Toxoplasma gondii infections in sheep in Sicily, southern Italy

Seroprevalence and risk factors of Toxoplasma gondii infection among goats in Algeria

Toxoplasmosis is one of the most common zoonotic parasitic diseases worldwide and is caused by Toxoplasma gondii. It is implicated in reproductive disorders in small ruminants. This study aims to determine, for the first time in Algeria, the seroprevalence and associated factors of T. gondii infection in goats. The study was conducted in four regions, Ghardaia, Laghouat and Djelfa, southern Algeria, and Jijel region, northern Algeria. A total of 92 blood samples were collected including 74 females and 18 males. All sera were tested using an enzyme-linked immunosorbent assay (ELISA) to detect the T. gondii antibodies. The presence of anti-T. gondii antibodies was detected in 35 out of 92 goats (38.04%) (95% CI: 31.64%-44.44%) and in all flocks (100%). Risk factors that have a significant influence on the seroprevalence of T. gondii infection are breed, regions, production system, presence of cats, clinics and abortion history. However, variables such as age and gender were note significantly associated with toxoplasma infection in goats. The highest seroprevalences of infection was observed in saanen (52.94%) (p<0.001) and cross-breed race (44%) (p<0.01) in comparison with other breeds. Regarding regions, Jijel and Laghouat were most infected with seroprevalences of 50% (p<0.001) and 40.91% (p<0.01), respectively. Animals in intensive production systems were most infected, showing a seroprevalence of 51.85%, in comparison with extensive (28.13%) and semi-intensive systems (36.36%) (p<0.001). The presence of cats in farms was significantly associated with high seroprevalence (44.64%) (p<0.001). The infection was more prevalent in previously aborted females (50%) than females that had never aborted (3.35%) (p<0.001)and animals that have diarrhoea or poor health (41.67%) were significantly more infected than healthy animals (37.50%) (p<0.01). Seroprevalence in males (38.89%) was very close to those in females (37.84%) (p>0.05). Age-related seroprevalence did not vary significantly (ranged from 36.37% to 40%) between the three age classes. These results indicate that goat toxoplasmosis is widespread in Algeria, and goats may represent a high risk of contamination for humans. This requires more attention during consumption of goat meat.

Newly optimized ELISA kit and LAT reveal significantly higher seroprevalence in sheep raised in agro-ecological zone as against range-ecological zone, with a significant association of meteorological parameters

BACKGROUND

Toxoplasma gondii is a zoonotic and foodborne intracellular parasite capable of inducing congenital infections, stillbirths and abortions in humans and animals, globally. The consumption of undercooked or raw mutton is "one of the vital risks" for acquiring toxoplasmosis: an asymptomatic condition in healthy persons, while life-threatening in immunodeficient individuals like "HIV/AIDS" patients.

OBJECTIVES

The current study has multiple objectives: to optimize a newly ELISA kit for Sheep, to find out the seroprevalence of ovine toxoplasmosis of two ecological zones of the Punjab, Pakistan through LAT and newly Optimized Sheep ELISA kit, to do the comparison of efficacies of various tests (LAT with newly Optimized ELISA kit and newly Optimized ELISA kit with commercial ELISA kit) and to determine the different meteorological parameters as the risk factors for T. gondii infection in sheep.

METHODS

A cross-sectional study was conducted on 400 sheep sera, 200 were collected from sheep raised on open grazing system by local farmers in the adjoining areas of Civil Veterinary Dispensaries (CVDs) of range-ecological zone i.e. tehsil Kot Chutta (Dera Ghazi khan). Similarly, the remaining 200 were collected from agro-ecological zone i.e. tehsil Sharaqpur (Sheikhupura), to evaluate the comparative efficacy of LAT with optimized ELISA kit and newly optimized ELISA kit with commercial ELISA kit.

FINDINGS

The newly ELISA kit optimized against a commercial ELISA kit was found to have 100% sensitivity, 97.6% specificity with 98% Positive Predictive Value, 100% Negative Predictive Value, Cut off value = 0.505, 28.28 LR+, 0.0104 LR-, and 2719.23 DOR. Seroprevalence of toxoplasmosis was detected significantly (P < 0.01; χ2) higher in Sharaqpur (44.5% by LAT; 35.5% by ELISA) as compared to that in Kot Chutta (39.5% by LAT; 31% by ELISA). The highest seroprevalence was seen in the sheep of the 1-2 years age group (P < 0.01; χ2), whereas the lowest in the oldest animals (≥ 4 years). Investigation of meteorological data of both the regions reveals that the zone with higher seroprevalence has relatively higher rainfall, higher humidity, lower environmental temperatures, and higher altitude as the critical factors, potentially behind the significant difference seen in seroprevalence level. The partial correlation of both tests (newly optimized ELISA kit and LAT) was 0.991 at maximum temperature in Sharaqpur while it was 0.981 in Kot Chutta.

INTERPRETATION

A novel significant correlation was found between the meteorological parameters (relative humidity, minimum, maximum, and average temperatures) divided into yearly units of both the ecological zones, and year-wise seroprevalence (birth years of age-wise groups) of the corresponding regions. We hypothesize that such environmental conditions increase the risk of toxoplasmosis in grazing sheep, owing to a more favorable environment for coccidian oocyst survival. The ELISA kit optimized in this study will be helpful for the detection of seroprevalence of ovine toxoplasmosis in other ecological zones of Pakistan as well as of any other country in the world. More studies are recommended involving regions from other ecological zones of Pakistan to further explore the seroprevalence of ovine toxoplasmosis and to ratify the novel correlation of meteorological parameters with seroprevalence.

Serological survey of immunoglobulin G from Toxoplasma gondii infection in dairy goats in East Java, Indonesia

Background and Aim

Toxoplasma gondii infection is a significant issue of veterinary public health because it is potentially transmitted through goat milk. Therefore, the use of control measures and routine monitoring of toxoplasmosis in dairy goats is necessary. Serological analysis using antibodies can detect T. gondii infection. This study aimed to conduct an epidemiological study of T. gondii in dairy goats using antibody detection and risk factor identification.

Materials and Methods

This was a cross-sectional study. We performed a serological analysis of T. gondii infection in dairy goats to evaluate the prevalence of toxoplasmosis. Random sampling was performed, including 132 lactating dairy goats. Toxoplasma-modified agglutination test was used as a serological test for immunoglobulin G with a sensitivity of 98.55%, specificity of 86.21%, and accuracy of 94.9%. A structured questionnaire was used to collect risk factor data, which were analyzed using the Chi-square and Fisher's exact tests. The statistical package for the social sciences v. 21 was used for statistical analyses.

