Toxoplasma gondii seroprevalence in extensively farmed wild boars (Sus scrofa) in Denmark.

Toxoplasma gondii is a zoonotic parasite of worldwide importance. In this study, we estimated T. gondii seroprevalence in extensively farmed wild boars in Denmark, where little is known about T. gondii in animal hosts. Our study focused on wild boars because they are considered good indicator species for the presence of T. gondii, and wild boar meat is used for human consumption. Serum samples from 101 wild boars collected in 2016-2018 from five different locations from the continental part of Denmark, Jutland, were screened for anti-T. gondii antibodies. The samples were analysed using a commercial indirect enzyme-linked immunosorbent assay (ELISA). Samples from 28 (27.7%) of the 101 wild boars tested positive with the ELISA. The odds for a wild boar to test seropositive were higher if it was sampled during the hunting season 2017-2018 than during 2016-2017 and if it was reported to be at least 1 year old than if it was younger (logistic regression model with the two variables: odds ratios 17.5 and 3.9, respectively). A substantial proportion of the investigated extensively farmed wild boars had been exposed to T. gondii. Moreover, the parasite appeared widespread, at least in the continental part of Denmark, Jutland, as seropositive wild boars were found from all five sampled locations. Assuming seropositivity indicates hosting viable parasites, consumption of undercooked wild boar meat from Denmark is a potential source of T. gondii infections to other hosts, including humans.

First report on seroprevalence and risk factors of Toxoplasma gondii infection in sheep and goats in North Lebanon.

INTRODUCTION: Toxoplasmosis is of dual importance in both public and veterinary health due to the respective risk of transplacental transmission in primo-infected pregnant women and economic losses caused by abortions in mammals. One of the main routes of Toxoplasma gondii transmission to humans is the consumption of raw or undercooked meats containing parasitic cysts. Here, we performed the first epidemiological study to determine the seroprevalence and the risk factors of toxoplasmosis in livestock in Lebanon. METHODOLOGY: Using a modified agglutination test with a cut-off of 1:40, we tested the positivity rate of Immunoglobulin G antibodies in the sera of 100 sheep and 80 goats collected from 18 different livestock farms located in North Lebanon between March and June 2018. RESULTS: Anti-Toxoplasma gondii IgG antibodies were detected in 42% of sheep and 34% of goats. Adults (> 1 year) were significantly more infected by T. gondii than the lambs (< 1 year) in both species (p < 0.05). CONCLUSIONS: These findings indicated that food animals are highly exposed to T. gondii in Lebanon and could be potentially a major risk factor of T. gondii infection to humans. Consequently, national prophylactic strategies should be implemented to control and to prevent T. gondii transmission between animals and humans.

Prevalence of Toxoplasma gondii DNA in Processed Pork Meat.

Toxoplasma gondii infection may be attributed to the ingestion of pork meat and contaminated water. In southern Brazil, the prevalence of blindness caused by T. gondii is the highest in the world. Our purpose is to determine the frequency of T. gondii DNA in commercial fresh sausage and cured salami samples from Rio Grande do Sul state, south of Brazil. A total of 118 samples (sausage and salami) from 8 different producers were collected and DNA was extracted. Real-time polymerase chain reaction (qPCR) technique was performed to detect T. gondii DNA using B1 marker. The frequency of T. gondii DNA among the total number of samples (sausage and salami) was 39% (46/118). Among these, a higher frequency of positivity was observed in the sausage samples (47.5%) when compared with the salami samples (17%). However, the mean parasite concentration was significantly higher in the salami samples. The prevalence of T. gondii DNA in fresh sausage and cured salami may indicate that infected pigs may be an important source of infections and a public health hazard to be considered.

Experimental Toxoplasmosis in Japanese Quails (Coturnix coturnix japonica).

