri-parturient cow management, herd disease history and nutrition. Production and other herd parameters were obtained from DHI records. Logistic regression indicated that the following parameters were positively associated with a N. caninum abortion in a herd: the N. caninum herd seroprevalence (OR = 1.1), the total number of dogs on a farm (OR = 2.8), the frequency that dogs were observed defecating in mangers (OR = 2.8), the number of horses on a farm (OR = 3.1), the observed annual rate of retained fetal membranes (OR = 1.2) and the observed annual rate of cows returning to estrus after pregnancy confirmation (OR = 1.2). Factors negatively associated were the frequency of stray cats and wild canids observed on a farm (OR = 0.4 and OR = 0.7, respectively) and the housing of heifers on loafing packs (a housing pen divided into feed manger, scrape alley and bedded pack areas, OR = 0.1).
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Affiliation(s)
- J C Hobson
- Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Ont., Canada N1G 2W1.
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Abstract
Although the majority of pregnancy failures occur during the embryonic period, reports indicate that approximately 5% of detected pregnancies are lost during the fetal period, underlining the fact that fetal death is a substantial cause of economic loss. However, examination for fetal development or death during pregnancy is not performed routinely in domestic animals, and reference curves for normal fetal growth are, therefore, scarce. In this paper, the numerous possible causes of fetal death are reviewed briefly, with emphasis on the role of placental problems in fetal death and impaired fetal viability. In this respect, the role of placental insufficiency as a cause of pregnancy loss in twin pregnancies in monotocous species is well known, whereas the abnormal placental development leading to retarded fetal growth during pregnancies in recipients of in vitro produced (IVP) or nuclear transfer (NT) embryos has been less extensively documented. Fetal viability or death can be evaluated using hormonal, chemical and ultrasonographic parameters. For example, the viability of the feto-placental unit can be examined by measuring maternal plasma concentrations of oestrone sulphate or the placental proteins, including pregnancy-associated glycoprotein (PAG) and pregnancy-specific protein B-60 (PSPB-60). Low concentrations of any of these three indicate either no pregnancy, or if pregnancy was confirmed earlier, fetal death and abnormally high or low levels can indicate fetal abnormality. Ultrasound can be used to examine the fetal heart rate (FHR), the incidence of fetal movements (FM), the appearance of fetal fluids and the development of the fetus and placenta. However, although abnormal FHRs have been correlated to subsequent fetal death, it is important to remember that there is a large physiological variation in FHR at the end of gestation, due to different behavioural states and differences in FM patterns. Although monitoring fetal viability and death using hormonal and ultrasonographic evaluations is possible during pregnancy in domestic animals, there is considerable physiological variations in the 'normal' values. Therefore, suitable combinations of tests need to be identified and more accurate reference values generated before such approaches can be considered reliable for monitoring the status of individual fetuses.
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Affiliation(s)
- F H Jonker
- Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, The Netherlands.
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Hobson JC, Duffield TF, Kelton D, Lissemore K, Hietala SK, Leslie KE, McEwen B, Cramer G, Peregrine AS. Neospora caninum serostatus and milk production of Holstein cattle. J Am Vet Med Assoc 2002; 221:1160-4. [PMID: 12387387 DOI: 10.2460/javma.2002.221.1160] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine whether Neospora caninum serostatus was associated with milk production among Holstein cattle in Ontario. DESIGN Case-control study and cross-sectional observational study. ANIMALS 3,702 Holstein cows in 83 herds (case-control study) and 3,162 Holstein cows in 57 herds. PROCEDURE Herds in the case-control study were grouped on the basis of N. caninum abortion status. Herds in the observational study were considered representative of Ontario dairy herds. The N. caninum serostatus of individual cows was determined with a kinetic ELISA. Milk production was modeled to compare seropositive with seronegative animals while controlling for parity, days since parturition, and herd clustering. RESULTS In the case-control study, 305-day milk production of seropositive cows was significantly less than milk production of seronegative cows in herds with abortions attributable to N. caninum infection and in herds with abortions attributable to pathogens other than N. caninum, but not in herds without abortion problems. In the observational study, 305-day milk production for seropositive cows was not significantly different from milk production of seronegative cows. CONCLUSIONS AND CLINICAL RELEVANCE Results suggest that the association between N. caninum serostatus and milk production in Ontario Holstein dairy cattle may depend on abortion status of the herd. In herds with abortion problems, regardless of cause, N. caninum-seropositive cattle produced less milk, whereas in herds without abortion problems, N. caninum-seropositive cattle produced the same amount of milk as seronegative cattle.
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Affiliation(s)
- Jamie C Hobson
- Department of Population Medicine, Ontario Veterinary College, Guelph, Canada
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22
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Dijkstra T, Barkema HW, Hesselink JW, Wouda W. Point source exposure of cattle to Neospora caninum consistent with periods of common housing and feeding and related to the introduction of a dog. Vet Parasitol 2002; 105:89-98. [PMID: 11900922 DOI: 10.1016/s0304-4017(02)00009-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Eight dairy herds with evidence of post-natal transmission of Neospora caninum were used to test the hypothesis of a point source exposure by a retrospective analysis of the housing and feeding of infected age-groups. The first N. caninum-associated abortion or birth of N. caninum-seropositive offspring from the post-natally infected age-group was considered as the first indication of the infection. In seven of the eight dairy herds, a point source exposure to N. caninum of the infected age-groups was found during a limited period of common housing and feeding. In all herds studied, the analysis indicated that the cattle had been infected shortly before the first abortions occurred. In all, except one herd, the post-natal infection was more directly related to housing than to feeding. Therefore, it appeared that the feed was contaminated in the feeding alley. In one herd, the total mixed ration was found to be the probable path of infection. In all farms studied, a new dog (young, adult dog or litter) had been introduced within a period of 1.5 years prior to the first indication of N. caninum infection in the cattle. As there was evidence in all herds of vertical transmission of neosporosis for years, it is hypothesized that the newly introduced dog was infected with N. caninum by materials from already infected cattle and subsequently transmitted the infection to other cattle by shedding of oocysts.
