Toxoplasma gondii: level of carriage in sheep of Marrakech region (Mnabha)

Toxoplasma gondii is an ubiquitous parasite with a prevalence variable from country to country. In Morocco very few studies were devoted to this prevalence. To fill this gap we were interested to study the epidemiology of this parasite and to know the level of carriage by the different vectors which are the sources of contamination in humans. The study was done by directly detecting the cysts in the cerebral tissue of the 50 sheep killed and destined for consumption. The results of this preliminary study show that 30% of the cases carry the cysts of T. gondii. To confirm this result and verify the virulence, cerebral specimens were inoculated into mice. These findings are encouraging to complete this study with serological tests and to look for the parasite in cows and goats of this region.     

Seroprevalence of Toxoplasma gondii infection in goats and sheep in Zimbabwe

Seroprevalence rates of Toxoplasma gondii anti-antibodies in adult goats and sheep from different parts of Zimbabwe were determined. A total of 225 (67.9%) of the 335 serum samples tested were positive for anti-T. gondii IgG antibodies with the indirect fluorescent antibody test. There were differences in antibody seroprevalences among communal land goats from the different agro-ecological zones (Natural regions llb and III: 80 and 96.7%, respectively; Natural region IV: 65.9%; Natural region V: 45%; and Natural region III had a significantly higher seroprevalence than IV and V. The highest seroprevalences found in Natural regions II b and Ill are likely to be linked to the existence of more households and hence the possibility of a higher concentration of domestic cats that increases the chances of environmental contamination with their faeces harbouring T. gondii oocysts. The seroprevalence rate in sheep from a large commercial farm (10%) was significantly lower than that of sheep reared under the communal grazing system (80%). Overall, significantly higher proportions of seropositive animals had antibody titres of 1:50 (34.2% of 225) and 1:100 (44% of 225) as compared to the 9.8% and 12% with antibody titres of 1:200 and > or =1:400, respectively.     

Seroprevalence of Toxoplasma gondii infection in domestic sheep and goats in Borno state,Nigeria

Serum samples were collected from 372 sheep and same number of goats from the three geopolitical zones of Borno state, Nigeria. The samples were tested for the presences of Toxoplasma gondii antibodies by enzyme-linked immunosorbent assay. Of these, 6.7% (25/372) and 4.6% (17/372) of sheep and goats, respectively, were found to be seropositive to T. gondii antibodies, both far less than the estimated global average of 31%. Results were statistically analyzed by chi-square (χ²) test. The results showed that age, environmental conditions, and farm location are the main determinants of prevalence of antibodies against T. gondii in the study area. Older animals (>3 years) are significantly more infected than younger animals (between 6 months and 1 year).The prevalence of anti T. gondii antibodies is significantly higher (P < 0.05) in both sheep and goats sampled from the southern zone than the northern zone. Animals from the southern zones are about four times more likely to be exposed to T. gondii infection than those in the northern zone, (sheep; odds ratio (OR) = 4.25, 95% confidence interval (CI) = 1.177–15.36, P = 0.018), (goats; OR = 4.38, 95% CI = 0.925–20.73, P = 0.04). Farm location in urban area was identified as a risk factor for sheep (OR = 6.06, 95% CI = 2.53–14.54, P = 0.000), and goats (OR = 4.99, 95% CI = 1.59–15.62, P = 0.004). Current data on prevalence of ovine and caprine T. gondii in Borno state are provided by the study as well as identifying the main risk factors associated with T. gondii infection in the area.     

Seroprevalence of Toxoplasma gondii infection in sheep and alpacas (Llama pacos) in Chile.

