首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The consumption of ovine and caprine meat is considered one of the major transmission routes for Toxoplasma gondii infection in humans. The present study aimed at obtaining epidemiological and molecular data on T. gondii infection in small ruminants slaughtered or commercialized in Italy. Meat juices from 227 sheep and 51 goats were analyzed with a commercial ELISA and antibodies were detected in 28.6% sheep and 27.5% goats. A significant difference was highlighted between adult sheep and the other considered categories (young sheep, young and adult goats) concerning the detection of antibodies (94.1%; p-value = .008). Muscles of positives samples were submitted to molecular analysis, and T. gondii DNA was detected in 15 sheep and three goats; sequencing of B1 gene showed that all belonged to Type II. The present study confirmed small ruminants' meat as a possible source of T. gondii infection for consumers eating raw or undercooked meat, particularly in those countries where the consumption of sheep and goats' meat products is a traditional gastronomic habit.  相似文献   

2.
Control of the risk of human toxoplasmosis transmitted by meat   总被引:4,自引:0,他引:4  
One-third of the human world population is infected with the protozoan parasite Toxoplasma gondii. Recent calculations of the disease burden of toxoplasmosis rank this foodborne disease at the same level as salmonellosis or campylobacteriosis. The high disease burden in combination with disappointing results of the currently available treatment options have led to a plea for more effective prevention. In this review we describe Toxoplasma as a hazard associated with the consumption of undercooked meat or meat products and provide an analysis of the various options to control the risk of human toxoplasmosis via this source. Monitoring and surveillance programs may be implemented for pre-harvest control of Toxoplasma infection of farm animals, with the reduction of environmental oocyst load as the most important milestone. Alternatively, Toxoplasma safe meat can be obtained through simple post-harvest decontamination procedures, whereby freezing the meat may currently be the best option, although new technologies using irradiation or high-pressure treatment may offer promising alternatives. Influence of culture, religion and food handling customs may predispose a certain type of meat as an important source of infection, indicating that prevention needs to be tailored according to social habits in different regions in the world. The rationale for more stringent control measures to prevent toxoplasmosis both from disease and economic points of view is emphasized.  相似文献   

3.
Toxoplasma gondii is a protozoan parasite distributed globally. It causes toxoplasmosis, which is prevalent in animals, birds, and soil. T. gondii infection leads to severe pathological impacts in immunodeficient patients and congenital cases. This review indicated that high prevalence groups had close contact with cats, dogs, consumed uncooked raw fruits, meat, or vegetables and the socio-economic level noted to be one of the crucial factors that influence toxoplasmosis. Toxoplasmosis infection is high in low-income countries and low in developed European countries. Immunosuppressed groups and pregnant women were the highly vulnerable groups. The epidemiology of the parasite enumerated various routes of infections; but consumption of T. gondii contaminated food was the major route of disease transmission. However, the role of meat and meat-producing animals on disease transmission remained unclear. Unfiltered water acts as the primary reservoir of toxoplasmosis transmission. The diagnostic methods for determining T. gondii infection are not the gold standard, and different approaches have been prescribed to analyze the infected populations based on the organs affected. Although toxoplasmosis was reported before 70 years, no appropriate solution noted to be recommended to treat this disease. Based on the present analyses, it concluded that the eradication of toxoplasmosis would be challenging from the world until people''s socio-economic level is improved. The main aim of the present study was to analyze and update the disease transmission, epidemiology, and possible clinical interventions of toxoplasmosis.  相似文献   

