Investigation of Neospora sp. and Toxoplasma gondii antibodies in mares and in precolostral foals from Parana State, Southern Brazil

Invited review: Sarcocystis neurona, Neospora spp. and Toxoplasma gondii infections in horses and equine protozoal myeloencephalitis (EPM): five decades of personal experience, perspectives, and update

Sarcocystis neurona, Neospora spp. and Toxoplasma gondii are related protozoans; they were considered the same parasite until 1970s. Two of these parasites, S. neurona and Neospora spp. are associated with a neurological syndrome in horses, called equine protozoal myeloencephalitis (EPM). The diagnosis and treatment of EPM are difficult. Most cases of EPM are related to S. neurona while only a few are due to Neospora spp. infections. There are two species of Neospora, Neospora caninum that has a wide host range and Neospora hughesi that has been found only in horses. Currently, T. gondii is not considered as a cause of EPM in horses, although it causes neurological illness in many other hosts, including humans. The present review provides an update on history, life cycle, diagnosis and treatment of these three infections in horses.

Seroepidemiology of Sarcocystis neurona and Neospora spp. in horses, donkeys, and mules from Colombia

Sarcocystis neurona and Neospora spp. are related protozoa that can cause equine protozoal myeloencephalitis (EPM). The present study aimed to determine the frequency of antibodies to these parasites in 649 equids (351 horses, 267 donkeys, and 31 mules) from six departments in the North and Northwest of Colombia. For this purpose, the indirect fluorescent antibody test (IFAT) was used for detecting antibodies against S. neurona and Neospora spp. with a cut-off point of 1:20 and 1:50, respectively. A binomial logistic regression model was selected to predict variables associated with exposure. The frequency of anti-S. neurona antibodies was 14.24% (95% CI: 10.84-18.44) for horses, 2.99% (95% CI: 1.39-6.04) for donkeys, and 16.13% (95% CI: 6.09-34.47) for mules. The risk for S. neurona infection was significantly lower in donkeys (OR: 0.18 [0.08-0.38]; p<0.001) than horses and mules, and higher in animals with a poor body condition (OR: 2.82 [1.45-6.05]; p<0.05). Additionally, older animals (>12y) had a higher risk of seropositivity (OR: 5.26 [1.88-19.1]; p<0.05), as well as animals that inhabit climatic conditions associated with tropical very dry forest (OR: 1.85 [1.01-3.51]; p<0.05). Córdoba and Antioquia departments presented the highest seropositivity to S. neurona with 13.01 and 8.3%, respectively. The frequency of anti-Neospora spp. antibodies was 1.42% (95% CI: 0.52-3.48) for horses, 1.12% (95% CI:0.29-3.52) for donkeys and 0% (95%, CI: 0-0) for mules. Atlántico was the state with the highest seropositivity to Neospora spp. (10%). No risks associated with Neospora spp. infection were found. These findings allow us to conclude that equids from these regions of Colombia are exposed to S. neurona, but antibodies to Neospora spp. are uncommon. Further studies are necessary to explore the presence of these two agents in other areas of the country. In addition, we need to prove the importance of the above-mentioned risk factors over the susceptibility of horses to these protozoal agents and the epidemiological impact of these underdiagnosed coccidia.

An abortion storm in dairy cattle associated with neosporosis in southern Brazil

Between December 2016 and April 2017, a spate of abortions occurred in a closed dairy herd from the central eastern region of Paraná, Brazil, in which 75 cows aborted. To identify its cause, organ fragments were collected from an aborted fetus for histopathology, and the blood samples from a stillborn, 4 aborted fetuses, and 9 farm dogs for indirect fluorescent antibody technique (IFAT). These tests found multifocal non-suppurative encephalitis, periportal hepatitis, and multifocal lymphoplasmacytic myocarditis, and detected anti-Neospora antibodies in all aborted fetuses, and in 5 of the 9 dogs. DNA of Neospora caninum was detected in the brain tissue of an aborted fetus. Blood samples of 340 cows and 146 heifers showed 33.5% and 30.8% seropositivity, respectively. In this closed herd, the parasite was probably introduced by infected domesticated or wild carnivores inhabiting the farm, through the infective oocysts present in their stool.

