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

Equine Protozoal Myeloencephalitis

Advances in the understanding of equine protozoal myeloencephalitis (EPM) are reviewed. It is now apparent that EPM can be caused by either of 2 related protozoan parasites, Sarcocystis neurona and Neospora hughesi, although S neurona is the most common etiologic pathogen. Horses are commonly infected, but clinical disease occurs only infrequently; the factors influencing disease occurrence are not well understood. Epidemiologic studies have identified risk factors for the development of EPM, including the presence of opossums and prior stressful health-related events. Attempts to reproduce EPM experimentally have reliably induced antibody responses in challenged horses, but have not consistently produced neurologic disease. Diagnosis of EPM has improved by detecting intrathecal antibody production against the parasite. Sulfadiazine/pyrimethamine (ReBalance) and the triazine compounds diclazuril (Protazil) and ponazuril (Marquis) are effective anticoccidial drugs that are now available as FDA-approved treatments for EPM.

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.

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.

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.

Fatores de risco associados à prevalência de anticorpos anti-Sarcocystis neurona, Neospora spp. e Toxoplasma gondii em equinos de Roraima, Amazônia

RESUMO: Amostras de sangue de 303 equinos provenientes de 56 propriedades do município de Rorainópolis, Roraima, foram avaliadas por Reação de Imunofluorescência Indireta (RIF) para pesquisa de anticorpos contra Sarcocystis neurona, Toxoplasma gondii e Neospora spp. Algumas amostras de soros positivos para Sarcocystis spp. foram avaliadas pelo Western Blotting (WB) utilizando antígenos crus de S. neurona. A partir dos resultados sorológicos, possíveis fatores de risco foram avaliados frente a variáveis individuais e de propriedade. A prevalência de anticorpos anti-Sarcocystis spp. foi estimada em 43,2% (37,6-49,0%), anti-Neospora sp. em 26,7% (21,9-32,2%) e anti-T. gondii de 18,5% (14,3-23,4%). Quatorze amostras (14/15) testadas por WB resultaram positivas para antígenos de S. neurona. Das propriedades, 76,8% (43/56) apresentaram pelo menos um equino positivo para Sarcocystis spp.; 69,6% (39/56) para Neospora spp. e 55,4% (31/56) para T. gondii. Dos equinos, 13 (4,3%) apresentarem anticorpos para os três agentes, 50 (16,5%) para Sarcocystis spp. e Neospora spp., 10 (3,3%) para Neospora spp. e T. gondii, e oito (2,6%) para Sarcocystis spp. e T. gondii. As variáveis associadas (P≤0,05) à presença de anticorpos foram: para Neospora spp. não pastejar em áreas alugadas, ausência de assistência veterinária na propriedade, sexo masculino, não estabular animais e plantel equino acima de 5 animais; enquanto para T. gondii foram o contato com felinos, animais da raça lavradeiro, animal estabulado, criação de bovinos na propriedade e plantel equino acima de 5 animais. Não houveram variáveis associadas a presença de anticorpos contra S. neurona. Relata-se no presente estudo a primeira detecção de anticorpos anti-S. neurona, Neospora spp. e T. gondii em equinos do estado de Roraima, localizado na Amazônia Setentrional Brasileira, ressaltando para a elevada frequência de fazendas com equinos soropositivos.

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.

Equine Protozoal Myeloencephalitis: An Updated Consensus Statement with a Focus on Parasite Biology, Diagnosis, Treatment, and Prevention

Equine protozoal myeloencephalitis (EPM) remains an important neurologic disease of horses. There are no pathognomonic clinical signs for the disease. Affected horses can have focal or multifocal central nervous system (CNS) disease. EPM can be difficult to diagnose antemortem. It is caused by either of 2 parasites, Sarcocystis neurona and Neospora hughesi, with much less known about N. hughesi. Although risk factors such as transport stress and breed and age correlations have been identified, biologic factors such as genetic predispositions of individual animals, and parasite‐specific factors such as strain differences in virulence, remain largely undetermined. This consensus statement update presents current published knowledge of the parasite biology, host immune response, disease pathogenesis, epidemiology, and risk factors. Importantly, the statement provides recommendations for EPM diagnosis, treatment, and prevention.

