Abortion in association with transplacental Theileria equi infection in a mare from the State of Espírito Santo, southeast Brazil: case report / Aborto equino associado à infecção transplacentária de Theileria equi, Espírito Santo, Brasil: relato de caso

Equine piroplasmosis is a tick-borne disease caused by the protozoan parasites Babesia caballi and Theileria equi. We report a case of abortion in association with transplacental Theileria equi infection in a mare from the State of Espírito Santo, southeast Brazil. An apparently healthy mare aborted at the tenth month of gestation. At necropsy, the subcutaneous tissue, skeletal muscles, and visible mucosae of the aborted fetus were pale, and there was moderate hydrothorax and marked splenomegaly. Microscopic findings included splenic lymphoid hyperplasia and nephrosis. Merozoite-infected erythrocytes were found within blood vessels of all organs examined and were most numerous in the brain. DNA extracted from the spleen, liver, kidney, and thymus was used as a template for PCR. Generic primers were employed for the detection of piroplasm 18S ribosomal gene. All samples were positive for piroplasm DNA by PCR. Amplicons were purified and then sequenced. Sequencing analysis of these amplicons revealed 98% identity to T. equi sequences. Based on our findings, we suggest that abortion in this case resulted from transplacental Theileria infection.(AU)

A piroplasmose equina é transmitida por carrapatos, sendo causada pelos protozoários Babesia caballi e Theileria equi. O objetivo deste trabalho foi relatar um caso de aborto equino associado à piroplasmose fetal. Uma égua gestante, aparentemente saudável, abortou no 10º mês de gestação. Na necropsia do feto, foi observada palidez de subcutâneo, da musculatura esquelética e das mucosas visíveis, moderado hidrotórax e acentuada esplenomegalia. Histologicamente, havia hiperplasia linfoide esplênica e nefrose. Muitos merozoítos foram observados em eritrócitos nos vasos sanguíneos de todos os órgãos examinados, com maior intensidade no encéfalo. Amostras de DNA do baço, fígado, rim e timo foram utilizadas para PCR com primers genéricos para detecção de sequências do gene 18S ribossomal de piroplasmas, com resultado positivo para todas as amostras. Em seguida, os amplicons das amostras de baço foram purificados, sequenciados e, após análise, mostraram 98% de identidade com a sequência de T. equi. Portanto, as alterações microscópicas, os resultados de PCR e sequenciamento confirmam aborto associado à T. equi por transmissão transplacentária.(AU)

Evaluation of abortions spontaneously induced by Neospora caninum and risk factors in dairy cattle from Lima, Peru / Avaliação de abortos induzidos espontaneamente por Neospora caninum e fatores de risco em bovinos leiteiros de Lima, Peru

Abstract Our objective was to identify the direct and indirect presence of Neospora caninum in dairy cattle and their aborted fetuses from Lima, Peru. A total 219 blood samples obtained from dairy cattle with records of spontaneous abortion were collected to detect antibodies against N. caninum in serum with indirect ELISA and search for risk-factor associations. 68 fetal aborted tissue samples of these cows were analyzed by PCR, indirect ELISA and histopathology assay to detect N. caninum presence. The prevalence ratio (PR) and 95% confidence intervals (CI) were estimated. Univariate analysis was performed using the chi-squared test. Among the 68 aborted fetuses collected, 10 (15%) were positive in at least two diagnostic tests. Among 219 serum samples, 46.6% (95% CI: 40.0%-53.3%) were positive. Cows with 4 years or older (PR: 7.10; 95% CI: 4.89-10.67) and multiparous (PR: 1.76; 95% CI: 1.11-2.80) were found to be more likely to possess N. caninum antibodies. This study detects presence of N. caninum in dairy cattle and their aborted fetus from Lima valley, suggesting biosecurity management improve to neosporosis control.