4.
Consumption of sheep meat presents a risk of human contamination by Toxoplasma gondii. A nationwide study was conducted in France to evaluate the prevalence of Toxoplasma in fresh ovine meat. A sampling procedure was established to guarantee the representativity of consumption. As is the case for meat consumed, half of the samples were from France and half were imported from other countries. Animals were selected according to their age, as lamb (<12 months) represents 90% of the meat consumed. Available data for French samples allowed the selection of 16 districts distributed in seven areas according to their density of production. Diaphragms and hearts from 433 sheep were collected. Diaphragms were collected from 398 imported carcasses. Fluids from hearts and diaphragms were tested serologically. All hearts were bioassayed in mice and parasite isolates were genotyped using PCR-restriction fragment length polymorphism and microsatellite markers. Prevalence estimates were calculated, taking into account uneven distribution of production and age. For French meat, the effect of area, age and their interactions was evaluated. The overall estimate of Toxoplasma seroprevalence was 17.7% (11.6-31.5%) for lambs and 89% (73.5-100%) for adults (P < 0.0001). No significant difference was observed between imported and French meat. In France, seroprevalence in lambs showed an increasing North-western to Southern gradient. The proportion of French carcasses carrying live parasites according to bioassay results was estimated at 5.4% (3-7.5%) (45 genotype II; one genotype III). This study offers an accurate drawing of the toxoplasmosis pattern amongst sheep consumed in France and a model for a zoonosis hazard control survey.  相似文献   

5.
Toxoplasma gondii is an ubiquitous apicomplexan parasite which can infect any warm-blooded animal including humans. Humans and carnivores/omnivores can also become infected by consumption of raw or undercooked infected meat containing muscle cysts. This route of transmission is considered to account for at least 30% of human toxoplasmosis cases. To better assess the role of pork as a source of infection for humans, the parasite burden resulting from experimental infection with different parasite stages and different strains of T. gondii during the acute and chronic phases was studied. The parasite burden in different tissues was measured with a ISO 17025 validated Magnetic Capture-quantitative PCR. A high burden of infection was found in heart and lungs during the acute phase of infection and heart and brain were identified as the most parasitised tissues during the chronic phase of infection, independent of the parasite stage and the strain used. Remarkably, a higher parasite burden was measured in different tissues following infection with oocysts of a type II strain compared with a tissue cyst infection with three strains of either type II or a type I/II. However, these results could have been affected by the use of different strains and euthanasia time points. The parasite burden resulting from a tissue cyst infection was not significantly different between the two strains.  相似文献   

6.
In order to better understand the epidemiology of ovine toxoplasmosis in Sardinia, a serological survey was carried out on 22 flocks with no fertility problems. In total 1043 sera (9% of the 11,382 sheep raised in the flocks) were examined by means of a commercial ELISA kit. To verify the performance of ELISA test, 160 selected sera were tested again with a gold standard test (IFAT). Performance of the commercial ELISA kit was summarised in terms of Sensitivity (SE), Specificity (SP), positive and negative Likelihood Ratios (LR+; LR-). The overall seroprevalence with ELISA test was recorded as 51.3%. It was generally increasing according to age and was significantly lower in animals younger than one year (with the exception of < 1 month old lambs). This survey provided data on the current Toxoplasma gondii sheep seroprevalence in Sardinia, confirmed a still high parasite pressure and pointed out that consumption of raw or undercooked ovine meat can be considered a potential risk factor for humans.  相似文献   

7.
Toxoplasmosis is caused by the protozoan parasite Toxoplasma gondii. Consumption of raw or undercooked meat is the main risk factor for acquiring T. gondii infection in humans. Meat and meat products derived from goats and sheep are mainly consumed in Mongolia; however, there is limited epidemiological information on T. gondii infection in small ruminants in this country. The main objective of the present study was to investigate the seroprevalence of T. gondii in sheep and goats in Mongolia. The seroprevalence of T. gondii IgG antibodies was determined by an indirect enzyme-linked immunosorbent assay based on the recombinant antigens of dense granule protein 7 of T. gondii. A total of 1078 goat and 882 sheep blood samples were collected from 17 of 21 provinces and the capital city of Mongolia. Overall, the seroprevalence of T. gondii among the goat and sheep samples was 32% and 34.8%, respectively. The seroprevalence among goat samples was significantly higher in western (42.7%) and eastern (45.6%) regions compared with other regions (24%). Additionally, the seroprevalence among sheep was significantly higher in eastern regions (55.4%) compared with other regions (26%–33%). Age, but not sex, was considered a risk factor for T. gondii seropositivity in goats, whereas no statistically significant differences were observed in sheep for age or sex. In conclusion, the present study demonstrates the high seroprevalence of T. gondii in small ruminants in Mongolia. Our results highlight that country-wide control measures are required to minimize infections in livestock.  相似文献   