Serosurvey of Toxoplasma gondii, Neospora caninum and Sarcocystis neurona in raptors and risk factor analysis

Raptors are carnivorous birds with great hunting ability. Toxoplasma gondii, Neospora caninum and Sarcocystis spp. are intracellular Apicomplexan protozoans which infect a wide range of intermediate hosts, including birds. The aims of this study were to evaluate the serological reactivity of captive raptors serum to T. gondii, N. caninum and S. neurona antigens and identify possible risk factors associated with the infection. From August 2014 to September 2015, blood samples from 72 raptors were collected and serum samples were tested by immunofluorescence antibody test (IFAT). Antigen slides were prepared using tachyzoites of T. gondii and N. caninum and using merozoites of S. neurona. Serum samples were tested at the following cut-off dilutions: 1:16 for T. gondii and 1:50 for N. caninum and S. neurona. An anti-chicken IgY antibody conjugated with FITC was used as a secondary antibody at 1:50 dilution. Out of the 72 raptors serum tested by IFAT, 2.7% reacted to N. caninum, 8.3% to T. gondii and 11.1% to S. neurona antigens. The region in which the sample was collected, the reason the raptors were kept in captivity and diet were statistically associated with seropositivity to T. gondii and the use of the birds and diet were statistically associated with seropositivity to N. caninum and S. neurona (p ≤ 0.05). We highlight the occurrence of these protozoans in birds of prey and the importance of good hygiene and feeding management of these birds in captivity to reduce the risk of protozoal infections.

Transplacental transmission of Neospora caninum to lambs in successive pregnancies of naturally infected sheep in Southern Brazil

This study aims to report the detection of N. caninum DNA in a newborn lamb (1) with neurological signs and congenital neosporosis and in a stillborn lamb (2), both born from the same ewe in a herd of Southern Brazil. The lambs were born during different pregnancies of a Suffolk ewe seropositive to N. caninum and seronegative to T. gondii. Histopathological lesions were observed only in the central nervous system of the lambs. The newborn lamb (1) showed mild and focal gliosis in the frontal lobe. In the hippocampal region of the stillborn lamb (2), lymphoplasmacytic perivascular cuffs and N. caninum cysts were observed in the cytoplasm of neurons and confirmed by IHC. PCR was performed using brain samples to detect the protozoa N. caninum and Toxoplasma gondii. The infection with N. caninum was confirmed in the newborn lamb (1) by PCR and in the stillborn lamb (2) by histopathology, immunohistochemistry, and PCR tests.

Detection of Neospora caninum Infection in Aborted Equine Fetuses in Israel

In horses, Neospora caninum and Neospora hughesi have been associated with fetal loss, and neurological disease, respectively. This study investigated the role of Neospora spp. infection in equine abortion in Israel. The presence of anti-Neospora spp. antibodies was evaluated in 31 aborting mares by indirect fluorescent antibody test (IFAT) and the presence of parasite DNA in their aborted fetuses was evaluated by polymerase chain reaction (PCR), using two target loci (ITS1 and Nc5). The seroprevalence found in aborting mares was 70.9% and the prevalence by DNA detection in the aborted fetuses was 41.9%. Transplacental transmission from positive mares to their fetuses was 45.4% (10/22), while 33.3% (3/9) of fetuses of seronegative mares also tested positive for Neospora. The use of two PCR targets improved the sensitivity of parasite detection, and positive samples were identified by sequence analyses as N. caninum. These finding suggest that N. caninum could be a significant cause of abortion in horses, and that transplacental transmission in horses is an important way of transmission of N.caninum. The results presented here demonstrated the necessity to use several tests concurrently, including serological and molecular assays in order to confirm the involvement of Neospora in mare abortions.

Global seroprevalence of Neospora spp. in horses and donkeys: A systematic review and meta-analysis

Neospora infections due to Neospora caninum and N. hughesi are prevalent among equids of the world. The disease may affect reproductive and neurological consequences. The present systematic review and meta-analysis was performed to evaluate the global Neospora seroprevalence among horses and donkeys. A number of 57 out of 1575 total retrieved studies were included by searching the PubMed, Scopus, Science Direct, Web of Science and ProQuest. A total of 25,783 horses and 4377 donkeys were examined serologically, yielding a weighted seroprevalence of 13.46 % (95 % CI: 10.26 %-17.42 %) globally. Subgroup analysis revealed that there were statistically significant differences in the overall prevalence of Neospora spp. in the examined animals according to year, continent, WHO region, country, host, and diagnostic method. Age and sex in horses as well as sex in donkeys were significantly associated with the Neospora seroprevalence (P < 0.001). Our findings showed a relatively high exposure to Neospora spp. in horses and donkeys worldwide. Considering the possible economic impact, as well as the importance in animal health, more studies are needed to clarify the species causing equine neosporosis, correlate serological findings with clinical outcomes and assess the risk factors, in order to define adequate prevention and control strategies.