Resumo O objetivo do trabalho foi diagnosticar a presença direta e indireta de Neospora caninum em fetos abortados e de soros de bovinos leiteiros de Lima, Peru. Um total de 219 amostras de sangue obtido de vacas leiteiras, com registros de abortos espontâneos, foi coletado para detectar anticorpos contra N. caninum no soro (pelo ELISA indireto), e para estudar associações com fatores de risco. Foram examinadas 68 amostras de tecido fetal abortado das vacas soropositivas pela PCR, ELISA indireto e histopatologia para determinar a presença de N. caninum. A taxa de prevalência (PR) e o intervalo de confiança (CI) de 95% foram estimados. Análise univariada foi realizada usando o teste de Qui-quadrado. Entre os 68 fetos abortados, 10 (15%) foram positivos em pelo menos dois testes diagnósticos. Entre as 219 amostras de soro, 46,6% (95% IC: 40,0%-53,3%) foram positivas. Vacas com 4 anos ou mais de idade (RP: 7,10; 95% IC: 4,89-10,67) e multíparas (RP: 1,76; 95% IC: 1,11-2,80) apresentaram maior frequência de anticorpos contra N. caninum. Este estudo demonstrou a presença de N. caninum em bovinos leiteiros e em fetos abortados oriundos do vale de Lima, sugerindo a implementação de medidas de biossegurança, para o controle da neosporose.

Occurrence of abortions induced by Neospora caninum in dairy cattle from Santa Catarina, southern Brazil / Ocorrência de abortamentos induzidos por Neospora caninum em vacas de leite de Santa Catarina, sul do Brasil

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.

Resumo O objetivo deste estudo foi avaliar a ocorrência de N. caninum associado a abortamentos em vacas de leite do estado de Santa Catarina, sul do Brasil pelo uso das técnicas de ELISA (HerdCheck, IDEXX), reação em cadeia pela polimerase (PCR) e imunohistoquímica (IHC). O sangue das vacas leiteiras que abortaram, bem como, o líquido intratorácico e amostras de tecidos (cérebro, coração, fígado e pulmão) de seus fetos foram coletados e usados para sorologia, PCR (Np21+ e Np6+), e IHC. Vinte e uma vacas (51,2%) de um total de 41, bem como, oito fetos (26,7%) de um total de 30 foram positivos no ELISA (IDEXX) para N. caninum. As vacas > 36 meses de idade tiveram um maior risco de serem soropositivas do que os animais mais jovens. PCR e IHC revelaram que 38,8% e 25,0% dos fetos foram positivos para N. caninum, respectivamente para cada um dos testes. As vacas soropositivas tiveram uma maior frequência de fetos que também foram positivos no fluído intratorácico, na PCR ou na IHC. Em resumo, o presente estudo observou uma alta frequência de N. caninum em abortos de vacas leiteiras na região estudada, com maior prevalência de N. caninum em vacas com mais de 36 meses de idade. Além disso, sorologia, PCR e IHC deveriam ser utilizadas ​​conjuntamente para melhor diagnóstico de neosporose em bovinos.

Neosporose bovina: avaliação da transmissão vertical e fração atribuível de aborto em uma população de bovinos no Estado do Rio Grande do Sul / Bovine neosporosis: evaluation of vertical transmission and population etiological fraction of abortion in a bovine population in the State of Rio Grande do Sul, Brazil