Results

The seroprevalence of T. gondii in Malang and Lumajang Regency was 100% and 90.7%, respectively. A significant difference in prevalence of T. gondii was observed between the two districts. Livestock management practices that significantly influenced T. gondii seroprevalence included water sources (p < 0.05; relative risk [RR] = 1.151; 95% confidence interval [CI]: 1.044-1.269). Farmers' characteristics that significantly influenced T. gondii seroprevalence included education (p < 0.05; RR = 1.125; 95% CI: 1.037-1.221), main occupation (p < 0.05; RR = 1.118; 95% CI: 1.035-1.207), and position in the organization of dairy goats farmers (p < 0.05; RR = 1.141; 95% CI: 1.022-1.274).

Conclusion

In East Java, the prevalence of T. gondii in dairy goats is high. This study provides detailed information regarding risk factors associated with T. gondii seroprevalence in dairy goats in East Java, Indonesia.

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.

Toxoplasma gondii in sheep: Serological occurrence at slaughterhouse level in Italy and environmental risk factors

Toxoplasmosis is a parasitic disease affecting a wide range of species, including humans, and can be responsible for important clinical manifestations such as abortion and neurological signs. Sheep show a remarkable susceptibility to its causative agent, Toxoplasma gondii, and zoonotic transmission may occur in case of consumption of undercooked meat obtained from infected animals. Toxoplasma gondii seroprevalence in sheep can significantly vary on a geographical basis, as shown by numerous surveys conducted worldwide. To investigate environmental and climate conditions that may affect the likelihood of ovine infection, 405 serum samples from selected sheep raised in 91 farms were collected from two abattoirs, with each abattoir receiving animals from two regions (1/Tuscany-Latium and 2/Campania-Basilicata). The seroprevalence of infection in all examined animals was 53.8%. Young animals (n = 165) had a lower likelihood of being T. gondii positive compared to the adults (OR = 0.21), and the seropositive rate of animals slaughtered in abattoir 2 was significantly higher than that of animals slaughtered in abattoir 1 (60.5 vs. 43.2%, p < 0.01). The significant bioclimatic variables (p < 0.05) associated with the presence of T. gondii antibodies were related to areas with a lower range of temperature and higher precipitation. In conclusion, this study expands on the interpretation of serological data, with the inclusion of environmental and climatic variables, as possible risk factors in the spread of toxoplasmosis in the study area. These findings provide novel insights to support public health measures, such as risk-based control plan, and contribute to a "One Health" approach, taking into account the environmental and climatic perspectives.

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.

Serological Investigation of Bovine Toxoplasmosis Using Commercial and Indigenous ELISA Kits While Validating Cattle Toxo IgG ELISA Kit

Simple Summary

Toxoplasmosis is a zoonotic disease caused by T. gondii infection. The main aims of this study were to assess the seropositivity to toxoplasmosis of an exotic breed of cattle (n = 400) from different farms using the Latex Agglutination Test, validate the Cattle Toxo IgG ELISA kit with the help of the commercially available ELISA kit and compare the efficacy of the LAT and Cattle Toxo IgG ELISA kit for assessing seropositivity of cattle to toxoplasmosis. Four hundred cattle sera were collected from an exotic breed of cattle in Pakistan. These sera were evaluated through an LAT and Cattle Toxo IgG ELISA kit. Of 400 samples, 90 were elected and screened through a commercially available ELISA kit. The sensitivity and specificity of the Cattle Toxo IgG ELISA kit came out to be 100% and 96.15%, and in LAT, it was found as 26.31% and 61.53%, respectively. The Cattle Toxo IgG ELISA kit revealed 29.75% (119/400) seropositivity, 6% less than that found through LAT. The results of this study show that Cattle Toxo IgG ELISA kit is a highly accurate and reliable serodiagnostic tool to diagnose bovine toxoplasmosis.

Abstract

Toxoplasma gondii is a protozoan parasite that causes toxoplasmosis in warm-blooded vertebrates, globally. The main aims of this study were to assess the seropositivity to toxoplasmosis of an exotic breed of cattle (n = 400) from different farms using the Latex Agglutination Test and validate Cattle Toxo IgG ELISA kit. Of a total of 400 cattle sera that were evaluated by LAT, 143 (35.75%) were found positive. Based on these data, 90 samples (n = 60 seronegative by LAT; n = 30 seropositive by LAT) were elected for screening through a commercially available ELISA kit. The same 90 samples were screened through a Cattle Toxo IgG ELISA kit for validation purposes. Of 90 samples, 40 were seropositive in the Cattle Toxo IgG ELISA kit (100% sensitivity), and 38 were seropositive in a commercially available ELISA kit. All 50 samples in the Cattle Toxo IgG ELISA kit (96.15% specificity) were also seronegative in the commercially available ELISA kit. Hence, the sensitivity and specificity of the Cattle Toxo IgG ELISA kit came out to be 100% and 96.15%, and in LAT, it was found as 26.31% and 61.53%, respectively. Therefore, the Cattle Toxo IgG ELISA kit is a highly reliable serodiagnostic tool to diagnose bovine toxoplasmosis.

A survey on Apicomplexa protozoa in sheep slaughtered for human consumption

Infections with the Apicomplexa Toxoplasma gondii, Neospora caninum, and Sarcocystis spp. are common causes of reproductive disorders in sheep. However, few epidemiological studies regarding co-infections with these three protozoa are reported in sheep in Italy. For this reason, this study aims to evaluate possible co-infections with T. gondii, N. caninum, and Sarcocystis spp. in sheep slaughtered for human consumption. From April to July 2019, individual blood, brain, heart, and diaphragm samples were collected from 138 sheep after slaughtering. The presence of IgG anti-Toxoplasma in serum samples was evaluated through ELISA. DNA of the three protozoa was investigated using specific PCRs. Co-infection with T. gondii, N. caninum and Sarcocystis spp. was found in 66.7% of the examined sheep. Antibodies against T. gondii were found in the 36.2% of serum samples. The presence of T. gondii DNA was detected in the 67.4%, 77.5%, and 21.7% of the brain, heart, and diaphragm samples, respectively. Neospora caninum DNA was found in 72.5% of the examined brain samples. Sarcocystis spp. DNA was detected in 92% and 52.2% of the heart and diaphragm samples, respectively. Sequence analysis of the Sarcocystis spp. revealed the sole presence of Sarcocystis tenella. The present study demonstrates that sheep have a high risk of infection with the three Apicomplexa investigated, suggesting the need to adopt adequate measures to prevent the spread of these parasitic infections considering their clinical and economic impact on ovine production. Furthermore, the possible role sheep play in the zoonotic transmission of toxoplasmosis to humans was highlighted.