8.
The protozoan parasite Toxoplasma gondii is the causative agent of the zoonosis toxoplasmosis. In sheep and goats, it is one of the most prevalent causes of infectious abortion. Also in pregnant women, a primary infection can result in miscarriage. Humans acquire the infection either by ingestion of oocysts excreted by cats, the definitive host of the parasite, or by eating raw or undercooked meat from latently infected animals (Dubey & Beattie 1988). In Sweden, toxoplasmosis is a notifiable disease, and cases of clinical disease in humans as well as animals must be reported. In both veterinary and human medicine serological assays based on detecting the humoral antibody response of the host against the parasite are used as diagnostic tools. So far, solid phase assays, such as the indirect fluorescent antibody test (IFAT) and the enzyme-linked immunosorbent assay (ELISA), have been widely used to diagnose T. gondii infection in many species including cats, pigs and sheep (Dubey & Beattie 1988). However, both IFAT and ELISA require appropriate anti-species specific immunoglobulins (Ig) that must be carefully evaluated for each species prior to use. This makes these assays complicated and time consuming. Consequently, alternative, simpler methods that do not require specific antisera would be of great value. The direct agglutination test (DA), which is based on the principle that formalin-treated organisms agglutinate in the presence of specific IgG antibodies, is such an assay (Fulton & Turk 1959). The DA-test is widely used in human medicine as a screening test for T gondii infection but it has not yet been thoroughly evaluated for use in veterinary medicine (Uggla & Buxton 1990).  相似文献   

9.
Human serological profiles, and feline serological and fecal profiles were used to study the epidemiology of toxoplasmosis in Santa Clara County, California. The prevalence of human toxoplasmosis was determined to be 42.9% in a test population of 147 women. The prevalence of feline toxoplasmosis was indicated to be 34.8% based on serological analysis of 158 felines. Of 107 cats tested, 6.5% were shedding Toxoplasma gondii - like oocysts in their feces. Statistical analyses of questionnaire data indicated that the major infection sources for seropositive humans in this study were: (1) eating rare-medium cooked beef; (2) exposure to cats; and (3) working in an outside garden. Of these three sources, gardening represented the least risk. The data from questionnaires with reference to age, residence, and eating and toilet habits of owned felines were evaluated and found to show no significant statistical correlation with seropositivity. The infection sources for seropositive felines could not be determined. The plausible significance of feline-human interaction, human consumption of infected meat, and gardening habits is stressed.  相似文献   

10.
Foraging herbivores face twin threats of predation and parasite infection, but the risk of predation has received much more attention. We evaluated, experimentally, the role of olfactory cues in predator and parasite risk assessment on the foraging behaviour of a population of marked, free-ranging, red-necked wallabies (Macropus rufogriseus). The wallabies adjusted their behaviour according to these olfactory cues. They foraged less, were more vigilant and spent less time at feeders placed in the vicinity of faeces from dogs that had consumed wallaby or kangaroo meat compared with that of dogs feeding on sheep, rabbit or possum meat. Wallabies also showed a species-specific faecal aversion by consuming less food from feeders contaminated with wallaby faeces compared with sympatric kangaroo faeces, whose gastrointestinal parasite fauna differs from that of the wallabies. Combining both parasite and predation cues in a single field experiment revealed that these risks had an additive effect, rather than the wallabies compromising their response to one risk at the expense of the other.  相似文献   

11.
Infection with Toxoplasma gondii can have serious consequences in pregnant women and in immunocompromised individuals. For the farming industry it is a major cause of economic loss through neonatal mortality, particularly in sheep. In the following short review, David Buxton summarizes the main features of the complex immune response to the parasite and outlines how the first commercial vaccine was developed to control toxoplasmosis in pregnant sheep. Although the vaccine is inappropriate for use in human beings, the manner in which it induces immunity in sheep will prove vital to our understanding of the infection and the eventual development of a suitable vaccine to combat toxoplasmosis in people as well as in animals.  相似文献   

