Toxoplasma gondii and Neospora caninum seroprevalence in dairy sheep and goats mixed stock farming

Evaluation of frequency of antibodies against Neospora caninum, Toxoplasma gondii and Brucella melitensis, risk factors and spatial distribution of infection in goat and sheep flocks from Argentina

Neospora caninum, Toxoplasma gondii and Brucella melitensis are pathogens that cause abortion in small ruminants. Besides, B. melitensis and T. gondii are zoonotic pathogens. The aim of this study was to describe the frequency of antibodies against N. caninum, T. gondii and B. melitensis in sheep and goats from three provinces of the center region of Argentina. In addition, the spatial distribution of the infected flocks/herds and risk factors were evaluated. A cross-sectional study was conducted from 2015 through 2016. Serum samples from 4783 goats and 1524 sheep from 186 goat, 51 sheep and 38 mixed flocks/herds were analyzed. Competitive inhibition enzyme-linked immunosorbent assay (ciELISA) and indirect fluorescent antibody test (IFAT) were performed for detection of antibodies against N. caninum and IFAT for T. gondii. The buffered plate antigen test and complement fixation test were performed for detection of antibodies against B. melitensis. The frequency of anti-T. gondii antibodies was 41.2% and 29.7% for sheep and goats, respectively. The frequency of anti-N. caninum antibodies was 17.2% and 14% for sheep and goats, respectively. About 97.1% of the sheep flocks, 79.4% of the goat herds and the 91.3% of the mixed flocks had seropositive animals to T. gondii. About 61.8% of the sheep flocks, 58% of the goat herds and the 82.6% of the mixed flocks had seropositive animals to N. caninum. All the analyzed animals were negative to anti-B. melitensis antibodies. For T. gondii, a significant cluster of high risk of seropositive flocks/herds was detected in the littoral of the Parana River. The province of origin of the flock/herd was the only variable associated to T. gondii positivity (p = 0.003). Animals from Santiago del Estero and Santa Fe Provinces had 3.48 and 1.77 times more risk to be positive to T. gondii than animals from Entre Ríos Province, respectively. For N. caninum, a cluster of high risk of seropositive flocks/herds was detected in the north of Santa Fe Province. The only explanatory variable associated to N. caninum positivity was animal species (p = 0.003). Sheep had 1.73 times more risk to be positive to N. caninum than goats. The absence of antibodies against B. melitensis in all the analyzed animals is an important finding for the public health of the region. Since bordering provinces have infected flocks/herds, brucellosis in small ruminants should be under epidemiologic surveillance in the region.

Detection of Toxoplasma gondii Infection in Small Ruminants: Old Problems, and Current Solutions

Toxoplasmosis is a parasitic zoonosis of veterinary importance, with implications for public health. Toxoplasma gondii infection causes abortion or congenital disease in small ruminants. Moreover, the consumption of infected meat, cured meat products, or unpasteurized milk and dairy products can facilitate zoonotic transmission. Serological studies conducted in various European countries have shown the high seroprevalence of specific anti-T. gondii antibodies in sheep and goats related to the presence of oocysts in the environment, as well as climatic conditions. This article presents the current status of the detection possibilities for T. gondii infection in small ruminants and their milk. Serological testing is considered the most practical method for diagnosing toxoplasmosis; therefore, many studies have shown that recombinant antigens as single proteins, mixtures of various antigens, or chimeric proteins can be successfully used as an alternative to Toxoplasma lysate antigens (TLA). Several assays based on DNA amplification have been developed as alternative diagnostic methods, which are especially useful when serodiagnosis is not possible, e.g., the detection of intrauterine T. gondii infection when the fetus is not immunocompetent. These techniques employ multicopy sequences highly conserved among different strains of T. gondii in conventional, nested, competitive, and quantitative reverse transcriptase-PCR.

A Review of Toxoplasma gondii in Animals in Greece: A FoodBorne Pathogen of Public Health Importance

Toxoplasma gondii is a zoonotic protozoon with a complex life cycle and the second most important foodborne pathogen in Europe. Surveillance of toxoplasmosis is based on national considerations since there are no mandatory controls along the food chain in the European Union, and underreporting of meat is still a problem in many countries like Greece. The current review provides an overview of T. gondii prevalence, associated risk factors, and surveillance in animals in Greece, focusing on the transmission role of meat and highlighting the control measures that should be adopted by consumers. Sows, wild boars, hares, equines, and cats had lower, while sheep and goats generally had higher seroprevalence than their respective pooled European and global values. Seroprevalence in chickens was similar between Greece and Europe, while there was high variation in cattle studies, with no data regarding dairy products. Though a comprehensive meat safety assurance system is the most effective approach to control the principal biological hazards associated with meat, such as T. gondii, the prerequisite risk categorisation of farms and abattoirs based on EFSA's proposed harmonised epidemiological indicators has not materialised as yet in Greece. Therefore, comprehensive control strategies are still required to ensure food safety and safeguard public health.

Seroprevalence of Toxoplasma gondii infection in sheep and goats from different geographical regions of the world: Systematic review and meta-analysis

The Toxoplasma gondii is an obligate intracellular protozoan parasite which significantly impact small ruminant productivity, international animal trade and transboundary movement of animal across the globe. The seroprevalence of T. gondii infection (toxoplasmosis) in sheep and goats is widely studied in many parts of the world and there is a lack of comprehensive information on prevalence estimates considering the global and regional perspectives. The aim of the study was to use systematic review and meta-analysis methods to estimate the global and regional pooled seroprevalence of T. gondii infection in sheep and goats, as well as factors that influence prevalence estimations. Relevant articles reporting the seroprevalence of toxoplasmosis in sheep and/goats were searched in five electronic databases, including PubMed, Web of Science, Scopus, Embase and ProQuest. After the publications were checked to verify they fit the inclusion criteria, a total of 225 articles were included in the systematic review and meta-analysis, reflecting data from 70 countries/regions. The pooled prevalence was estimated using a random effect meta-analysis model. Overall, the seroprevalence of T. gondii infection was 33.86% (95% CI: 30.47-37.25%) in sheep and 31.78% (95% CI: 28.99-34.58%) in goats, with significant variation in prevalence estimates across geographical locations (p < .001). Substantial heterogeneity (I²  > 75%) was observed in most pooled seroprevalence estimates. The T. gondii infection in global sheep and goat population showed uptrend over the period. This information would be useful for epidemiologist, health authorities and farmers in order to plan future T. gondii survey and infection management strategies both locally and internationally.