Spatial distribution and risk factors for sheep toxoplasmosis in Goiás, Brazilian Cerrado Region

The present study aimed to evaluate the spatial distribution and risk factors for infection by Toxoplasma gondii in sheep in the state of Goiás, located in the central-western region of Brazil. Through the immunofluorescence antibody test (IFAT), the seroprevalence of anti-T. gondii antibodies was analyzed in 1000 blood serum samples obtained from sheep in all macro and micro regions of the state of Goiás. Data related to sex, age of the animals, size of the farm, type of farm, water source, veterinary assistance, replacement of the herd, presence of domestic cats, presence of wild cats and presence of other wild animals were obtained at the sampling time. The differences between the seroprevalences obtained in relation to the variables analyzed were estimated using Pearson's chi-square test (χ2). The odds ratio (OR) values for each risk factor evaluated were statistically analyzed with a confidence interval of 95%. Positivity for IgG anti-T. gondii was observed (titer ≥64) in 34.3% (343/1000) of the samples, which ranged from 26.9% (31/115) to 44.2% (53/120) and from 21.8 (12/55) to 55.2% (16 / 29), respectively in the analyzed mesoregions and microregions. In all investigated regions of the State of Goiás, serum-reactive animals were detected with the age of the animals, the source of water, the form of replacement of the herd and the presence of domestic cats and wild animals risk factors statistically associated with the occurrence of T. gondii in animals.

Seroprevalence and risk factors of Toxoplasma gondii in cattle from Unai, Minas Gerais state, Brazil

Toxoplasma gondii is a widespread protozoan parasite that causes infections in animals and humans. The presence of tissue cysts in cattle musculature evidences their epidemiological significance in transmission to humans. The present study aimed to evaluate the seroprevalence of and risk factors of T. gondii seropositivity in beef cattle in the municipality of Unaí, Minas Gerais state, Brazil. Bovine blood samples (n = 612) were collected from 31 herds. Risk factors associated with the animal-level and herd-level seroprevalence were analysed using a questionnaire that investigates the epidemiological aspects of toxoplasmosis. A search for anti-T. gondii antibodies was performed by means of an indirect fluorescent antibody test (IFAT). Analysis of 612 samples showed 369 animals positive for anti-T. gondii antibodies (IFAT ≥64), with a seroprevalence of 60.29% (95% confidence interval (CI): 56.35-64.10). The herd-level seroprevalence was 96.77% (95% CI: 79.00-99.58). Applying a multivariate logistic regression analysis, a test of the association between seroprevalence of T. gondii infection and the potential predictors showed that cats (domestic or wild) with access to the drinking water of cattle were a significant (P = 0.001) predictor. The seroprevalence of T. gondii in cattle destined for human consumption is widely distributed throughout the entire study area. Thus, integrated control measures and strategies are suggested to prevent T. gondii infection in cattle.

Towards an Integrated Approach for Monitoring Toxoplasmosis in Southern Italy

Simple Summary

Toxoplasmosis is a significant public health issue worldwide, caused by the intracellular protozoan Toxoplasma gondii. It has a heteroxenous life cycle in which felines act as definitive reservoirs and a wide range of warm-blooded animals, including humans, act as intermediate hosts. Due to the complex life cycle, monitoring, prevention and control of this parasite are very difficult. A thorough analysis of the epidemiology of T. gondii in humans, animals and food as well as the risk factors associated with the infection are needed to plan adequate control strategies in a given geographical area. Based on this, an integrated approach for monitoring toxoplasmosis was developed and conducted in an endemic area of southern Italy. The main tasks of this approach were based on the following strategies: parasitological and risk factor analysis for T. gondii in livestock farms, serological and molecular monitoring in meat-producing livestock at slaughterhouses, hospital discharge records (HDRs) analysis and outreach activities. The findings of this study confirmed the spread of T. gondii infection in southern Italy with high prevalence values in ruminants and the need of valid control strategies based on comprehensive and transdisciplinary actions according to the One Health approach.

Abstract

Toxoplasmosis is a widespread worldwide zoonotic infection caused by the intracellular protozoan Toxoplasma gondii. This protozoan infection is considered one of the most important food-borne parasitic zoonoses globally. Beyond its impact on public health, toxoplasmosis has also important veterinary implications, because it causes miscarriage or congenital malformations in livestock with negative economic impacts. An integrated monitoring programme aimed to deepen the epidemiological data on toxoplasmosis and to identify the risk factors that may favour T. gondii infections in animals and humans was conducted in an endemic area of southern Italy. The monitoring activities were based on the following tasks: (i) parasitological analysis and risk factors for T. gondii in livestock (sheep, goat, cattle and water buffalo) farms; (ii) serological and molecular monitoring at slaughterhouse in meat-producing livestock; (iii) analysis of hospital discharge records (HDRs); (iv) outreach activities (information, dissemination and health education) to farmers, vet practitioners and school-age children. The present study confirmed a very high seroprevalence of T. gondii infection in livestock farms (e.g., up to 93.1% in sheep farms) in southern Italy and highlighted the potentially significant public health risk in this area.

From weaning to breeding age: Presence of antibodies to Toxoplasma gondii in sheep in the state of Espírito Santo, southeastern Brazil

Sheep are intermediate hosts of the protozoon Toxoplasma gondii, a zoonotic parasite that that may cause abortion and reproductive losses in this species. Previous studies have shown that its prevalence is high in sheep herds in Brazil, but no information from the state of Espírito Santo was available. The aim of this study was to improve the epidemiological data in different regions of this state by analyzing occurrences of anti-T. gondii antibodies in young female sheep, before reproductive age, using IFAT (cutoff ≥64). In addition, variables relating to these animals and farm management were investigated for significance of associations. A total of 312 sheep, aged 3 to 12 months, on five farms in five municipalities, were sampled. Among these 312 animals, 135 (43.26%) were reactive, and 70 positive sheep (51.8%) presented high titers (more than three times the cutoff).Eight-month-old sheep presented the lowest occurrence and 7 and 11-month-old sheep, the highest. At least one animal was positive in each municipality, thus confirming the endemic status of toxoplasmosis in sheep in this region. None of the variables analyzed, relating to animals and herds, presented any association with T. gondii occurrence (p > 0.05). The number of females that were close to sexual maturity (12 months) and which were reactive to T. gondii was less than 50%. These ewes would probably be more susceptible to reproductive problems.