Aborto infeccioso por Neospora spp. em equino ˗ relato de caso

RESUMO O abortamento na espécie equina é responsável por grandes perdas econômicas e, entre as possíveis causas, está a neosporose, uma enfermidade que nem sempre é investigada como provável diagnóstico. Assim, o objetivo deste trabalho foi relatar um caso de aborto equino aos 129 dias de gestação, resultante da infecção por Neospora spp.. Amostras sanguíneas da égua e do feto abortado foram enviadas para um laboratório especializado. À necrópsia, constatou-se edema gelatinoso e hemorrágico em subcutâneo, fígado ictérico e friável com autólise de alguns órgãos, como baço, rins e glândulas adrenais. Fragmentos dos órgãos coletados na necrópsia foram submetidos à histopatologia e à pesquisa de agentes infecciosos, em que se identificou hepatite e epicardite não purulentas e onfalite purulenta, bem como exame positivo para Neospora spp. pela técnica de reação em cadeia da polimerase (PCR) convencional e Nested. O soro sanguíneo obtido da égua foi submetido à pesquisa de Neospora spp. pela técnica de imunofluorescência indireta, de herpesvírus por soroneutralização em cultura de células e de Leptospira sp. por PCR, todas com resultados negativos. Dessa forma, é importante considerar a neosporose como diagnóstico diferencial em casos de abortamento e natimortalidade, uma vez que a presença de cães nas propriedades é extremamente comum, representando uma importante fonte de infecção.

Age, gender and climate associations with the seroprevalence of Neospora species infection in horses in Jordan

A cross-sectional study was carried out on a sample of 379 horses to determine the seroprevalence of Neospora spp. in Jordan using the indirect fluorescent antibody test. Five variables, namely locality (n=10), climatic zone (n=4), age group (n=3), gender, and breed were tested as risk factors for Neospora-immunoglobulin (Ig)G seropositivity at four cutoff titers (1:50, 1:200, 1:400, and 1:800) using univariate and multivariate logistic regression analyses. A total of 122 (32%; 95% CI: 28, 37) sera samples had anti-Neospora-IgG at a cutoff titer of 1:50. Increased Neospora-IgG seropositivity was found in horses in three localities (Madaba, Zarka, and Petra) and was associated with the following variables: cool temperate climate; age >14 years; and female gender. Seropositivity was found among horses from Madaba at all cutoff titers, Zarka at titers >1:200, and Petra at titers <1:200. Cool temperate climate was associated with titers <1:400. Horses aged >14 years were found to be associated with seropositivity at titers ≥1:200. Female gender was associated with high seropositivity at >1:800.

Survey of Toxoplasma gondii, Neospora caninum and Sarcocystis neurona antibodies in wild red-tailed Amazon parrots (Amazona brasiliensis)

Toxoplasma gondii, Neospora caninum and Sarcocystis neurona are obligate intracellular parasites within the phylum Apicomplexa. The red-tailed Amazon parrot (Amazona brasiliensis) is a near-threatened species of psittacine that is endemic to the Atlantic Forest of Brazil and has been designated as a bioindicator because of its sensitivity to environmental qualitative status and changes. The aim of this study was to evaluate the presence of antibodies against T. gondii, N. caninum and S. neurona in wild red-tailed Amazon parrot nestlings on Rasa Island, Brazil. Blood samples were collected from 51 parrots and plasma samples were stored at - 20 °C until immunofluorescence antibody tests (IFAT) were performed. Antigen slides were prepared using tachyzoites of T. gondii (RH strain) and, N. caninum (NC-1 strain) and using merozoites of S. neurona (SNR37 strain). Plasma samples were tested at initial dilutions of 1:16 for T. gondii, 1:50 for N. caninum and 1:5 for S. neurona. An anti-chicken antibody conjugated with FITC was used as a secondary antibody at 1:50 dilution. No antibodies for any of these three protozoa were found, thus suggesting that these wild red-tailed Amazon parrot nestlings had not been exposed to these parasites.

Serosurvey of Toxoplasma gondii, Sarcocystis sp. and Neospora caninum in geese (Anser sp.) from urban parks and captivity

Geese, ducks, mallards, and swans are birds of the order Anseriformes, which are found in the wild, in zoos and parks, and raised for meat consumption. Toxoplasma gondii, Sarcocystis sp., and Neospora caninum are protozoans of several species of animals. Wild and domestic birds can serve as intermediate hosts, disseminators and potential sources of infection of these protozoa to humans through contaminated meat. The aims of this study were: (i) to perform a serological survey of T. gondii, Sarcocystis sp. and N. caninum in geese (Anser sp.) from public parks and from captivity and (ii) to compare seroprevalence between these two locations. Antibodies were detected by Immunofluorescence antibody test using the serum of 149 geese. Antibodies to Sarcocystis sp., T. gondii, and N. caninum were detected in 28.18%, 18% and 0.67% of geese, respectively; 57% of geese from urban parks and 26.53% of geese from captivity were seropositive for at least one protozoa. The results indicate environmental contamination, particularly for the occurrence of antibodies against T. gondii - a zoonosis that causes toxoplasmosis and is transmitted through oocyte ingestion. This is the first serological survey of T. gondii, Sarcocystis sp. and N. caninum in geese from urban parks in Curitiba, Brazil.