Seroprevalence and risk factors of Toxoplasma gondii and Neospora caninum infection in black goats in Yunnan Province, Southwestern China

Toxoplasma gondii and Neospora caninum are two obligate intracellular protozoan parasites that can cause reproductive failure and production losses. To date, there is no data of T. gondii and N. caninum seroprevalence in black goats in Yunnan Province, southwestern China. In the present study, a total of 734 serum samples were collected from black goats in four different counties of Yunnan Province. 734 and 590 serum samples were examined for antibodies against T. gondii and N. caninum by using MAT and indirect ELISA, respectively. A total of 123 and 76 samples were T. gondii-positive and N. caninum-positive, respectively. The overall seroprevalence of T. gondii in black goats was 16.76% (123/734, 95% CI: 14.06-19.46) with the titer ranged from 1:25 to 1:3200. The seroprevalence of N. caninum was 12.88% (76/590, 95% CI: 10.18-15.58). There was significant difference in seroprevalence of N. caninum in different regions (P < 0.01, χ² = 30.63) and age groups (P < 0.05, χ² = 11.85). Significant differences in seroprevalence of T. gondii were observed in different regions (P < 0.05, χ² = 9.21) and different gender groups (P < 0.01, χ² = 12.29). Results of seroprevalence of T. gondii and N. caninum indicated that T. gondii and N. caninum were prevalent parasites in black goats in Yunnan Province. This is the first report of seroprevalence of T. gondii and N. caninum in black goats in Yunnan Province. The results of this study indicated that some measures should be taken to control these two parasites and to reduce economic losses to the livestock industry in Yunnan Province.

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.

Toxoplasma gondii and Neospora caninum infections in sheep and goats in Switzerland: Seroprevalence and occurrence in aborted foetuses

Toxoplasma gondii and Neospora caninum infections are important causes of abortion in ruminants. Besides, meat from T. gondii infected animals represent a major infection source for humans. The occurrence of these protozoan parasites in Switzerland was investigated both, in a nationwide cross-sectional serological survey, and by molecular methods in aborted sheep and goat foetuses. A total of 653 sheep from 143 farms and 748 goats from 164 farms were tested by commercial ELISAs and inconclusive results were defined by immunoblot. Besides, a risk factor analysis for seropositivity was performed. The observed seroprevalences for T. gondii in sheep and goats were 66.3% and 50.5% at the animal level, and 90.9% and 81.1% at the farm level, respectively. For N. caninum, the detected seroprevalences in sheep and goats were 0.8% and 0.9% at the animal level, and 2.8% and 1.8% at the farm level, respectively. Older small ruminants, and sheep (vs. goats) had a higher risk of being seropositive to T. gondii. Alpine grazing in summer was identified as a protective factor for seropositivity to T. gondii in both animal species. Toxoplasma gondii and N. caninum DNA were detected in 6.1% and 2.4% (n = 82), and in 6.8% and 1.4% (n = 73) of the tested ovine and caprine foetuses, respectively. These results suggest the involvement of these parasites in abortions and reveal a high prevalence of T. gondii and lower prevalence of N. caninum infections in small ruminants in Switzerland. They also suggest that consumption of undercooked meat from T. gondii infected sheep and goats may represent a risk for public health.

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Toxoplasma gondii infections are very frequent in Swiss small ruminants.

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Meat from infected small ruminants represents a source for T. gondii human infection.

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Sheep have a higher risk of T. gondii seropositivity than goats.

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Neospora caninum seroprevalences in Swiss sheep and goats are very low.

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T. gondii and N. caninum were detected in ovine and caprine abortions in Switzerland.

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T. gondii and N. caninum should be considered in diagnosis of small ruminant abortion.

Co-Infection of L. monocytogenes and Toxoplasma gondii in a Sheep Flock Causing Abortion and Lamb Deaths

Abortion in livestock is a public health burden, and the cause of economic losses for farmers. Abortion can be multifactorial, and a deep diagnostic investigation is important to reduce the spread of zoonotic disease and public health prevention. In our study, a multidisciplinary investigation was conducted to address the cause of increased abortion and lamb mortality on a farm, which detected a co-infection of Listeria monocytogenes and Toxoplasma gondii. Hence, it was possible to conclude that this was the reason for a reduced flock health status and the cause of an increased abortion rate. Furthermore, the investigation work and identification of the L. monocytogenes infection root allowed the reduction of economic loss.

Ovine Neosporosis: The Current Global Situation

Simple Summary

This review summarizes the current global situation of Neospora caninum infection in sheep by referring to all of the available descriptions of natural ovine neosporosis to date, focusing on epidemiology, clinical signs, lesions, and diagnosis. The data suggest that ovine neosporosis is more prevalent than currently thought, that it has increased in the last few decades, and that it should now be considered in the differential diagnosis when investigating abortion in sheep.

Abstract

In the past 20 years, Neospora caninum infection in sheep has been reported in at least 31 countries worldwide from all sheep-rearing continents (Europe, Asia, the Americas, Africa, and Oceania), and its role as an abortifacient agent is becoming more evident. Most studies of ovine neosporosis have focused on its epidemiology, based primarily on serological analysis, with only a few studies investigating the actual presence of the parasite by PCR and/or IHC. Individual seroprevalence rates were highly variable between countries, and even between regions within the same country, ranging from 0.0% to 67.4% positive. Furthermore, most of the studies were not directly comparable due to differences in experimental designs, sample sizes, husbandry systems, ecological factors, and serological tests (e.g., IFAT, ELISA, MAT, Western blot). The latter, along with the scarcity of studies on the relevance of N. caninum as an abortifacient agent, may bias the perception of the importance of this disease. This review summarizes the situation of N. caninum infection in sheep using all available published studies describing natural ovine neosporosis. The epidemiology shows that ovine neosporosis is found worldwide, and it poses a relevant risk to the sustainability of sheep flocks.