Toxoplasma gondii in small ruminants in northeastern areas of Colombia: Seroprevalence and risk factors

Sheep and goats are susceptible to infections with Toxoplasma gondii and could play an important role in the transmission of the zoonotic parasite to human. We conducted a cross sectional study to estimate the seroprevalence and to assess the risk factors for T. gondii seropositivity in small ruminants under traditional husbandry systems. This study was carried out from November 2015 to April 2016 in randomly selected small ruminants (n = 1038) from 48 farms located in Colombia, in the departments of northern Cesar in the north and La Guajira in the south. An indirect ELISA was used to detect IgG antibodies to T. gondii in the animals. A standardized questionnaire was used to obtain information on putative risk factors. We conducted the association analyses by using univariable and multivariate logistic regression and report odds ratios (OR) with 95% confidence interval (C.I). The overall seroprevalence in small ruminants was 23.5% (C.I: 21–26.2%). Sheep showed a higher seroprevalence (25.1% C.I: 22.4–28.6%) than goats (18.4% C.I: 22.4–28.6%). The association analysis recognized as risk factors for T. gondii seropositivity farming pigs in addition to small ruminants (OR = 1.96 C.I: 1.414–2.743), the inexistence of manure heap (OR = 2.254 C.I: 1.480–3.433) and drinking water from locally aqueducts (OR = 1.489 C.I: 1.006–2.204). The results of the study confirmed that exposure to T. gondii is common in sheep and goats in dry Caribbean regions of Colombia.

Serological Survey and Associated Risk Factors on Toxoplasma gondii Infection in Goats in Mila District, Algeria

Toxoplasma gondii is a protozoan parasite prevalent in humans and other animals worldwide having medical and veterinary importance on account of reproductive failure causing significant socioeconomic losses. The aims of this study were to estimate the seroprevalence of T. gondii infection in goats, determined the possible risk factors associated, and evaluate the performances of the latex agglutination test (LAT) to anti-T. gondii antibodies screening using the indirect Enzyme-linked immunosorbent assay as a reference test (iELISA). A total of 184 serum samples from goats reared on 25 farms in Mila district from North-Eastern Algeria were collected and tested for anti-T. gondii IgG antibodies using two commercial serological tests (ELISA and LAT). A seroprevalence rate of 71.73 % and 63.58 % was obtained by both ELISA and LAT tests, respectively. The analysis of some factors thought to be related to the onset of this infection such as age, sex, management system, locality and presence of cats showed no significant relationship (P > 0.05); these factors did not seem to affect the frequency of the infection. The seropositivity level of T. gondii was significantly higher in aborted goats (P = 0.007), which suggested that they may play a significant role in pregnancy failure. In the concordance evaluation between the two serological tests (ELISA and LAT), the Cohen’s Kappa value was calculated and the results showed a K of 0.519 (p = 0.000) belonging to the range of 0.41—0.60 indicating just average agreement. The results of the Mc Nemar test showed that both tests gave significantly different results and seropositivity values (P < 0.05). The high prevalence observed in this study indicated a widespread exposure to T. gondii from goats and the potential risk of T. gondii infection for humans in North-Eastern Algeria. These results elucidate the challenges of applying serology to estimate goat exposure to T. gondii. The choice between the two serological tests will depend on their performances, as well as the availability of the equipment, laboratory conditions and the number of samples to be tested.

Seroprevalence and Clinical Outcomes of Neospora caninum, Toxoplasma gondii and Besnoitia besnoiti Infections in Water Buffaloes (Bubalus bubalis)

One hundred twenty-four water buffaloes (Bubalus bubalis) originating from 9 farms located in southern Italy were tested to investigate simultaneously, for the first time, the seroprevalence of the protozoa Neospora caninum, Toxoplasma gondii and Besnoitia besnoiti by ELISA tests and to evaluate the clinical findings potentially associated to the presence of these aborting parasitic pathogens. Twenty-five of 124 buffaloes (20.2%) were positive for N. caninum, while 17/124 (13.7%) for T. gondii. No buffalo showed specific antibodies for B. besnoiti. Nineteen of 124 animals (15.3%) were found seropositive for both T. gondii and N. caninum. The univariate statistical analysis showed that the seroprevalence of N. caninum is significantly associated with abortion and presence of retained foetal membranes, while the seroprevalence of T. gondii is significantly associated with an increase of days open. The logistic regression models showed that the co-infection by N. caninum and T. gondii strengthened the abortive effects (OR = 7.330) and showed further negative effects on the parameter embryonic death (OR = 2.607). The outcome revealed herein represents a high exposure of N. caninum and T. gondii in water buffaloes with reproduction disorders that deserves attention for both economic reasons, animal health and welfare.

Molecular Detection of Toxoplasma gondii in the Slaughter Sheep and Goats from Shandong Province, Eastern China

It is generally recognized that sheep are susceptible to Toxoplasma gondii and play a very important role in the transmission of toxoplasmosis to humans. In China, sheep toxoplasmosis has been reported in some regions based on serological investigations. However, little is known about sheep toxoplasmosis in Shandong province, eastern China. Thus, this study was conducted to investigate the prevalence of T. gondii infection in the slaughter sheep and goats from three cities (Weihai, Yantai, and Rizhao) of Shandong province, eastern China. From November 2016 to March 2018, a total of 692 meat samples (438 sheep and 254 goats) were collected and detected by a seminested PCR-targeted T. gondii B1 gene. The overall prevalence of T. gondii in sheep and goats were 9.84% and 10.73%, respectively. Meat collected from rural markets (16.04%) had a significantly higher T. gondii prevalence than those collected from supermarkets (6.84%) (p < 0.001). Moreover, sheep and goats raised in backyard were more easily to be infected by T. gondii compared with those raised in farms (p < 0.001). This is the first report of the molecular prevalence of T. gondii infection in sheep and goats in Shandong province, eastern China, which would provide effective data for prevention and control of sheep and human toxoplasmosis in China.