Histologically, immunohistochemically, ultrastructurally, and molecularly confirmed neosporosis abortion in an aborted equine fetus

Neosporosis is a common cause of abortion in cattle worldwide but is rare in horses. Here, the first case of histologically, ultrastructurally, immunohistochemically, and molecularly confirmed equine abortion caused by neosporosis is reported. Samples of lung, heart, liver, skeletal muscle, tongue, brain, and the placenta from a female fetus aborted at 280 days of gestation were fixed in formalin and submitted for diagnosis. Histologically, there was disseminated neosporosis with severe lesions in lungs, liver and the heart. Protozoal tachyzoites in all tissues reacted with polyclonal anti-Neospora caninum rabbit antibodies. Transmission electron microscopic observation on lung tissue revealed tachyzoites consistent with Neospora, including many rhoptries. Polymerase-chain reaction (PCR) using primers designed to amplify the rRNA gene internal transcribed spacer 1 (ITS1) of the Sarcocystidae was performed on DNA extracted from fetal tissues. Comparison of the ITS1 amplified from the foal tissue to sequences available in GenBank revealed 100% sequence identity to the ITS1 from three isolates of Neospora hughesi.

Soroprevalência de Toxoplasma gondii em equídeos do Nordeste do Brasil

RESUMO: Este estudo teve como objetivo determinar a soroprevalência da toxoplasmose em equídeos mantidos em diferentes formas de manejo no estado de Pernambuco. Para tanto, um total de 400 amostras de soro sanguíneo de equídeos clinicamente saudáveis foram analisados através do teste de aglutinação modificado (MAT) considerando-se cut-off de 1:25. Dados referentes às características dos animais e dos rebanhos, sistema de criação, presença de outros animais, idade, sexo, raça, aptidão, condição física foram coletados por meio de questionários investigativos. Anticorpos IgG anti-Toxoplasma gondii foram detectados em 12,5% (50/400) dos animais analisados. Dos 12 municípios estudados, houve positividade em 91,67% (11/12) com variação entre 4,4% e 33,3%. Quando avaliados os fatores de risco, apenas o fator mesorregião (p=0,029) apresentou associação com a infecção, particularmente Zona da Mata (OR=3), seguida de Região Metropolitana do Recife (OR=2,2), Agreste (OR=1,7) e Sertão (OR=1). Os resultados revelam a presença do parasito na área estudada, o que pode representar um elo na cadeia de transmissão da toxoplasmose a qual tem repercussão em saúde pública tendo em vista que o Brasil é o oitavo maior exportador de carne equina do mundo.

All about neosporosis in Brazil

Neospora caninum is protozoan parasite with domestic and wild dogs, coyotes and grey wolves as the definitive hosts and many warm-blooded animals as intermediate hosts. It was cultivated and named in 1988. Neosporosis is a major disease of cattle and has no public health significance. Since 1990's N. caninum has emerged as a major cause of abortion in cattle worldwide, including in Brazil. N. caninum also causes clinical infections in several other animal species. Considerable progress has been made in understanding the biology of N. caninum and there are more than 200 papers on this subject from Brazil. However, most of the reports on neosporosis from Brazil are serological surveys. Overall, little is known of clinical neosporosis in Brazil, particularly cattle. The few reports pertain to sporadic cases of abortion with no information on epidemics or storms of abortion. The objective of the present review is to summarize all reports from Brazil and suggest topic for further research, including prevalence of N. caninum oocysts in soil or in canine feces, and determining if there are additional definitive hosts, other than the domestic dog. There is need for a national survey in cattle using defined parameters. Future researches should focus on molecular characterization of N. caninum strains, possibility of vaccine production and relationship between wildlife and livestock epidemiology.

