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

The seroprevalence and risk factors for exposure to Neospora caninum and Neospora hughesi in Ontario broodmares

The seroprevalence and risk factors for exposure to Neospora caninum and Neospora hughesi in broodmares in Ontario were investigated. Sixty of the 219 (27.4%) study broodmares were seropositive for N. caninum and 65/219 (29.7%) for N. hughesi with cut-offs of ≥1:40 and ≥1:160, respectively. Thirty-one of 63 participating farms (49.2%) had at least 1 broodmare seropositive for N. caninum. Thirty-three of the 63 (52.4%) participating farms had at least 1 broodmare positive for N. hughesi. Risk factors for N. caninum included presence of farm dogs (OR = 6.70; 95% CI = 2.14-20.97; p = 0.001), and high stocking density (OR = 2.83; 95% CI = 1.27-6.30; p = 0.011). Presence of livestock, excluding cattle, was associated with reduced risk of exposure (OR = 0.17; 95% CI = 0.06-0.53; p = 0.002). The only risk factor for exposure to N. hughesi was feeding hay on the ground in the paddock (OR = 4.31; 95% CI = 1.65-11.22; p = 0.003). This study demonstrated widespread exposure to Neospora spp. in broodmares in Ontario.

Anti-Toxoplasma gondii and Anti-Neospora caninum Antibodies in Urban Traction Equids in Northeast Brazil: Seroprevalence and Risk Factors

The aim of this study was to describe the prevalence of anti-T. gondii and anti-N. caninum antibodies in equids that carry out traction work in Northeastern Brazil, and to establish the potential risk factors associated with seropositivity for these agents. Blood samples were collected from 322 traction equids (horses, donkeys and mules) in urban areas of 16 municipalities in the State of Paraíba, Brazil. The samples were sent for serological diagnosis using the Immunofluorescence Antibody Test (IFAT). Epidemiological questionnaires were given to the owners to assess the possible risk factors associated with infections. It was observed that 13.7% (44/322, CI: 10.9-16.5) of the equids tested positive for anti-T. gondii antibodies and 5% (16/322, CI: 2.6-7.4) tested positive for anti-N. caninum antibodies. Conducting traction work for over four years was considered a risk factor associated with T. gondii infection (odds ratio: 6.050; CI: 4.38-8.54, p = 0.025). There were no risk factors associated with N. caninum infection. It was concluded that traction equids have a significant prevalence of anti-T. gondii and anti-N. caninum antibodies in urban areas in the State of Paraíba, with an identified risk factor for seropositivity for anti-T. gondii as conducting traction work for more than four years.

Neospora caninum, a cause of abortion in donkeys (Equus asinus) in Iran

Neospora caninum is an Apicomplexan parasite that can cause enormous economic losses due to abortions in cattle. The present study investigated the role of Neospora spp. infection in equine abortion in Iranian donkeys using molecular and phylogenetic analyses. Twenty-nine-aborted fetuses and 29 blood samples from their dams were collected from six different regions in the West and Northwest of Iran. They were tested for N. caninum by PCR at the Nc5 locus, followed by sequencing of five of the PCR products. The overall molecular prevalence was 34.5% in blood samples and the prevalence by DNA detection in the aborted fetuses was 13.8%. Evidence of transplacental transmission from positive jennies to their fetuses was detected in 40% of aborting jennies. Comparison of the five partial Nc5 sequences (227 bp length) exhibited 98-100% similarity with N. caninum GenBank sequences. This is the first molecular study and genetic characterization of N. caninum in Iranian donkeys suggests that N. caninum may be a significant cause of abortion in donkeys.

Apicomplexan Protozoa Responsible for Reproductive Disorders: Occurrence of DNA in Blood and Milk of Donkeys (Equus asinus) and Minireview of the Related Literature

Donkeys may be susceptible to many pathological agents and may act as carriers of pathogens for other animal species and humans. This study evaluated the occurrence of potentially abortifacient apicomplexan protozoa DNA in blood and milk samples collected at different time periods during lactation (1, 6, and 10 months) from 33 healthy dairy jennies. A total of 73 blood and 73 milk samples were used for DNA extraction and analysis. Blood specimens from 11/33 (33%) jennies scored positive for Theileria equi, while milk samples scored negative. Blood and milk of 3/33 jennies yielded DNA of Toxoplasma gondii at 6 months (n. 1) and 10 months (n. 2) after parturition. Neospora caninum DNA was found in four milk and in five blood samples only at one month after parturition. This study is the first report about the presence of N. caninum DNA in milk of naturally infected jennies. Moreover, the excretion of N. caninum DNA in some of these jennies at 30 days from the parturition may suggest a possible occurrence of an endogenous cycle, while the presence of T. gondii DNA in the milk collected at 6 and 10 months after parturition may be suggestive of a discontinuous excretion.

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.

Seroprevalence of Neospora caninum Infection in Dog Population Worldwide: A Systematic Review and Meta-analysis

PURPOSE

Neospora caninum is an obligate intracellular apicomplexan protozoan that causes neurological disorders in dogs. This systematic review and meta-analysis targeted at evaluating the worldwide seroprevalence rate of N. caninum in dogs.

METHODS

Five electronic databases, including PubMed, Scopus, Web of Science, Science Direct, and Google Scholar, until December 2018 were thoroughly searched for relevant English language articles. Papers were selected based on inclusion criteria. Data were analyzed in StatsDirect statistical software (version 2.7.9).