The HLA-DRB1 risk alleles for multiple sclerosis are differentially expressed in blood cells of patients from Southern Italy

HLA gene expression has an important role in the autoimmune disease predisposition. We investigated the mRNA expression profile of the risk alleles HLA-DRB1*15 and HLA-DRB1*13 in a cohort of subjects both multiple sclerosis (MS) patients and healthy controls. Moreover, we explored the expression of the allele HLA-DRB1*11 that is very frequent in our cohort from southern Italy. We found that the expression of MS-associated alleles in heterozygous MS patients was always higher than the nonassociated alleles. The differential risk allele expression occurred also in nonaffected subjects, though with a lower increment compared to MS patients.

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.

The One Health Approach to Toxoplasmosis: Epidemiology, Control, and Prevention Strategies

One Health is a collaborative, interdisciplinary effort that seeks optimal health for people, animals, plants, and the environment. Toxoplasmosis, caused by Toxoplasma gondii, is an intracellular protozoan infection distributed worldwide, with a heteroxenous life cycle that practically affects all homeotherms and in which felines act as definitive reservoirs. Herein, we review the natural history of T. gondii, its transmission and impacts in humans, domestic animals, wildlife both terrestrial and aquatic, and ecosystems. The epidemiology, prevention, and control strategies are reviewed, with the objective of facilitating awareness of this disease and promoting transdisciplinary collaborations, integrative research, and capacity building among universities, government agencies, NGOs, policy makers, practicing physicians, veterinarians, and the general public.

Serosurvey of anti-Toxoplasma gondii antibodies in sport horses from Paraiba state, Northeastern Brazil

Although the infection by Toxoplasma gondii in horses is usually asymptomatic, it may be characterized by the presence of tissue cysts and maintenance of detectable antibody titers. The aim of this study was to detect anti-T.gondii antibodies and to determine risk factors associated in sport horses from Paraíba State, Northeastern Brazil. A total of 138 apparently healthy sport horses of different age and gender were sampled. Anti-Toxoplasma gondii antibodies were detected in 16/138 (11.6%; 95% CI: 6.77-18.14%) horses by indirect immunofluorescence antibody assay (IFA). A significant association was found between the water source and seropositivity to T. gondii (p<0.05). The present study highlights the importance of providing good quality water to the animals.

Risk factors for Toxoplasma gondii infection in sheep and cattle from Fernando de Noronha Island, Brazil

Abstract Toxoplasmosis is a zoonotic disease of global distribution that affects all warm-blooded animals. The purpose of this investigation was to determine the prevalence of T. gondii infection and identify the risk factors associated with its occurrence in domestic ruminants raised on the island of Fernando de Noronha, Brazil, and to confirm that cattle and sheep raised in Fernando de Noronha Island present statistically different T. gondii prevalence rates. Serum samples were collected from sheep (n=240) and cattle (n=140) for the detection of antibodies by indirect immunofluorescence. Samples were collected from all the animals on all the farms. Risk factors were analyzed by univariate analysis and logistic regression. The prevalence rate of positive sheep was 85.0% while that of cattle was 10.7%. A multivariate analysis revealed that the site of contact of sheep with felines was a risk factor. For cattle, the risk factors identified in this study were: extensive farming system, water source, more than three cats per farm, and the presence of rats in feed storage locations. The findings revealed a significant difference in the prevalence rates in sheep and cattle raised in this insular environment.

Toxoplasma gondii: Pig seroprevalence, associated risk factors and viability in fresh pork meat

This study was conducted on 161 fattening pig farms located in Aragón (Northeast Spain). Serum samples from 1200 pigs were tested for antibodies against T. gondii by indirect immunofluorescence assay (IFA). Antibodies to T. gondii (≥1:20) were detected in 301 pigs (24.52%). The seroprevalence observed in the present study indicates a widespread exposure to T. gondii, as seropositive pigs were found in 96.67% of the farms studied although low pig titers were determined. Risk factors associated with T. gondii seroprevalence were presence of cats in or around the farms, presence of dogs around the facilities, low number of animals in the farms, poor hygiene and bad maintenance of the farms. Finally, it was observed that where rodent baits were used, Toxoplasma prevalence was lower. Risk management measures including control of cats and rodents on the farms, among others, could help to reduce the observed prevalence levels. By mouse bioassay, T. gondii was detected in 73.7% and isolated from 42.1% of seropositive pigs and a significant relation between the titers of pigs and the presence and viability of T. gondii in the tissues was found. The detection of T. gondii is not possible by currently practiced meat inspection. Nevertheless, the increased probability of detecting viable forms of T. gondii in tissues of pigs with titers ≥1: 80 could be used as the cutoff for discriminating higher risk animals, and could be used as an effective control tool for the industry of cured meat products. In practical terms, we propose that this value could be used as a critical limit in the HACCP system.

Prevalence and risk factors for Toxoplasma gondii infection in meat animals and meat products destined for human consumption

Toxoplasma gondii is a protozoan parasite that is responsible for approximately 24% of all estimated deaths attributed to foodborne pathogens in the United States. Human infection results from accidental ingestion of oocysts from the environment, in water, or on insufficiently washed produce or from consumption of raw or undercooked meat products that contain T. gondii tissue cysts. This review focused on studies of T. gondii in meat because many human T. gondii infections are acquired through consumption of raw or undercooked meat. Prevalence of T. gondii is higher in conventionally reared pigs, sheep, and poultry than in cattle and is greater in meat products from organic than from conventionally reared meat animals because of outdoor access, which poses substantially greater opportunities for exposure to infected rodents, wildlife, and oocyst-contaminated feed, water, or environmental surfaces. Risk factors related to T. gondii exposure for livestock include farm type, feed source, presence of cats, methods of rodent and bird control, methods of carcass handling, and water quality. This review serves as a useful resource and information repository for informing quantitative risk assessment studies for T. gondii infection in humans through meat consumption.

