Survey of the parasite Toxoplasma gondii in human consumed ovine meat in Tunis City

First Molecular and Phylogenetic Identification of Toxoplasma Gondii in Sheep Liver Intended for Human Consumption in Northern Tunisia

The aim of this study was to estimate the molecular infection prevalence of Toxoplasma gondii in sheep liver tissues destined for human consumption. A total number of 224 liver tissues were collected from slaughtered sheep in Sejnane slaughterhouse (Northwest Tunisia). PCR was used to detect T. gondii DNA in liver tissues followed by phylogenetic analysis of amplicons. The phylogenetic tree was then constructed to compare the partial sequences of the ITS1 gene with GenBank sequences.The overall molecular prevalence of T. gondii in sheep livers was 25% (56/224). The highest molecular prevalence of T. gondii was recorded in sheep aged of less than one year old (27.3%; 52/190). Infection prevalence was significantly higher in Noire de Thibar breed (33%; 17/51) compared to other breeds (p = 0.023). There were no differences depicted according to sheep's gender. The T. gondii sequences obtained in the present study (GenBank accession numbers: OR509829 and OR509830) were 98.40-100% homologous to T. gondii sequences published in the GenBank. These results highlight a high level of T. gondii contamination of tissues destined for human consumption. Further studies are needed to improve our knowledge on different genotypes of T. gondii that infect Tunisian sheep population.

Seroprevalence of Toxoplasma gondii and Associated Risk Factors among Pregnant Women in Algeria

Toxoplasma gondii is an obligate intracellular protozoan parasite affecting all warm-blooded vertebrates, including humans. Infections in humans can lead to severe clinical manifestations in pregnant women and immunocompromised patients. The aim of the present study was to assess seroprevalence of T. gondii infection and to identify the associated risk factors among pregnant women from southern Algeria. A cross-sectional study was conducted from March 2021 to May 2022 among 1,345 pregnant women. A structured questionnaire was used to obtain information on risk factors associated with infection. Participants were screened for anti T. gondii IgG and IgM antibodies using the enzyme-linked fluorescent assay. The overall IgG and IgM seroprevalence was 13.6% and 0.89%, respectively. A significant association was found between seroprevalence of anti T. gondii IgG and history of spontaneous abortion (P = 0.016). Moreover, an increasing trend of seroprevalence was detected in the autumnal season (P = 0.030), and eating raw or undercooked meat was found to be significantly associated with anti-T. gondii IgM seropositivity (P = 0.002). Multivariate analysis showed that women who had experienced spontaneous abortion, regularly ate undercooked meat, and used bottled water in summer were more likely to contract infection with T. gondii. The majority (86.4%) of the studied pregnant women were serologically negative for toxoplasmosis and hence were susceptible to primary acute infection during pregnancy and possible fetal anomalies. Therefore, health education and awareness of the disease and its transmission to women, especially during pregnancy, is imperative.

Comparison of Direct and Indirect Detection of Toxoplasma gondii in Ovine Using Real-Time PCR, Serological and Histological Techniques

Toxoplasma gondii is a zoonotic pathogen and the ingestion of tissue cysts by consumption of lamb or mutton has been identified as a possible cause of infection in humans. Many serological surveys in sheep have been performed, showing relevant serological rates; however, while the detection of antibodies indicates an exposure to T. gondii, this does not necessarily imply the presence of tissue cysts in edible tissue. The current study aims to provide further understanding on the occurrence of T. gondii in sheep muscles and the strength of correlation between serological positivity and presence of the parasite in sheep. From 349 sheep, samples (i.e., blood, heart and diaphragm) were collected and subjected to ELISA tests, real-time PCR and histological tests. Despite the high seroprevalence, T. gondii DNA was detected in the heart and/or the diaphragm from 13 out of the 349 tested sheep (3.7%); all were adults (13/191). Furthermore, the histological tests did not reveal the presence of T. gondii tissue cysts in any of the examined portions of interventricular septum. It should be considered that the likelihood of detecting genetic material of the parasite is probably influenced by the uneven distribution of the tissue cysts in the carcass as well as the methodology applied. The findings of this study support the importance of describing the uncertainty associated with the data used for risk assessment to reduce inaccurate estimation or risk overestimation.

