Fluctuations of antibody serum titers for Toxoplasma gondii and Neospora caninum in naturally infected crossbred cows during gestation.

This study aimed to assess the fluctuations of antibody serum titers for Toxoplasma gondii and Neospora caninum in naturally infected crossbred cows during gestation and to investigate transplacental transmission of T. gondii; 51 cows were monitored during pregnancy by monthly serologic testing by indirect fluorescent antibody test. 33 cows were seronegative for both N. caninum and T. gondii, 10 were seropositive only for N. caninum, 5 were seropositive only for T. gondii, and 3 were seropositive for both N. caninum and T. gondii. In both protozoan infections, great variation in antibody levels in pregnant cows was observed, and there was significant increase (p<0.05) in the comparison between the averages of serological titration per trimester. There was a significant correlation (p<0.05) between month and probability of seropositivity for T. gondii. We conclude that pregnancy influences antibody titers of crossbred cows naturally infected with N. caninum and/or T. gondii, and that serologic testing for T. gondii in pregnant cows from the sixth month of gestation onward may decrease the number of false negative results.

O objetivo deste estudo foi avaliar a flutuação dos títulos séricos de anticorpos para Neospora caninum e Toxoplasma gondii em vacas mestiças naturalmente infectadas durante a gestação e investigar a transmissão transplacentária desses protozoários. 51 vacas foram monitoradas durante a gestação, através de sorologia mensal pela Reação de Imunoflorescência Indireta. 33 vacas foram soronegativas para N. caninum e T. gondii, 10 foram soropositivas somente para N. caninum, 5 somente para T. gondii e 3 para N. caninum e T. gondii. Em ambas as infecções, observou-se grande variação nos níveis de anticorpos em vacas gestantes, e houve um aumento significativo (p<0.05) na comparação entre as medias da titulação sorológica por trimestre. Houve correlação significativa (p<0,05) entre os meses e a probabilidade de soropositividade para T. gondii. Conclui-se que a gestação influencia os títulos de anticorpos de vacas mestiças naturalmente infectadas por N. caninum e/ou T. gondii e que testes sorológicos para T. gondii em vacas gestantes a partir do sexto mês podem diminuir o número de resultados falsos negativos.

Sarcocystis neurona, seroprevalence of antibodies in equines and research of oocystis in opossum in Ilhéus - Itabuna microregion, Bahia, Brazil.

The aims of this study were to determine the seroprevalence of Sarcocystis neurona antibodies in equines in the Ilhéus-Itabuna microregion (BA), and identify possible factors associated with infection. The presence of sporocysts/oocysts of Sarcocystis spp. was also verified in Didelphis spp. A total of 669 serum samples were collected from equines in 56 properties located in 12 municipalities in the region. Indirect fluorescent antibody test was performed with slides containing merozoites of the S. neurona, using a cut-off titer of 1:80. Occurrence of 7.92% of anti-S. neurona antibodies was observed in the sampled equines. The purposes trade and work were significantly associated with the presence of antibodies (p<0.05), and being used for the purpose of work (21.6%) was considered a risk factor, while being used for the purpose of trade (3.6%) was a protective factor. A total of 25 Didelphis spp. was captured for research on sporocysts/oocysts in stool samples and intestinal scrapings, being all negative. Didelphis spp. were all negative for the presence of Sarcocystis spp. and this circumstance does not change the fact that seroprevalence of S. neurona has been observed in horses raised in the southern Bahia.

Frequency and factors associated of potential zoonotic pathogens (Borrelia spp., Rickettsia spp., Leishmania spp., and Anaplasma phagocytophilum) in equids in the state of Bahia, Brazil.

BACKGROUND: Currently, various zoonotic diseases are classified as emerging or reemerging. Because equids have a direct relationship with various vectors, they are possibly more frequently exposed to zoonotic agents than are humans. The undeniable importance of diseases such as human granulocytic anaplasmosis, spotted fever, and leishmaniasis for both public and animal health, as well as the possibility of equids acting as sources, reservoirs, or even sentinels for these pathogens, justifies the detection of their frequency and factors associated with infection in equids from northeastern Brazil. METHODS: Blood samples were collected from 569 equids (528 horses, 33 donkeys, and 8 mules), 516 from a rural area and 53 from an urban area. Pathogen detection was carried out as follows: Borrelia spp. and Rickettsia spp., serological analysis; Leishmania spp., serological analysis and polymerase chain reaction (PCR); Anaplasma phagocytophilum, PCR. Determination of associated factors was carried out through generalized linear models. RESULTS: The frequencies of positivity for the pathogens observed in equids were as follows: Borrelia spp., 13.9% (79/569); Leishmania spp., 3.5% (20/569); Rickettsia spp. 33.4% (190/569). Regarding factors associated with infection, male sex was associated with protection against Borrelia spp.; donkeys and mules were associated with protection against Rickettsia spp., while a younger age was a risk factor. The infection of A. phagocytophilum was not detected in the sampled population. Co-infection was detected in 5.1% (29/569) of the animals. CONCLUSIONS: Most of the studied pathogenic agents are present in the prospected area, indicating a possible risk for both human and animal health. This demonstrates that equids can be considered important sentinels in the assessment of pathogens with zoonotic potential in the region.

