Prevalence of Toxoplasma gondii infection in HIV-infected patients and food animals and direct genotyping of T. gondii isolates,Southern Ghana

Toxoplasma gondii is of public health and veterinary importance causing severe diseases in immunocompromised individuals including HIV/AIDS patients and in congenital cases and animals. There is limited information on the epidemiology of T. gondii infection in humans, particularly HIV patients and food animals and the parasite genotypes in Ghana. A total of 394 HIV-infected patients from three hospitals were screened for T. gondii anti-IgG and IgM using ELISA. DNAs from blood samples of seropositve participants and 95 brain tissues of food animals were PCR assayed to detect Toxoplasma gra6. DNA positive samples were genotyped using multilocus nested polymerase chain reaction restriction fragment length polymorphism at 10 loci: sag1, alt.sag2, sag3, btub, gra6, l358, c22-8, c29-2, pk1, and apico. The overall seroprevalence was 74.37% (293/394). Toxoplasma DNAs were detected in 3.07% of the seropositive participants and 9.47% of the animals. Six of the human DNA positive samples were partly typed at sag3: 33.33, 50, and 16.67% isolates had type I, II, and III alleles, respectively. All nine isolates from food animals typed at nine loci except apico were atypical: six isolates were identical to ToxoDB #41 and #145, and one was identical to TgCkBrRj2 all identified in Brazil. The genotype of two isolates has not been reported previously and was named as TgCtGh1. T. gondii seroprevalence is high among the HIV-infected individuals with T. gondii circulating in Ghana being genetically diverse.

     

Seroprevalence of Toxoplasma gondii and Neospora caninum in dogs from Korea

Toxoplasma gondii and Neospora caninum are closely related protozoan parasites, they share many common hosts, and can cause neurological diseases in dogs. Dogs can have close contacts with humans and livestock and therefore they can act as reservoirs of these parasites. The aim of this study was to survey the seroprevalence of antibodies against T. gondii and N. caninum and their co-infection rate in dogs in Korea. In total, sera from 553 domestic dogs were collected from different breeds, sexes, and ages of dogs from nine provinces across the country of Korea during 2006 and 2007. The presence of antibodies against T. gondii and N. caninum was analyzed using the latex agglutination test (LAT) with a cut-off value of 1:32, and the indirect fluorescent antibody test (IFAT) using a serum titer of 1:100. In the total dog population, 71 (12.8%) dogs were positive for anti-T. gondii antibodies and only 20 (3.6%) were positive for anti-N. caninum antibodies. Relatively higher seropositive frequencies of antibodies against T. gondii (20.1%) and N. caninum (4.9%) were detected in the dog population from the Gyeonggi. A higher proportion of animals seropositive for anti-T. gondii antibodies was found in stray dog populations as compared to household dog populations: 18.5% (59/319) vs 5.1% (12/234), respectively. The Chi-square tests revealed significant differences in the seropositive frequencies of antibodies against T. gondii between stray and household dogs in the total population (p<0.0001), and in dogs from the Gyeonggi (p<0.01). No significant differences were observed for the presence of antibodies against T. gondii or N. caninum when compared across the sex or age (p>0.05). The first serological survey on antibodies against both T. gondii and N. caninum parasites across the entire country showed that co-infection was not common in these canine populations with a seropositive level of 0.72%. The significantly higher positive frequency of T. gondii antibodies in stray dogs in both, Gyeonggi and in the total dog populations suggests that further investigation on the seroprevalence of parasites should focus on stray dogs.     

In Romania, exposure to Toxoplasma gondii occurs twice as often in swine raised for familial consumption as in hunted wild boar, but occurs rarely, if ever, among fattening pigs raised in confinement