Molecular Prevalence of Sarcocystis spp. and Toxoplasma gondii in Slaughtered Equids in Northern Tunisia

Sarcocystis spp. and Toxoplasma gondii are two apicomplexan protozoa that infect a broad range of vertebrates, however, little is known about the infection of equids with these parasites. A total of 184 slaughtered equids from slaughterhouses of Bizerte and Tunis located in Northern Tunisia, were examined for meat infections with Sarcocystis spp. and T. gondii by PCR. The prevalence of infections with Sarcocystis spp. and T. gondii were 38% (95% CI: 31-45) and 39.7% (95% CI: 32.6-46.7), respectively. The highest prevalence of infection with Sarcocystis spp. was observed in donkeys (48.6%; 95% CI: 37.3-60) followed by mules (32.8%; 95%CI: 21.3-44.3), and horses (28.3%; 95% CI: 15.2-41.2) (P = .04). Similarly, the highest prevalence of infection with T. gondii was also observed in donkeys (66.2%; 95% CI: 55.4-77), followed by mules (18.7%; 95%CI: 9.2-28.3), and horses (26.1%; 95%CI: 13.4-38.8) (P < .001). The coinfection prevalence was estimated to be 17.4% (95%CI: 11.9-22.9). Taking into consideration that humans can be infected following consumption of infected equid meat with T. gondii and/or some Sarcocystis species, it is important to assess the risk of human infection. Thus, further studies are needed to better understand the epidemiology of these zoonoses.

Microbial Safety of Beef Along Beef Value Chains in the Ashaiman Municipality of Ghana

Food from animal sources continues to be a significant food safety hazard. This study determined the microbial quality and safety of beef along beef value chains with case studies in the Ashaiman Municipality of Ghana. Raw beef samples were collected from four slaughter slabs in the Ashaiman Municipality and analyzed using standard microbiological methods to determine the quality and prevalence of specific pathogens, including Salmonella species, Listeria monocytogenes (L. monocytogenes), and Brucella species, as well as Toxoplasma gondii (T. gondii), Cyclospora cayetanensis (C. cayetanensis), and Cryptosporidium parvum (C. parvum). Data regarding food safety knowledge and practices were collected and observed from stakeholders (cattle farmers, butchers, and beef retailers). Salmonella typhimurium was isolated from 7.5% (6/80) of the total raw beef samples. However, L. monocytogenes, Brucella spp., T. gondii, C. cayetanensis, and C. parvum were not isolated in this study. The mean level of microbial contamination of beef from the slaughter slabs/abattoir [5.2 Log10 colony-forming unit (CFU)/g] was not significantly different (p &gt; 0.05) from the mean level observed at retail points (5.4 Log10 CFU/g). However, the mean coliform count of 4.3 Log10 CFU/g recorded at retail shops exceeded the permissible limits of 104 CFU/g (4 Log10 CFU/g) required by the Ghana Standards Authority for safety of meat and carcasses. Knowledge on food safety was at average level for butchers and retailers. Unhygienic practices and poor sanitary conditions at the abattoirs and retail shops observed could be the main contributing factors to microbial contamination of raw beef. Continuous education for meat handlers on issues of food safety and monitoring of slaughter activities will reduce the rate and level of contamination of beef.

Detección molecular de Toxoplasma gondii en carnes para consumo humano en Ibagué, Colombia

Introducción. Toxoplasma gondii es un parásito con gran potencial zoonótico que puede infectar un amplio rango de huéspedes de sangre caliente, incluidos los animales del sector pecuario, lo que causa pérdidas a la industria. En el humano, es patógeno en personas inmunosuprimidas y afecta el desarrollo del feto en infecciones congénitas. Además, se asocia con diversos trastornos del comportamiento en personas sanas. El humano puede adquirir T. gondii al consumir carnes contaminadas mal cocidas.Objetivo. Determinar la positividad de T. gondii en carnes de consumo humano (res, pollo y cerdo) en Ibagué, Colombia.Materiales y métodos. Se utilizó la PCR convencional anidada y la secuencia del gen B1 de T. gondii como blanco de amplificación. Se tomaron 186 muestras de carne comercializada en la zona urbana de Ibagué (62 de res, 62 de pollo y 62 de cerdo) y se obtuvo el porcentaje de positividad en cada tipo de carne evaluada.Resultados. Se encontró un porcentaje de positividad de 18,8 % en las muestras, siendo la carne de cerdo la del mayor porcentaje (22,5 %; 14/62), seguida por las muestras de carne de res (19,3 %; 12/62) y de pollo (14,5 %; 9/62). Los mejores productos amplificados fueron secuenciados en Macrogen, y alineados con las secuencias del gen B1 depositadas en el GenBank, con lo que se confirmó su identidad.Conclusiones. Este es el primer estudio sobre prevalencia de T. gondii en carnes para consumo humano en Ibagué y el departamento del Tolima. Se demostró que los tres tipos de carne representan un riesgo para la infección en humanos a nivel local.