OBJECTIVE: In this study, forming of experimental toxoplasmosis in quails; clinical, pathological, and serological determination of tissue lesions and bioassay techniques, which were aimed to compare them and determine pathogenesis. METHODS: A total of 120 one-year-old female quails (Coturnix coturnix japonica) were divided into oral infection, parenteral infection, and control groups. The oral group was infected with 0.5 ml inoculum suspension containing 106 tachyzoites of Toxoplasma gondii, whereas the control group was administered 0.5 ml of saline. The parenteral group was further divided into the following four subgroups: intraperitoneal, intramuscular, intravenous, and cloacal. The quails of the parenteral group were also divided into two groups and one by control group within itself for the 105 and 104 doses of the tachyzoite inoculums. RESULTS: Because of acute toxoplasmosis, death occurred in a quail that as intramuscularly infected with 105 tachyzoites; the quail exhibited neurological clinical symptoms such as torticollis, ataxia, and tremor. In histopathologic examination, T. gondii tissue cysts were detected in infected quails that were intramuscularly infected with 105 tachyzoites. Mouse trials were conducted using tissues of seropositive quails and isolated from peritoneal fluids infected mice. By Sabin-Feldman dye test and indirect hemagglutination test, seropositivity was observed in quails infected with 105 and 104 tachyzoites. CONCLUSION: Similar studies and subclinical cases, which may overlooked was concluded for diagnosis of toxoplasmosis with useful bioassay applications and serological tests.

Risk factors associated with Toxoplasma gondii infection in free-range chickens in the semiarid region of Brazil.

This study aimed to investigate the frequency of anti-Toxoplasma gondii antibodies in serum from 629 chickens on 39 family farms in seven municipalities in the semiarid region, Pernambuco, Brazil, and to identify risk factors associated with T. gondii infection. The risk factors were studied in 421 samples from 29 farms. Anti-T. gondii antibodies were investigated by indirect fluorescent antibody test with a 1:16 cutoff. The frequency of positive chickens was 27.9% (176/629) and 94.8% of the farms studied had chickens infected by T. gondii. Multivariate analysis showed variables significantly associated with anti-T. gondii antibodies in serum: slaughter of animals on the farm, reproductive disorders in sheep, consumption of fetal adnexa and placentas by chickens, presence of sheep in the property and birth of sheep the property. The results suggest that there is a complex relationship between general management practices for different animal species raised on the same farm and the prevalence of T. gondii infection in chickens. In addition, the results draw attention to the risk of human infection by T. gondii via consumption of infected chicken meat, because the farming conditions and the low human development indices observed in the region studied result in inappropriate meat preparation practices.

Occurrence of Toxoplasma gondii and risk factors for infection in pigs raised and slaughtered in the Triângulo Mineiro region, Minas Gerais, Brazil / Ocorrência e fatores de risco da infecção por Toxoplasma gondii em suínos criados e abatidos na região do Triângulo Mineiro, Minas Gerais, Brasil

The Triângulo Mineiro region from Minas Gerais state, is an important meat-exporting region of Brazil and data about Toxoplasma gondii infection in pigs raised and slaughtered in this area are scarce. Therefore, the aim of this study was to evaluate the occurrence of T. gondii in swine and establish the risk factors associated with the infection. Samples were collected from 600 pigs raised under intensive system in farms located at three different counties (Carmo do Paranaíba, Patrocínio and Perdizes). The samples were submitted to indirect hemagglutination antibody test with dilution of 1:32 and to indirect immunofluorescence antibody test with a cutoff of 1:64. The occurrence of positive pig was 3.3% (n=20) and 51.8% (n=311) respectively. A significant difference was observed between toxoplasmatic infection and factors such as lineage, animal origin, size of the farm, collective raising with others species, presence of rodents and type of water offered (p≤0.05). There was no difference between gender and the farm goals. The results demonstrated an occurrence of anti-T.gondii antibodies higher than expected for intensive pig raising system on the studied area, which could indicate a possible sanitary management problem on the studied proprieties. Improvements on the raising techniques are necessary to reduce T. gondii infection sources.(AU)