O protozoário Nespora caninum é um parasito que causa grandes perdas reprodutivas e econômicas em bovinos no mundo inteiro. Os objetivos deste estudo foram verificar tanto a associação entre o histórico de aborto e a presença de anticorpos contra N. caninum, quanto a transmissão vertical como forma de manutenção da infecção nos rebanhos bovinos em regiões do Rio Grande do Sul, através da sorologia pareada de mães e filhas. Foi realizada amostragem de 60 propriedades distribuídas em duas regiões do Rio Grande do Sul, das quais foi coletado sangue de 40% dos animais presentes para a detecção de anticorpos anti-N. caninum por imunofluorescência indireta (IFI). Para verificar a relação aborto e soropositividade foi utilizado o teste de regressão logística univariada, e para sorologia de mães e filhas o teste de qui-quadrado de McNemar para dados pareados. Foram confrontados os dados de sorologia e aborto, sendo encontrada a frequência de 58,5% (24/41) de soropositivos quando havia histórico de aborto, e 16,4% (199/1215) dentre os sem histórico de aborto. Os animais soropositivos apresentaram um risco 7,21 (IC 95%, 3,65-14,32) vezes maior de possuir histórico de abortamento (estatística de Wald χ2=44,93, P<0,001). A fração atribuível à neosporose como causa de aborto na população em risco nas duas regiões foi estimada em 9,73% (λpop). O resultado sorológico de cada mãe foi pareado com o de sua filha e, pelo teste de qui-quadrado de McNemar (χ2=59,84, P<0,001), houve associação significativa entre as sorologias de mães e filhas, sugerindo transmissão vertical. Ressalta-se ainda a importância do acompanhamento sorológico para N. caninum, evitando assim manutenção de animais portadores que sirvam como reservatório do protozoário nas propriedades.

The protozoa Nesporora caninum is a parasite that causes great economic and reproductive losses in cattle worldwide. The objective of this study was to verify the association between abortion and the presence of antibodies against N. caninum and the vertical transmission as a means of maintaining the infection in cattle herds in Rio Grande do Sul by matching the serology of mothers and daughters. Sampling was performed in 60 dairy farms of two regions of the state, where blood was collected from 40% of the herds for the detection of anti-N. caninum by indirect immunofluorescence (IFI). To verify the association between abortion and seropositivity we used the univariate logistic regression test, and for the serology of mothers and daughters the chi-square McNemar test for paired data. In comparing serology and abortion data, a prevalence of 58.5% (24/41) among cattle with history of abortion, and 16.4% (199/1215) prevalence between those with no history of abortion was found; seropositive animals were 7.21 times more likely (95% CI, 3.65-14.32) to have previously aborted (Wald statistic χ 2=44.93, P<0.001). The fraction affected by neosporosis in the population studied was estimated as 9.73% (λpop). The serologic result of each mother was paired with her daughter and showed by the McNemar chi-square (χ2=59.84, P<0.001) significant association between the serology of mothers and daughters, suggesting vertical transmission. It is worth to note the importance of serological monitoring for N. caninu to avoid maintenance of animals that may serve as carries of the parasite reservoir on the farms.

Detection and identification of Toxoplasma gondii type one infection in sheep aborted fetuses in Qazvin province of Iran

The aim of this study was to apply the nested-PCR and bioassay methods in detection and genotyping of Toxoplasma gondii infection in provided sheep aborted fetus samples from Qazvin Province of Iran. Eighteen sheep aborted fetal samples were studied by nested-PCR-RFLP, histopathological observation and microbiological assay. Bioassay in mice was carried out by inoculating the brain samples intraperitoneally. The results demonstrated the frequency of 66% infected sheep aborted fetal samples with T. gondii type one. Although we could not isolate any parasite from inoculated mice even after three passages, but it was confirmed histopathologically formation of cyst like bodies in prepared mice brain sections. The results of the performed nested-PCR and formation of brain cyst in inoculated mice exhibited that T. gondii type one infection might be considered as one of the major causative agents for abortion in ewes

Aborto ovino associado com infecção por Sarcocystis sp / Ovine abortion associated with Sarcocystis sp. infection