Molecular identification of Neospora caninum and co-infection with Toxoplasma gondii in genital apparatus of naturally infected cows in North Tunisia

The aim of this study was to estimate the molecular prevalence of Toxoplasma gondii, Neospora caninum and the co-infection by both Apicomplexan parasites in uterus tissues of cows. PCR was used to detect T. gondii and N. caninum DNA in uterus from 140 uteri of slaughtered cows in the regional slaughterhouse of Béja (Northwest Tunisia). Positive PCR products were sequenced and used for the phylogenetic analysis. The overall molecular prevalence of T. gondii and N. caninum in cows' uterus was 5 and 15.57%, respectively. Co-infection prevalence by the two parasites was estimated to be 2.85%. Risk factors including the age categories significantly affected the molecular prevalence of T. gondii and N. caninum in cows' uterus. The highest molecular prevalence of T. gondii (11.5 ± 3.1) and N. caninum (21.1 ± 11.1; p = 0.038) was observed in cows aged of more than 8 years. There were no differences depicted according to cow's breeds and localities. Comparison of the partial sequences of the ITS1 gene revealed 100% similarity among our N. caninum sequence (MW136256) and those deposited in GenBank. The T. gondii sequence described in this study (MW260335) was 99.4-100% homologous to T. gondii sequences published in the GenBank.To the best of our knowledge, this is the first molecular evidence of N. caninum and T. gondii co-infection in naturally infected cows in North Africa. This information is pertinent in designing control programmes that would reduce economic losses in the livestock industry.

High Toxoplasma gondii frequency of infection in the genital tract of ewes previously positive for the parasite DNA in meat, in Sidi Bouzid, Tunisia

The aim of the present study was to estimate the molecular prevalence of T. gondii along various segments of the genital tract of confirmed chronically infected ewes. Genital tracts were collected from 42 ewes; meat samples from the same ewes were previously confirmed positive for T. gondii DNA. The whole DNA was extracted from 4 parts of the genital tract (ovary, horns, body of the uterus and vagina). PCR was used to amplify a 114 base-pairs of T. gondii B1 gene. For all studied samples, 95.2 % had at least one infected genital part. Toxoplasma gondii infection was confirmed by sequencing 20 amplicons randomly chosen. The majority of infected animals has 4 T. gondii-infected genital anatomical parts. Principal component analysis (PCA) revealed a cluster of adult animals (>24 months) with positive PCR in the ovaries and the vagina and another cluster of Barbarine animals having positive PCR in the horns and body of the uterus. General linear model confirmed PCA results and showed a significant higher prevalence of T. gondii in the ovaries and vagina of older animals (p = 0.001 and p = 0.02, respectively) and a higher prevalence of T. gondii in the horns of the uterus of Barbarine animals (p = 0.03). Toxoplasma gondii seems to highly persist along the various segments of the ewe's genital tract but further investigations are necessary to link such prevalence with the pathological implications.

First isolation and genotyping of Toxoplasma gondii strains from domestic animals in Tunisia

The isolation and molecular typing of Toxoplasma gondii strains provide an essential basis for a better understanding of the parasite’s genetic diversity, determinants of its geographical distribution and associated risks to human health. In this study, we isolated and genetically characterized T. gondii strains from domestic animals in Southern and coastal area of Tunisia. Blood, hearts and/or brains were collected from 766 domestic animals (630 sheep and 136 free-range chickens). Strain isolation from these samples was performed using mouse bioassay and genotyping was carried out with a multiplex PCR technique using 15 microsatellite markers. Thirty viable strains of T. gondii were successfully isolated from tissues of sheep (19/142) and chickens (11/33). In addition, 3 strains could be successfully genotyped from animal tissues for which mouse bioassay was unsuccessful. A large predominance of type II strains (n = 29) was found in the sampled regions, followed by type III (n = 3) and, for the first time in Tunisia, a single isolate of Africa 4 lineage from a sheep. Analyses of population genetics showed the presence of a divergent population of type II lineage in Tunisia, supporting limited recent migrations of strains between Tunisia and other countries of the world.