A região do Triângulo Mineiro, no estado de Minas Gerais, é uma importante região exportadora de carne do Brasil e pesquisas sobre a infecção por Toxoplasma gondii em suínos criados e abatidos nesta região são escassos. Portanto, o objetivo deste estudo foi avaliar a ocorrência de T. gondii nesses animais e estabelecer os fatores de risco associados com a infecção. Foram coletadas amostras de 600 suínos criados sob sistema intensivo, em fazendas localizadas em três municípios diferentes (Carmo do Paranaíba, Patrocínio e Perdizes). As amostras foram submetidas à Hemaglutinação Indireta com diluição de 1:32 e à Reação de Imunofluorescência Indireta com ponto de corte 1:64. A ocorrência de suínos positivos foi de 3,3% (n=20) e 51,8% (n=311), respectivamente. Foi observada diferença significativa entre a infecção toxoplásmica e fatores como linhagem, procedência dos animais, tamanho das propriedades, criação em conjunto com outras espécies, presença de roedores e tipo de água consumida (p≤0,05). Não houve diferenças estatísticas entre o sexo e finalidade de produção em relação à infecção por T. gondii. Os resultados demonstraram uma ocorrência de anticorpos anti-T. gondii superior à esperada em criações intensivas de suínos na região estudada, o que poderia indicar uma possível falha no manejo sanitário das propriedades estudadas. Melhorias nas técnicas de criação são necessárias para redução das fontes de infecção por T. gondii nos rebanhos.(AU)

Risk factors associated with Toxoplasma gondii infection in free-range chickens in the semiarid region of Brazil / Fatores de riscos associados com a infecção de Toxoplasma gondii em galinhas de vida livre na região do semiárido do Brasil

Abstract This study aimed to investigate the frequency of anti-Toxoplasma gondii antibodies in serum from 629 chickens on 39 family farms in seven municipalities in the semiarid region, Pernambuco, Brazil, and to identify risk factors associated with T. gondii infection. The risk factors were studied in 421 samples from 29 farms. Anti-T. gondii antibodies were investigated by indirect fluorescent antibody test with a 1:16 cutoff. The frequency of positive chickens was 27.9% (176/629) and 94.8% of the farms studied had chickens infected by T. gondii. Multivariate analysis showed variables significantly associated with anti-T. gondii antibodies in serum: slaughter of animals on the farm, reproductive disorders in sheep, consumption of fetal adnexa and placentas by chickens, presence of sheep in the property and birth of sheep the property. The results suggest that there is a complex relationship between general management practices for different animal species raised on the same farm and the prevalence of T. gondii infection in chickens. In addition, the results draw attention to the risk of human infection by T. gondii via consumption of infected chicken meat, because the farming conditions and the low human development indices observed in the region studied result in inappropriate meat preparation practices.

Resumo Objetivou-se investigar a prevalência de anticorpos anti-Toxoplasma gondii em 629 soros de galinha em 39 propriedades da agricultura familiar em sete municípios de Pernambuco, Brasil e identificar os fatores de risco associados à infecção. Para a pesquisa de anticorpos anti-T. gondii empregou-se a reação de imunofluorescência indireta com ponto-de-corte 1:16. O estudo dos fatores de risco foi realizado em 29 propriedades, totalizando 421 amostras. A prevalência de aves positivas foi de 27,9% (176/629) e 94,8% das propriedades tinham galinhas infectadas por T. gondii. Na análise multivariada, obteve-se como variáveis significativas associadas com anticorpos anti-T. gondii a ocorrência de abate de animais na propriedade, relato de distúrbios reprodutivos em ovinos, ingestão de anexos fetais e placentas pelas galinhas, presença de ovinos na propriedade e nascimento de ovinos na propriedade. Os resultados sugerem relações complexas entre o manejo das espécies animais criados nas propriedades e a prevalência da infecção nas galinhas. Em adicional, chama-se atenção para o risco de infecção humana por T. gondii via consumo de carne de galinha infectada, uma vez que as condições de criação e os baixos índices de desenvolvimento observados na região resultam em inapropriada preparação da carne para consumo.