A wide range of swine husbandry practices prevail in Romania: pork for human consumption is derived from hunting wild boar, from household rearing of small numbers of backyard pigs, and from indoor, industrial production of swine raised in confinement indoors. Romania thus represents an instructive place for evaluating the influence of animal management on the exposure risk of the zoonotic parasite, Toxoplasma gondii. The fact that many Romanians eat uncooked or undercooked pork, especially when raised for household consumption, elevates the public health imperative to understand these risks. The aim of the study, therefore, was to evaluate the seroprevalence of T. gondii in pigs and wild boars from Romania. During 2008–2010, we collected 3,595 serum samples from pigs (fattening pigs, sows, backyard pigs) and 150 serum samples from wild boars. The sera were assayed by immunofluorescence antibody test (cutoff, 1:32) for antibodies against T. gondii. The overall seroprevalence of T. gondii infection was 23.1 % (829/3,595) in pigs and 16 % (24/150) in wild boars. The seroprevalence was significantly higher (p?<?0.001) in backyard pigs (30.5 %; 783/2,564) than in sows (12.4 %; 46/371) or fattening pigs (none of the sera was positive). The management system (indoor pigs versus backyard pigs) represented the most important factor in the epidemiology of T. gondii infection. The proximity of backyard pigs to the definitive host of this parasite (cats), as well as their access to contaminated meat products, elevated their exposure risk well above that of pigs raised in confinement, and even above that of wild boars inhabiting sylvatic environments.     

Antibody responses to Toxoplasma gondii antigen in human peripheral blood lymphocyte-reconstituted severe-combined immunodeficient mice reproduce the immunological status of the lymphocyte donor

These studies describe the production of specific antibodies in human peripheral blood lymphocyte-reconstituted severe-combined immunodeficient (PBL-SCID) mice following vaccination with antigen from the protozoan parasite Toxoplasma gondii. To determine the effect of previous exposure of the lymphocyte donor to antigen, human-PBL-SCID animals were created by transferring peripheral blood lymphocytes from either a single T. gondii-seronegative or a single seropositive donor. These reconstituted animals were subsequently inoculated with T. gondii soluble tachyzoite antigen (STAg) entrapped within non-ionic surfactant vesicles as an immunological adjuvant. Animals were bled at pre-determined time points post-vaccination and the expression of human anti-STAg antibodies in the plasma determined by enzyme-linked immunosorbent assay. Human antibodies specific for STAg were readily inducible in both groups of reconstituted animals, although the pattern of isotype production differed markedly between groups. The response in animals reconstituted with lymphocytes from the T. gondii-seronegative donor consisted primarily of IgM and subsequently of IgG (predominantly IgG1). In animals reconstituted with lymphocytes from the seropositive donor, no parasite-specific IgM could be demonstrated. The detectable response to STAg consisted entirely of human antibodies of the IgG isotype (IgG1), indicative of a memory-type response. These results mimicked exactly the antibody responses that would be expected had the lymphocyte donors been directly challenged with either the antigen or the live infectious agent, demonstrating that the immune system within these animals is functional and reproducible with regard to both the primary and secondary responses of the human donors.     

Susceptibility of heat shock protein 70.1-deficient C57BL/6 J,wild-type C57BL/6 J and A/J mice to Trypanosoma congolense infection

Toxoplasma gondii is a protozoan parasite with a worldwide distribution. In both sheep and humans, if the parasite is encountered during pregnancy, fetal infection and abortion can occur. Therefore, Toxoplasma infection in sheep has a major economic impact upon sheep farming. Clinically, there is a need to distinguish recent (acute) infections from longstanding (chronic) infections. However, current serological techniques, such as detection of anti-T. gondii IgG, cannot discriminate between acute and chronic infections. Increasing immunoglobulin avidity is a good determining factor of how recent an infection is. In this study, we describe the application and validation of a T. gondii IgG avidity ELISA, based on the use of an affinity-purified, native T. gondii P30 antigen. The assay was used to examine sera from eight sheep experimentally infected with T. gondii and found that all seroconverted within 21 days post-infection (p.i.), beginning with avidities that were initially low but that increased over time, with all sheep reaching high IgG avidity within 10 weeks p.i. In addition, sera from clinically healthy but T. gondii-seropositive lambs and ewes and seropositive ewes with a history of abortion were also subjected to a preliminary serological investigation. High IgG avidities were found in 80% of the seropositive lambs, in 90% of the clinically healthy ewes and in 97% of the ewes with abortion problems. These findings indicate that the animals had most likely contacted the parasite a longer time ago.     