Seroprevalence and risk factors for Neospora caninum in goats in Santa Catarina state, Brazil

Neosporosis is an infectious disease caused by the parasite Neospora caninum. Knowledge regarding neosporosis in goats is still quite limited, especially in the state of Santa Catarina (SC), southern Brazil. Therefore, this study aimed to assess the seroprevalence and risk factors for N. caninum in goats in the western and mountain regions of SC. Blood samples were collected from 654 goats in 57 municipalities. The indirect immunofluorescence test was used for antibody detection against N. caninum. Thirty samples (4.58%) were seropositive, with titers ranging from 1:50 to 1:6400. An epidemiological survey was also conducted in order to identify risk factors for neosporosis in goats. It was found that reproductive problems on the farms, as well as the diet and direct contact with dogs were casual risks for neosporosis. These results indicate that N. caninum infects goats in these regions, which may lead to reproductive problems.

Seroepidemiology of Sarcocystis neurona, Toxoplasma gondii and Neospora spp. among horses in the south of the state of Minas Gerais, Brazil

Abstract The present study used the indirect fluorescent antibody test (IFAT) to determine the seroprevalence of Sarcocystis neurona, Toxoplasma gondii and Neospora spp., and evaluated the variables associated with these infections among 506 apparently healthy horses, reared in the south of the state of Minas Gerais, Brazil. This study was conducted between April 2012 and October 2013. Among the horses, the true prevalence of S. neurona was 26% (95% CI: 22.0-30.4%), T. gondii 19.9% (95% CI: 15.5-24.8%) and Neospora spp. 23.9% (95% CI: 19.9-28.1%); and among the farms, 88.3% (95% CI: 74.4-91.6%), 71.6% (95% CI: 41-92.8%) and 85% (95% CI: 70.7-96.1%), respectively. Regarding mixed infection, 17 horses (3.4%) were seropositive for both S. neurona and T. gondii, 16 (3.2%) for T. gondii and Neospora spp. and 14 (2.8%) for S. neurona and Neospora spp. The associations between seropositivity and variables relating to the structure of the farm, management and health were analyzed using the logistic regression analysis, through the generalized estimating equations (GEE). The results suggest that the south of Minas Gerais is an enzootic area for S. neurona, T. gondii and Neospora spp. among horses, with prevalence of asymptomatic subclinical or chronic infections.

Intra-uterine exposure of horses to Sarcocystis spp. antigens

The aim of this study was to examine the intra-uterine exposure to Sarcocystis spp. antigens, determining the number of foals with detectable concentrations of antibodies against these agents in the serum, before colostrum ingestion and collect data about exposure of horses to the parasite. Serum samples were collected from 195 thoroughbred mares and their newborns in two farms from southern Brazil. Parasite specific antibody responses to Sarcocystis antigens were detected using the indirect immunofluorescent antibody test (IFAT) and immunoblot analysis. In 84.1% (159/189) of the pregnant mares and in 7.4% (14/189) of foals we detected antibodies anti-Sarcocystis spp. by IFAT. All samples seropositive from foals were also positive in their respective mares. Serum samples of seropositive foals by IFAT, showed no reactivity on the immunoblot, having as antigens S. neurona merozoites. In conclusion, the intra-uterine exposure to Sarcocystis spp. antigens in horses was demonstrated, with occurrence not only in mares, but also in their foals, before colostrum ingestion these occurrences were reduced.

Relation between Neospora caninum and abortion in dairy cows: Risk factors and pathogenesis of disease

Neosporosis is a parasitic disease cause by Neospora caninum, a parasite of great importance in livestock. This study aimed to evaluate the presence of antibody against N. caninum in dairy cattle with history of abortion, as well as to identify associated risk factors for neosporosis. Animals suspected of neosporosis (n = 130) after clinical examination were randomly selected. Sera samples from 29 farms were submitted to indirect immunofluorescence technique (IFA) in order to detect antibodies against N. caninum, and animals were considered positive if ≥ IFA 1:200. An epidemiological questionnaire was used to verify probable risk factors for neosporosis and their cause-effect relation. Serological results showed that 43.8% of the animals were seropositives for N. caninum. The univariate statistical analysis found a significant relation between neoporosis and age. The number of pregnancies and the number of years that the farms had been producing milk were found as associated risk factors for the disease either by univariate or by multivariate analyses. The cause-effect model found a possible relation between reproductive problems and positive serology for neosporosis (P = 0.06). Therefore, it was concluded that approximately 44% of dairy cows with history of abortion were seropositives for N. caninum and that age and the number of years that the farms had been producing milk are risk factors for parasite infection in dairy cattle.