Risk factors for Toxoplasma gondii infection in sheep in the northeastern region of Brazil / Fatores de risco para a infecção de Toxoplasma gondii em ovinos da região nordeste do Brasil

Toxoplasma gondii is an infective parasite that causes reproductive disorders such as abortion, fetal mummification, birth of weak offspring, and stillbirth, thereby causing economic losses to sheep production. The northeastern region of Brazil has approximately 171 million small ruminants, of which 5.4% are sheep. The present study aimed at determining the rate of occurrence of T. gondii in sheep flocks on 60 farms in 19 municipalities in the three mesoregions (eastern, semi-arid, and sertão or backlands) of the state of Sergipe, Brazil, and the risk factors associated with this infection. Serum samples were collected between 2011 and 2012, from 60 farms located in 19 municipalities in the three mesoregions: 680 in the eastern region, 280 in the semi-arid region, and 240 in the backlands, totaling 1,200 samples (990 females and 210 males). Anti-T. gondii antibodies were detected by means of the indirect fluorescence antibody test (IFAT ≥ 64). The highest occurrence was detected in the eastern region (45.3%, p = 0.001). On farms with subsistence production, the risk of having animals infected by T. gondii was approximately twice as high as on breeding/rebreeding/fattening farms (OR: 3.03; CI: 1.97-4.68). There was a significant lack of sanitary care, such as absence of a dunghill (p = 0.000; OR: 1.60; CI: 1.26-2.03), quarantine (p = 0.000; OR: 1.87; CI: 1.45-2.41) and disinfection (p = 0.003; OR: 1.46; CI: 1.13-1.88). Regarding feeding, the risk of infection was 1.74 and 1.37 times higher in places that used a trough and/or that cats could access, respectively. The present study allows the conclusions that T. gondii is found on farms in the three mesoregions of the state of Sergipe and that environmental and management factors have an influence on sheep infection.(AU)

Toxoplasma gondii é um parasita cuja infecção leva a desordens reprodutivas como aborto, mumificação fetal, nascimento de cordeiros fracos e natimortos, provocando perdas econômicas na produção ovina. A região nordeste do Brasil possui aproximadamente 171 milhões de pequenos ruminantes, dos quais 5,4% são ovinos. Este estudo tem como objetivo determinar a ocorrência de T. gondii nos rebanhos ovinos de 60 propriedades de 19 municípios de três mesorregiões (leste, semiárido e sertão) do estado de Sergipe, Brasil, e os fatores de risco associados a essa infecção. Amostras de soro foram coletadas entre 2011 e 2012, em 60 propriedades localizadas em 19 municípios das três mesorregiões: 680 na região leste, 280 no semiárido e 240 no sertão, totalizando 1.200 amostras (990 fêmeas e 210 machos). Anticorpos anti-T.gondii foram detectados por reação de imunofluorescência indireta (RIF ≥ 64). A maior ocorrência foi detectada na região leste (45,3%, p = 0.001). Em propriedades com produção de subsistência, o risco de animais infectados por T. gondii é aproximadamente duas vezes maior que nas de cria/recria/engorda (OR = 3.03/ IC: 1.97-4.68). A ausência de cuidados sanitários, como ausência de esterqueira (p = 0.000/ OR: 1.60; CI: 1.26-2.03); quarentena (p = 0.000/ OR: 1.87; CI: 1.45-2.41) e desinfecção (p = 0.003/ OR: 1.46; CI: 1.13-1.88) foram significantes. Em relação à alimentação, o risco de infecção aumenta 1.74 e 1.37 em locais que utilizam cocho ou com presença de gatos, respectivamente. Este estudo permite concluir que o T. gondii é encontrado em propriedades das mesorregiões do estado de Sergipe e fatores ambientais e de manejo estão influenciando nas infecções em ovinos.(AU)

Risk factors for Toxoplasma gondii infection in sheep and cattle from Fernando de Noronha Island, Brazil / Fatores de risco para infecção por Toxoplasma gondii em ovinos e bovinos na Ilha de Fernando de Noronha, Brasil

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.