Neosporosis in sheep: a systematic review and meta-analysis of global seroprevalence and related risk factors

Neosporosis is recognized as the main cause of abortions in cattle worldwide and there is an increasing concern about its role in ovine reproductive losses; however, epidemiological studies regarding neosporosis in sheep are still limited. This meta-analysis aimed to estimate the global pooled seroprevalence and associated risk factors of ovine neosporosis. In the current report, a comprehensive strategy of search and data collection from 7 worldwide databases was performed. A final set of 73 studies (80 datasets) published from 2000 to 2021 were selected based on inclusion criteria, comprising data on 35,740 sheep (corresponding to 37,565 evaluated samples) from 30 countries worldwide. The global pooled seroprevalence of Neospora caninum infection in sheep estimated by the random-effects model was 13% (95% CI, 10-15) and showed high heterogeneity (Q = 5147.15, I² = 98%, p< 0.001). Furthermore, by meta-analyses of subgroups it was demonstrated for the first time that seroprevalence significantly varied between continents (highest in Africa; 20%, 95% CI, 4-44), WHO regions (highest in African Region; 42%, 95% CI, 36-48), countries (highest in Colombia; 79%, 95% CI, 61-92%) and diagnostic methods (highest by IFAT; 17%, 95% CI, 12-23). Meta-regression indicated significant increasing trends in the prevalence of ovine neosporosis with decrease in geographical latitude (coefficient = -0.013; p<0.001), whereas longitude did not influence it (coefficient = -0.001; p=0.365). Regarding associated risk factors, older sheep were more likely to be infected with N. caninum than younger ones (OR 1.42; 95% CI 1.08-1.87), and sheep bred under intensive or semi-intensive systems resulted less susceptible to be seropositive than those bred under extensive system (OR 0.65; 95% CI 0.42-0.99 and OR 0.74; 95% CI 0.62-0.89, respectively). Conversely, no apparent association was found between seroprevalence and other variables, such as sex (OR 1.06; 95% CI 0.9-1.24), the presence of dogs on the farm (OR 1.15; 95% CI 0.63-2.12) or the presence of abortion (OR 1.80; 95% CI 0.87-3.74). In conclusion, the seroprevalence of ovine neosporosis is widely and heterogeneously distributed throughout the world, and it is negatively associated with increasing geographical latitude. In addition, age and extensive production system represent risk factors, which suggest that the horizontal transmission route is relevant for this host species. It is recommended to pay more attention to this disease and emphasize the global need for more indexed studies concerning the seroprevalence and risk factors of ovine neosporosis to better understand the epidemiology of this coccidian infection.

A systematic literature review and meta-analysis of Toxoplasma gondii seroprevalence in goats

The aim of this study was evaluate to seroprevalence of Toxoplasma gondii in goats worldwide and the main risk factors associated from 2000 to 2020, through meta-analysis with 55,317 goats from 75 reports published in seven electronic databases of major global importance. A global seroprevalence detected was 27.49% (95% CI 24.15-30.95; I2 = 99%), with the lowest percentage in Asia (20.74%; 95% CI 16.45-25.39) and highest in Central America (62.15%; 95% CI 57.28-66.90) and Europe (31.53%; 95% CI 21.71-42.26). The seropositivity in Africa and South America were (29.41%; 95% CI 19.11-40.89) and (29.76%; 95% CI 25.84-33.83), respectively. The seroprevalence was associated with presence of cats (OR 2.22; 95% CI 1.30-3.82), goats older than one year (OR 1.77; 95% CI 1, 37-2.29), females (OR 1.43; 95% CI 1.23-1.65), rearing system (extensive vs. intensive) (OR 4.82; 95% CI 1.96-11, 84) and rearing system (semi-intensive vs. intensive) (OR 1.48; 95% CI 1.48-6.13). The heterogeneity was evidenced in most world regions and the risk factors may play roles in varying the seroprevalence.

The Global Prevalence of Neospora caninum Infection in Sheep and Goats That Had an Abortion and Aborted Fetuses: A Systematic Review and Meta-Analysis

Neospora caninum (N. caninum) can be a potential factor causing a significant rate of miscarriages in small ruminants (sheep and goats) worldwide. Therefore, the present study aimed to determine the global status of N. caninum in sheep and goats that had an abortion and aborted fetuses. Five English databases (PubMed, ScienceDirect, Web of Science, Scopus, and ProQuest) were searched for relevant scientific articles published from their inception until November 4, 2021. Finally, 21 studies conducted on sheep (1,671 aborted fetuses and 935 abortive sheep) and 10 studies on goats (130 aborted fetuses and 80 abortive goats) were included for the final meta-analysis. A random-effects meta-analysis model was used to estimate the pooled prevalence with 95% confidence intervals (CIs). Moreover, sensitivity analysis, publication bias test, and quality assessment were performed in this study. The pooled prevalence of N. caninum in aborted fetuses of sheep and goats globally was estimated to be 15% (95% CI: 9-21%) and 7% (95% CI: 2-12%) using molecular methods. Besides, the seroprevalence of N. caninum was estimated to be 17% for aborted fetuses of sheep. The overall prevalence rate of N. caninum infection in sheep that had an abortion was 3%. The present results show a relatively high prevalence of N. caninum infection in sheep that had an abortion and aborted fetuses compared to goats. Therefore, further studies using different diagnostic techniques to more accurately estimate the rate of infection in sheep and goats may help provide adequate control measures and strategies to reduce the rate of abortion in sheep and goats and reduce economic damage to the livestock industry. This study was registered at the International Prospective Register of Systematic Reviews (PROSPERO; code: CRD42020216694).

A Meta-Analysis of the Prevalence of Toxoplasmosis in Livestock and Poultry Worldwide

Toxoplasma gondii causes toxoplasmosis with a global prevalence in the world. A large proportion of human illness is most frequently associated with consuming raw and undercooked meat or other animal products containing infective parasitic stages of T. gondii. This systematic review and meta-analysis study evaluated the prevalence of toxoplasmosis in cattle, sheep, camels, goats, and poultry worldwide. The search was performed in databases including PubMed, WoS, Scopus, Science Direct, Google Scholar, and ISC from 2000 to 2019 in Persian and English. The main inclusion criteria were the prevalence of toxoplasmosis among livestock and poultry and the prevalence indices by sample size. During these 20 years, the overall prevalence of toxoplasmosis in livestock and poultry was 28.3% (95% confidence interval (CI) 25-31.9%) using the random-effects meta-analysis model. The highest prevalence of T. gondii in livestock and poultry animals was found in Asia in 2014 with 89.8% (95% CI 78.5-95.5%). The lowest prevalence was found in Asia in 2013 with 1.26% (95% CI 0.4-3.8%). A quarter of livestock and poultry were infected with T. gondii. Since livestock products are globally important sources of people's diet, our findings are useful for policymakers to control T. gondii infection in livestock.