12.
The aim of this study was to determine the seroprevalence of anti-Toxoplasma gondii antibodies and factors associated with infection in goats, and to isolate protozoan strains in tissue samples from seropositive goats that were destined for human consumption in the state of Paraíba, northeastern Brazil. Serum samples from 229 slaughtered goats were tested using the indirect fluorescence antibody test (IFAT), with a cutoff point of 1:64. Epidemiological questionnaires were applied to the producers, to acquire information about the sanitary management used in their herds. Tissue samples from the animals were collected during slaughter, in order to perform bioassays in mice. The seroprevalence found was 21.39% (49/229), with antibody titers ranging from 1:64 to 1:32,768. The municipalities of origin, Patos (OR: 3.047; CI: 1.384–6.706) and Sousa (OR: 3.355; CI: 1.536–7.327), were considered to be factors associated with infection by T. gondii. Thirty-eight bioassays were performed in mice, using tissues from seropositive goats, with an isolation rate of 50% (19/38). There was no correlation between isolation rate and antibody titers. Only one mouse died, at 30 days post-infection, which demonstrated that the strains isolated had low virulence towards mice. It was concluded that there is high seroprevalence in goats in northeastern Brazil, as well as a high percentage of viable tissue cysts in slaughtered animals destined for human consumption. These results demonstrate that there is an imminent one health problem relating to toxoplasmosis, especially in the most populous municipalities in the study (Patos and Sousa), which were identified as factors associated with T. gondii infection in goats.  相似文献   

13.
Toxoplasmosis is a zoonosis caused by Toxoplasma gondii. Risk factors include consumption of undercooked meat, raw vegetables, and unfiltered water. This study aims to determine the seroprevalence and spatial distribution of toxoplasmosis in Middle Java, Indonesia, using an EcoHealth approach, combined with geographic information system (GIS). A total of 630 participants were randomly selected from seven districts. Each participant completed a questionnaire and provided a blood sample. The seroprevalence of toxoplasmosis was 62.5%. Of those who were seropositive, 90.1% were IgG+, and 9.9% were IgG+ and IgM+. Several risk factors were identified, including living at elevations of ≤200 m, compared with >200 m (OR = 56.2; P < 0.001), daily contact with raw meat (OR = 1.8; P = 0.001), unfiltered water (OR = 1.7; P = 0.003), and density of cats (OR = 1.4; P = 0.045). Visualizing the spatial distribution of seropositive respondents highlighted clustering in lowland areas. This study highlighted that Middle Java has a high prevalence of toxoplasmosis and identified some important environmental, ecological, and demographic risk factors. When researching diseases, such as toxoplasmosis, where animal hosts, human lifestyle, and environmental factors are involved in transmission, an EcoHealth method is essential to ensure a fully collaborative approach to developing interventions to reduce the risk of transmission in high-risk populations.  相似文献   

14.
Toxoplasmosis is considered as an important risk factor for bad obstetric history (BOH) and one of the major causes of congenitally acquired infections. The present study aimed to estimate the seropositivity of T. gondii infection and associated risk factors among the attendees of high risk pregnancy and low risk antenatal care clinic of Minia Maternity and Pediatric University Hospital, Minia, Egypt. The study was carried out from April 2013 to April 2014 through 2 phases, the first phase was case-control study, and the second phase was follow-up with intervention. A total of 120 high risk pregnant and 120 normal pregnant females were submitted to clinical examinations, serological screening for anti-Toxoplasma IgM and IgG antibodies by ELISA, and an interview questionnaire. Seropositive cases were subjected to spiramycin course treatment. The results showed that the seroprevalence of toxoplasmosis in high-risk pregnancy group was 50.8%, which was significantly different from that of normal pregnancy group (P<0.05). Analysis of seropositive women in relation to BOH showed that abortion was the commonest form of the pregnancy wastage (56.5%). The high prevalence of T. gondii seropositive cases was observed in the age group of 21-30 years. Post-delivery adverse outcome was observed in 80.3% of high-risk pregnancy group compared to 20% of normal pregnancy group. There was a statistically significant relationship between seropositivity and living in rural area, low socioeconomic level, and undercooked meat consumption (P<0.05). Serological screening for anti-Toxoplasma antibodies should be routine tests especially among high-risk pregnant women.  相似文献   

15.