Serum levels of nitric oxide and protein oxidation in goats seropositive for Toxoplasma gondii and Neospora caninum

The aim of this study was to assess and analyze the levels of nitric oxide (NO) and advanced oxidation protein products (AOPP) in serum of goats naturally infected by Toxoplasma gondii, Neospora caninum, or concomitantly infected by these two parasites. Thus, it was measured NOx and AOPP levels in twenty (n=20) sera samples of goats seronegative for T. gondii and N. caninum [negative control group (A)]; while the positive groups were composed by sera of infected animals, twelve (n=12) seropositive for N. caninum [group B]; eighteen (n=18) positive for T. gondii [group C]; and thirteen (n=13) seropositive for N. caninum and T. gondii [group D]. As results, it was observed that animals seropositive for N. caninum and T. gondii (Groups B to D) showed higher serum levels of NOx (P<0.001; F=9.5), when compared with seronegative animals. Additionally, it was observed a positive correlation between NOx levels and antibodies titrations for N. caninum (P<0.01; r=0.68) and T. gondii (P<0.05; r=0.56). AOPP levels were increase in groups C and D (P>0.05). Interestingly, group B did not show increase in AOPP, what led us to hypothesize that the major protein damage is linked to T. gondii infection. Therefore, our results showed an increased in NOx levels, which was probably related to the immune response, since it is an important inflammatory mediator; and AOPP were increased in groups where there was seropositivity for T. gondii, but not for the group composed only by animals seropositive for N. caninum, allowing us to suggest higher protein damage in toxoplasmosis.

Verificação da transmissão vertical de Neospora spp. em equinos

O gênero protozoário Neospora é reconhecido como causador de desordens reprodutivas e abortos em bovinos. Entre os equinos pouco se sabe sobre os efeitos da infecção por estes protozoários. Atualmente é admitido que os efeitos da infecção por Neospora hughesi em equinos possam ocorrer no sistema nervoso central e, os efeitos provocados pela infecção por Neospora caninum recaiam sobre o sistema reprodutor de éguas. O presente trabalho verificou a presença de imunoglobulinas da classe G no soro sanguíneo de uma população de éguas de cria e, em seus respectivos potros antes da ingestão do colostro. Para execução deste trabalho foi empregada técnica de imunofluorescência indireta (RIFI), utilizando como antígeno taquizoítos de Neospora caninum, a diluição inicial dos soros das éguas foi de 1:50 e a diluição do soro dos potros empregada foi de 1:16. Foram assistidos 78 partos e todos os potros tiveram seu soro sanguíneo coletado imediatamente após o nascimento. A pesquisa de anticorpos contra Neospora spp. apontou que 50 (64%) éguas e 32 (41%) potros foram positivos. Das 50 éguas que apresentaram anticorpos contra Neospora spp. 24 geraram potros positivos. Entre as 28 éguas que não reagiram, oito deram a luz a potros positivos. De posse dos resultados encontrados podemos concluir que ocorreu a transmissão vertical de Neospora spp. nos equinos pesquisados.

Serological study of Toxoplasma gondii infection in Turkoman horses in the North Khorasan Province, Iran

Toxoplasmosis is an important zoonotic disease with worldwide distribution. The infection is observed in an unusually wide range of warm-blooded animals, including most of the livestock and humans. Many studies have shown high prevalence of toxoplasmosis in man and animals in Iran. The present study was conducted to investigate the seroprevalence of toxoplasmosis in Turkoman horses in the North Khorasan Province. During 2011-2012, 100 blood samples from horses were collected and tested for antibodies against toxoplasmosis using indirect fluorescent antibody test. The seroprevalence of toxoplasmosis was detected in 14 % (14) horses. The antibodies titres were detected in the range of 1:20-1:160 dilution. The lowest and highest frequencies of toxoplasmosis were observed in the age groups of <1 year and 1-10 years, respectively (P < 0.05). No significant difference was observed between toxoplasmosis frequencies and gender and usage of horses. With regard to the high frequency of toxoplasmosis in the sampled horses, attention must be paid to the animal health for the control and prophylaxis of the disease.

Association of antibodies against Neospora caninum in mares with reproductive problems and presence of seropositive dogs as a risk factor