Molecular Identification of Neospora caninum Infection in Aborted Fetuses of Sheep, Cattle, and Goats in Mazandaran Province, Northern Iran

Background:

We aimed to identify Neospora caninum DNA in the brain samples of aborted fetuses of cattle, goats, and sheep in Mazandaran, northern Iran, using PCR.

Methods:

In total, 133 aborted fetuses (51 sheep, 78 cattle, and 4 goats) were randomly collected from different stages of gestation in various regions of Mazandaran, Iran, from Mar 2016 to May 2017. The DNA was extracted from all the brain samples using phenol chloroform isoamyl alcohol instructions. The Nc-5 gene was used for the detection of N. caninum DNA by nested-PCR assay.

Results:

The detection of N. caninum DNA was confirmed by the observation of a 227 bp band in 24 samples of 133 aborted fetuses (18.1%). The highest prevalence rate of N. caninum was detected in the cattle (20.5%) followed by the sheep (15.6%); however, no positive cases were reported in the goats. The highest and lowest prevalence rates of the infection were reported as 23.8% and 8.6% in Qaemshahr, and Behshahr, respectively. The prevalence rate of infection (32%) in the early gestational period was higher than those in the middle (15%) and late (3.8%) gestational periods.

Conclusion:

The obtained data of the present study indicated that N. caninum infection may partly be responsible for abortion and economic loss in livestock farming in Mazandaran Province.

Neospora caninum and/or Toxoplasma gondii Seroprevalence: Vaccination against PCV2 and Muscle Enzyme Activity in Seropositive and Seronegative Pigs

Neospora caninum and Toxoplasma gondii affect both humans and animals worldwide. To investigate their seroprevalence and differences in seropositivity between pigs vaccinated and unvaccinated against porcine circovirus 2 (PCV2), as well as differences in muscle enzyme activity between seropositive and seronegative pigs, blood samples were collected from 380 sows. Antibodies against T. gondii and N. caninum were detected by an indirect immunofluorescence antibody (IFA) assay, while the activities of creatine kinase (CK) and aspartate aminotransferase (AST) were biochemically assessed. Out of the 364 sows finally included in the study, 4.4%, 3.5%, and 0.5% were seropositive to T. gondii, N. caninum, or both. A significantly higher percentage of seropositivity against T. gondii and/or N. caninum in PCV2 unvaccinated pigs compared with vaccinated pigs was observed. Increased serum activities of CK and AST were detected in 71.43% and 100% of only against T. gondii (T+) and 63.64% and 90.91% of only against N. caninum (N+) seropositive sows, respectively, and were significantly higher compared to seronegative animals. T. gondii and N. caninum seropositivity, especially in presumed immunocompromised pigs, and the evidence of muscle damage highlight their importance as a zoonotic pathogen and animal model of human infection, respectively.

First isolation and genotyping of Toxoplasma gondii strains from domestic animals in Tunisia

The isolation and molecular typing of Toxoplasma gondii strains provide an essential basis for a better understanding of the parasite’s genetic diversity, determinants of its geographical distribution and associated risks to human health. In this study, we isolated and genetically characterized T. gondii strains from domestic animals in Southern and coastal area of Tunisia. Blood, hearts and/or brains were collected from 766 domestic animals (630 sheep and 136 free-range chickens). Strain isolation from these samples was performed using mouse bioassay and genotyping was carried out with a multiplex PCR technique using 15 microsatellite markers. Thirty viable strains of T. gondii were successfully isolated from tissues of sheep (19/142) and chickens (11/33). In addition, 3 strains could be successfully genotyped from animal tissues for which mouse bioassay was unsuccessful. A large predominance of type II strains (n = 29) was found in the sampled regions, followed by type III (n = 3) and, for the first time in Tunisia, a single isolate of Africa 4 lineage from a sheep. Analyses of population genetics showed the presence of a divergent population of type II lineage in Tunisia, supporting limited recent migrations of strains between Tunisia and other countries of the world.

The presence of Toxoplasma gondii in soil, their transmission, and their influence on the small ruminants and human population: A review

The ecosystem approach has been developed since the 1940s. An ecosystem is a community of living organism and their interaction and conjugation with abiotic factors of the environment. The ecosystem is not endemic to the aquatic environment only but, the terrestrial environment is also considered to be a part of an ecosystem. Soil act as mother role for the survival of different microorganism. The Toxoplasma gondii oocysts stay survive for a long time in the soil. This presence of these oocysts might critically enhance the success of this parasite in two ways. First, this parasite can widespread; second, it can create a lot of consequences regarding animals and their economic value. Soil contamination caused by Toxoplasma gondii Y is a significant and profound issue for animals and public health. Therefore, the current study was aimed to summarize and correlate the soil and parasite, their transmission, infection, and some aspects related to T. gondii. The small animals are pose at a high risk therefore, it was concluded that some preventive measures should be taken to keep secure itself from zoonotic diseases.

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.

Epidemiological survey of Toxoplasma gondii and Neospora caninum infections in dairy goats in Central-Southern Taiwan

Toxoplasma gondii and Neospora caninum are intracellular protozoan parasites that cause reproductive disorders in ruminants and humans. Information on the risk factors of T. gondii and N. caninum infections in goats is very limited in Taiwan. The aim of the study was to investigate the epidemiology and identify the risk factors of these two infections in goats. A total of 630 caprine sera were collected from 42 dairy goat farms and the owners were interviewed by a structured questionnaire. The apparent seroprevalences of T. gondii in farm- and individual- levels were respectively 88.1% and 32.22%, while those of N. caninum were 19.05% and 2.54%, respectively. Toxoplasma gondii B1 gene was identified in 7 feed samples and 8 from the water samples whereas N. caninum was not found. Wooden flooring was the main risk factor for T. gondii infection while the frequency of visits by staff to other farms and the breed of goat were risk factors for N. caninum. The improvement of flooring materials or thorough cleaning, periodic disinfection and maintenance of dryness on the floor are highly recommended for the prevention of T. gondii infection in farmed goats. In addition, unnecessary visits to other farms should be limited to prevent the spread of N. caninum. These factors should be highlighted for the prevention of T. gondii and N. caninum in goats, particularly when raised in intensive housing system with flooring on height.