Resumo A toxoplasmose é uma zoonose cosmopolita que acomete animais de sangue quente. Objetivou-se nessa investigação determinar a prevalência e identificar os fatores de risco associados à ocorrência da infecção por T. gondii em ruminantes domésticos criados na Ilha de Fernando de Noronha e demonstrar que bovinos e ovinos criados na ilha de Fernando de Noronha, Brasil, apresentam prevalências estatisticamente distintas. Foram obtidas amostras de soro sanguíneo de todos os ovinos (n=240) e bovinos (n=140) de todas as propriedades da ilha para a pesquisa de anticorpos na Reação de Imunofluorescência Indireta. Os fatores de risco foram analisados por meio da análise univariada e regressão logística. A prevalência de ovinos reagentes foi de 85,0% e 10,7% para bovinos, que foram significativamente diferentes. Na análise multivariada, local de contato de ovinos com outras espécies foi identificado como fator de risco. Para os bovinos, os fatores de risco foram: sistema extensivo, fonte de água, número de gatos nas propriedades e a presença de rato. Os resultados obtidos demonstram diferença significativa nas prevalências em ovinos e bovinos criados neste ambiente insular.

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

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.

Toxoplasmosis in camels (Camelus dromedarius) of Borana zone, Oromia region, Ethiopia: seroprevalence and risk factors.

Toxoplasmosis is one of the most prevalent parasitic infections of medical and veterinary importance. A cross-sectional study was conducted from November 2013 to January 2014 to estimate the seroprevalence of Toxoplasma gondii infection in camels from four districts of Borana zone, Southern Oromia, Ethiopia. In addition, a questionnaire survey was administered to 124 pastoralists to identify possible risk factors and to assess the awareness level of pastoral communities about toxoplasmosis. A total of 396 serum samples were examined for anti-Toxoplasma IgG antibodies using the direct agglutination test (DAT). Fisher's exact test and logistic regression were used for data analysis. An overall seroprevalence of 8.33 % (95 % confidence interval [CI] 5.60 %, 11.07 %) at animal-level and 37.5 % (95 % CI: 20.1 %, 57.4 %) at herd-level was found. The seroprevalence was significantly high in Moyale district (23.07 %) followed by Yabello (7.20 %), Dirre (3.77 %), and Arero (0.0 %) districts (P < 0.001). Multivariable logistic regression analysis revealed that the likelihood of acquiring T. gondii infection was significantly higher in camels of Moyale district (adjusted OR = 5.89, 95 % CI 2.15, 16.12; P = 0.001) than Dirre district, in camels of >8 years old (adjusted odds ratio [OR] = 4.95, 95 % CI 1.68, 14.55; P = 0.004) than camels of ≤4 years old. There was no significant association between herd-level seroprevalence of T. gondii infection and abortion history, herd size, and presence of domestic cats and wild felids (P > 0.05). The majority of interviewees were uneducated (82.25 %), and all had no knowledge of toxoplasmosis. All camel herders drink raw camel milk but consume cooked meat (90.32 %). Of the interviewees, 93.06 % are aware about soil-eating habit of camels and provide salt supplement for their camels. Majority of the respondents practice improper disposal of aborted materials (throw along the way) (88.70 %), and 73 % of the study participants do not wash their hands after handling aborted fetus. The results of the present study confirm relatively lower prevalence of T. gondii infection in camels reared in Borana zone. Age and study district are significant predictors of T. gondii seropositivity. The vast majorities of interviewed pastoralists were uneducated and practice poor biosecurity measures to prevent diseases. Education of pastoralists about biosecurity measures to prevent toxoplasmosis and further studies are warranted to unravel the economic and public health consequences of T. gondii infection.