Sera from 112 mares from 5 horse-breeding farms was examined for the presence of antibodies to Neospora caninum and Toxoplasma gondii by an indirect fluorescent antibody test (IFAT), as well as from dogs and cattle present on these properties for the presence of antibodies to N. caninum. Among the 112 mares, 35 had a history of reproductive problems in the last breeding season and 77 had no reproductive problems. The rates of seroprevalence of N. caninum in mares with and without a history of reproductive problems were 25.71% and 6.49% and from T. gondii 2.85% and 1.29%, respectively. In dogs and cattle, the rates of seroprevalence of N. caninum were 10.52% and 15.55%, respectively. A positive correlation was found between the presence of antibodies against N. caninum (p=0.010) in mares and the occurrence of reproductive problems using the Fisher's exact test. Significantly higher seroprevalence for N. caninum in mares was observed on the farm that had seropositive dogs (p=0.018). Cattle on this farm were also seropositive. No significant differences in seropositivity were found on farms where dogs were seronegative, or absent. This result suggests, for the first time, the presence of seropositive dogs as a risk factor for N. caninum in mares and the necessity for further investigation of the epidemiology of this parasite in horse-breeding farms with reproductive problems and the presence of cattle and dogs. This is the first report on the occurrence of antibodies against N. caninum in horses from the state of Santa Catarina, Brazil.

Neospora spp. antibodies in horses from two geographical regions of the state of Santa Catarina, Brazil

The aims of this study were to determine occurrences ofNeospora spp. IgG antibodies in horses from two geographical regions of the state of Santa Catarina, southern Brazil, and identify risk factors for infection. Analyses were performed on 615 samples using the immunofluorescent antibody test (IFAT ≥ 1:50). Out of the 615 samples, 25 (4.1%) were positive for Neospora spp. The titers for Neospora spp. were distributed as follows: 1:50 (13), 1:100 (eight), 1:200 (three) and 1:400 (one). Out of the 311 samples taken in the mountain region, eight were positive (2.6%). Among the samples from the coastal region (304), 17 had Neospora spp. antibodies, thus indicating occurrence of 5.6%. Although no statistically significant difference was observed (P = 0.06704), the prevalence among animals of the coast was 2.2 times higher than that of the mountain region. Contact with dogs and/or cattle (P = 0.007596) were identified as risk factor forNeospora spp. infection.

Detection of Neospora sp. antibodies in cart horses from urban areas of Curitiba, Southern Brazil

Neospora caninum is a protozoan parasite which affects dogs as definitive hosts and several mammalian species as intermediate hosts mainly causing abortions and central nervous system disorders. The reemerging population of cart horses for carrying recycling material in urban areas of major cities in Brazil may have an impact on disease spreading, and these animals may be used as sentinels for environmental surveillance. Thus, the present study investigated the frequency of Neospora sp. antibodies in cart horses from Curitiba and surrounding areas, Paraná State, Southern Brazil. IgG antibodies against Neospora sp. were detected using indirect fluorescence antibody test (IFAT), and titers equal to or higher than 1:50 were considered reactive. Of all samples, 14/97 (14.4%) were positive: 2/29 (6.9%) were younger than 5; 5/26 (19.2%) between 6 and 9; and 6/31 (19.4%) older than 10 years of age. One of the 11 animals with unknown age was positive (9.1%). Cart horses are likely to be more exposed to dog feces and to Neospora sp. oocyst contamination in urban settings and a lower frequency of disease in dogs may have a negative impact on horse infection risk in these areas.

The importance of vertical transmission of Neospora sp. in naturally infected horses

Neospora spp. is a intracellular protozoan phylogenetically closely related to Toxoplasma gondii and Sarcocystis neurona, and it can infect horses leading to the development of reproductive or neurological diseases. We determined the presence of antibodies to Neospora sp. in mares at their parturition time and determine the frequency of vertical transmission in healthy foals to verify the importance of transplacental transmission. The samples were analyzed by indirect immunofluorescence antibody test, showing that seroprevalence in mares is higher than in foals and seropositive mares are likely to transmit the neosporosis to their offspring. This shows that endogenous challenge occurs in horses, and it suggests that this protozoan can be disseminated by means of transplacental transmission in horse species.

Occurrence of antibodies against Neospora caninum and/or Toxoplasma gondii in dogs with neurological signs

This study aimed to evaluate occurrences of antibodies against Neospora caninum and Toxoplasma gondii in dogs with neurological signs. Blood samples from 147 dogs were collected: 127 from owned dogs (attended at the Veterinary Teaching Hospital of the Federal University of Paraná (HV-UFPR) and at private veterinary clinics in the city of Curitiba), and 20 from stray dogs found in Curitiba's metropolitan region. The dogs presented one or more of the following neurological signs: seizures, paresis or paralysis, ataxia, behavioral abnormalities, sensory and somatic disorders and chorioretinitis. The samples were analyzed by means of the indirect fluorescent antibody test (IFAT), at a cutoff dilution of 1:50. Out of the 147 samples obtained, 17 (11.56%) were seropositive for N. caninum, 31 (21.08%) for T. gondii and four (2.72%) for both protozoa. Serum titration on the positive animals showed that 54.83% (17/31) and 41.18% (7/17) had titers > 1:200 against T. gondii and N. caninum, respectively. A significant difference in seropositivity for T. gondii (P = 0.021; OR = 2.87; CI = 1.1 > 2.8 > 7.4) was observed between owned dogs (18.11%) and stray dogs (40%). Inclusion of serological tests for neosporosis and toxoplasmosis is recommended in diagnosing neurological diseases in dogs.