Meat-borne parasites in the Arab world: a review in a One Health perspective

Meat-borne parasitic zoonoses are generally not well-monitored, and so understanding extent and overall prevalence is problematic. Without sufficient attention, their prevalence can become unexpectedly and unacceptably high. This review sheds light on meat-borne parasites in the Arab world, which includes all the Arab countries situated in the continents of Asia and Africa, with more than 400 million inhabitants distributed in 22 countries. Meat-borne parasites can be divided into two main categories-helminths and protozoa. The main helminths included in this review are Taenia saginata, Taenia solium, Taenia asiatica, Echinococcus spp., Fasciola spp., and Trichinella spiralis, while the meat-borne protozoan parasites are Toxoplasma gondii, Cryptosporidium spp., and Sarcocystis spp. In addition, Linguatula serrata, which belongs to the class Pentastomida, was included. Among those, the genus Taenia is the most frequently reported in the Arab world, particularly T. saginata. Many parasitic infections that are mainly transmitted through pork, although widespread in many parts of the world, are rare in the Arab countries, primarily due to religious proscriptions. The majority of the publications concerning meat-borne parasites were from Egypt, which contains the largest population in the Arab world and the highest population density, in addition to various economic, social, and environmental reasons.

Toxoplasma gondii in Sheep and Goats from Central Iran

OBJECTIVE

Toxoplasmosis, caused by Toxoplasma gondii, infects humans by consuming infected raw or undercooked meat and foods harboring mature oocysts. In this study, we assessed the prevalence of T. gondii in sheep and goats coming from central Iran. After completing the questionnaire, about one gram of liver or diaphragm tissue was taken as a sample from 90 sheep and 90 goats slaughtered in Yazd Province and stored at - 20 ºC. DNA extraction was done, and then T. gondii was detected using nested PCR.

RESULTS

This study indicated that the prevalence of T. gondii in all slaughtered animals was 11.6% (21 of 180), including 14.4% (13/90) in sheep and 8.8% (8/90) in goats. The infection rates in liver and diaphragm samples were 12.2% (11/90) and 11.1% (10/90), respectively (p = 0.8163). The infection rate in animals older than one was 16.3% (15/92), and it was 6.8% (6/88) in animals under one year of age. Therefore, no significant differences were found (p = 0.475). Infection rates were 19.5% (18/92) in males and 3.4% (3/88) in females (p = 0.0007). In conclusion, the infection rates of toxoplasmosis in livestock in this area are almost high, and therefore, it is necessary to design appropriate prevention programs to control the disease.

Effect of Toxoplasma gondii on Ram Sperm Quality After Experimental Infection

The aim of this study was to investigate the effect of experimental Toxoplasma gondii infection on ram sperm quality. Five months old, pre-pubertal, rams were divided into four groups (n = 8 per group). Group A was the control group; the remaining animals received per os (p.o.) 5000 oocysts per ram. Group B did not receive treatment post-infection (p.i.). Group C received sulphadimidine (intermuscular injection (i.m.) 33 mg/kg for eight days; every 48 hrs) two months p.i. and Group D received the same drug twice (24 hours p.i. and two months later). Blood samples were collected every 15 days to detect serum immunoglobulin G (IgG). Epididymal sperm samples were analyzed for concentration, kinetics, morphology/viability, functional membrane integrity, DNA integrity, and the presence of parasite DNA. Histopathological examination was performed on the testes. The IgG titres in infected groups raised two weeks p.i. and remained high for four months. Higher values were noticed in viability and functional membrane integrity in positive spermatozoa in the control group compared to other groups, level of significance p < 0.05. Abnormal sperm was higher in groups C and D vs. A and C vs. B (p < 0.05). T. gondii DNA was detected in three sperm samples of the infected rams (12.5%). Histopathology revealed similar findings with little variation among all infected groups, characterized mostly by increased interstitial connective tissue, non-purulent inflammation, and presence of seminiferous tubules with spermatogenic cell depletion, which increased gradually from D to C and B groups. In conclusion Toxoplasmosis in pre-pubertal age negatively affected mature ram sperm quality, while sulphadimidine administration failed to alter this.

Foodborne transmission of Toxoplasma gondii infection in the last decade. An overview

Toxoplasmosis is a zoonotic disease of global distribution and importance. It is caused by the protozoan parasite Toxoplasma gondii, the only species in the Toxoplasma genus. This parasite can infect most warm-blooded animals, including humans and livestock. Main routes of transmission are by ingestion of tissue cysts in raw or undercooked meat of infected animals, ingestion of raw vegetables or water contaminated with T. gondii oocysts from cat feces, and transplacental. Around one-third of human beings are chronically infected with T. gondii. Most infections appear to be asymptomatic in immunocompetent persons, but toxoplasmosis can be fatal to the fetus and immunocompromised adults. Water and foodborne outbreaks have been caused by this parasite worldwide, but few are well documented. Importantly, T. gondii is a parasite of high importance in animal health, causing reproductive failure, particularly in small ruminants, and clinical toxoplasmosis in many species. This overview discusses the knowledge of T. gondii infections in the last decade focusing on the foodborne transmission of this parasite.

