Seroprevalence of Neospora caninum in dairy goats from Bahia, Brazil

Seroprevalence and associated factors with Neospora caninum infection in sheep and goats slaughtered in the state of Paraíba, Brazil

The objective was to describe the seroprevalence of anti-Neospora caninum antibodies in goats and sheep slaughtered in the state of Paraíba and to identify possible associated factors with the infections. Two hundred twenty-nine samples from goats and two hundred five from sheep were analyzed by Indirect Immunofluorescence Reaction (IFAT) using a cutoff point of 1:50. The presence of anti-N. caninum antibodies was identified in 28.4% (65/ 229; 95% Confidence Interval: 22.6-34.2) of the goat samples and in 12.7% (26/ 205; 95% CI: 8.2 - 17.2) of the sheep samples. Contact between goats and dogs (Odds ratio 4.81; CI 1.13 - 2.67; p = 0.041) and cattle (OR. 1.87; CI 1.13 - 2.67; p = 0.002) was identified as a risk factor for goats and contact between sheep and dogs (OR 2.32; CI 1.58 - 3.14; p = 0.026) and history of abortion (OR 1.94; CI 1.28 - 2.90; p = 0.001) was considered a risk factor for sheep. The study revealed a high seroprevalence of anti-N. caninum antibodies in slaughtered goats and sheep in Paraíba. Risk factors such as contact with dogs/cattle and abortion history underscore the need for preventive measures to control infection and enhance animal health management.

Seroprevalence of Neospora caninum in Goats from Korkuteli District of Antalya

OBJECTIVE

This study aimed to determine the seroprevalence of Neospora caninum in goats from the Korkuteli district of Antalya.

METHODS

During the study, sera samples were obtained from 184 female goats and analyzed for the presence of antibodies against N. caninum using a commercial ELISA kit.

RESULTS

Seroprevalence of N. caninum was determined as 4.89%. Seropositivity of N. caninum in goats was not statistically significant (p>0.05) in terms of study centers, age groups, and abort situation.

CONCLUSION

This study reports the first data on the presence and seroprevalence of N. caninum in the goats in the region.

Seroprevalence and risk factors for Neospora caninum and Toxoplasma gondii in goats of Maranhão State, Brazil

We estimated the seroprevalence and possible risk factors for neosporosis and toxoplasmosis in goats in the state of Maranhão, Brazil. In addition, the variables related to these animals and the management of the farm were investigated in terms of the significance of the associations. In total, 383 serum samples from goats, of both sexes and different ages, were collected from 15 farms in four municipalities. The indirect immunofluorescence test was used for antibody detection against Neospora caninum and Toxoplasma gondii. The overall seroprevalence of N. caninum in goats was 26.4% (101/382; IC 95% 22.3-31.1), and 114 out of 383 serum samples were T. gondii-seropositive (29.8%, IC 95% 25.4-34.5). In addition, the seroprevalence of coinfection of T. gondii and N. caninum in goats was 8.6% (33/382; IC 95% 6.2-11.8). The risk factors significantly associated with the seroprevalence of N. caninum were age, type of sheepfold floor, rearing system, feeding, pasture area cultivated, cats having access to the feed deposits, worming, slaughter place of the animals, history of abortion and the presence of dogs and cats. Regarding the seroprevalence of T. gondii infection, age, category, presence of other species and purpose of breeding were the risk factors. To our knowledge, this is the first report of the seroprevalence and risk factors for N. caninum and T. gondii in goats in the state of Maranhão, Brazil, which provides basic data for the implementation of strategies and control measures against neosporosis and toxoplasmosis.

A systematic literature review and meta-analysis of risk factors for Neospora caninum seroprevalence in goats

This meta-analysis aimed to estimate N. caninum seroprevalence in goats worldwide to determine the main risk factors for seropositivity that could be associated with parasite infection in herds. Four electronic databases were searched: PubMed, SciELO, Scopus and the VHL Regional Portal. Firstly, 367 articles were identified. After removing duplicates and non-eligible papers. A total of 36 articles were selected, which contained information concerning 22,234 goats, between 2004-2019. The combined seroprevalence of infection using a meta-analysis of the random effects model was 5.99 % (95 %, CI 4.38-7.83). The overall estimated N. caninum seroprevalence showed high heterogeneity, I² = 97 %. The present study showed that seropositive goats were 3.07 times more likely to abort (OR 3.07; 95 % CI 1.02-9.22) than seronegative animals. The presence of dogs on farms also increased the odds of N. caninum seropositivity (OR 1.40; 95 % CI 1.01-1.94). In addition, male animals had higher odds of being seropositive to neosporosis than females (OR 1.31; 95 % CI 1.00-1.71). N. caninum seroprevalence in goats is widely distributed worldwide, with the American continent having a higher proportion of seropositive animals.