Economic and public health importance of Toxoplasma gondii infections in sheep: 2009-2020

Toxoplasma gondii infections are common in humans and animals worldwide. The present review summarizes worldwide information on the prevalence of clinical and subclinical infections, epidemiology, diagnosis, control, and genetic diversity of T. gondii in sheep in the past decade. There is debate and uncertainty concerning repeat congenital infection as evidenced by finding T. gondii DNA in progeny of chronically infected sheep. However, there is no concrete evidence that T. gondii is the cause of repeated abortions in sheep. Recent data concerning pathogenesis of abortion in acutely infected sheep are reviewed. PCR-RFLP typing of T. gondii DNA derived from viable T. gondii isolates or tissues of infected sheep revealed low genetic diversity in sheep in Europe, Africa, Asia and North America but high diversity in South America. This review will be of interest to biologists, parasitologists, veterinarians, and public health workers.

Public health and economic importance of Toxoplasma gondii infections in goats: The last decade

Toxoplasma gondii infections are common in humans and animals worldwide. Toxoplasmosis in goats continues to be of public health and economic concern. The present review summarizes worldwide information on the prevalence of clinical and subclinical infections, epidemiology, diagnosis, treatment, and genetic diversity of T. gondii in goats in the past decade. There is debate and uncertainty regarding excretion of T. gondii in milk and the ingestion of raw milk as sources of T. gondii infection for humans. Toxoplasmosis can cause abortion and deaths even in adult goats. PCR-RFLP typing of T. gondii DNA derived from viable T. gondii isolates has revealed genetic diversity in goats in North and South America. The significance of T. gondii isolates in domestic goats usually associated with wildlife in USA is discussed. This review will be of interest to biologists, parasitologists, veterinarians, and public health workers.

Serological evidence of Toxoplasma gondii and Neospora caninum infection in black-boned sheep and goats in southwest China

Toxoplasma gondii and Neospora caninum are two closely related protozoan parasites which can cause abortion and significant economic losses in sheep and goats. However, it is yet to know whether black-bone sheep and goats are infected with T. gondii and N. caninum in China. In the present investigation, the seroprevalence and risk factors of T. gondii and N. caninum infections in black-boned sheep and goats were investigated in Yunnan Province, subtropical southwest China between July and August of 2017. A total of 481 serum samples were tested for T. gondii antibodies using the Modified Agglutination Test (MAT), and 468 serum samples were examined for N. caninum antibodies by indirect Enzyme-Linked Immunosorbent Assay (iELISA). The overall seroprevalence of T. gondii in black-boned sheep and goats was 36.80% (177/481, 95% CI 32.49-41.11), and 40 out of 468 serum samples were N. caninum-seropositive (8.55%, 95% CI 6.02-11.08). There was significant difference in the seroprevalence of T. gondii infection in different regions (χ² = 19.869, df = 2, P<0.01). As for the seroprevalence of N. caninum infection, region (χ² = 8.558, df = 2, P<0.05), age (χ² = 16.631, df = 3, P < 0.01), gender (χ² = 11.219, df = 1, P < 0.01) and species (χ² = 8.673, df = 1, P < 0.01) were the risk factors. In addition, the seroprevalence of coinfection of T. gondii and N. caninum in black-boned sheep and goats was 3.63% (17/468, 95% CI 1.94-5.32). To our knowledge, this is the first report of T. gondii and N. caninum seroprevalence in black-boned sheep and goats in China, which provided base-line data for the execution of control strategies and measures against T. gondii and N. caninum infection in black-boned sheep and goats.

Spatial Analysis of Infections by Toxoplasma gondii and Neospora caninum (Protozoa: Apicomplexa) in Small Ruminants in Northern Italy

The objectives of this study were: (i) To investigate possible geographical or environmental factors influencing the infections by Toxoplasma gondii and Neospora caninum in sheep and goats in northern Italy; (ii) to identify areas at risk of infection to set up preventive measures. Forty-three sheep and goat farms were included. Their locations were plotted and associated with T. gondii and N. caninum seroprevalence, then the distribution of farms' prevalence was evaluated by spatial analysis. Significant clusters for both low and high prevalence were obtained, and a generalized linear model with ordinal logistic regression was implemented to verify if spatial clustering could be due to climate factors (temperature, rainfall, and their interaction). Clusters of high (80.0%) and low prevalence (28.12%) resulted for T. gondii seroprevalence in sheep farms. No significant clusters resulted for goat farms. Clusters of high (38.68%) and low prevalence (21.23%) resulted for N. caninum seroprevalence in sheep farms. One high-prevalence cluster (15.62%) resulted for goat farms. For goats, spatial analysis and analysis on climatic data showed the absence of environmental significant risk factors associated with T. gondii or N. caninum infection. On the contrary, for sheep, annual temperature, rainfall, and their association affected the risk of T. gondii and N. caninum infection. Particularly, high temperatures and abundant rainfalls were related to T. gondii seroprevalence, while low temperatures and scarce rainfalls were related to N. caninum seroprevalence.

Serological and molecular rapid diagnostic tests for Toxoplasma infection in humans and animals

Infection by Toxoplasma gondii is prevalent worldwide. The parasite can infect a broad spectrum of vertebrate hosts, but infection of fetuses and immunocompromised patients is of particular concern. Easy-to-perform, robust, and highly sensitive and specific methods to detect Toxoplasma infection are important for the treatment and management of patients. Rapid diagnostic methods that do not sacrifice the accuracy of the assay and give reproducible results in a short time are highly desirable. In this context, rapid diagnostic tests (RDTs), especially with point-of-care (POC) features, are promising diagnostic methods in clinical microbiology laboratories, especially in areas with minimal laboratory facilities. More advanced methods using microfluidics and sensor technology will be the future trend. In this review, we discuss serological and molecular-based rapid diagnostic tests for detecting Toxoplasma infection in humans as well as animals.

Sheep and goats raised in mixed flocks have diverse immune status around parturition

Several physiological and metabolic changes take place in dairy ruminants around parturition (late pregnancy, parturition, and early lactation). Dairy species are genetically selected for their higher milk production compared with non-dairy species. This fact causes a constant stress that impairs the immune status of the animal, with consequences for its welfare and performance. In the present study, we assessed the immune status of high-yield dairy sheep and goats by quantifying IgG and IgM concentrations, as well as chitotriosidase (ChT) and complement system [total complement system (TC) and alternative complement pathway (AC)] activity in blood plasma around parturition. We also measured IgG and IgM concentrations and ChT activity in colostrum and milk during the first 40 d postpartum. The lowest blood IgG concentration was at parturition in both species. We detected no differences in blood IgG concentrations between species. Blood IgM concentrations were constant in both species throughout the study period. However, blood IgM concentrations were greater in sheep than in goats. Blood ChT activity was greater in goats than in sheep, and both species showed constant activity of this enzyme throughout the study period. We observed no differences in complement system (TC and AC) activity between sheep and goats. In addition, both TC and AC activity were constant in both species throughout the experiment. In general, IgG and IgM concentrations were greater in sheep colostrum than in goat colostrum, but these differences disappeared after d 4 (IgG) and d 3 (IgM) postpartum. In both species, the highest IgG and IgM concentrations were measured in colostrum, gradually decreasing during the first days postpartum. Chitotriosidase activity decreased in both species from colostrum to milk, although goats always showed greater ChT activity than sheep. Both sheep and goats seemed to be more susceptible to infectious diseases around parturition. As well, goats showed greater ChT activity in blood, colostrum, and milk than sheep. This fact may give these animals additional protection against parasite and fungal infections.