Serum samples from 408 sheep from different regions of Chile and 447 alpacas (Llama pacos) from the north of the country were tested for Toxoplasma gondii antibodies. The indirect haemagglutination test (IHAT) was used in both species and the indirect immunofluorescence test (IIFT) was also used on the sheep samples in order to compare the performance of the tests in that species. In both tests, titers ≥1:16 were considered diagnostically significant. Sera from 49 sheep (12%) were positive to T. gondii antibodies by the IHAT. When using the IIFT, 114 sheep sera (28%) were positive. The different results obtained in sheep sera between the tests were significant (p<0.0001). No differences were observed between geographical locations or sex of the sampled sheep regarding serological detection of T. gondii antibodies in sheep. As expected, adult sheep showed higher T. gondii reactivity than young sheep (p=0.0008). The corrected prevalence of toxoplasmosis in alpaca was 16.3% (32 positive out of 447). The rather low prevalence in alpacas may be associated with their extensive management as well as the extreme climatic conditions of The Andes which apparently would not be favorable for the transmission of the parasite.     

Seroprevalence of Toxoplasma gondii in captive neotropical felids from Brazil.

Seroprevalence of Toxoplasma gondii was determined in 865 captive neotropical felids from 20 states from Brazil, sampled from September 1995 to April 1997. Sera were tested by the modified agglutination test (MAT) using formalin-fixed whole tachyzoites and mercaptoethanol. Antibodies (MAT> or =1:20) to T. gondii were found in 472 of 865 (54.6%) cats: in 45 of 99 (45.9%) jaguarundis (Herpailurus yagouaroundi), in 97 of 168 (57.7%) ocelots (Leopardus pardalis), in 68 of 131 (51.9%) oncillas (L. tigrinus), in 35 of 63 (55.5%) margays (L. wiedii), in 1 of 8 (12.5%) Pampas-cat (Oncifelis colocolo), in 9 of 12 (75.0%) Geoffroys-cat (O. geoffroyi), in 134 of 212 (63.2%) jaguars (Panthera onca), and in 83 of 172 (48.2%) pumas (Puma concolor). Antibody titers were: 1:20 in 27 felids, 1:25 in 142 felids, 1:40 in 6 felids, 1:50 in 292 felids, and > or =1:500 in 5 felids. The high seroprevalence of T. gondii antibodies found in the present study suggested a widespread exposure of neotropical cats to T. gondii in zoos in Brazil. The results warrant an investigation on the mode of exposure and oocyst shedding by neotropical cats.     

Seroprevalence of maedi-visna in Canadian sheep.

A serological survey of Canadian sheep over one year of age was conducted to estimate the seroprevalence of maedi-visna. An indirect enzyme-linked immunosorbent assay was used. An analysis of 14,047 sera from 286 randomly selected flocks provided an estimate of the seroprevalence of 19% and a mean flock prevalence of 12%. Sixty-three percent of the sampled flocks had one or more seropositive sheep. There appeared to be higher prevalences in sheep in Quebec (40%) and Nova Scotia (27%). An increased prevalence with increased age and flock size was noted.     

Seroprevalence of Toxoplasma gondii antibodies from wild canids from Brazil

The prevalence of anti-Toxoplasma gondii antibodies was evaluated by the indirect immunofluorescent-antibody test in serum of 57 wild canids from three different species: Lycalopex gymnocercus, Cerdocyon thous and Dusicyon vetulus from the northeast, southeast and southern regions of Brazil. The prevalence was 35.1%, with 20 of the 57 canids demonstrating antibodies anti-T. gondii at dilutions of 1:16 in 2, 1:32 in 4, 1:64 in 2, 1:128 in 2, 1:256 in 6, 1:512 in 2 and 1:2048 in 2 animals. None of the D. vetulus were positive. Among the L. gymnocercus 11 (91.7%) of the 12 samples were positive and among C. thous 9 (60%) of the 15 had antibodies anti-T. gondii.     