Seroprevalence of Toxoplasma gondii infection in shepherd dogs from Sarab District,Northwest Iran

The aim of this study was to compile initial epidemiological data on the prevalence of Toxoplasma gondii antibodies in Sarab area. We evaluated the titers of anti-T. gondii antibodies by latex agglutination test (LAT; titer?>?1:64) serological test in 39 (10.1 %) serum samples from shepherd dogs exhibiting clinical signs of infectious diseases. The largest age group was 2–4 years, with 170 (44.3 %) dogs out of which only 21 dogs (12.3 %) were seropositive and the lowest age group was 4–6 years, with 87(22.6 %) out of which only 3 dogs (3.4 %) were seropositive. The highest rate of infection was seen in Ardaha village, with 11 (27.5 %) dogs. The lowest rate of infection was detected in Khaki and Asbfroshan villages, with only one dog. According to dog breed, the seropositivity rate of T. gondii was 14.3 % in pure breed dogs and 11.2 % in mongrel dogs. No sex or breed predispositions to T. gondii infection were detected during this serological assays (P?≤?0.05). The antibody titres of T. gondii ranged from 1:64 to 1:2,084. 39 Seropositive dogs with titers of 1:64 in 10, 1:128 in 13, 1:256 in 5, 1:512 in 6, 1:1,024 in 3, and 1:2,084 in 2 dog. In the present study, there was no correlation between antibody titers and, age or location. Our results show that presence and exposure of shepherd dogs to T. gondii in Sarab city confirm that dogs are exposed to T. gondii and play an important role in the epidemiology of T. gondii of this region.     

Seroepidemiology of Toxoplasma gondii, Neospora caninum, and Leishmania spp. infections and risk factors for cats from Brazil

The seroprevalence of infection by Toxoplasma gondii, Neospora caninum, and Leishmania spp. was detected through an indirect immunofluorescence in 70 cats from the Andradina Municipality, S?o Paulo State, Brazil. Anti-T. gondii antibodies (titer >64) were detected in 15.7% (11/70) of animals, whereas positivity for N. caninum (titer 16) was not observed in any animal. Of the cats from urban and rural areas, 10.4% (5/48) and 27.2% (6/22) were positive for T. gondii, respectively. Breed, age, food, and contact with animals of other species were significant for considering the positivity for T. gondii (P ≤ 0.0001). Cats having access to streets (17.1%, 11/64), cats cohabiting with rats (19.6%, 10/51), and cats feeding on homemade food and raw milk (27.2%, 6/22) were positive for T. gondii. In addition, 4.2% (3/70) of the cats were positive for Leishmania spp. by ELISA technique and negative by IFAT without coinfection with T. gondii and Leishmania spp. There was no serological positivity against feline immunodeficiency virus or feline leukemia virus. In conclusion, T. gondii infection in part of the feline population from Andradina is not linked to immunosuppressions or coinfections but probably to postnatal infection in association with the type of diet and presence of rats.     

Toxoplasma gondii in Capybara (Hydrochaeris hydrochaeris) antibodies and DNA detected by IFAT and PCR

Toxoplasmosis is considered nowadays as one of the most important foodborne diseases in the world. One of the emerging risks in acquiring infection with Toxoplasma gondii is the increasing popularity of wild animals and game meat. Capybara (Hydrochaeris hydrochaeris) is the world’s largest extant rodent and is used for human consumption in many areas of South America, and in case it carries T. gondii cysts, it may act as a source of infection. In the present study, we detected infection with T. gondii in capybaras from the south of Brazil. Antibodies to T. gondii were assayed in the serum of capybaras using the indirect fluorescent antibody test (IFAT ≥ 1:16). Blood, liver, heart, lymph nodes, and spleen tissues were collected and tested by polymerase chain reaction (PCR) for B1 gene and ITS1 region. The results showed that 61.5% (16/26) capybaras were seropositive to T. gondii. Titers of specific antibodies to T. gondii ranged from 1:16 to 1:512. Among the feral rodents studied, 7.7% (2/26) were PCR positive for B1 gene assay and 11.5% (3/26) were positive for ITS1 PCR assay; for both test, the prevalence was 15.4%. Liver, heart, and blood tissues were those which tested positive for the apicomplexan. Our findings show a high percentage of infection with T. gondii in asymptomatic capybaras. Based on those data, we hypothesize that the consumption of raw or undercooked capybara meat could be a source of infection for humans.     