Toxoplasma gondii infection and toxoplasmosis in farm animals: Risk factors and economic impact

The protozoan parasite Toxoplasma gondii is a zoonotic parasite that can be transmitted from animals to humans. Felids, including domestic cats, are definitive hosts that can shed oocysts with their feces. In addition to infections that occur by accidental oral uptake of food or water contaminated with oocysts, it is assumed that a large proportion of affected humans may have become infected by consuming meat or other animal products that contained infective parasitic stages of T. gondii. Since farm animals represent a direct source of infection for humans, but also a possible reservoir for the parasite, it is important to control T. gondii infections in livestock. Moreover, T. gondii may also be pathogenic to livestock where it could be responsible for considerable economic losses in some regions and particular farming systems, e.g. in areas where the small ruminant industry is relevant. This review aims to summarize actual knowledge on the prevalence and effects of infections with T. gondii in the most important livestock species and on the effects of toxoplasmosis on livestock. It also provides an overview on potential risk factors favoring infections of livestock with T. gondii. Knowledge on potential risk factors is prerequisite to implement effective biosecurity measures on farms to prevent T. gondii infections. Risk factors identified by many studies are cat-related, but also those associated with a potential contamination of fodder or water, and with access to a potentially contaminated environment. Published information on the costs T. gondii infections cause in livestock production, is scarce. The most recent peer reviewed reports from Great Britain and Uruguay suggest annual cost of about 5-15 million US $ per country. Since these estimates are outdated, future studies are needed to estimate the present costs due to toxoplasmosis in livestock. Further, the fact that T. gondii infections in livestock may affect human health needs to be considered and the respective costs should also be estimated, but this is beyond the scope of this article.

Large-Scale Epidemiological Study on Toxoplasma gondii Seroprevalence and Risk Factors in Sheep in Estonia: Age, Farm Location, and Breed Associated with Seropositivity

Toxoplasma gondii is a zoonotic parasite of major veterinary and public health importance. The parasite is common in many host species in Estonia, however, information about the seroprevalence in the local sheep population is lacking. We estimated T. gondii seroprevalence and evaluated a limited selection of possible risk factors for T. gondii seropositivity in sheep raised in Estonia. Sera from 1599 sheep from 122 flocks, collected during 2012-2013, were diluted to 1:40 and screened for the presence of anti-T. gondii immunoglobulin G antibodies using a commercial direct agglutination test. The cutoff titer for seropositivity was 40. A total of 667 of the 1599 sheep were T. gondii seropositive, yielding an apparent seroprevalence estimate of 41.71% (95% confidence interval 39.31-44.14). At least one seropositive sheep was detected on the majority (88.53%) of the farms. T. gondii seroprevalence was significantly lower in lambs (age <12 months) than in adults (age ≥12 months) (11.11% and 42.16%, respectively). The seroprevalence increased steeply with age in the first years of life. A multivariable random-effects logistic regression model identified being an adult (odds ratio [OR] 9.55) and being from a farm located on the islands (OR 2.51) as risk factors for T. gondii seropositivity, while being of Texel breed appeared as a protective factor (OR 0.34) when compared with the Estonian Blackhead breed. Exposure to T. gondii was widespread among the investigated sheep. Undercooked meat and unpasteurized milk from sheep from Estonia should be considered possible sources of T. gondii infections to other hosts, including humans.

Risk factors associated with seropositivity to Toxoplasma among sheep and goats in Northern Iraq

Serum samples from 423 small ruminants (335 sheep and 97 goats) from 72 farms in 6 districts in the province of Dohuk, north Iraq, were tested for the presence of antibodies against Toxoplasma gondii using a latex agglutination test (Latex) and an indirect enzyme-linked immunosorbent assay (iELISA). When the test results were interpreted in parallel, 42.1% (95% confidence interval (CI): 36.7, 47.7) of sheep and 36.1% (95% CI: 26.6, 46.5) of goats were found to have antibodies against Toxoplasma. A multivariable logistic regression model was developed to determine the risk factors for Toxoplasma seropositivity in small ruminant flocks. Factors which increased the risk of infection included the presence of cats near the feed of animals (Odds ratio (OR) = 6.3; 95% CI 1.6, 24.6) and a history of abortions in sheep in the preceding 12 months (OR = 13.4; 95% CI 2.1; 86.7). For every ten goats aborting in the preceding 12 months the odds of seropositivity increased significantly (OR = 6.7; 95% CI 1.3; 32.9). Results of the regression model indicate that for every 1000 Iraqi Dinars (~0.85 USD) spent by the farmers on prophylactic treatment in their flocks the odds of Toxoplasma seropositivity decreased significantly (OR = 0.94; 95% CI 0.90, 0.98). This study contributes to the epidemiology of toxoplasmosis in small ruminants in northern Iraq.

How does toxoplasmosis affect the maternal-foetal immune interface and pregnancy?

Toxoplasma gondii is a zoonotic parasite which, depending on the geographical location, can infect between 10% and 90% of humans. Infection during pregnancy may result in congenital toxoplasmosis. The effects on the foetus vary depending on the stage of gestation in which primary maternal infection arises. A large body of research has focused on understanding immune response to toxoplasmosis, although few studies have addressed how it is affected by pregnancy or the pathological consequences of infection at the maternal-foetal interface. There is a lack of knowledge about how maternal immune cells, specifically macrophages, are modulated during infection and the resulting consequences for parasite control and pathology. Herein, we discuss the potential of T. gondii infection to affect the maternal-foetal interface and the potential of pregnancy to disrupt maternal immunity to T. gondii infection.

