Prevalence of Toxoplasma gondii infection in Belgian house cats

Five hundred and sixty seven sera of healthy house cats aged 3 months to 7 years, were examined for the presence of anti-toxoplasma antibodies by indirect immunofluorescence assay and compared to SAG1 and TLA enzyme linked immunosorbent assays as alternative test. Twenty-five percent of cats tested positive for IgG and/or IgM. Seroprevalence increased with age from 2% below 12 months of age up to 44% at age 7. Sensitivities of SAG1 and TLA ELISA were 84.1% and 88.6%, respectively. Peak levels in seroprevalence were correlated to increased IgG titers in TLA ELISA. Our results suggest that T. gondii infections are common in house cats and that there is a high chance for a negative cat to seroconvert in its second life-year.     

Seroprevalence of Toxoplasma gondii infection in stray and household cats in Tehran

The prevalence of anti-Toxoplasma gondii specific IgG in stray and household cats in Tehran was determined by Indirect Fluorescent Antibody Test (IFAT) on serum samples from 100 cats (50 stray and 50 households). Overall infection rate was 63%. The infection rate in stray cats (90%) was significantly higher (p<0.001) than that of household cats (36%). Last serum positive dilutions varied from 1: 32 to 1: 512 titres in which the highest percentage (27%) was for 1:256 and the least (4.8%) was at 1:32. The rate of infection between male and female cats of both groups was not significantly different; 90.3% versus 89.5% for male and female in stray cats, respectively. Different sexes of household cats were seropositive at the same rate (36%). A high positive correlation (r(2)=0.97) between age and the rate of infection was observed. The prevalence of Toxoplasma gondii infection in cats in Tehran was high, especially in stray cats which are probably the main source of Toxoplasma infection in this area.     

北京地区犬猫弓形虫病血清学调查

比较了酶联免疫吸附试验（ELISA）和乳胶凝集试验对犬猫进行龚地弓形虫（Toxoplasma gondii）抗体检测的结果.在66只犬猫的血清中,ELISA方法检测的阳性率为24.0%,乳胶凝集试验阳性率为21.0%,二者的检测结果差异不显著（P＞0.05）.后采用ELISA方法对北京地区家养的159只犬和128只猫进行了弓形虫IGg抗体的检测,共有21只犬（13.21%）和18只猫（14.06%）检测结果为阳性.1岁以下犬（3.70%）、猫（4.35%）低于1至3岁犬（11.29%）和猫（6.98%）的感染率.3～6岁犬猫的感染率分别是27.27%和16.22%,6岁以上犬（30.0%）、猫（32.0%）的感染率最高.不同性别之间感染无明显差异（P＞0.05）.     

Seroprevalence of Toxoplasma gondii and Neospora caninum infection of cats in Hungary

Blood samples were collected from 330 cats in Hungary in order to evaluate their seroconversion to Toxoplasma gondii and Neospora caninum using the indirect fluorescent antibody test (IFAT). The overall prevalence of toxoplasmosis was 47.6%, the prevalence being 22.4% among urban, 50% among suburban and 61.3% among rural animals. Significantly more cats had high IFAT titres (1:640 to 1:5120) in the countryside. Female cats were more frequently infected with T. gondii than males (53.3% vs. 39.3%), and seropositivity increased with the age of animals. The prevalence (0.6%) and titre (1:40) of antibodies to N. caninum was low. Sixty-two cats were also screened for seroconversion to feline infectious peritonitis (FIP) virus. Higher titres to T. gondii were more frequently detected among FIP-positive cats, but this difference was non-significant due to the small number of cats with concurrent infection.     

Serological survey of Toxoplasma gondii infection in domestic cats from northeastern Portugal

Cats are very important hosts in the epidemiological cycle of Toxoplasma gondii, a zoonotic protozoan parasite that can infect humans and many other animal species worldwide. We report a serological survey of antibodies to T. gondii in domestic cats from northeastern Portugal, by means of the modified agglutination test. Three cats had titres of 20 (3.9%), 18 had titres of 40 (23.7%) and 55 animals had titres of > or =800 (72.4%). Results of three seropositive kittens with less than 4 months were not considered for determining the seroprevalence of infection, which was found to be 35.8% (73/204). Differences in the seroprevalence levels were not statistically significant between males (35.6%) and females (36.0%) or pure non-European (26.7%) and European or mixed-breed cats (39.6%). Animals aged 36-71 months and 72-180 months had the highest seroprevalences of infection, i.e. 51.7% and 51.2%, respectively, which significantly differ from the values observed in cats with 2-11 months (14.6%) and 12-35 months (26.3%). Infection levels were also significantly different between cats that lived totally indoors (7.7%) and those that had access to outdoors (45.4%), as well as between cats living alone (13.8%) and those that had contact with other cats (39.4%). Seroprevalence values in cats fed only commercial canned or dried food (22.9%) and animals whose diet included raw or undercooked viscera and/or meat (53.5%) were also significantly different. Furthermore, considering only 108 cats, differences of seropositivity to T. gondii were significant between feline immunodeficiency virus infected and non-infected animals, but this was not observed for feline leukaemia virus. Age, habitat and diet were identified as risk factors for the feline T. gondii infection by logistic regression analysis. Some control measures are suggested based on these findings.     