Seroepidemiology of <Emphasis Type="Italic">Toxoplasma gondii</Emphasis> in pet dogs and cats in Beijing,China

Sera from 534 pet dogs and 335 pet cats from Beijing (China) were tested for anti-Toxoplasma gondii antibodies using an enzyme-linked immunosorbent assay or the latex agglutination test. The seropositivity by year, season, sex and age was analysed. Overall, 128 dogs (24.0%) and 50 cats (14.9%) had antibodies to T. gondii. When analysed by season, the highest seroprevalence was found in spring for dogs (31.3%) and cats (25.1%), and the differences in seroprevalence by season was statistically significant in cats (P<0.01) but not in dogs. The seroprevalence in male dogs (23.7%) and cats (15.1%) were slightly higher than their female counterparts (18.0% in dogs and 12.3% in cats). There was no obvious pattern of seropositivity or significant difference in different age groups in dogs or cats; nonetheless, a high proportion of dogs at 4 years of age were positive to T. gondii (31.8%) while cats with relatively high seropositivity rates were at 1 or 3.4 years of age (13.14%).     

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.     

Diagnosis of pulmonary infection with Toxoplasma gondii in immunocompromised HIV-positive patients by real-time PCR

The aim of the study presented here was to evaluate the use of PCR for improving the diagnosis of Toxoplasma gondii infection in immunocompromised hosts. Three hundred thirty-two bronchoalveolar lavage (BAL) fluid samples were analyzed by real-time PCR targeting a 529 bp element of T. gondii. In positive samples, the genotype of the parasite was determined by sequence analysis of the GRA6 gene. Positive results were achieved for 2% (7/332) of the samples tested. Genotyping was possible in two samples and revealed GRA6 type II T. gondii. PCR for detecting T. gondii in BAL samples should be performed in all immunosuppressed HIV-positive patients with symptoms of a systemic infection of unknown etiology. Trimethoprim-sulfamethoxazole prophylaxis does not exclude concomitant infection with T. gondii.     

Seroprevalence of and risk factors for Toxoplasma gondii antibodies among asymptomatic blood donors in Egypt

A cross-sectional study was conducted to evaluate the seroprevalence of and risk factors for Toxoplasma gondii antibodies in 260 blood donors seen at blood banks in Mansoura University Hospital, Egypt. Blood donors were interviewed about sociodemographic characteristics and risk factors for T. gondii infection. A blood sample was taken to document their T. gondii antibody status using enzyme-linked immunosorbent assay. Overall, 155 (59.6%) of 260 blood donors were positive for anti-T. gondii IgG antibodies. Multivariate logistic regression analysis showed a significant association between T. gondii seropositivity and eating meat by-products (luncheon/shawerma) (adjusted odds ratio [OR] 80.82 [95% CI 18.62–350.81], P < 0.0001) or being non-educated (adjusted OR 32.25 [95% CI 7.46–139.44], P < 0.0001). These findings highlight that T. gondii is prevalent among blood donors in Egypt.     

Calomys callosus (Rodentia: Cricetidae) trophoblast cells as host cells to Toxoplasma gondii in early pregnancy

The potential of the RH strain of Toxoplasma gondii to invade trophoblast cells of the cricetid rodent Calomys callosus in a congenital infection in the initial third of pregnancy was investigated in this study using morphological and immunocytochemical approaches. The animals were intraperitoneally inoculated on the 1st day of pregnancy and the infection was observed on day 7. Various numbers of parasites could be observed inside the parasitophorous vacuoles in trophoblastic cells under light and electron microscopy. The trophoblast cells showed characteristics of healthy cells, and no alteration other than parasite vacuoles in their cytoplasm could be detected. Polyclonal or monoclonal anti-T. gondii antibodies (respectively, anti-T. gondii components and the major surface parasite antigen p30) labeled both the parasite surface and parasitophorous vacuole membranes, regardless of the number of parasites inside the compartment. In addition, p30-containing trails were detected in the extracellular matrix surrounding trophoblastic cells similar to those found with other parasites during locomotion and the invasion process. Our results show the ability of T. gondii to infect trophoblast cells during the early blastocyst-endometrial relationship and open new possibilities for more accurate study of the invasion process of this parasite and the role of the trophoblast as an embryo defense barrier. Received: 30 December 1998 / Accepted: 7 February 1999     