Seroprevalence and risk factors of Toxoplasma gondii in Tibetan Sheep in Gansu province, Northwestern China.

BACKGROUND: Toxoplasma gondii, a protozoan parasite, infects almost all warm-blooded animals and humans. Limited information is available about T. gondii infection in Tibetan Sheep in Gansu province, northwestern China. In the present study, we estimated the seroprevalence and risk factors of T. gondii infection in this region of China. RESULTS: A total of 1732 Tibetan Sheep were included from Tianzhu and Maqu in Gansu province. Antibodies to T. gondii were examined by modified agglutination test (MAT), and 352 (20.3%) out of 1732 Tibetan sheep were found positive. Multivariate logistic regression analysis was used to analyze the risk factors associated with seroprevalence, the results showed that age, gender, and numbers of past pregnancies were not the significant risk factors. However, Tibetan sheep in Maqu had a 1.64 times (odds ratio [OR] =1.637, 95% CI =1.291-2.075, P < 0.001) higher seroprevalence compared to Tianzhu, and the seropositivity in summer were 1.61 times (OR =1.608, 95% CI =1.122-2.303, P = 0.010) higher compared to Tibetan sheep in winter, followed by 1.42 times (OR =1.419, 95% CI =1.002-2.011, P = 0.049) in spring. Thus, season and location were considered as risk factors associated with T. gondii infection in this study. CONCLUSIONS: This is the first report of T. gondii seroprevalence in Tibetan sheep in Gansu province, which enriches the epidemiological data of T. gondii infection in Tibetan sheep in China. The results of this study indicate that Tibetan sheep in Gansu province are frequently exposed to T. gondii, posing a direct threat to the public health as well as to local sheep industry. These data is useful to strengthen future prevention and control of T. gondii infection in Tibetan sheep in this region.

Investigation of persistence of infectious Toxoplasma gondii in raw sausages using in-house developed and validated real time-PCR.

The question, if and to what extent raw-sausage-products represent a possible source of infection for the globally distributed and potentially health-threatening toxoplasmosis gave reason for this study. For this, the survival capability of Toxoplasma gondii in relation to the raw-sausage-manufacturing-process including different ripening-processes was investigated. To enable a fast and reliable parasite-detection, a real time-PCR-system based on a specific 529-bp-fragment of T. gondii and an internal amplification control (IAC) was developed and established. The applicability was tested in various experiments where T. gondii-tachyzoites were mixed into different types of raw-sausages and then investigated by using the real time-PCR-system. The latter was also used to investigate the possible infection-risk of raw-sausages. For this, two pigs were intravenously infected with T. gondii-tachyzoites and after having reached the typical slaughtering age, their meat was manufactured to different raw-sausage-products ("Mett"- and "Teewurst" as well as "Salami"). In order to prove the potential infectivity of these products under conditions close to reality, sausages in different ripening stages were fed to laboratory mice. The animals' organs (brain, heart and spleen) were examined employing the real time-PCR. T. gondii-DNA was detected in four out of 288 (1.4%) mice indicating that marketable raw-sausage-products generally bear a risk for consumers. However, the probability of an infection seems to be quite marginal.

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.

ATF6beta is a host cellular target of the Toxoplasma gondii virulence factor ROP18.