Seroprevalence, isolation, molecular detection and genetic diversity of Toxoplasma gondii from small ruminants in Egypt

Toxoplasmosis is an infectious zoonotic disease caused by protozoan Toxoplasma gondii. Detection of T. gondii infection with touchy and particular strategies is a key advance to control and prevent toxoplasmosis. Genotyping can explain the virulence, epidemiology and setting up new methodologies for diagnosis and control in human and animals. The point of this study was to assess the seroprevalence of T. gondii in sheep and goat in Egypt and to comprehend the genetic variety of T. gondii isolates circling in Egypt. Blood samples were gathered from 113 ewes and 95 she-goats from three Egyptian governorates (Cairo, Giza and Al-Sharkia). Also blood and tissue samples were gathered from 193 sheep and 51 goats from Cairo and Giza abattoirs. All samples were assayed serologically utilizing ELISA and OnSite Toxo IgG/IgM Rapid test cassettes (OTRT) tests and the tissue samples of the seropositive animals were digested and microscopically examined then bio-assayed in mice as viability test. All the T. gondii isolates undergo molecular identification using PCR and genotyped utilizing nPCR/RFLP analysis of SAG2 gene. The total seropositivity of live sheep and goat was 47.15 and 39.2% utilizing ELISA and OTRT respectively. Concerning abattoirs, seropositivity, positive microscopic examination, mice viability from sheep samples were 47.1%, 37.3% and 44.1% respectively while that of goats were 45.5%, 33.3% and 48.6% respectively. Eighteen T. gondii isolates were affirmed utilizing PCR. Genotyping confirmed 10 isolates (55.5%) as type II, 6 (33.3%) as type III and 2 (11.1%) as atypical genotypes. Type II and III are the genotypes mostly circling among small ruminants in Egypt and this is most significance for the public health in Egypt.

Seroprevalence of Toxoplasma gondii and Neospora caninum infection in sheep, goats, and fallow deer farmed on the same area

Toxoplasma gondii and Neospora caninum are coccidian parasites with a global distribution that cause reproductive failure and production losses in livestock. The seroprevalence of both parasite species in ruminants and Cervidae has been investigated worldwide and found to vary greatly. Studies carried out on mixed flocks with 3 ruminant species (sheep, goats, and fallow deer) living under the same conditions are excellent models for identifying any differences in the rate of infection with the 2 parasites between the animal species. Additionally, the species used in the present study differ in their feeding categories: grazers, browsers, and intermediate feeders. The aim of the study is to identify any variation in the prevalence of the 2 parasites in mixed flocks and to identify any possible relationships with food choice. The seroprevalence against T. gondii and N. caninum in 167 captive fallow deer, 64 sheep, and 39 goats were detected using commercially available ELISA. The seroprevalence for T. gondii achieved 10% in fallow deer, 21% in goats, and 47% in sheep. The seroprevalence for N. caninum achieved 13% in sheep and fallow deer and 21% in goats. Overall, 53% of the sheep, 33% of the goats, and 22% of the fallow deer were seropositive for both infections. Coinfection of T. gondii and N. caninum was detected in 6% of sheep, 8% of goats, and 2% of fallow deer. Statistical analyses of the seroprevalence levels observed between 2 parasites for each animal species revealed that only the results obtained for sheep were significant (P < 0.01). Additionally, the differences in the seroprevalence levels for T. gondii between sheep and goats and between sheep and fallow deer were statistically significant (P < 0.01). The results of the N. caninum seroprevalence levels observed among animal species were not significant. Although the variations in susceptibility to T. gondii and N. caninum infections demonstrated by the examined animals may affect the differences in seropositivity, these appear to be related to the feeding habits of the animal species. Therefore, the risk of infection by agents found close to the ground, such as coccidian oocysts, varies. Sheep as grazers are at a greater risk of infection by T. gondii than goats and fallow deer.

Seroprevalence and risk factors of Neospora caninum infection among domestic sheep in Henan province, central China

This study aimed to determine the frequency of antibodies to Neospora caninum in domestic sheep raised in Henan province, central China. Serum samples from 779 domestic sheep were collected from March 2015 to May 2016, and antibodies to N. caninum were evaluated using an enzyme-linked immunosorbent assay (ELISA). The results showed an overall IgG positive rate of 7.32% (57/779). The risk factors significantly related to seropositivity to N. caninum in sheep were the age, the presence of dogs, and the rearing system. This is the first report of N. caninum infection and associated risk factors in domestic sheep in central China.

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.

Resistance to Chronic Toxoplasma gondii Infection Induced by a DNA Vaccine Expressing GRA16

Toxoplasma gondii can infect all warm-blooded animals including human beings. T. gondii dense granule protein 16 (TgGRA16) as a crucial virulence factor could modulate the host gene expression. Here, a DNA vaccine expressing TgGRA16 was constructed to explore the protective efficacy against T. gondii infection in Kunming mice. The immune responses induced by pVAX-GRA16 were also evaluated. Mice immunized with pVAX-GRA16 could elicit higher levels of specific IgG antibody and strong cellular response compared to those in controls. The DNA vaccination significantly increased the levels of cytokines (IFN-γ, IL-2, IL-4, and IL-10) and the percentages of CD4+ and CD8+ T cells in mice. After lethal challenge, mice immunized with pVAX-GRA16 (8.4 ± 0.78 days) did not show a significant longer survival time than that in controls (7.1 ± 0.30 days) (p > 0.05). However, in chronic toxoplasmosis model (administration of 10 brain cysts of PRU strain orally), numbers of tissue cysts in mice immunized with pVAX-GRA16 were significantly reduced compared to those in controls (p < 0.05) and the rate of reduction could reach 43.89%. The results indicated that the TgGRA16 would be a promising vaccine candidate for further development of effective epitope-based vaccines against chronic T. gondii infection in mice.

Enzyme-linked immunosorbent assays using recombinant TgSAG2 and NcSAG1 to detect Toxoplasma gondii and Neospora caninum-specific antibodies in domestic animals in Turkey

Considering the scarce information on occurrences of Toxoplasma gondii and Neospora caninum in domestic animals from Turkey, the aim of this study was to investigate the seroprevalence of these parasite infections in cattle, horses, sheep, goats and dogs in Turkey. The specific antibodies against T. gondii and N. caninum were detected by iELISAs based on the recombinant TgSAG2 or NcSAG1 in a total of 2,039 serum samples from eleven provinces. The seroprevalence of T. gondii infections was 46.3%, 4.0%, 20.0%, 12.9% and 19.8%, that of N. caninum infections was 0.3%, 7.4%, 2.1%, 3.2% and 16.6% in the horses, cattle, sheep, goats and dogs, respectively. These results indicated that T. gondii and N. caninum infections are prevalent in Turkish domestic animals.