Serological response to Neospora caninum infection in goats and agreement between three diagnostic techniques to detect caprine neosporosis

ABSTRACT: The present study aimed to measure the serological response of goats infected with Neospora caninum by assessing the diagnostic performance and agreement between three techniques (indirect immunofluorescent antibody test, IFAT; Neospora agglutitation test, NAT; enzyme-linked immunosorbent assay, ELISA). The panel of sera were comprised of 500 samples of goats, and 60 reference serum samples. These reference and field serum samples were tested by ELISA, NAT, and IFAT. In the field serum samples tested, the seroprevalences of anti-N. caninum antibodies were 3.2%, 4.6%, and 6.4% in the NAT, IFAT and ELISA, respectively. Using the IFAT as the gold standard, the NAT and the ELISA agreement was considered weak (k=0.28) and strong (k=0.75), respectively. When the IFAT performance was used for comparison purposes, the ELISA showed 91.3% sensitivity and 97.7%, specificity with a PPV of 65.2% and a NPV of 99.6%; The NAT presented sensitivity of 26.1% and specificity of 97.9% with a PPV of 37.5% and a NPV of 96.5%. Accordingly, the IFAT should remain the assay of choice for studies about N. caninum infection in goats in individual serum samples. A combination of serological assays with high sensitivity and specificity is recommended in serosurveys of caprine neosporosis.

Seroepidemiology of Neospora caninum among goats (Capra hircus) in the state of Paraíba, northeastern Brazil

ABSTRACT Although goat dairy farms in Brazil may have a higher risk of infection by Neospora caninum than beef farms, risk factor evaluation on a representative population remains to be fully established in Brazil. Accordingly, this study aimed to establish the occurrence of anti-N. caninum antibodies and factors associated with exposure in 406 blood samples from five dairy and three beef goat farms in the state of Paraíba, northeastern Brazil. Anti-N. caninum antibodies were detected by indirect immunofluorescence assay (IFA), with samples considered positive when reacting with dilution ≥ 1:50. A total of 106/406 goats (26.11%; 95% CI: 21.96-30.72%) were seroreactive comprising 2/61 (3.28%), 10/45 (22.22%), 13/50 (26.00%), 17/51 (33.33%) to 29/46 (63.04%) in dairy farms, and from 3/54 (5.56%), 12/50 (24.00%) to 20/49 (40.82%) on the beef farms. No significant associations were found in relation to age, gender, dairy versus beef farms, occurrence of abortions or mummified fetuses, and seroreactivity to N. caninum (P>0.05). In conclusion, goat farms in the state of Paraíba showed the highest occurrence of anti-N. caninum antibodies to date in Brazil.

Transplacental transmission of Neospora caninum in naturally infected small ruminants from northeastern Brazil

ABSTRACT: Toxoplasma gondii and Neospora caninum are causative agents of abortion in sheep and goats. Thus, the present study aimed to describe the transplacental transmission of these protozoans in small ruminants of northeastern Brazil. Seventeen fetuses (6 goats and 11 sheep) from farms with history of abortion were necropsied and samples were collected from different tissues (brain, liver, lung, kidney and heart). The samples were analyzed by PCR, histopathology (HP) and immunohistochemistry (IHC) to evaluate whether T. gondii and/or N. caninum infection were the cause of abortion. None of the samples was positive for T. gondii according to PCR and IHC results. Some brain, liver, lung, kidney and heart samples of goat fetuses were positive for N. caninum by PCR. In the histopathology, mild mononuclear infiltration and necrosis with calcification were observed in the liver and brain of one goat fetus, respectively, that also was positive for N. caninum by PCR and IHC. The results confirmed vertical transmission of N. caninum in naturally infected goats of northeastern, Brazil.

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.

Occurrence of anti-Neospora caninum and anti-Toxoplasma gondii IgG antibodies in goats and sheep in western Maranhão, Brazil

Neosporosis and toxoplasmosis are parasitic diseases which can cause reproductive problems in goats and sheep. The current study aimed to determine the occurrence of anti-Neospora caninum and anti-Toxoplasma gondii IgG antibodies in goats and sheep from the districts of Amarante do Maranhão and Buritirana, Imperatriz microregion, western area of Maranhão State, northeastern Brazil, and to assess factors associated to infection by these etiologic agents. Blood samples from 110 animals (46 goats and 64 sheep) from five herds were collected, and indirect immunofluorescence assay was used for serological testing. Of 46 goat samples, 17.39% (n = 8) showed anti-N. caninum antibodies and 4.35% (n = 2) anti-T. gondii, while of 64 sheep samples 4.69% (n = 3) and 18.75% (n = 12) showed anti-N. caninum and anti-T. gondii antibodies, respectively. No significant difference regarding the presence of domestic cats and/or dogs on the property and veterinary care was seen for both etiologic agents studied. However, food supplementation and animal reproductive failure were significantly (p < 0.05) for N. caninum among sheep and goats, respectively. The current study showed that goats and sheep in western Maranhão are exposed to N. caninum and T. gondii. It is the first evidence of these agents in small ruminants in this region.