Sarcocystis neurona, seroprevalence of antibodies in equines and research of oocystis in opossum in Ilhéus - Itabuna microregion, Bahia, Brazil / Sarcocystis neurona, seroprevalência de anticorpos em equinos e pesquisa de oocistos em gambás na microrregião de Ilhéus - Itabuna, Bahia, Brasil

Abstract The aims of this study were to determine the seroprevalence of Sarcocystis neurona antibodies in equines in the Ilhéus-Itabuna microregion (BA), and identify possible factors associated with infection. The presence of sporocysts/oocysts of Sarcocystis spp. was also verified in Didelphis spp. A total of 669 serum samples were collected from equines in 56 properties located in 12 municipalities in the region. Indirect fluorescent antibody test was performed with slides containing merozoites of the S. neurona, using a cut-off titer of 1:80. Occurrence of 7.92% of anti-S. neurona antibodies was observed in the sampled equines. The purposes trade and work were significantly associated with the presence of antibodies (p<0.05), and being used for the purpose of work (21.6%) was considered a risk factor, while being used for the purpose of trade (3.6%) was a protective factor. A total of 25 Didelphis spp. was captured for research on sporocysts/oocysts in stool samples and intestinal scrapings, being all negative. Didelphis spp. were all negative for the presence of Sarcocystis spp. and this circumstance does not change the fact that seroprevalence of S. neurona has been observed in horses raised in the southern Bahia.

Resumo O presente estudo foi realizado na microrregião de Ilhéus-Itabuna, Bahia. Os objetivos deste estudo foram determinar a soroprevalência de anticorpos contra Sarcocystis neurona em equinos da microrregião Ilhéus-Itabuna (BA) e identificar possíveis fatores associados à infecção. A presença de esporocistos/oocistos de Sarcocystis spp. também foi pesquisada em Didelphis spp. Foram coletadas 669 amostras de soro de equinos em 56 propriedades localizadas em 12 municípios da região. Foi utilizada a reação de imunofluorescência indireta (RIFI), utilizando-se lâminas confeccionadas com merozoítos de Sarcocystis neurona (cepa SN138) e ponto de corte na diluição de 1:80. A ocorrência de anticorpos anti- S. neurona, nos equinos amostrados, foi de 7,92%. As finalidades dos animais - comércio e trabalho - apresentaram-se significativas (p<0.05), sendo que a finalidade trabalho (21,6%) foi considerada fator de risco, enquanto a finalidade comércio (3,6%) foi considerada fator de proteção. Foram capturados 25 Didelphis spp., para pesquisa de esporocistos/oocistos em amostras de fezes e raspado de mucosa intestinal. Todos os Didelphis spp. foram negativos para a presença de Sarcocystis spp., mesmo assim essa circunstância não alterou o fato da ocorrência de S. neurona ter sido observada em cavalos criados na mesorregião do sul da Bahia.

Factors associated with the distribution of natural Toxoplasma gondii infection among equids in Northeastern Brazil.

The aim of this study was to determine the frequency and factors associated with Toxoplasma gondii in naturally infected equids in northeastern Brazil. Serum samples from 569 equids (528 horses, 8 mules and 33 donkeys) were subjected to the indirect fluorescent antibody test. Generalized linear models were used to evaluate associated factors. Among the 569 animals sampled, 118 (30.6%) living in rural areas and 14 (26.42%) in urban areas were seropositive (p>0.05). Seropositive animals were observed on 95% of the farms and in all the municipalities. Donkeys/mules as the host, presence of domestic cats and rats on the farm, ingestion of lagoon water and goat rearing remained in the final model as factors associated with infection. Preventive measures such as avoiding the presence of domestic cats close to rearing areas, pastures and sources of water for the animals should be adopted. The wide-ranging distribution of positive animals also indicated that infection in other domestic animals and in humans, through the contaminated environment, was possible. It should be highlighted that there was the possibility that donkeys and mules would continue to have detectable titers for longer, thus explaining the prevalence found. Further studies are needed to confirm this possibility.