Background

Toxoplasmosis is an important, widespread, parasitic infection caused by Toxoplasma gondii. The chronic infection in immunocompetent patients, usually considered as asymptomatic, is now suspected to be a risk factor for various neurological disorders, including epilepsy. We aimed to conduct a systematic review and meta-analysis of the available literature to estimate the risk of epilepsy due to toxoplasmosis.

Methods

A systematic literature search was conducted of several databases and journals to identify studies published in English or French, without date restriction, which looked at toxoplasmosis (as exposure) and epilepsy (as disease) and met certain other inclusion criteria. The search was based on keywords and suitable combinations in English and French. Fixed and random effects models were used to determine odds ratios, and statistical significance was set at 5.0%.

Principal findings

Six studies were identified, with an estimated total of 2888 subjects, of whom 1280 had epilepsy (477 positive for toxoplasmosis) and 1608 did not (503 positive for toxoplasmosis). The common odds ratio (calculated) by random effects model was 2.25 (95% CI 1.27–3.9), p = 0.005.

Conclusions

Despite the limited number of studies, and a lack of high-quality data, toxoplasmosis should continue to be regarded as an epilepsy risk factor. More and better studies are needed to determine the real impact of this parasite on the occurrence of epilepsy.  相似文献   

16.
《Small Ruminant Research》2010,91(1-3):34-40
Acetyl-CoA carboxylase (ACACA) is the rate-limiting enzyme in the biosynthesis of palmitic acid and long-chain fatty acids. The dietary intake of palmitic acid, which represents approximately 22% of sheep milk fatty acids, increases low-density lipoprotein (LDL) levels and the risk of developing human cardiovascular diseases. Following the candidate gene approach for improving sheep milk composition, and as a first step in assessing the possible influence of the ovine ACACA gene on milk fatty acid composition and its potential use as an animal genetic model of human atherosclerosis disease, we present here an investigation into the genetic variability of the ovine ACACA gene. We sequenced approximately 6.6 kb of ovine ACACA cDNA, including most of the coding sequence of the protein (except 348 bp), in Spanish Churra sheep. A total of 22 synonymous single nucleotide polymorphisms (SNPs) were identified in the analysed sequence, which were genotyped in a set of eight sheep breeds with different productive aptitudes (dairy, meat and double aptitudes). Two of the SNPs identified, SNP03 (c.1450T>C) and SNP15 (c.5134T>C), which appeared to be breed-specific variations, were situated in the gene sequence coding for the biotin-carboxylase (BC) and acetyl-CoA carboxyltransferase (ACCT) domains of the protein, respectively. Particularly interesting is SNP12 (c.4579G>A), which displayed higher frequencies in the dairy-specialised breeds relative to the meat-producing breeds. Moreover, in the dairy breeds studied, the frequency of this SNP showed a positive correlation with the degree of dairy specialisation. A previously described alternative splicing site (Ser-1200) affecting an important regulatory region of the enzyme was observed in one of the Churra animals. Despite the high genetic variability observed in this gene, none of the identified SNPs caused an amino acid change. However, these polymorphisms could be in linkage disequilibrium with other mutations showing a functional effect on the ACACA enzyme. Hence, the characterisations of the allelic variants reported herein lay the groundwork for evaluation of the potential use of these SNPs as genetic markers of fat content and fatty acid composition in sheep dairy products.  相似文献   

17.
Toxoplasmosis is caused by Toxoplasma gondii, an apicomplexan parasite that is able to infect any nucleated cell in any warm-blooded animal. Toxoplasma gondii infects around 2 billion people and, whilst only a small percentage of infected people will suffer serious disease, the prevalence of the parasite makes it one of the most damaging zoonotic diseases in the world. Toxoplasmosis is a disease with multiple manifestations: it can cause a fatal encephalitis in immunosuppressed people; if first contracted during pregnancy, it can cause miscarriage or congenital defects in the neonate; and it can cause serious ocular disease, even in immunocompetent people. The disease has a complex epidemiology, being transmitted by ingestion of oocysts that are shed in the faeces of definitive feline hosts and contaminate water, soil and crops, or by consumption of intracellular cysts in undercooked meat from intermediate hosts. In this review we examine current and future approaches to control toxoplasmosis, which encompass a variety of measures that target different components of the life cycle of T. gondii. These include: education programs about the parasite and avoidance of contact with infectious stages; biosecurity and sanitation to ensure food and water safety; chemo- and immunotherapeutics to control active infections and disease; prophylactic options to prevent acquisition of infection by livestock and cyst formation in meat; and vaccines to prevent shedding of oocysts by definitive feline hosts.  相似文献   