Infecções por protozoários têm distribuição mundial e podem causar aborto, nascimentos prematuros e ou morte fetal em diversas espécies animais. Em julho de 2004, oito ovinos Corriedale apresentaram problemas reprodutivos caracterizados por aborto e natimortalidade no terço final da gestação. Dessas oito perdas, um natimorto macho foi enviado ao Setor de Patologia Veterinária para necropsia. Alterações macroscópicas não foram observadas durante a necropsia. Lesões histológicas foram observadas principalmente no cérebro e coração e se caracterizaram por encefalite não-supurativa multifocal acentuada associada à presença de protozoários no interior de células endoteliais e vasos sanguíneos e miocardite não-supurativa focal leve. Alguns desses organismos apresentaram formato de roseta. O teste de imunoistoquímica anti-Toxoplasma gondii foi negativo, mas houve reação cruzada com anticorpo anti-Neospora caninum. O exame de imunofluorescência direta para Leptospira sp. foi negativo. A bacteriologia aeróbica e micro-aeróbica não revelou crescimento significativo. Esses achados foram compatíveis com o diagnóstico de Sarcocystis sp.

Protozoal infection has worldwide distribution and may cause abortion, premature parturition or fetal death in almost all domestic animals. In July 2004, eight Corriedale sheep showed abortion and stillbirth in the third trimester of gestation. Of these reproductive losses, one stillborn male was submitted to the Laboratory of Veterinary Pathology for necropsy investigation. The direct immunofluorescence test for Leptospira sp. was negative. No significant bacteria was isolated from lung and liver by aerobic and microaerobic cultures. Macroscopic lesions were not found in any fetal tissue. The histological lesions were observed mainly in the brain and heart and consisted primarily of severe multifocal nonsupurative encephalitis and nonsuppurative myocarditis. Schizonts of a protozoan parasite consistent with Sarcocystis sp. were found in the endothelial cells and vascular endothelium in several organs. Many schizonts with merozoites arranged in a rosette-like pattern were observed in brain and kidney tissues. In sections stained with periodic acid-Schiff (PAS), the limiting membrane of some schizonts appeared to be weakly PAS-positive. Merozoites and nuclei were PAS-negative. Protozoa did not react immunohistochemically to the antibody anti-Toxoplasma gondii; however, cross-reactivity was observed with Neospora caninum antibody. These findings were consistent with the diagnosis of Sarcocystis sp.

Neosporosis bovina: conceptos generales, inmunidad y perspectivas para la vacunación / Bovine neosporosis: general concepts, immunity and perspectives for vaccination

Neospora caninum es agente causal de aborto en bovinos de regiones ganaderas de todo el mundo. Su ciclo de vida es heteroxeno siendo el perro (Canis familiaris) y el coyote (Canis latrans) los hospedadores definitivos reconocidos hasta el presente. La infección transplacentaria es un eficiente mecanismo de transmisión de la enfermedad pero existe evidencia que demuestra la transmisión postnatal en los bovinos. Debido a las pérdidas económicas que causa la neosporosis, diversas técnicas diagnósticas han sido desarrolladas. La fisiopatología del aborto causado por N. caninum no ha sido completamente esclarecida. La modulación del sistema inmune por efecto de la preñez ocasiona un período de susceptibilidad al aborto por N. caninum. Aunque la resistencia al parásito ha sido asociada con una respuesta de linfocitos T tipo 1, dicha respuesta inmune es incompatible con una preñez exitosa. Sin embargo, los mecanismos inmunes presentes en animales crónicamente infectados protegen del aborto ante una segunda exposición al protozoo. La comprensión de esa respuesta inmune adquirida constituye un desafío para el desarrollo de inmunógenos. Este trabajo menciona conceptos generales de la neosporosis bovina haciendo énfasis en los mecanismos inmunes y las perspectivas para la vacunación.