Mini-FLOTAC for counting Toxoplasma gondii oocysts from cat feces--comparison with cell counting plates

Oocysts of Toxoplasma gondii represent one of the most common environmental contaminants causing the zoonotic infection toxoplasmosis. The aim of the present study was to compare the Mini-FLOTAC device with traditional cell counting plates (Kova Slide) for the detection of T. gondii oocysts from feline feces. Two types of experiments were performed: (i) purified oocysts were counted in different dilutions and (ii) specific pathogen free T. gondii-negative cat feces was inoculated with numbers of purified oocysts and counting was performed directly from feces. Our analysis showed a thousand times higher sensitivity of Mini-FLOTAC (5 × 10(2) oocysts) compared to Kova Slide (5 × 10(5) oocysts). Also, when compared by McNemar's test, counting of the purified oocysts showed a higher sensitivity of Mini-FLOTAC compared to Kova Slide, for a dilution of 10(3) oocysts/ml (chi(2) = 6.1; P < 0.05). A better sensitivity was also found with Mini-FLOTAC in dilutions of 10(5) and 10(4) oocysts/ml, when counted from feces (chi(2) = 4.2 and 8.1, respectively, P < 0.05). Our results show that Mini-FLOTAC is more sensitive than traditional methods of T. gondii oocysts detection and quantification is more accurate. Furthermore, Mini-FLOTAC simplicity and cost effectiveness allow it to be used with light microscopes in any laboratory or field conditions. We therefore recommend its use for regular screening. Further studies are needed to validate Mini-FLOTAC for the detection of oocysts in soil and water samples in field conditions.

Animals are key to human toxoplasmosis

Toxoplasma gondii is an extremely sucessfull protozoal parasite which infects almost all mamalian species including humans. Approximately 30% of the human population worldwide is chronically infected with T. gondii. In general, human infection is asymptomatic but the parasite may induce severe disease in fetuses and immunocompromised patients. In addition, T. gondii may cause sight-threatening posterior uveitis in immunocompetent patients. Apart from few exceptions, humans acquire T. gondii from animals. Both, the oral uptake of T. gondii oocysts released by specific hosts, i.e. felidae, and of cysts persisting in muscle cells of animals result in human toxoplasmosis. In the present review, we discuss recent new data on the cell biology of T. gondii and parasite diversity in animals. In addition, we focus on the impact of these various parasite strains and their different virulence on the clinical outcome of human congenital toxoplasmosis and T. gondii uveitis.

Genotyping of samples from German patients with ocular, cerebral and systemic toxoplasmosis reveals a predominance of Toxoplasma gondii type II

Toxoplasmosis is an important zoonosis transmitted from animals to humans world-wide. In order to determine Toxoplasma gondii genotypes in individuals living in Germany and to compare findings with those in animals, we analysed nine independent and unlinked genetic markers (nSAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) by PCR-RFLP in 83 archived T. gondii-positive DNA samples from patients with ocular toxoplasmosis (n=35), toxoplasmic encephalitis (n=32), systemic toxoplasmosis after bone-marrow transplantation (n=15) and congenital toxoplasmosis (n=1). In 46 of these 83 samples the presence of T. gondii DNA was confirmed by conventional end-point PCR. Among these, 17 T. gondii-positive samples were typed at all nine loci. The majority (15/17, 88.2%) of these samples were of T. gondii type II (i.e., including both, the Apico type II and Apico type I variants). In addition, in one sample a T. gondii type II/type III allele combination and in another sample a T. gondii genotype displaying type III alleles at all markers was observed. In the remaining 11 samples, in which T. gondii could only be partially typed, exclusively type II (n=10) or type III (n=1) alleles were observed. Results of the present study suggest that the majority of patients in Germany are infected with type II T. gondii regardless of the clinical manifestation of toxoplasmosis. This finding is in accord with the predominance of type II T. gondii in oocysts isolated from cats and in tissues of other intermediate hosts in Germany.

Toxoplasma gondii in sympatric wild herbivores and carnivores: epidemiology of infection in the Western Alps

Background

Toxoplasma gondii is an apicomplexan parasite that is able to infect almost all warm blooded animals. In Europe, the domestic cat is the main definitive host. Worldwide, 6 billion people are infected with this parasite. The goal of our research is to evaluate the prevalence of T. gondii infection in wild animals from a previously unsampled area in Northern Italy where 0.1% of women seroconvert during pregnancy each year.

Methods

We sampled and tested skeletal muscle and central nervous system tissue of 355 wild animals by PCR (n = 121 roe deer Capreolus capreolus, n = 105 wild boar Sus scrofa, n = 94 red fox Vulpes vulpes, n = 22 alpine chamois Rupicapra rupicapra, n = 13 red deer Cervus elaphus).

Results

The overall prevalence of infection with T. gondii was 10.99% (confidence interval (CI) 95% 8.14%-14.67%). A higher rate of infection was recorded in carnivores and omnivores (red fox 20.21%, CI 95% 13.34%-29.43%; wild boar 16.19%, CI 95% 10.36%-24.41%) compared to ruminants (2.48%, CI 95% 0.85%-7.04% in roe deer; 0.00%, CI 95% 0.00%-22.81% in red deer, and 0.00% alpine chamois (CI 95% 0.00%-14.87%) confirming the importance of tissue cysts in transmitting infection.

Conclusions

The relatively high prevalence of T. gondii DNA in highly consumed game species (wild boar and roe deer) gives valuable insights into T. gondii epidemiology and may contribute to improve prevention and control of foodborne toxoplasmosis in humans.

Prevalence and risk factors associated to ovine toxoplasmosis in northeastern Brazil

In this study, we aimed to determine the prevalence and risk factors associated to Toxoplasma gondii infection in sheep from northeastern Brazil. A total of 932 ovine serum samples from 54 properties in 19 municipalities of the state of Sergipe were collected and assayed using indirect fluorescent antibody test. The assay used antibodies against Toxoplasma gondii (IFAT-IgG) with a cutoff point of 1:64. We observed that 28.22% (263/932) of the ovine samples were serum-reactive. In a logistic regression, factors such as consumption of water directly from the source, consumption of water from a deep well, and age below 12 months were associated with protection; whereas factors such as presence of cats on the property, presence of slatted floor, and use of exchanged or borrowed breeding males were associated with infection. The studied area can be considered endemic for toxoplasmosis, so it is necessary to adopt preventive and control measures because this zoonotic infection poses risks to public health.

Prevalence and risk factors associated with anti-Toxoplasma gondii antibodies in sheep from Bahia state, Brazil

In this study, we aimed to determine the prevalence ofToxoplasma gondii antibodies and identify risk factors associated with this infection in sheep from the southern region of Bahia state. Between February and December 2010, 795 sheep from 31 farms located in nine municipalities were tested. We found seroprevalence of 30.2% (240/795), with titers of 64 (38.3%), 256 (34.2%), 1,024 (18.3%), and 4,096 (9.2%) by Indirect Fluorescent Antibody Test (IFAT). Seropositive sheep were detected in all farms sampled. Univariate statistical analysis detected association between T. gondii seropositivity and the variables age, use of fresh food mainly, water source, stocking rate, production system, presence and number of cats on the farm, and transit of cats (p < 0.05). In the logistic regression model, transit of cats (p = 0.001), production system (p = 0.007), and age (p = 0.027) were identified as risk factors associated with T. gondiiinfection.