Toxoplasma gondii Infection Suppresses House Dust Mite Extract-Induced Atopic Dermatitis in NC/Nga Mice

Purpose

Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite that infects humans and animals via congenital or postnatal routes, and it is found worldwide. Modulation of the immune system by parasite infection is proposed to suppress allergic inflammation. Growing evidences have shown that interleukin (IL)-10-producing regulatory B cells (B_regs) and CD4⁺CD25⁺FoxP3⁺ regulatory T cells (T_regs) induced by parasite infection play a critical role in allergic or autoimmune diseases because these cells regulate negatively cellular immune responses and inflammation. Currently, the role of IL-10-producing regulatory B cells in host immune response during T. gondii infection is unknown. In this study, we investigate whether T. gondii infection can suppress the development of unrelated atopic dermatitis (AD)-like lesions.

Methods

AD is a chronically relapsing inflammatory skin disease accompanied by severe itching; for this, we used NC/Nga mice, a well-known experimental model of systemic AD. Repeated exposure to Dermatophagoides farinae crude extract (DfE), known as a major environmental allergen, evokes AD-like skin lesions in NC/Nga mice under specific pathogen-free conditions. NC/Nga mice were intraperitoneally infected with 10 cysts of T. gondii.

Results

T. gondii infection significantly ameliorated AD-like skin lesions in NC/Nga mice. The subpopulation of B_regs and T_regs in the AD mice was expanded in the course of T. gondii infection. In addition, T. gondii infection inhibited Th2 and enhanced Th1 immune response in the DfE-treated AD mice.

Conclusions

We have experimentally demonstrated for the first time that T. gondii infection ameliorated AD-like skin lesions in a mouse model of AD. Our study could in part explain the mechanisms of how parasite infection prevents the development of allergic disorder. Therefore, these immunemechanisms induced by T. gondii infection may be beneficial for the host in terms of reduced risk of allergic immune reactions.     

Detection of toxoplasma antibodies in sera of Salmonidae by ELISA

Toxoplasma gondii is a protozoan parasite with a worldwide distribution. It is capable of infecting all warm-blooded animals. Toxoplasmosis was not considered a waterborne zoonoses, but recently, it has been reported in many marine mammals. Coastal pollution by sewage from humans and pets has been suggested as a source for toxoplasma infection in these animals. Recent reports of toxoplasmosis in marine mammals raise concern that cold-blooded marine animals are potential sources of T. gondii infection. Conversely, the increasing proclivity for eating fish, crabs, shrimp, and mollusks—raw, undercooked, smoked, or dried—facilitates zoonoses infections caused by protozoan microorganisms; and one of them is toxoplasma. Detection of antibodies against T. gondii can be achieved by different serological tests such as enzyme-linked immunosorbent assay (ELISA). To determine whether toxoplasmosis has a role in Salmonidae infection, which is the most common seafood in Shahrekord district, this research was carried out on 50 Salmonidae aged 4 months (weight 700 ± 200 g). ELISA was performed on serum samples for detecting T. gondii-specific immunoglobulin M (IgM) and immunoglobulin G (IgG). As a result, toxoplasmic IgM antibody was detected in five of 50 samples (cut-off value of ≥0.183). Based on these findings, we believe that Salmonidae may be susceptible to primary T. gondii infection. While there is still no evidence of T. gondii transmission from cold-blooded sea animals to human via consuming their meat or other products, further research can be done to prove the possibility of this hypothesis.     

<Emphasis Type="Italic">Toxoplasma gondii</Emphasis>: host–parasite interaction and behavior manipulation

Toxoplasma gondii is an obligate intracellular parasite that causes different lesions in men and other warm-blooded animals. Humoral and cellular immune response of the host against the parasite keeps the protozoan in a latent stage, and clinical disease ensues when immunological response is compromised. Brain parasitism benefits the parasite causing behavioral changes in the host, not only in animals but also in humans. Schizophrenia and epilepsy are two neurological disorders that have recently been reported to affect humans coinfected with T. gondii. Further studies based on host–parasite interaction in several wild or domestic warm-blooded species are still necessary in order to better understand parasitism and behavioral changes caused by T. gondii.     