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Affiliation(s)
- Th Dijkstra
- Animal Health Service, P.O. Box 9, 7400 AA Deventer, The Netherlands.
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Sager H, Fischer I, Furrer K, Strasser M, Waldvogel A, Boerlin P, Audigé L, Gottstein B. A Swiss case-control study to assess Neospora caninum-associated bovine abortions by PCR, histopathology and serology. Vet Parasitol 2001; 102:1-15. [PMID: 11705647 DOI: 10.1016/s0304-4017(01)00524-6] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Neospora caninum is one of the most frequent infectious organisms causing abortion in cattle worldwide. The present case-control study was designed to assess the importance of bovine neosporosis for causing abortion in Swiss cattle and to identify selected risk factors. Infection was primarily diagnosed by a N. caninum-specific PCR and serology, complemented with histopathology and immunohistochemistry. A total of 113 case and 113 corresponding control-farms were studied for 1.5 year. During this time period, 242 abortions were reported and referred for bacteriological, virological, parasitological and pathohistological examinations. N. caninum was detected by PCR in the brains of 21% of all aborted fetuses. Microscopic lesions indicative for cerebral protozoa infection were detected in 84% of PCR-positive fetal brains. Bovine viral diarrhea virus (BVDV) was demonstrated in 7% of the cases, and bacterial infections were detected in 4% of the abortions. One or more N. caninum-abortions occurred in 20% of the herds (41 case-farms and 3 control-farms). Serological examination of aborting mother cows revealed a significantly higher percentage of N. caninum-seropositive animals (44%) in comparison to the prevalence in a randomly selected population (12%). However, in eight cases (4% of all investigated abortions) seronegative cows aborted N. caninum PCR-positive fetuses, and in 50 cases the fetus remained negative although the respective mother cow was N. caninum-seropositive. Repetitive serological investigations (at a 3-12 months interval) of 3551 cows from case- and control-farms showed a decrease of the overall N. caninum-seroprevalence from 17 to 12%. Ninety out of 3008 seronegative animals were converted to N. caninum-seropositivity. Conversely, 212 out of 543 initially seropositive animals became seronegative for their second serum sample. The obtained data underlined the importance of N. caninum as a causative agent for abortion in Swiss cattle. Furthermore, PCR was confirmed to be a valuable diagnostic tool for the primary diagnosis of N. caninum in aborted fetuses. On the other hand, the value of serology appears to be hampered by the temporal instability of N. caninum antibody concentrations in adult cattle, including especially seronegativity of some individual animals. Thus, seronegativity in a mother cow or heifer does not exclude N. caninum-associated abortions.
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Affiliation(s)
- H Sager
- Institute of Parasitology, University of Berne, Länggass-Strasse 122, CH-3001 Berne, Switzerland
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Morales E, Trigo FJ, Ibarra F, Puente E, Santacruz M. Seroprevalence study of bovine neosporosis in Mexico. J Vet Diagn Invest 2001; 13:413-5. [PMID: 11580063 DOI: 10.1177/104063870101300508] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
An indirect enzyme-linked immunosorbent assay was used to obtain epidemiologic information on bovine neosporosis in dairy herds of the Mexican central plateau. Sera were collected from 1,003 cows from 50 dairy herds. Forty-three herds (group A) had been experiencing a high abortion rate. The abortion rates for the remaining 7 herds (group B) were within normal limits for Mexico. Five-hundred sixty-one (56%) of the 1,003 sera were positive. The seroprevalence of Neospora caninum antibodies was 72% (95% CI = 68-75%) in group A and 36% (95% CI = 31-40%) in group B. These results clearly show that infection with N. caninum is widespread in Mexican dairy herds, as indicated by seropositive cows in group A and group B herds at the time of the sample collection.
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Affiliation(s)
- E Morales
- Departamento de Patología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Cludad Universitaria, México, DF
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Robertson ID, Irwin PJ, Lymbery AJ, Thompson RC. The role of companion animals in the emergence of parasitic zoonoses. Int J Parasitol 2000; 30:1369-77. [PMID: 11113262 DOI: 10.1016/s0020-7519(00)00134-x] [Citation(s) in RCA: 175] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Pets offer individuals and the community significant benefits, however cognisance must be taken of the potential for transmission of infectious agents from these animals to humans. The prevalence of many parasites, such as Giardia and Cryptosporidium, has increased over the past few decades while others, such as Toxocara and Ancylostoma, have decreased. These changes could be real, associated with the ready availability of efficacious anthelmintic products or could be artificial due to the type of surveys conducted, the animals surveyed and the diagnostic tests used. Immunocompromised people, in particular, must be aware of the potential risk of acquiring parasitic infections from their pets. However, with the adoption of good hygiene and a thorough knowledge of the transmission of these parasites, immunocompromised people should be able to continue to enjoy the significant benefits of pet ownership. As many owners are not aware of the zoonotic parasites that could be carried by their pets or their mode of transmission, it is concluded that veterinarians need to play a greater role in the education of their clients.
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Affiliation(s)
- I D Robertson
- Division of Veterinary and Biomedical Sciences, Murdoch University, Western Australia 6150, Murdoch, Australia.
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