Factors associated with the distribution of natural Toxoplasma gondii infection among equids in Northeastern Brazil / Fatores associados à distribuição da infecção por Toxoplasma gondii em equídeos naturalmente infectados no Nordeste do Brasil

Abstract The aim of this study was to determine the frequency and factors associated with Toxoplasma gondii in naturally infected equids in northeastern Brazil. Serum samples from 569 equids (528 horses, 8 mules and 33 donkeys) were subjected to the indirect fluorescent antibody test. Generalized linear models were used to evaluate associated factors. Among the 569 animals sampled, 118 (30.6%) living in rural areas and 14 (26.42%) in urban areas were seropositive (p>0.05). Seropositive animals were observed on 95% of the farms and in all the municipalities. Donkeys/mules as the host, presence of domestic cats and rats on the farm, ingestion of lagoon water and goat rearing remained in the final model as factors associated with infection. Preventive measures such as avoiding the presence of domestic cats close to rearing areas, pastures and sources of water for the animals should be adopted. The wide-ranging distribution of positive animals also indicated that infection in other domestic animals and in humans, through the contaminated environment, was possible. It should be highlighted that there was the possibility that donkeys and mules would continue to have detectable titers for longer, thus explaining the prevalence found. Further studies are needed to confirm this possibility.

Resumo O objetivo deste estudo foi determinar a frequência e os fatores associados a Toxoplasma gondii em equídeos naturalmente infectados no Nordeste do Brasil. Amostras de soro de 569 equídeos (528 cavalos, 8 asnos e 33 muares) foram submetidas a reação de imunofluorescência indireta. Modelos lineares generalizados foram utilizados na avaliação dos fatores associados. Dos 569 animais amostrados, 118 (30,6%) soropositivos eram de área rural e 14 (26,42%) perteciam a áreas urbanas (p>0,05). Observaram-se animais soropositivos em 95% das fazendas e em todos os municípios. Asininos/muares como hospedeiro, presença de gatos domésticos e ratos na fazenda, ingestão de água de lagoa e criação de caprinos permaneceram no modelo final como fatores associados à infecção. Medidas de prevenção, como evitar a presença de gatos domésticos próximos aos locais de criação, de pastejo e fontes de água dos animais, devem ser adotadas. A ampla distribuição de animais positivos sinaliza a possibilidade de infecção também em outros animais domésticos, bem como em humanos pelo ambiente contaminado. Ressalta-se a possibilidade de que asininos e muares permaneçam com títulos detectáveis por mais tempo, justificando a prevalência encontrada, sendo necessários estudos para confirmar este possibilidade.

Frequency and factors associated with Theileria equi, Babesia caballi and Trypanosoma evansi in equids from Bahia (Northeast Brazil) / Frequência e fatores associados a Theileria equi, Babesia caballi e Trypanosoma evansi em equídeos da Bahia (Nordeste do Brasil)

Abstract The aim of this study was to determine the frequency and factors associated to Babesia caballi, Theileria equi and Trypanosoma evansi in naturally infected equids from the northeast Brazil. Blood samples from 569 equids (528 horses, 8 mules, and 33 donkeys) were collected and tested for the presence of DNA of each of these protozoan parasites by PCR. Generalized linear models were used to evaluate risk factors associated with the infection. The frequency of T. equi infection was 83.5% (475/569) - 84.3% in horses, and 73.2% in donkeys and mules. The results of the final model indicated that age (senior group) and animal species (mule and donkey group) were protective factors against this pathogen. The frequency of B. caballi infection was 24.3% (138/569) - 23.5% in horses and 34.1% in donkeys and mules. Age (adult and senior group) was considered a protective factor against B. caballi infection whereas animal species (donkey and mule group) were considered a risk factor for the infection. Trypanosoma evansi infection was not detected in any of animals. Our results suggest that equids from the area studied may be infected earlier in life with the etiological agents of equine piroplasmosis and become asymptomatic carriers.

Resumo Este estudo teve como objetivos conhecer a frequência e os fatores associados à infecção por Babesia caballi, Theileria equi e Trypanosoma evansi em equinos naturalmente infectados do nordeste do Brasil. Amostras de sangue de 569 equídeos (528 equinos, 8 muares e 33 asininos) foram coletadas e testadas para a presença do DNA destes parasitos através da PCR. Modelos lineares generalizados foram utilizados na avaliação dos fatores associados às infecções. A frequência de infecção por T. equi foi de 83,5% (475/569) -84,3% (445/528) em eqüinos e 73,2% (30/41) em asininos e muares. Os resultados do modelo final indicam idade (sênior) e espécie (muar e asinina) como possíveis fatores de proteção para este patógeno. A frequência de infecção por B. caballi foi de 24,3% (138/569) - 23,5% (124/528) em eqüinos e 34,1% (14/41) em asininos e muares. As faixas etárias (adulto e sênior) foram identificadas como possíveis fatores de proteção, e a espécie (asinina e muar) como risco para ocorrência de infecção por B. caballi. Infecções por Trypanosoma evansi não foram detectadas. Estes resultados indicam que os equídeos na região estudada se infectam precocemente com agentes da piroplasmose equina tornando-se portadores assintomáticos.