Seroprevalence of Toxoplasma gondii antibodies in wild carnivores from Spain

Serum samples from 282 wild carnivores from different regions of Spain were tested for antibodies to Toxoplasma gondii by the modified agglutination test using a cut-off value of 1:25. Antibodies to T. gondii were found in 22 of 27 (81.5%) of Iberian lynx (Lynx pardinus), 3 of 6 European wildcats (Felis silvestris), 66 of 102 (64.7%) red foxes (Vulpes vulpes), 15 of 32 (46.9%) wolves (Canis lupus), 26 of 37 (70.3%) Eurasian badgers (Meles meles), 17 of 20 (85.0%) stone martens (Martes foina), 4 of 4 pine martens (Martes martes), 6 of 6 Eurasian otters (Lutra lutra), 4 of 4 polecats (Mustela putorius), 1 of 1 ferret (Mustela putorius furo), 13 of 21 (61.9%) European genets (Genetta genetta), and 13 of 22 (59.1%) Egyptian mongooses (Herpestes ichneumon). Serological results indicated a widespread exposure to T. gondii among wild carnivores in Spain. The high T. gondii seroprevalence in Iberian lynx and the European wildcat reported here may be of epidemiologic significance because seropositive cats might have shed oocysts.     

Seroprevalence of Toxoplasma gondii in cattle, sheep and goats slaughtered for food in Mazandaran province, Iran, during 2005

Serum samples from 290 cattle, 400 goats and 588 sheep slaughtered for food in various areas of the Mazandaran province, Iran were tested for antibodies to Toxoplasma gondii by the indirect immunofluorescence antibody test (IFAT), from December 2004 to April 2005. Antibodies to T. gondii were found in 30% (120/400) goats and 35% (206/588) sheep and 0% (0/290) cattle, at a dilution of 1:16 or more for goats and sheep and 1:128 or more for cattle. The highest titres observed in cattle, goats and sheep were 1:64 (0.7%), 1:128 (1%), 1:64 (2%), respectively. These results indicate that T. gondii antibodies are widespread in the animal populations and suggest that toxoplasmosis is a widely spread zoonotic infection in northern Iran.     

Seroprevalence and Toxoplasma gondii-IgG avidity in sheep from Lajes, Brazil

Sheep are important domestic animals in the Northeast region of Brazil due to their minimal rearing and maintenance costs, and to their production of both meat and milk. In animals, Toxoplasma gondii infection results in significant reproductive and economic losses. The epidemiology of toxoplasmosis in sheep in the Northeast of Brazil has been little studied; particularly in Rio Grande do Norte State. Sera from 102 sheep intended for consumption in Lajes were subjected to the Toxoplasma-ELISA test to detect anti-T. gondii specific IgG confirming a past infection. Of the total tested, 30 (29.41%) sera were positive for IgG with an increasing number of positive animals with advancing age. We used IgG avidity ELISA in 30 positive samples and observed that 6 (20%) had low avidity antibodies and 24 (80%) had high avidity antibodies. Epidemiological studies are required in order to identify sources of infection for these hosts as well as their impact on animal breeding in the region and risk of transmission to humans.     

Detection of T. gondii in tissues of sheep and cattle following oral infection.

It has been reported in the literature that cattle are more resistant to toxoplasmosis than sheep. Congenital disease due to T. gondii infection is rarely reported in cattle whereas the parasite is a major cause of abortion and neonatal mortality in sheep. It is believed that sheep remain chronically infected for life. Undercooked meat from infected sheep is an important source of infection for man. In contrast cattle are thought to harbour fewer parasite tissue cysts which may not persist for the lifetime of the host. Therefore, cattle are believed to pose less of a risk for human infection. In this study we examined the presence of T. gondii within a range of tissues in sheep and cattle at 6 weeks and 6 months following oral infection with 10(3) or 10(5) sporulated oocysts of T. gondii. The presence of parasite was determined by bioassay in mice and using polymerase chain reaction (PCR). The results from this study show that T. gondii was more frequently and consistently detected in sheep, in particular within brain and heart tissues, whereas parasites were not detected in the samples of tissues taken from cattle. T. gondii was more frequently detected in sheep given the higher dose of T. gondii. Examination of tissues at either 6 weeks or 6 months after infection did not appear to affect the distribution of T. gondii. The polymerase chain reaction has more specificity and sensitivity when detecting the presence of T. gondii in large animals than histological detection.     