Neospora caninum causes abortions in cattle worldwide. The Neospora-cycle of life is heteroxenous. Dogs (Canis familiaris) and coyotes (Canis latrans) are the definitive hosts known at present. Although, transplacental infection is an efficiently mode of transmission in cattle; there are also experimental and field data that prove horizontal transmission. Several techniques are available for diagnosis since neosporosis is recognized as a disease that causes economic losses in cattle. The mechanisms that produce the abortion are not completely understood. The immunomodulation observed during the pregnancy, is associated with a susceptible period where Neospora-abortion can occur. Resistance to the parasite is dependent on T helper cell 1 cytokine responses. This has important repercussions for pregnant female bovine because strong T helper cell 1 cytokine responses are incompatible with successful pregnancy. However, it was demonstrated that chronically infected cows develop immune mechanisms against the abortion caused by a second Neospora-exposure. The comprehension of those mechanisms is needed for the formulation of Neospora-vaccines that prevent bovine neosporosis. General concepts about neosporosis with emphasis in the immune response and perspectives for vaccination are mentioned in the present review.

Fate of Neospora-seropositive animals: an opinion

Neospora caninum es un protozoo que causa abortos en los bovinos produciendo importantes pérdidas económicas en todo el mundo. Existe evidencia reciente que demuestra que los bovinos infectados en forma crónica desarrollan mecanismos inmunes de protección contra el aborto causado por N. caninum. Por otro lado, la existencia de otras pérdidas económicas distintas del aborto es aún tema de controversia. Aunque la eliminación de bovinos seropositivos a la enfermedad a sido recomendado como medida de control sanitaria, un rodeo libre de infección no está exento de sufrir una exposición postnatal y "tormentas" de abortos. La utilización de una vacuna inactivada disminuye la tasa de abortos; sin embargo los anticuerpos vacunales no pueden ser diferenciados de aquellos producidos por infecciones naturales. Considerando que los anticuerpos maternos desaparecen a los 6 meses de vida, la serología de terneras de reemplazo antes del servicio y la vacunación podría ser una posible estrategia de control. Este artículo discute las estrategias de control para limitar la difusión de la neosporosis en bovinos y brinda posibles líneas de investigación.

Neospora caninum is an abortive protozoon in cattle, which causes severe economic losses worldwide. Chronically infected cattle however develop immune responses protecting against further Neospora induced abortions. Controversy about losses other than abortion in Neospora-infected cattle still exists. Although, culling of seropositive animals has been recommended as a strategy for reducing economic losses due to N. caninum, there is no guarantee of escaping postnatal infection and abortion storms by having a "Neospora-sterile herd". An inactivated vaccine has been demonstrated to reduce abortion rates. Antibodies generated by natural infection can not presently be differentiated from those induced by vaccination; however, since maternal antibodies disappear by 6 months in calves born to vaccinated heifers, a test-and cull strategy could be performed in replacement heifers before breeding and vaccination. This review article discusses control strategies for Neospora-infection in cattle, and provides suggestions for further research.

Epidemiology of swine toxoplasmosis in Taiwan.

From July 1987 to June 1988, serum samples from 3,880 pigs from eight geographic locations in Taiwan were examined for Toxoplasma gondii antibodies using the latex agglutination test (LA test) and IgM-enzyme-linked immunosorbent assay (IgM-ELISA). A total of 1,073 samples (27.65%) were positive by the LA test. The percentage of positive reactions varied by location as follows: Taoyuan 44.44% (128/288), Taichung 27.60% (183/663), Tainan 22.28% (119/534), Kaohsiung 19.60% (98/500), Pingtung 17.92% (86/480), Hualien 33.95% (163/480), Ilan 31.66% (152/480), Taitung 31.64% (144/455). In the IgM-ELISA 1,828 of 3,880 samples (47.11%) were positive and the distribution of positive reactions were: Taoyuan 59.02% (170/288), Taichung 53.69% (356/663), Tainan 52.24% (279/534), Kaohsiung 54.60% (273/500), Pingtung 18.95% (91/480), Ilan 47.50% (228/480), Hualien 42.70% (205/480), Taitung 49.67% (226/455). On one farm, 20 of 120 sows experienced abortion and stillbirths due to Toxoplasma gondii. Lesions and T. gondii were found in lungs, liver, kidneys, heart, and placenta of one of the aborted fetuses.