Identification of latent neosporosis in sheep in Tehran, Iran by polymerase chain reaction using primers specific for the <i>Nc-5</i> gene

Little is known about latent infection and molecular characterisation of Neospora caninum in sheep (Ovis aries). In this study, 330 sheep samples (180 hearts and 150 brains) were analysed for N. caninum DNA by nested polymerase chain reaction (PCR) targeting the Nc-5 gene. Neospora caninum DNA was detected in 3.9% (13/330) of sheep samples. The parasite's DNA was detected in 6.7% of heart samples (12/180) and 0.7% (1/150) of brain samples. No clinical signs were recorded from infected or uninfected animals. Sequencing of the genomic DNA revealed 96% - 99% similarity with each other and 95.15% - 100% similarity with N. caninum sequences deposited in GenBank. To our knowledge, this is the first report on the use of PCR to identify latent neosporosis in sheep in Iran. The results of this study have the potential to contribute to our understanding of the role of N. caninum-infected sheep in the epidemiology of neosporosis.

Canine neosporosis: perspectives on pathogenesis and management

Canine neosporosis is a worldwide disease caused by the obligate intracellular parasite protozoan Neospora caninum, manifesting mainly neurological symptoms. N. caninum has a heteroxenous life cycle and affects a wide range of warm-blooded animals. The domestic and wild canids are the definitive host of the parasite. They shed oocysts after ingestion of tissue cysts from infected intermediate hosts (ovine, equine, bovine, canine, and many other species), containing bradyzoites, or oocyst-contaminated water and food. The presence of dogs in farms is considered a risk factor for production animals. A wide range of diagnostic methods are currently available, but the most used is serology, ie, indirect fluorescent antibody test specific to the antibody detection in blood serum samples. No vaccine is available, but control strategies should be focused on the vertical and horizontal transmission of the parasite, ie, avoid feeding dogs with raw or undercooked meat, and taking care with water for human and animal consumption. No medicines to control the transplacental transmission are available yet.

Cross-Sectional Serosurvey and Risk Factors Associated with the Presence of Toxoplasma gondii Antibodies in Pigs in Greece

INTRODUCTION

Toxoplasmosis is a worldwide reported zoonotic infection caused by the protozoon Toxoplasma gondii. Pigs may become infected by ingesting feed or water contaminated with cat faeces, by cannibalism, and/or by eating infected rodents. T. gondii infected edible tissues of pigs are a source of infection for humans. This study was undertaken to detect seropositivity of pigs against T. gondii and identify possible risk factors as well as to compare two serological methods.

METHODS

A total of 609 blood samples were collected from 10% of the sows from 65 pig farms located in mainland Greece. Information about the geographical location, size, and biosecurity level of the herd was recorded. Samples were tested for the presence of antibodies against T. gondii employing the indirect fluorescent antibody test and the enzyme-linked immunosorbent assay.

RESULTS

Twenty-six positive samples were detected (4.3%) in 17 out of the 65 farms tested (26.2%). The average seroprevalence in affected herds was 26.8% (95% confidence interval 21.0-32.6%). Among the categorical data evaluated, the biosecurity level (odds ratio 0.17, p < 0.01) and the geographical characteristics (odds ratio 13.55, p < 0.05) significantly affected the presence of toxoplasmosis in the herd. Toxoplasmosis was recorded in significantly higher percentages in mountainous farms as compared to lowlands (p < 0.05) and in those with poor biosecurity levels than in those with very good (p < 0.05). A very good agreement (κ = 0.958) was observed between the two serological methods.

CONCLUSION

The presence of antibodies in pigs is indirect information on the risk of the infection and an indication of the necessity of biosecurity measures to be taken in order to control infection at least in the areas at highest risk.

Seroprevalence and risk factors of Toxoplasma gondii and Neospora caninum infections in small ruminants in China

Little information is available about the seroprevalence of Toxoplasma gondii and Neospora caninum infections in sheep and goats in China. In the present investigation, the seroprevalence of T. gondii and N. caninum infections in sheep and goats were investigated in Qinghai province, China between January 2012 and June 2013. A total of 1250 serum samples (600 sheep and 650 goats) collected from 8 administrative regions of Qinghai province, China were evaluated by enzyme-linked immunosorbent assay for the detection of specific antibodies, and sera positive were subsequently confirmed with indirect fluorescent antibody test. Specific IgG against T. gondii were detected in 21.33% (95% confidence interval [CI]: 18.06-24.61%) (128/600) and 29.54% (95% CI: 26.03-33.05%) (192/650) and against N. caninum in 10.33% (95% CI: 7.9-12.77%) (62/600) and 7.23% (95% CI: 5.24-9.22%) (47/650) of the sheep and goats, respectively. The risk factors significantly associated with T. gondii and N. caninum seroprevalence were the presence of cats and dogs, the pasturing system, the herd size, the hygiene in the farms. The results of the present survey indicate that T. gondii and N. caninum infections are highly prevalent in sheep and goats in Qinghai province, China. This is the first time that antibodies to N. caninum have been detected in sheep and goats in China.

Seroprevalence of Toxoplasma gondii in small ruminants from four Caribbean islands

BACKGROUND

Toxoplasma gondii is a protozoan parasite capable of infecting all warm-blooded animals including livestock. In these animals, the parasite forms cysts in the tissues which may pose a risk to public health if infected meat is consumed undercooked or raw. Little is known of the epidemiology of T. gondii in the Caribbean; therefore, the aim of this study was to determine T. gondii exposure in small ruminants from four Caribbean island nations.

FINDINGS

Sera from 305 sheep and 442 goats from Dominica, Grenada, Montserrat and St. Kitts and Nevis were examined for T. gondii antibodies using an in house ELISA. Reactive antibodies were detected in sheep and goats, respectively, from Dominica (67%, 37/55; 58%, 79/136), Grenada (48%, 40/84; 57%, 54/94), Montserrat (89%, 25/28; 80%, 25/31) and St. Kitts and Nevis (57%, 78/138; 42%, 76/181).

CONCLUSIONS

Our results suggest widespread environmental contamination with T. gondii oocysts and that small ruminants could be a potentially important source of T. gondii infection if their infected meat is consumed undercooked.