The ROP18 kinase has been identified as a key virulence determinant conferring a high mortality phenotype characteristic of type I Toxoplasma gondii strains. This major effector molecule is secreted by the rhoptries into the host cells during invasion; however, the molecular mechanisms by which this kinase exerts its pathogenic action remain poorly understood. In this study, we show that ROP18 targets the host endoplasmic reticulum-bound transcription factor ATF6ß. Disruption of the ROP18 gene severely impairs acute toxoplasmosis by the type I RH strain. Because another virulence factor ROP16 kinase modulates immune responses through its N-terminal portion, we focus on the role of the N terminus of ROP18 in the subversion of host cellular functions. The N-terminal extension of ROP18 contributes to ATF6ß-dependent pathogenicity by interacting with ATF6ß and destabilizing it. The kinase activity of ROP18 is essential for proteasome-dependent degradation of ATF6ß and for parasite virulence. Consistent with a key role for ATF6ß in resistance against this intracellular pathogen, ATF6ß-deficient mice exhibit a high susceptibility to infection by ROP18-deficient parasites. The results reveal that interference with ATF6ß-dependent immune responses is a novel pathogenic mechanism induced by ROP18.

Seroprevalence of and risk factors for Toxoplasma gondii in sheep raised in the Jaboticabal microregion, São Paulo State, Brazil.

Seroprevalence of and risk factors for toxoplasmosis in sheep from different properties in the Jaboticabal microregion, São Paulo State, Brazil were determined. Antibodies to Toxoplasma gondii were found in sera of 52.0% of 488 sheep tested by indirect fluorescent antibody test (IFAT > or =64). T. gondii seropositivity in sheep was significantly associated with gender of the sheep, pasturing system, contact with cats, and the use of mineral supplements and the type of feed.

A serological study on the prevalence of Toxoplasma gondii in sheep of Lithuania.

In the present study the seroprevalence of the protozoan parasite Toxoplasma gondii infection in sheep was investigated in 6 regions of Lithuania. Blood samples were taken from 354 sheep and were tested using commercial ELISA method. The total seroprevalence of Toxoplasma gondii infection in sheep was 42.1%. Significant differences in seroprevalence were observed between age groups (P < or = 0.05). The results of this investigation suggest that the Toxoplasma gondii parasite is widely spread, and can be one of reasons of sheep abortion in Lithuania.

Antemortem diagnosis and treatment of toxoplasmosis in two cats on cyclosporin therapy.

Clinical toxoplasmosis was diagnosed antemortem in two cats being treated with therapeutic doses of cyclosporin. The diagnosis was made by detecting tachyzoites on cytological examination of bronchoalveolar lavage fluid from one case and pleural effusion from the other. Despite early diagnosis and aggressive treatment in both cases, only one cat survived. Reactivation of latent Toxoplasma gondii infection secondary to cyclosporin-induced immunosuppression was considered likely in both cases. The presence of respiratory signs in cats treated with cyclosporin should alert clinicians to the possibility of clinical toxoplasmosis. Consideration should be given to determining the serostatus of cats to T gondii prior to use of drugs which are potent inhibitors of cell mediated immunity, such as cyclosporin. Two cases of feline toxoplasmosis are presented.

Bayesian modeling of animal- and herd-level prevalences.

We reviewed Bayesian approaches for animal-level and herd-level prevalence estimation based on cross-sectional sampling designs and demonstrated fitting of these models using the WinBUGS software. We considered estimation of infection prevalence based on use of a single diagnostic test applied to a single herd with binomial and hypergeometric sampling. We then considered multiple herds under binomial sampling with the primary goal of estimating the prevalence distribution and the proportion of infected herds. A new model is presented that can be used to estimate the herd-level prevalence in a region, including the posterior probability that all herds are non-infected. Using this model, inferences for the distribution of prevalences, mean prevalence in the region, and predicted prevalence of herds in the region (including the predicted probability of zero prevalence) are also available. In the models presented, both animal- and herd-level prevalences are modeled as mixture distributions to allow for zero infection prevalences. (If mixture models for the prevalences were not used, prevalence estimates might be artificially inflated, especially in herds and regions with low or zero prevalence.) Finally, we considered estimation of animal-level prevalence based on pooled samples.