Neosporose equina: ocorrência de anticorpos anti-Neospora spp. e associação entre status sorológico de éguas e de suas crias

Os protozoários Neospora caninum e N. hughesi infectam os equinos e podem provocar diferentes sinais clínicos associados a problemas reprodutivos ou a distúrbios neurológicos, respectivamente. A patogenia da neosporose é pouco conhecida nos equinos, bem como as fontes de infecção horizontal de N. hughesi. Além disso, há dúvidas quanto ao papel da transmissão vertical de Neospora spp. na sua manutenção em populações equinas. Neste estudo avaliaram-se: (1) a ocorrência da infecção por Neospora spp. na população de éguas em idade reprodutiva em um haras de cavalos da raça Crioula; e (2) a possível associação entre o status sorológico destas éguas com o de suas crias, como meio de investigar, indiretamente, a relevância da transmissão transplacentária na ocorrência da infecção por Neospora spp. nestes animais. A associação entre o status sorológico das éguas e o de suas crias foi altamente significativa. Os animais descendentes de éguas soropositivas tiveram maior ocorrência de anticorpos anti-Neospora spp. do que os descendentes de éguas soronegativas, embora expostos aos mesmos fatores de risco ambientais. A associação entre parentesco em primeiro grau e status sorológico indica a influência da infecção vertical (transplacentária) na ocorrência de Neospora spp. na população equina estudada.

Neospora spp. and Toxoplasma gondii antibodies in horses in the Czech Republic

During January 2007, blood samples were collected from 552 healthy horses from nine different regions of the Czech Republic. Sera were tested for serum antibodies to Neospora caninum by a competitive-inhibition enzyme-linked immunosorbent assay and confirmed by an indirect fluorescent antibody test. The same samples were tested for serum antibodies against Toxoplasma gondii by a latex agglutination test. In total, 131 of 552 (24%) horses reacted positively for Neospora antibodies in competitive-inhibition enzyme-linked immunosorbent assay; seven of them had > or =50% of inhibition. Samples were confirmed in indirect fluorescence test, and only two samples were positive with final titres 50 and 100, while others were negative. Antibodies against T. gondii were found in 125 (23%) horses. This is the first serologic survey for Neospora spp. antibodies performed on horses in the Czech Republic.

Frequency of antibodies against Neospora caninum in stray and domiciled dogs from urban, periurban and rural areas from Paraná State, Southern Brazil

Antibodies to Neospora caninum were analyzed by an indirect fluorescent antibody test (IFAT), in stray and domiciled dogs from urban, periurban and rural areas from Curitiba, Paraná State, Brazil. Of the total of 556 dogs, 18.17% (101) were positive for N. caninum (titer 50). Frequency of antibody was 12.71 in urban, 15.73 in periurban, and 25.38% in rural dogs. Rural dogs had a significantly higher frequency of antibodies than urban dogs (P< 0.05). There were no significant differences between the frequencies of antibodies in urban and periurban dogs (P>0.05), and between dogs from periurban and rural areas (P>0.05). Antibodies to N. caninum were detected in 34 of 233 domiciled dogs (14.59%) and in 17 of 126 stray dogs (13.49%). No statistical differences were observed considering life-style and geographic location of origin (P>0.05). Neospora caninum is widespread among dogs from urban, periurban and rural areas of the municipal district of Curitiba, Paraná, Brazil.

Epidemiology and control of neosporosis and Neospora caninum

Neospora caninum is a protozoan parasite of animals. Until 1988, it was misidentified as Toxoplasma gondii. Since its first recognition in dogs in 1984 and the description of the new genus and species Neospora caninum in 1988, neosporosis has emerged as a serious disease of cattle and dogs worldwide. Abortions and neonatal mortality are a major problem in livestock operations, and neosporosis is a major cause of abortion in cattle. Although antibodies to N. caninum have been reported, the parasite has not been detected in human tissues. Thus, the zoonotic potential is uncertain. This review is focused mainly on the epidemiology and control of neosporosis in cattle, but worldwide seroprevalences of N. caninum in animals and humans are tabulated. The role of wildlife in the life cycle of N. caninum and strategies for the control of neosporosis in cattle are discussed.