Seroprevalence of Toxoplasma gondii and Neospora caninum in dairy goats from Romania

Little information is available about the seroprevalence of Toxoplasma gondii and Neospora caninum infections in goats in Romania and even in Europe. During 2007-2010, 735 serum samples were collected from dairy goats located in 4 historical regions (Cri?ana, Maramure?, Transylvania and Muntenia) of Romania. Sera were analyzed for T. gondii and N. caninum antibodies (IgG type) by enzyme-linked immunosorbent assay (ELISA) using two commercial kits (Chekit Toxotest Antibody ELISA and Chekit Neospora caninum Antibody ELISA; Idexx-Bommeli, Switzerland). Three hundred and eighty-eight out of 735 (52.8%) goats presented T. gondii antibodies and 12 out of 512 (2.3%) goats had N. caninum antibodies. The high seroprevalence of T. gondii suggests that infection with this parasite is common in dairy goats in Romania, and less common the infection with N. caninum. This is the first time that infection with N. caninum in goats has been reported in Romania and the first extended study on seroepidemiology of T. gondii.     

Prevalence of Toxoplasma gondii in cats from Colombia, South America and genetic characterization of T. gondii isolates

Cats are important in the epidemiology of Toxoplasma gondii infection because they are the only hosts that can excrete the environmentally-resistant oocysts. In the present study, prevalence of T. gondii was determined in serum, feces, and tissues of 170 unwanted cats from Colombia, South America. Antibodies to T. gondii were assayed by the modified agglutination test and found in 77 of 170 (45.2%) cats with titers of <1:5 in 93, 1:5 in eight, 1:10 in 17, 1:20 in 10, 1:40 in seven, 1:80 in four, 1:160 in eight, 1:320 in six, and 1:640 or higher in 17 cats. T. gondii oocysts were not found in feces of any cat as ascertained by bioassay in mice. Tissues (brain, heart, tongue) of 116 cats were bioassayed in mice or cats. T. gondii was isolated from tissues of 15 of the 42 cats with titers of 1:40 or higher and not from any of the 90 cats titers of 1:20 or lower. Of the 29 cats whose tissues were bioassayed individually, T. gondii was isolated from the tongues of nine, hearts of eight, and brains of five. Mice inoculated with tissues of 12 of 15 infected cats died of toxoplasmosis; with nine T. gondii isolates all infected mice died. Overall, 65 of 92 (70%) of T. gondii-infected mice died of toxoplasmosis. Genotyping of these 15 isolates using polymorphisms at the SAG1, SAG2, SAG3, BTUB, and GRA6 loci revealed that three isolates (TgCtCo1, 2, and 7) had Type I alleles and one isolate (TgCtCo8) had Type II allele at all five loci. Eleven isolates contained the combination of Type I and III alleles and were divided into three genotypes, with TgCtCo3,5,6,9,12,13 and 15 had alleles I, I, III, I and III, TgCtCo4,10,11 had alleles I, III, III, I and I, and TgCtCo14 had alleles I, III, III, III, and III, at loci SAG1, SAG2, SAG3, BTUB and GRA6, respectively. All infected mice from each group had identical genotype except one mouse infected with TgCtCo5 had a Type III allele at locus BTUB and a unique allele (u-1) at locus SAG1 indicating mixed infection for TgCtCo5, whereas the rest seven mice had a Type I alleles at both loci.     

北京地区被救护的野生鸟类弓形虫感染的血清学调查

本次调查运用改良凝集试验(MAT)技术对北京地区野生鸟类进行弓形虫感染的血清学调查。调查发现,在隶属于8目14科46种共131只的野生鸟类中,总体的血清阳性率为27.48%。鹳形目、鸮形目、鸡形目、雁形目、鹤形目、鹃形目和雀形目的阳性率分别为38.98%(23/59),21.05%(4/19),9.09%(2/22),30.77%(4/13),16.67%(1/6),33.33%(1/3)和0.00%(0/8),其中鹳形目与鸡形目鸟类的阳性率存在显著性差异(P<0.05)。按照食性分类,食肉性、杂食性和食鱼性鸟类的血清阳性率分别为36.76%(25/68),11.76%(4/34)和24.14%(7/29)。本研究首次对北京地区野生鸟类进行弓形虫感染的血清学调查,为野生鸟类弓形虫病的研究提供了重要的数据支持。     