Frequency and factors associated with Theileria equi, Babesia caballi and Trypanosoma evansi in equids from Bahia (Northeast Brazil).

The aim of this study was to determine the frequency and factors associated to Babesia caballi, Theileria equi and Trypanosoma evansi in naturally infected equids from the northeast Brazil. Blood samples from 569 equids (528 horses, 8 mules, and 33 donkeys) were collected and tested for the presence of DNA of each of these protozoan parasites by PCR. Generalized linear models were used to evaluate risk factors associated with the infection. The frequency of T. equi infection was 83.5% (475/569) - 84.3% in horses, and 73.2% in donkeys and mules. The results of the final model indicated that age (senior group) and animal species (mule and donkey group) were protective factors against this pathogen. The frequency of B. caballi infection was 24.3% (138/569) - 23.5% in horses and 34.1% in donkeys and mules. Age (adult and senior group) was considered a protective factor against B. caballi infection whereas animal species (donkey and mule group) were considered a risk factor for the infection. Trypanosoma evansi infection was not detected in any of animals. Our results suggest that equids from the area studied may be infected earlier in life with the etiological agents of equine piroplasmosis and become asymptomatic carriers.

Transplacental transmission of bovine tick-borne pathogens: Frequency, co-infections and fatal neonatal anaplasmosis in a region of enzootic stability in the northeast of Brazil.

Bovine tick-borne disease (TBD) constitutes a worldwide group of diseases that result in great losses for dairy and beef cattle. With regard to the epidemiological profile of the diseases, the importance of transplacental transmission is still not very well understood. The aim of this study was to determine the transplacental transmission of TBD agents (Anaplasma marginale, Babesia bovis and B. bigemina) in a herd of dairy cattle that had been naturally infected in an area of enzootic stability in northeastern Brazil. Blood for serology of the three agents was collected from cows within 120 days of gestation and serology, haemogram and nPCR assays were performed after birth. Blood was collected from the calves within 3h of birth, and haemogram and nPCR assays were performed in all animals. Pre-colostrum serology was achieved in 34 animals. The Student's t-test was used to compare the haemogram results between animals that were positive and negative for the haemoparasites. The cows were seropositive for all agents in at least one of the examinations. We detected 15 cases of vertical transmission of A. marginale, 4 of B. bovis and 2 of B. bigemina in the 60 cows. In infected animals, co-infection was detected for A. marginale and B. bovis in 1 of 60 calves, and a triple infection was detected in one other calf. Fatal neonatal anaplasmosis was observed in 1 of 15 calves, in which death occurred within 24h of birth. From the results, we concluded that transplacental transmission of TBD agents occurs, including in cases of co- and triple-infection. Such transplacental transmission can cause neonatal death, increasing the importance of this form of epidemiological transmission and suggesting its role as a cause of undiagnosed neonatal death.

Transmission paths of Neospora caninum in a dairy herd of crossbred cattle in the northeast of Brazil.

The aim of this study was to determine the transmission paths of Neospora caninum in a dairy herd of crossbred cattle. Two hundred and ninety animals were grouped according to the year of their birth to verify the distribution of infection according to age. The blood of 196 cattle was collected thrice, with an average interval of 210 days, to evaluate the existence of horizontal transmission in the herd. To evaluate vertical transmission, the blood of 64 calves was collected prior to ingestion of colostrum and from their mothers at parturition. Moreover, 63 family trees were built. The presence of anti-N. caninum antibodies was detected using an indirect fluorescent antibody test. The chi-square test (χ(2)) with Yates' correction or Fisher's exact test was used to evaluate the relation between the serology and age groups and between the serostatus of cows and their progeny in different calvings. A higher seropositivity (p=0.035) was found in animals born in 2008 compared to those born in 1997-2007. The serological status of only 13 animals presented changes, of which six (3.1%) became seropositive, indicating a low proportion of horizontal transmission. All seropositive cows gave birth to seropositive calves, resulting in 100% vertical transmission. Sixty-three family trees were constructed. In 29 (46%) of these families, there were animals seropositive for N. caninum. Congenital infection in relation to the number of births was estimated from the relation of Mother+ and Daughter+, without significant differences (p=0.84) between the number of births and the transmission of the parasite from infected cows to their progeny. The low proportion of horizontal transmission combined with the high proportion of vertical transmission allowed us to conclude that transplacental transmission is the principal route of N. caninum infection in the herd.