Seroprevalence and risk factors for Toxoplasma gondii in sheep in Grosseto district, Tuscany, Italy

Background

Serum samples from 630 milk sheep, in 33 dairy flocks representative of the southern area of the Tuscany region, were tested for the presence of antibodies to Toxoplasma gondii using an indirect immunofluorescence antibody test (IFAT). Questionnaires exploring the management system were completed by the veterinarian in charge of the flocks.

Results

At least one seropositive animal was found in 32 of the 33 flocks tested (97.0%; 95% CI: 84.2%, 99.9%). In the positive flocks, median seroprevalence was 29.4% (interquartile range: 15.9%-46.1%). Overall animal-level seroprevalence, adjusted for sampling weights and test sensitivity and specificity, was 33.3% (95% CI: 24.8%, 42.7%). In a multivariable negative binomial regression model the number of seropositive animals in a flock decreased with increasing flock size (for >400 vs. <300 animals: count ratio (CR) = 0.62; 95% CI: 0.41, 0.95; P = 0.028) and was greater on farms where stray cats had access to animals’ water (CR = 1.54; 95% CI: 1.05, 2.26; P = 0.027).

Conclusions

Small flock size and access of cats to water are potential risk factors for Toxoplasma infection in sheep in the Grosseto district in Tuscany, Italy. Sheep could be an important source of T. gondii infection in humans, since we estimate that between 25% and 43% of sheep in the district were seropositive. Toxoplasmosis is also likely to be an important cause of abortion in sheep in the district. Control and prophylactic measures must be adopted to improve the rearing system and the implementation of health promoting programmes in a joint effort between sheep farmers, farmers’ associations and veterinarians to inform about the means of transmission of the infection and for a better understanding of the disease.

Toxoplasma gondii antibodies sheep in Lages, Santa Catarina, Brazil, and comparison using IFA and ELISA

Toxoplasmosis in sheep is a disease of great importance in veterinary medicine, which causes economic losses in livestock and has a great impact on human health, since consumption of infected meat facilitates transmission of zoonotic infections. Blood samples from sheep (n = 360) were collected from 13 farm properties in the municipality of Lages, Santa Catarina, to estimate the prevalence of toxoplasmosis and identify risk factors associated with Toxoplasma gondii infection. T. gondii, antibodies were investigated by means of the indirect immunofluorescence assay (IFA) and enzyme-linked immunosorbent assay (ELISA). Animals infected with T. gondii were found on 100% of the farms. IFA detected 56.9% (205/360) and ELISA 42.5% of the infected sheep. Breed was the only risk factor associated with the presence of T. gondii antibodies. ELISA showed sensitivity of 61%, specificity of 82% and kappa of 0.41, which was considered moderate. This allows use of ELISA as an alternative technique for diagnosing T. gondii in sheep.

Serological survey of Toxoplasma gondii and Campylobacter fetus fetus in sheep from New Zealand

AIM

To determine the prevalence of antibody titres to Toxoplasma gondii and Campylobacter fetus fetus in sheep from New Zealand.

METHODS

As part of a free screening service, unsolicited blood samples were supplied by veterinarians wishing to gauge the exposure of their clients' ewe flocks to T. gondii and C. fetus fetus. Blood samples were submitted from mixed-age ewes throughout New Zealand, from 2006 to 2009, that had not been vaccinated for T. gondii and C. fetus fetus. A total of 2,254 sera were serologically titrated for T. gondii and 3,429 for C. fetus fetus. A latex agglutination kit available commercially was used to quantify antibodies to T. gondii, and an agglutination test developed in-house was used for C. fetus fetus. For T. gondii, titres of ≥1:16 and ≥1:64 were used to define a positive response, and for C. fetus fetus a titre of ≥1:10 was defined as positive. A flock was defined as positive if ≥1 ewe had a positive titre.

RESULTS

Of the sera tested for T. gondii, 1,917/2,254 (85%) were positive, using a titre of ≥1:16, and 1,384/2,254 (61%) with a titre of ≥1:64. All 198 ewe flocks tested were seropositive to T. gondii, at a titre of ≥1:16, and all but three were at a titre of ≥1:64. A bimodal distribution was evident in the prevalence of titres to T. gondii suggesting that a percentage of titres ≤1:64 may have been non-specific. Of the sera tested for C. fetus fetus, 1,644/3,429 (48%) were positive to at least one of the four test antigens at titre of ≥1:10. Only 34/298 (11%) flocks tested for C. fetus fetus were completely seronegative. The percentage of seropositive ewes to both T. gondii and C. fetus fetus was significantly higher in the North Island than the South Island.

CONCLUSIONS

The study demonstrated that exposure to these two important infectious abortifacients was both considerable and widespread. Minimum titres were postulated to establish a 'cut-off' for a positive result and to allow comparison with past and future studies. The bimodal distribution evident for T. gondii suggested a titre of 1:64 may be an appropriate cut-off. The widespread on-farm exposure probably stimulates the immune response of vaccinated ewes.

CLINICAL RELEVANCE

Further studies are required to confirm the clinical significance of flock-based antibody responses, and to validate their use in identifying recently aborted ewes, especially where there are no aborted fetuses for examination.

Investigation and management of Toxoplasma gondii infection in pregnancy and infancy: a prospective study

AIM

Toxoplasma gondii infection during pregnancy poses a serious risk to the fetus, therefore timely and accurate diagnosis is essential. The aim of this study was to estimate the frequency of congenital infection via evaluating mother's immunological status and the possibility to improving the diagnostic and therapeutic approaches.

METHODS

Eighty five mothers with Toxoplasma seroconversion and their offspring were enrolled (among them, 2 spontaneous abortions were documented in the first trimester). Prenatal PCR diagnosis was carried out on 50 patients (60%), with 7 positive cases (14%). Morphological ultrasound scanning revealed anomalies in one fetus. Long-term follow-up included general physical examinations, serological status tested using Western blot, neuro-radiological, ophthalmologic and neurologic examinations, psychological and developmental tests, visual evoked potential tests and audiology tests, as well as anti-Toxoplasma treatment regimes.