Prevalence of Toxoplasma gondii in dogs from Colombia, South America and genetic characterization of T. gondii isolates

The prevalence of Toxoplasma gondii in 309 unwanted dogs from Bogotá, Colombia, South America was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT) and found in 52 (16.8%) of 309 dogs with titers of 1:20 in 20, 1:40 in six, 1:80 in 17, 1:160 in three, 1:320 in three, 1:1280 or higher in three. Some organs obtained after necropsy of dogs (hearts, tongues and brains, either separately or pooled) were used in bioassays carried out in mice (37 samples, of which 20 were assayed with separate organs and 17 were assayed with pooled organs), cats (pooled organs from six) and pooled organs of two dogs both in mice and cat. Mice receiving dog tissues were examined for T. gondii infection. Feces of cats that received dog tissues were examined for oocyst shedding. In total, T. gondii was isolated from tissues of 20 dogs (16 by bioassays in mice, 3 by bioassay in cats and 1 by bioassay in mice and cat). All infected mice from 7 of 17 isolates bioassayed in this host died of toxoplasmosis during primary infection. Only 10 of the 20 dogs whose tissues were bioassayed separately induced infections in mice. Interestingly, dog organs varied in their capacity to induce T. gondii infection in mice, hearts and tongues producing more positive results than the brain. The 20 T. gondii isolates obtained from seropositive dogs were PCR-RFLP genotyped using polymorphisms at 10 nuclear markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, a new SAG2 and an apicoplast marker Apico. Ten genotypes were revealed. These genotypes are different from the three predominant Types I, II and III lineages that are widely spread in North America and Europe. A new allele denoted u-3 at PK1 locus was identified in three isolates. This result supports previous findings that T. gondii population is highly diverse in Colombia.     

Seroprevalence of Neospora caninum, Toxoplasma gondii and Sarcocystis sp. in llamas (Lama glama) from Jujuy, Argentina

Llamas (Lama glama) are South American camelids described as intermediate hosts of Neospora caninum, Toxoplasma gondii and Sarcocystis aucheniae. Due to the potential role of these protozoan infections as a cause of economic losses, the aim of this study was to determine the seroprevalence for T. gondii, N. caninum and Sarcocystis sp. in llamas from Argentina. Serum samples from 308 llamas (>2 years old) were collected between 2005 and 2007. A total of 55 farms located in six departments of Jujuy province, Argentina were sampled. Presence of antibodies to N. caninum, T. gondii and Sarcocystis sp. was determined by the indirect fluorescent antibody test (IFAT). For Sarcocystis, 2 different bradyzoites-based antigens were prepared using S. aucheniae and S. cruzi. Sera were tested at dilutions 1:25 and 1:50. Antibodies to N. caninum were found in 4.6% serum samples. Fifty percent of departments and 14.5% of farms had positive animals. Antibodies to T. gondii were found in 30% of samples, distributed in 66% of departments and 43.6% of farms. Antibodies to Sarcocystis sp. were detected in 96% of samples and all departments and farms had positive animals, suggesting frequent contact between llamas and canids. Co-infection with N. caninum, T. gondii and Sarcocystis sp. was also recorded. Low seroprevalence of N. caninum in llamas detected in this study could be related to climatic and geographical conditions that limit cattle breeding activity, reducing the source of infection for definitive hosts. Seroprevalence of T. gondii and the positive animal distribution suggest frequent contamination of grass with felid faeces. In conclusion, this is the first report of combined seroprevalence for N. caninum, T. gondii and Sarcocystis sp. in llamas. Further studies are needed to determine the potential role of these protozoan infections as cause of abortion in Argentina as well as presence of these protozoans in llama meat used for human consumption.     