Prevalence of Neospora caninum antibodies in sheep and goats in Pakistan

The purpose of the present study was to obtain seroepidemiological information on the Neospora caninum infection status of sheep and goats in different areas of Punjab Province and Azad Kashmir (Pakistan). A cross-sectional study, with the use of a competitive ELISA, showed an overall 27.7% (35 of 128) (95% confidence interval [CI] ± 7.7%) and 8.6% (13 of 142) (95% CI ± 4.6%) seroprevalence of N. caninum antibodies in sheep and goats, respectively. The difference in seroprevalence between sheep and goat populations was statistically significant (P < 0.05). The highest prevalence (37.4% ± 13.2%) was recorded in the tailless breed of sheep.

Fatores associados a soroprevalência de Neospora caninum e Toxoplasma gondii em rebanhos caprinos na região sul de Minas Gerais

Este estudo estabelece a soroprevalência de Neospora caninum e Toxoplasma gondii em rebanhos caprinos no Sul de Minas Gerais e verifica a sua associação com o desempenho reprodutivo dos rebanhos analisados, uma vez que não há dados sobre neosporose em caprinos neste Estado. Amostras de soro de 401 caprinos provenientes de 11 propriedades foram submetidas à reação de imunofluorescência indireta anti-N. caninum e T. gondii. A prevalência média de animais positivos foi de 10,7% e 21,4%, respectivamente. Houve diferença significativa entre as faixas etárias. Neste quesito os maiores índices de positividade, para ambos os parasitas, foram observados nos caprinos acima de três anos de idade. Estes apresentaram uma probabilidade 2,6 e 4,8 maior, em relação aos animais de até um ano de idade, para N. caninum e T. gondii, respectivamente. No teste T não houve associação positiva entre as médias de prevalência de N. caninum (p=0,553) e T. gondii (p=0,098) com a ocorrência de problema reprodutivo nos rebanhos. Porém, propriedades com histórico de problemas reprodutivos apresentaram uma média de reagentes para N. caninum de 18,64%, se comparadas a 13,97% de criatórios que não relataram essas alterações. Quando os problemas reprodutivos foram separados em categorias a relação entre a ocorrência de aborto e a soroprevalência de N. caninum e de T. gondii foi significativa (p<0,05) por meio dos testes Exato de Fisher e Qui-quadrado. Não houve diferença (p>0,05) entre as médias de prevalência de T. gondii e o acesso de gatos ao rebanho no teste T. Entretanto, a média de prevalência nas propriedades em que os gatos tinham acesso foi de 31,01%, se comparada a 17,34% em criatórios onde não existiam gatos. Foi constatado o acesso de cães em 100% das propriedades. Os resultados obtidos neste estudo demonstram que N. caninum e T. gondii infectam caprinos no Sul de Minas Gerais e que estes parasitas podem estar associados à ocorrência de abortos nessa espécie animal.

Evaluation of Toxoplasma gondii and Neospora caninum infections in sheep from Uberlândia, Minas Gerais State, Brazil, by different serological methods

Toxoplasmosis and neosporosis have been recognized as economically important diseases with considerable impact on the livestock industry. Considering the scarce information on the occurrence of Toxoplasma gondii and Neospora caninum infections in sheep from Uberlândia, Minas Gerais State, Brazil, this study aimed to investigate the frequency of antibodies against these parasites in sheep sera from this region by using different serological methods. A total of 155 sheep serum samples were analyzed by the indirect fluorescence antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA) for the detection of IgG against T. gondii and N. caninum. Seroreactivity by IFAT showed 80% of samples with titers between 512 and 2048 for T. gondii (cutoff ≥ 64) and 78% presenting titers between 50 and 200 for N. caninum (cutoff ≥ 50). Seroreactivity by ELISA showed 75% of samples with ELISA index (EI) between 2.0 and 3.0 for T. gondii (cutoff ≥ 1.3) and 54% presenting EI between 1.3 and 2.0 for N. caninum (cut off ≥ 1.3). Discordant results by both tests were analyzed by immunoblot, resulting in a total seropositivity of 61% for T. gondii and 23% for N. caninum, with 41% to T. gondii only, 3% to N. caninum only, and 20% to both parasites. There was a significant positive association between seropositivity to T. gondii and age over one year (P<0.001), but such association was not found for N. caninum infection. In conclusion, as T. gondii and N. caninum infections are simultaneously present in sheep flocks of this region, it should be emphasized the importance to carry out a regular monitoring of Toxoplasma infection due to its high prevalence, its zoonotic potential and induction of reproductive disorders leading to economic losses. For neosporosis, sheep farmers should be instructed about the presence of the parasite in the flock, its risk factors and potential abortifacient role in sheep. Differential flock management could be valuable tool to establish the association of serological positivity and reproductive disease induced by N. caninum in sheep.