RESULTS

The searching process yielded a total number of 156 papers. The total prevalence (95% confidence intervals) of N. caninum infection in dog population worldwide was measured as 17.14% in data analyses (15.25-19.10). In addition, a significant association was also detected between neosporosis infection in dogs and continent, country, year, WHO regions, sample size and diagnostic method (P < 0.001).

CONCLUSION

Dogs are a matter of concern to public health officials as a source of N. caninum infection. Therefore, it is of paramount importance to provide comprehensive data and systematically analyze the prevalence of N. caninum infection in dogs. Accordingly, it is recommended that researchers carry out further studies to prevent and control neosporosis among dog population worldwide.

Serological survey of Neospora spp. and Besnoitia spp. in horses in Portugal

Equine neosporosis is regarded to be caused either by Neospora hughesi or Neospora caninum and equine besnoitiosis is caused by Besnoitia bennetti, both of which are apicomplexan parasites. N. caninum is the only known Neospora species in Europe, where equine N. caninum infections have been reported as being associated to abortion and reproductive failure. N. hughesi is prevalent in North America and was predominantly linked to neurological disorders. B. bennetti is considered an emergent disease in donkeys in North America and evidence for B. bennetti infection was recently reported in Europe. Though N. caninum and Besnoitia besnoiti are prevalent in cattle in Portugal, little is known about neosporosis in horses and, to the best of our knowledge, no information was hitherto available for Besnoitia spp. The aim of this study was thus to carry out a serological survey to determine the seroprevalence of these parasites in naturally exposed horses in Portugal. A total of 385 animals were screened by the Indirect Fluorescent Antibody Test at the cut-off value 1:50 and positive results were confirmed by Western blot. Exposure to Neospora spp. and Besnoitia spp. was confirmed in 9.1% (95% Confidence Interval [CI]: 6.6-12.4%) and 0.3% (95% CI: 0.0-1.5%) of horses, respectively. Considering the putative economic and animal health impact of neosporosis in horses and the consequences of a possible spread of equine besnoitiosis in Europe and elsewhere, more comprehensive studies are needed to characterize the species detected in serological surveys, evaluate the geographical distribution and assess possible risk factors that could favor transmission.

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.

First report of antibodies to Neospora spp. in horses from Portugal

Neospora spp. are intracellular protozoa with worldwide distribution and closely related to Toxoplasma gondii, which can infect a variety of mammals including horses. From September 2013 to June 2014, 185 horses from northern, central and southern parts of mainland Portugal were randomly sampled and tested for detection of immunoglobulin (Ig) G antibodies to Neospora spp. using an indirect multi-species enzyme-linked immunosorbent assay (ELISA) commercial test (ID Screen® Neospora caninum Indirect Multi-species; ID.vet Innovative Diagnostics, Grabels, France). Two horses (1.1%; CI: 0.1-3.8%), one male and one female, were found to be seropositive for Neospora spp. Both seropositive animals were horses housed indoors but with access to outdoors, used for leisure activities and were apparently healthy, with good body condition and with no alterations at physical examination. This was the first serologic survey of antibodies to Neospora spp. carried out in horses from Portugal.

Prevalence and risk factors for IgG antibodies to Neospora spp. in three types of equids from Southern Punjab, Pakistan

Equine hosts suffer from neurological disease, congenital infection, and reproductive problems associated with Neospora spp. infection. We conducted a cross sectional study using sera from 631 equids (324 horses, 218 donkeys and 89 mules) from the southern region of Punjab province, Pakistan to determine the prevalence of antibodies against Neospora spp. in this diverse group of equines. Fisk factors associated with seropositivity were evaluated statistically based on equine type, breed, age, husbandry, breeding methods, and reproductive history. Prevalence of antibodies to Neospora spp. was detected using a commercially available competitive ELISA kit. We detected IgG antibodies to Neospora spp. in 23.3% of the equids with prevalence by host being 16.0% in horses, 32.6% in donkeys and 26.9% in 89 mules. Statistically significant (P < 0.05) differences in prevalence were observed among these hosts. Prevalence ranged in breeds of horses from 3.7% in the Morna breed, 12.4% in breeding stock, 26.8% in draughting stock, to 31.4% in unknown breeds. No significant (P > 0.05) difference in prevalence was noted among age groups. Prevalence was significantly (P < 0.05) higher in female equines with a history of abortion than those with no history of abortion. This is the first report documenting Neospora spp. in equines from Pakistan and it provides evidence that Neospora spp. is associated with abortions in female equines in Pakistan.

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.

Theileria equi infection causing abortion in a mare in Brazil

The aim of this report was to confirm the cause of abortion to be Theileria equi acquired transplacentally in a mare in Federal District, Brazil. The aborted fetus showed a high parasitemia of erythrocytes (80%) by the oval and Maltese cross forms of T. equi. Necropsy of the fetus demonstrated congestion of organs, jaundice, anemia and pronounced spleno- and hepatomegaly. Twelve breeding mares, including the one that aborted and her fetus, tested positive for T. equi infection by universal and multiplex PCR assay. The absence of histopathologic changes such as inflammation and necrosis in the placenta and fetal tissues as well as the negative microbiological results and negative serology for Leptospira spp. in the mare that aborted were important to exclude other infectious agents that may be involved in equine abortion. This report highlights the transplacental transmission of T. equi infection in horses in endemic areas and reinforces the importance of investigating equine theileriosis as a possible cause of abortion in mares.

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.