Seroprevalence of Toxoplasma gondii in captive felids in Thailand

The prevalence of antibodies against Toxoplasma gondii was investigated by commercial latex agglutination test kit (Toxocheck-MT 'Eiken') in captive felids maintained at zoos and a wildlife breeding center in different geographic regions of Thailand. Sera from a total of 136 captive felids of 12 species was obtained between 2002 and 2004. The overall seroprevalence of T. gondii was found in 21 of 136 (15.4%) felids. The titers varied from 1:64 (eight samples) to 1:8192 (one sample). The seroprevalence in different geographic regions were from 0% in the northern area to 23% in the southern area. This study suggested a widespread exposure of captive felids to T. gondii in Thailand and this is the first report of serologic analysis for T. gondii in captive felids in Southeast Asia.     

Seroprevalence of Toxoplasma gondii in wild pigs (Sus scrofa) from Spain

Sera collected from 507 hunter-killed wild pigs (Sus scrofa) between 1993 and 2004 from five geographic regions in northern Spain and seven regions in southern Spain were assayed for antibodies to Toxoplasma gondii by the modified agglutination test (MAT). Antibodies to T. gondii were detected in 185 (38.4%) of 507 pigs with titers of 1:25 in 71, 1:50 in 111 and > or =1:500 in 3; seroprevalence was significantly higher (P<0.05) in pigs from southern regions. Seroprevalence was density dependent; it was higher in pigs from high stocking per hectare and availability of forage. Statistically significant differences were not observed between T. gondii seroprevalence and hunting estates (open versus fenced), sex or age. Serological results indicate a widespread exposure to T. gondii among Spanish wild boars, suggesting that this population could represent a public health risk for persons that handle or consume raw or undercooked infected wild pig meat.     

Seroprevalence of Neospora,Toxoplasma gondii and Sarcocystis neurona antibodies in horses from Jeju island,South Korea

Parasite-specific antibody responses to Neospora spp. and Toxoplasma gondii, antigens were detected using the indirect fluorescent antibody test (IFAT) and immunoblot analysis in a korean equine population located on Jeju island, South Korea (126 degrees 12' E and 33 degrees 34' N). For comparison, a naturally infected Neospora hughesi horse and an experimentally inoculated T. gondii equid (pony) were used. In addition, all samples were tested for antibodies to Sarcocystis neurona by immunoblot analysis. A total of 191 serum samples from clinically normal horses were evaluated. Only 2% (4 out of 191) and 2.6% (5 out of 191) of the samples had showed reactivity at 1:100 using the IFAT for Neospora spp. and T. gondii, respectively. For T. gondii, two samples matched the antigen banding pattern of the positive control by immunoblot analysis. No sample was positive for N. hughesi by immunoblot analysis in this study. Overall, there was a 1% seroprevalence for T. gondii antibodies in the horses tested based on immunoblot analysis. The seroprevalence for S. neurona and N. hughesi antibodies was 0%. We concluded that these horses are either not routinely exposed to these parasites or antibody titers are not sufficiently elevated to be detectable. It is most likely the former explanation since Jeju island equine farms are isolated from the main land, and the horses were all less than 3 years of age. This na?ve population of horses could be useful when evaluating S. neurona serodiagnostic tests or evaluating potential S. neurona vaccines since exposure risks to S. neurona and closely related parasites are negligible.     

Seroprevalence of Toxoplasma gondii infection in Norwegian dairy goats

Background

Toxoplasma gondii is a major problem for the sheep industry as it may cause reproduction problems. The importance of T. gondii in Norwegian goat herds is uncertain, but outbreaks of toxoplasmosis in dairy goat farms have been recorded. The aim of this study was to describe the prevalence of T. gondii infection in Norwegian dairy goats by using serology.

Findings

Goat serum originally collected as part of two nationwide surveillance and control programmes between 2002 and 2008 were examined for T. gondii antibodies by using direct agglutination test. In total, 55 of 73 herds (75%) had one or more serologically positive animals, while 377 of 2188 (17%) of the individual samples tested positive for T. gondii antibodies.

Conclusions

This is the first prevalence study of T. gondii infection in Norwegian goats. The results show that Norwegian goat herds are commonly exposed to T. gondii. Nevertheless, the majority of goat herds have a low prevalence of antibody positive animals, which make them vulnerable to infections with T. gondii during the gestation period.