18.
Introduction. Mammomonogamus laryngeus is a nematode parasite that is usually found in the larynx of mammals in the tropics, especially in cattle, sheep and cats. Objective. The prevalence of M. laryngeus was determined in cattle brought to an abattoir as an indicator of its prevalence in the general population. Materials and methods. The present study was undertaken in the municipality of La Tebaida, Quindio, Colombia, to determine the presence of M. laryngeus infection in cattle brought to a local abattoir between December and February 2009. The tracheae and lungs of 500 slaughtered cattle were examined. Results. Parasite prevalence was 14.8% (n=74). The majority of worms were located on aryteno-epiglottic folds, but never in the tracheae or bronchi. The infection rate was highest (47%) in 2 to 2.5 year old animals. In infected animals, an average of 6.4 parasite pairs was found, with higher numbers in older animals. The prevalence of infection in cattle was greater than seen in the provinces of Valle del Cauca (10.0%), Quindío(3,0%) pr Caquetá (1.2%). Conclusions. Reports of this parasite in cattle indicate its circulation throughout Colombia and recommend surveillance studies where cattle are raised and prepared for human consumption.  相似文献   

19.
Toxoplasma gondii: from animals to humans   总被引:23,自引:0,他引:23  
Toxoplasmosis is one of the more common parasitic zoonoses world-wide. Its causative agent, Toxoplasma gondii, is a facultatively heteroxenous, polyxenous protozoon that has developed several potential routes of transmission within and between different host species. If first contracted during pregnancy, T. gondii may be transmitted vertically by tachyzoites that are passed to the foetus via the placenta. Horizontal transmission of T. gondii may involve three life-cycle stages, i.e. ingesting infectious oocysts from the environment or ingesting tissue cysts or tachyzoites which are contained in meat or primary offal (viscera) of many different animals. Transmission may also occur via tachyzoites contained in blood products, tissue transplants, or unpasteurised milk. However, it is not known which of these routes is more important epidemiologically. In the past, the consumption of raw or undercooked meat, in particular of pigs and sheep, has been regarded as a major route of transmission to humans. However, recent studies showed that the prevalence of T. gondii in meat-producing animals decreased considerably over the past 20 years in areas with intensive farm management. For example, in several countries of the European Union prevalences of T. gondii in fattening pigs are now <1%. Considering these data it is unlikely that pork is still a major source of infection for humans in these countries. However, it is likely that the major routes of transmission are different in human populations with differences in culture and eating habits. In the Americas, recent outbreaks of acute toxoplasmosis in humans have been associated with oocyst contamination of the environment. Therefore, future epidemiological studies on T. gondii infections should consider the role of oocysts as potential sources of infection for humans, and methods to monitor these are currently being developed. This review presents recent epidemiological data on T. gondii, hypotheses on the major routes of transmission to humans in different populations, and preventive measures that may reduce the risk of contracting a primary infection during pregnancy.  相似文献   

20.
Sheep and goats are among other herbivorous animals that serve as intermediate hosts (containing the larval stage Cysticercus tenuicollis) of Taenia hydatigena tapeworm. This infection can lead to serious complications or cause death. The genetic diversity and epidemiological significance of cysticercosis due to T. hydatigena is poorly understood. We examined 11,651 goats and 23,542 sheep slaughtered at the municipal abattoir in Makkah, for C. tenuicollis infection. The resulted DNA sequences were compared with previously available sequences from different hosts. Phylogenetic analysis and Pairwise nucleotide variations of cox1 gene were performed. Sheep and goats revealed infection rates of (4.95%) and (4.75%) respectively. DNA sequence analysis of all isolates from both sheep and goats showed that the total haplotypes number was 7. T. hydatigena population with high haplotypes diversity values. The nucleotide diversity was low, while Tajima’s D and Fu’s tests were negative (with no statistical significance). The present work will give valuable information regarding the prevalence and implementation of control and prevention measures of C. tenuicollis.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号