RESULTS

Fourteen (17%) of the infants were infected at one-year serological follow-up. Chi-square for linear trend of vertical transmission from the first to the third trimester was significant (P=0.009). Western blot analysis showed IgM and IgA in half of the infected infants. In 69 uninfected infants, anti-Toxoplasma IgG immunoblot analysis excluded infection within the 3 months in 18 infants (26%) and in the others within 6 months of life. The most relevant instrumental findings are described.

CONCLUSION

Western blot analysis may help to evaluate infection within the 6 months of life. The accuracy of ultrasound imaging to determine the brain damage in the fetus and newborns is doubtful, and should be combined with MR imaging. Multistep approaches can improve the timing of postnatal follow-up.

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.

Mic1-3 Knockout Toxoplasma gondii is a good candidate for a vaccine against T. gondii-induced abortion in sheep

This study assessed the effectiveness of a mutant strain of Toxoplasma gondii (RH strain) lacking the mic1 and mic3 genes (Mic1-3KO) against Toxoplasma abortion in sheep. Ewes were inoculated subcutaneously with 10⁵ Mic1-3KO tachyzoïtes in three independent experiments. Following vaccination, Mic1-3KO induced a mild febrile response and serum IgG antibodies, which persisted throughout the experiments. Tissue cysts formed in the sheep, but were not, under our experimental conditions, infectious when given orally. Ewes were mated two months after vaccination and were orally challenged with the PRU strain of T. gondii at mid-gestation (400 oocysts in Experiments 1 and 2; 100 oocysts in Experiment 3). Challenge of vaccinated pregnant ewes resulted in a slight febrile response, whereas unvaccinated ewes developed a more severe, characteristic febrile response of longer duration. After challenge, all unvaccinated ewes aborted whereas 62%, 91% and 64% (Experiments 1, 2 and 3 respectively) of the lambs from vaccinated ewes were viable, with no clinical signs of infection. Mic1-3KO was as effective as S48, the strain used as a live vaccine for sheep (Toxovax^®). A dose of 10⁵ Mic1-3KO tachyzoites was sufficient to induce protection (versus a dose of 2 × 10⁶). Both subcutaneous and intraperitoneal injections were effective. Moreover, preliminary results showed the potential of Mic1-3KO to reduce the development of tissue cysts in lambs born to vaccinated ewes. This study demonstrates that Mic1-3KO is a potent vaccine candidate.

What do we know about risk factors for infection in humans with Toxoplasma gondii and how can we prevent infections?

Fourteen case-control studies evaluating the importance of different risk factors for infection of humans with Toxoplasma gondii were identified. Surprisingly, up to two-thirds of infections could not be explained by risk factors such as consuming raw or undercooked meat or poor kitchen hygiene. Few studies reported population attributable risk, and when reported, it was low. Protocols including questionnaires used for collecting data, age and socio-economic groups studied, and sample sizes varied among studies. There is a need for carefully planned, case-control studies to identify sources of infection with T. gondii in humans. New risk factors, such as the manufacture of organic meat, and possible ways to sterilize meat to inactivate T. gondii tissue cysts are discussed.

Seroprevalence of Toxoplasma gondii in sheep and goats in Rahim Yar Khan (Punjab), Pakistan

Toxoplasmosis, an infection caused by Toxoplasma (T.) gondii Apicomplexa protozoan, is widespread in humans and other animal species, having already been reported in many countries and different climates. In Pakistan, no data is available on this aspect among food animals. This study was undertaken to determine the seroprevalence of T. gondii infection in sheep and goats. A total of 200 serum samples from sheep and goats, were collected from urban area of Rahim Yar Khan (Punjab), Pakistan and tested for Toxoplasmosis with a commercial latex agglutination kit (Eiken Chemical Co., Ltd. Japan). The overall seroprevalence of Toxoplasmosis was 19%. Goats had a significantly higher (p < 0.01) prevalence (25.4%) as compared to the sheep (11.2%); and higher (p < 0.01) in the female (24%) than in the males (19%) for both species. In the present study the male (both in sheep and goat) are found less seropositive T. gondii (OR = 0.23; 99% C.I. = 0.01, 1.81) as compared to female sheep and goat. The prevalence was significantly higher (p < 0.01) in adult sheep than younger animals. Among both the sheep and goats the group from 1-1.5 years are highly seropositive (OR = 1.75; 99% C.I. = 0.47, 6.51) as compared to the group less than one year of age followed by the 2-2.5 years age group (OR = 1.63; 99% C.I. = 0.50, 5.74) whereas group with more than 3 years of age least seropositive.

Risk factors for toxoplasmosis in pigs bred in Sicily, Southern Italy

The aim of the study was to determine the seroprevalence of Toxoplasma gondii infection in pigs raised and slaughtered in Sicily, Southern Italy, and to evaluate the risk factors associated with the infection. Samples were collected in seven slaughterhouses and on-site on 274 raising farms across Sicily, in the period from January 2006 until March 2007. For each sampled pig born and raised in Sicily, information was obtained on gender, age, origin, final destination of meat and farm management. Data on the farm included: farming type, presence of cats and dogs, rodent control by rodenticides, cleaning methods, water supply, altitude and herd size.T. gondii-specific antibodies were detected using a commercial Enzyme-Linked Immunosorbent Assay (Institut Pourquier, France).Antibodies against T. gondii were found in 16.3% of Sicilian pigs. The lowest seroprevalence, 7%, was found in the age group 5-7 months (market pig) and the highest, 19%, in the age group >24 months. Risk factors for seropositivity were: age 11-24 months compared to younger (OR 5.62; CI 1.52-20.8); farrow-to-finish farming type (OR 6.85; CI 1.87-25.01) compared to finishing and farrow-to-breed type; less than 50 pigs on the farm (OR 6.8; CI 1.76-26.2); no use of rodenticides (OR 2.71; CI 1.10-6.64), use of water coming from private sources (especially wells; OR 2.8; CI 1.03-7.72).Pigs raised in Sicily shows a high prevalence of antibodies against T. gondii. Pre-harvesting interventions to lower the risk of locally produced meat consumption for consumers should point as soon as possible to increase hygienic condition on the farm, by carefully removing waste with automatic cleaning and reducing biohazard by rodent control. Consumers must receive information on the correct handling and cooking locally produced pork meat derivatives.