Seroprevalence of Toxoplasma gondii and Neospora spp. Infections in Arab Horses, Southwest of Iran

BACKGROUND

Because of the economic importance of the Arab race horses and also the role of Toxoplasma gondii and Neospora spp. in abortion and reproductive failure of these animals, we decided to perform this study.

OBJECTIVES

We designed this study to investigate the seroprevalence of anti-Toxoplasma gondii and anti-Neospora spp. antibodies in Arab horses from 12 cities of Khuzestan province in southwest of Iran.

MATERIALS AND METHODS

From October 2009 to March 2011, a total of 235 blood samples were collected from jugular veins of Arab horses of different ages and genders from 12 cities of Khuzestan province. All the sera were tested for anti-Toxoplasma antibodies using the modified agglutination test (MAT) and the existence of anti-Neospora antibodies were tested using N-MAT for Neospora spp.

RESULTS

According to the MAT results, antibodies to T. gondii were found in 114 (48.5%) of 235 sera with titers of 1:20 in 84, 1:40 in 19, 1:80 in four, 1:160 in four, and 1:320 in three horses. According to the N-MAT results, antibodies to Neospora spp. were found in 47 (20%) of 235 sera with titers of 1:40 in 39, 1:80 in five, and 1:160 in three horses. We did not observe any statistically significant differences regarding age groups and genders between seropositive and seronegative horses for Neospora spp. using chi-square (χ(2)) test, but it seemed that anti-Toxoplasma antibodies were more prevalent in older horses (≥ 10 years old).

CONCLUSIONS

The results indicated that Arab horses are exposed to these parasites in southwest of Iran. Further research is required to determine the genomic structures of these parasites in Arab horses in southwest of Iran.

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.

Equine protozoal myeloencephalitis

Equine protozoal myeloencephalitis (EPM) can be caused by either of 2 related protozoan parasites, Sarcocystis neurona and Neospora hughesi, although S. neurona is the most frequent etiologic pathogen. Horses are commonly infected, but clinical disease occurs infrequently; the factors influencing disease occurrence are not well understood. Risk factors for the development of EPM include the presence of opossums and prior stressful health-related events. Attempts to reproduce EPM experimentally have reliably induced antibody responses in challenged horses but have not consistently produced acute neurologic disease. Diagnosis and options for treatment of EPM have improved over the past decade.

Ocorrência de anticorpos anti-Neospora spp. em jumentos (Equus asinus) no estado de Sucre - Colômbia

A neosporose tem grande importância em bovinos, e sua patogênese neste hospedeiro, em termos gerais, está esclarecida, porém, em equídeos é pobremente conhecida. Na Colômbia ainda não foram reportados anticorpos Anti-Neospora spp. em equídeos, sendo assim objetivou-se no presente estudo avaliar a ocorrência do parasito em jumentos (Equus asinus) de fazendas que apresentavam risco da doença nestes animais. Foram utilizados 56 animais no estado de Sucre (Colômbia), escolhidos aleatoriamente dentro das fazendas selecionadas. Utilizou-se um peptídeo recombinante originado de Neospora caninum (NcGRA1) para o diagnóstico por Dot-ELISA, e o soro foi diluído em 1:200. Este estudo reporta, pela primeira vez no estado de Sucre e na Colômbia, a presença de anticorpos anti-Neospora spp. na espécie Equus asinus, com uma ocorrência de 19,7% (11/56) dos animais amostrados.

Prevalence of antibodies to Sarcocystis neurona and Neospora hughesi in horses from Mexico

Equine protozoal myeloencephalitis (EPM) is a debilitating disease of horses caused by Sarcocystis neurona and Neospora hughesi. Sera from 495 horses in Durango State, Mexico were tested for anti-protozoal antibodies using enzyme-linked immunosorbent assays (ELISAs) based on major surface antigens of these two parasites. Antibodies to S. neurona were detected in 240 (48.5%) of the 495 horse sera tested with the rSnSAG2/4/3 trivalent ELISA. Multivariate analysis showed that exposure to S. neurona was associated with age, feeding grains and crops, and small herd size. Antibodies to N. hughesi were found in 15 (3.0%) of the 495 horse sera tested with the rNhSAG1 ELISA and confirmed by Western blot of N. hughesi tachyzoite antigen. This is the first report of S. neurona and N. hughesi exposure in horses in Mexico, and it affirms that EPM should be in the differential diagnosis for horses exhibiting signs of neurologic disease in this country.