Attempted transmission of Toxoplasma gondii infection from pregnant cats to their kittens

Sixteen 1- to 7-week-old pregnant specific-pathogen free cats were inoculated orally with Toxoplasma gondii cysts. Fetuses and neonatal kittens were examined for toxoplasma infection by inoculating suspensions of their tissues into mice. Toxoplasma gondii was not isolated from 23 fetuses and 16 newborn kittens from 13 queens. Six (3 litters) of the 15 kittens from the 3 remaining queens were killed on the day of or a day after birth, and the remaining 9 kittens were housed with their mothers for 7 to 33 days. None of the 9 kittens from the 2 litters examined between 0 and 33 days of age was infected with T gondii. In the other litter, T gondii was isolated from 3 kittens killed at 9, 16, and 22 days of age but not from 3 littermates killed on days 1, 1, and 22. Internal organs from the 3 kittens with proved toxoplasma infectivity in mice were examined histologically. Multifocal granulomatous encephalitis, hepatitis, nephritis, myocarditis, myositis, and interstitial pneumonia were found in all 3 kittens. Toxoplasma forms were demonstrated histologically in the tissues of 2 of these kittens. The mode of toxoplasma infection in newborn kittens was not determined but did not appear to be either transplacental or via fecal contamination from oocysts excreted by the mother cat. Evidence obtained in these experiments suggests that transplacental toxoplasma infection in the cat is not an important epidemiologic factor in perpetuation of the disease in the feline population.     

Seroprevalence and risk factors for Toxoplasma gondii infection in domestic cats in The Netherlands

Cats, as definitive hosts, play an important role in the transmission of Toxoplasma gondii. To determine the seroprevalence and risk factors for T. gondii infection in Dutch domestic cats, serum samples of 450 cats were tested for T. gondii antibodies by indirect ELISA. Binary mixture analysis was used to estimate the seroprevalence, the optimal cut-off value and the probability of being positive for each cat. The seroprevalence was estimated at 18.2% (95% CI: 16.6-20.0%) and showed a decrease with age in very young cats, an increase up to about 4 years old and ranged between 20 and 30% thereafter. Hunting (OR 4.1), presence of a dog in the household (OR 2.1), former stray cat (OR 3.3) and feeding of raw meat (OR 2.7) were identified as risk factors by multivariable logistic regression analysis. Prevalence differences were estimated by linear regression on the probabilities of being positive and used to calculate the population attributable fractions for each risk factor. Hunting contributed most to the T. gondii seroprevalence in the sampled population (35%).     

Relation between the occurrence of antibodies against Toxoplasma gondii and clinical findings in cats

Within a three-year period, 178 clinically healthy and 442 sick cats (patients of the Clinic for Small Animal Diseases of the University of Veterinary Medicine, Brno) were examined for the presence of antibodies to Toxoplasma gondii. Antibodies to T. gondii were detected in 34.8% of the animals without clinical signs of the disease and in 54.3% of the sick cats (P less than 0.01). Compared with the group of clinically healthy cats, the specific antibodies occurred significantly more frequently in the cats suffering from diseases of the digestive tract (P less than 0.01), particularly in those with acute gastroenteritis, and in those having liver disorders (P less than 0.01; P less than 0.05). A statistically significantly higher occurrence of antibodies to T. gondii was also recorded in the cats with disorders of the nervous system (P less than 0.05; P less than 0.01), particularly in those with symptoms of extraordinary aggressivity at the age span from four months to three years. Enlarged lymph nodes were found out in 44% of the cats having antibodies to T. gondii. This is 15% more than the average for the investigated set of animals, which is a statistically significant dependence (P less than 0.01).     