Prevalence of <Emphasis Type="Italic">Toxoplasma gondii</Emphasis> antibodies in cats in maiduguri,northeastern nigeria

Cats play an important role in the spread of Toxoplasma gondii because they are the only animals that excrete resistant oocysts into the environment. Prevalence of T. gondii antibodies in cats in Maiduguri, Northeastern Nigeria was determined using the latex agglutination test (LAT). Thirty eight cats (36.2%) were seropositive using a cut off point of 1:64 with antibody titer ranging from 1:64 to 1:1024. Seroprevalence was higher in older animals and stray cats. Age and ownership status of cats were identified as risk factors but not gender or area of capture.     

Effect of hyperprolactinaemia on <Emphasis Type="Italic">Toxoplasma gondii</Emphasis> prevalence in humans

Recent studies have shown that hormones could induce anti-parasitic functions of the host immune system; thus, the aim of the present study was to estimate the seroprevalence of Toxoplasma gondii antibodies by an enzyme-linked immunosorbent assay in a Polish population of women and men with hyperprolactinaemia (n = 234) and hypoprolactinaemia (n = 41) and in a control group (n = 281) with the physiological level of prolactin (PRL). Women with hyperprolactinaemia revealed lower seroprevalence than those with normal PRL level (33.90% and 45.58%, respectively; p = 0.025). Detailed analysis of the results showed that twofold, threefold, fourfold and fivefold increase of the PRL concentration above the normal was correlated to the decrease of the T. gondii seroprevalence, but only in the group of women with a very high PRL level (>86 ng/ml) seroprevalence (12.50%) was significantly lower (p = 0.0004) than in the control subjects. These results confirm previously described suggestions on the relationship between hyperprolactinaemia and parasitic infection frequency. We postulate that a high level of PRL may be one of the important factors preventing T. gondii infection in women.     

First description of naturally acquired Tritrichomonas foetus infection in a Persian cattery in Spain

Tritrichomonas foetus has been identified as the causative agent of feline intestinal trichomonosis, characterized by clinical signs of chronic large bowel diarrhoea. This disease has been reported in cats from the USA, Europe and Australia. However, its epidemiology is still unclear. The aim of the present study was to describe T. foetus infection in a Persian cattery in Spain. T. foetus infection was sequentially diagnosed in 20 cats by direct faecal smear examined under the microscope, specific culture (In Pouch TF medium) and PCR. A standard coprological sedimentation method was also performed in order to screen for other intestinal parasites in all the cats included. In addition, sera were tested for IgG antibodies against Leishmania infantum, Toxoplasma gondii, and for the detection of feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). Five out of 20 cats were positive for T. foetus (25%), two of them by microscopy, culture and PCR and three by culture and PCR. No association was found between T. foetus infection and age or sex. L. infantum and T. gondii seroprevalence rates were 15% and 10%, respectively. The prevalence of FeLV p27 antigen and of FIV antibodies in the study population was zero. Cystoisospora spp. oocysts were detected in one cat. These preliminary results show that the transmission of T. foetus infection in cluster conditions may occur between asymptomatic cats and young or immunocompromised animals.     

Occurrence and genetic characterization of Toxoplasma gondii in naturally infected pigs

The protozoan Toxoplasma gondii is an obligate intracellular parasite that infects a wide range of warm-blooded vertebrates. The data about the occurrence of toxoplasmosis in slaughter pigs in the Slovak Republic are still missing. The aim of our study was to estimate the prevalence of toxoplasmosis in pigs from Slovakia during the period of 2006–2010 by ELISA and PCR methods. In sera of 970 slaughter pigs, 2.16% seropositivity to T. gondii was detected. In tissue samples of seropositive pigs the presence of T. gondii DNA was confirmed. In six monitored Slovak regions the seropositivity varied between 1.11 and 3.48%. The statistically significant differences were recorded between the Ko?ice and Pre?ov region. The seroprevalence of toxoplasmosis in sows (4.26%) was two times higher than that in slaughter pigs (2.06%) (OR = 2.12; 95% CI = 0.48–9.36). Presence of Toxoplasma gondii in tissues of seropositive pig isolates was confirmed by TGR1E and B1 genes and analysis of DNA polymorphism at SAG2 and ROP1 genes revealed the presence of virulent strain of genotype I in 85.7% of infected pigs and an avirulent strain (genotype II) in 14.3% of pigs.