Toxoplasma gondii antibody in domestic cats in Melbourne

OBJECTIVES: To determine the prevalence of Toxoplasma gondii in a population of domestic cats in Melbourne. DESIGN: An ELISA assay was used to measure T gondii antibody titres in 103 cats from north-eastern Melbourne. Cats were obtained from outer suburban areas (less than 30 km from the Melbourne GPO) and from rural areas (more than 30 km from the Melbourne GPO). RESULTS: Thirty-nine percent of cats were positive for T gondii IgG. Older cats tended to have higher antibody titres. There was no significant difference in the T gondii antibody titres between males and females, or between cats living in urban areas and cats from rural areas. CONCLUSIONS: A significant proportion of cats from Melbourne have been exposed to Toxoplasma. This may have implications for the health of wildlife and humans.     

猫源弓形虫虫株的分离与鉴定

将猫的心、脑、舌用盐酸-胃蛋白酶溶液消化处理后接种小白鼠，经连续传代分离弓形虫虫株，用特异PCR方法对所分离的虫株进行了鉴定。分别从24只猫的样品中分离出8株弓形虫虫株，用弓形虫种特异的PCR方法对8个虫株进行鉴定。均得到弓形虫的特异条带；测序证明所扩增出的DNA片段确为弓形虫的核糖体DNA第一 内转录间隔区（ITS1）部分序列。研究结果表明，将动物组织用盐酸-胃蛋白酶溶液消化处理后接种小白鼠是一种分离弓形虫虫株较为理想的方法．特异PCR方法能准确、快速地鉴定弓形虫虫株。     

Serodiagnosis of Toxoplasma gondii infection in cats by enzyme-linked immunosorbent assay using recombinant SAG1

The gene encoding surface antigen 1 (SAG1, P30) of Toxoplasma gondii (T. gondii) was cloned into the plasmid pGEX-4T-3 and subsequently expressed in Escherichia coli (E. coli) as a glutathione-S-transferase (GST) fusion protein. The recombinant SAG1 (rSAG1) was refolded using 8M urea solution followed by dialysis and thereafter evaluated in an enzyme-linked immunosorbent assay (ELISA) for serological diagnosis of toxoplasmosis. The test sera were adsorbed with GST to block non-specific reactivity to the GST-SAG1 fusion protein. The ELISA with rSAG1 was able to differentiate very clearly between sera from cats or mice experimentally infected with T. gondii and sera from normal cats or mice. The ELISA detected no cross-reactivity with sera from mice experimentally infected with the closely related parasite Neospora caninum (N. caninum). Some 193 cat sera were tested for antibodies to T. gondii, out of which 40 (20.7%) reacted positively by ELISA with the rSAG1 while another 79.3% cats reacted negative to the assay. Both positive and negative sera were confirmed by Western blot analysis. The results of ELISA were in agreement with those of a commercially available latex agglutination test (LAT) kit, although the former had higher titers than the latter.     

Toxoplasma gondii infection in Polish farmed mink

The aim of this study was to determine the seroprevalence of Toxoplasma gondii antibodies in Polish farmed mink according to way of feeding as well as to confirm the role of toxoplasmosis in reproductive losses in mink farms. The serological examinations were carried out on 961 mink randomly selected from 12 Polish farms. Blood sera were examined for the presence of T. gondii antibodies with the use of the latex agglutination test. The examinations for the presence of T. gondii in organ tissues were performed on five neonatal mink kits with the use of immunofluorescence method. In total 133 (13.9%) out of 961 examined mink had T. gondii antibodies. In large farms the seropositivity was lower (2.9%), than in small farms (26.33%) (P < 0.001). Significant difference was found in seroprevalence according to way of feeding. In farms feeding fish, percentage of seropositivity was lower (2.2%), than in farms based on non-frozen slaughter offal (43.4%). Titres of T. gondii antibodies were usually lower than 120 IU/ml. Using the immunofluorescence method, T. gondii was detected in impression smears from liver and brain of two neonatal mink kits derived from one seropositive female.     

Prevalence of Toxoplasma gondii infection in raccoons.

Serum samples from 427 raccoons (93 from Pennsylvania, 45 from New Jersey, 72 from South Carolina, 68 from Virginia, 30 from Iowa, and 119 from Ohio) were evaluated for Toxoplasma gondii antibodies in dilutions of 1:25, 1:50, and 1:500. The distribution of T gondii antibody titers was less than 1:25 for 212 raccoons (49.6%), 1:25 for 34 raccoons (7.9%), 1:50 for 117 raccoons (27.4%), and greater than or equal to 1:500 for 64 raccoons (14.9%). Tissue cysts were seen in the liver, and tachyzoites were in the brain of a raccoon with abnormal neurologic signs and concurrent infection with canine distemper virus. Organisms in the liver were stained with anti-T gondii serum, and the raccoon had a T gondii titer of 1:160 in the agglutination test.