Molecular detection of the B1 gene of Toxoplasma gondii in blood samples of female sheep and goats in Tebessa, northeastern Algeria

Toxoplasmosis, caused by Toxoplasma gondii, is a parasitic zoonosis of crucial medical and veterinary importance. It is mainly diagnosed by serological methods which are limited by insufficient sensitivity. Therefore, it is necessary to rely on direct detection of the parasite. The present study was aimed for direct detection of the parasite DNA in the blood samples of sheep and goats using PCR targeting the B1 gene. The study was carried out in 20 small ruminant farms between 2016 and 2018 in Tebessa region, part of north-eastern Algeria, and concerned 227 and 91 aborted female sheep and goats respectively. DNA of T. gondii was detected in 35.24 % and 18.68 % blood samples of sheep and goats respectively (p < 0.001). Molecular prevalence was higher in 13-24 month old female sheep (93.33 %) than 1-12 month old female sheep (14.37 %) (p < 0.0001). While, in goats no significant difference was observed in relation to age. Female sheep that aborted between 1-60 days of gestation were found to be more infected (46.41 %) compared to females that aborted between 61-120 days of gestation (12.16 %) (p < 0.001). Whereas, female goats that aborted between 61-120 days of gestation were found to be more infested (30.77 %) compared to females that aborted between 1-60 days of gestation (16.67 %) (p < 0.001). This study revealed that small ruminants are highly infected with T. gondii, which represents a major risk for the consumer in Tebessa. Further studies are needed to improve our knowledge of the different genotypes of T. gondii infecting small ruminant population.

Economic and public health importance of Toxoplasma gondii infections in sheep: 2009-2020

Toxoplasma gondii infections are common in humans and animals worldwide. The present review summarizes worldwide information on the prevalence of clinical and subclinical infections, epidemiology, diagnosis, control, and genetic diversity of T. gondii in sheep in the past decade. There is debate and uncertainty concerning repeat congenital infection as evidenced by finding T. gondii DNA in progeny of chronically infected sheep. However, there is no concrete evidence that T. gondii is the cause of repeated abortions in sheep. Recent data concerning pathogenesis of abortion in acutely infected sheep are reviewed. PCR-RFLP typing of T. gondii DNA derived from viable T. gondii isolates or tissues of infected sheep revealed low genetic diversity in sheep in Europe, Africa, Asia and North America but high diversity in South America. This review will be of interest to biologists, parasitologists, veterinarians, and public health workers.

First isolation and molecular characterization of Toxoplasma gondii strains from human congenital toxoplasmosis cases in Monastir, Tunisia

Toxoplasma gondii is a protozoon parasite that can cause severe clinical problems such as congenital toxoplasmosis. The distribution of T. gondii genotypes varies from one geographic area to another. So far, little is known about the parasite genotypes in Tunisia, North Africa. The present study aimed isolating and genotyping T. gondii from the amniotic fluid (AF) and placenta of pregnant women in Monastir, Tunisia. Amniotic fluid and/or placenta from 80 women who acquired toxoplasma infection during pregnancy were tested by PCR and/or mouse bioassay. Genotyping of T. gondii isolates from these samples was performed with 15 microsatellite markers. Four viable T. gondii strains were isolated from either the AF or placenta of four women. Specifically, strains TUN001-MON1 and TUN002-MON2 were isolated from both the AF and placenta, TUN003-AHA from only the placenta, and TUN004-NEL from only the AF. The four viable strains were not virulent for mice. Genotyping revealed that the four strains were type II strains. This is the first report on isolation and genotyping of T. gondii from AF human samples in Tunisia. Further studies focused on T. gondii genotyping on a larger number of human cases and on animals in Tunisia are needed to improve the knowledge and epidemiology of toxoplasmosis.

Prevalence and predictors of Toxoplasma gondii infection in pregnant women from Dhamar, Yemen

BACKGROUND

Toxoplasmosis is a common and serious parasitic infection caused by the ubiquitous obligatory intracellular protozoan organism, Toxoplasma gondii. Although infection with T. gondii is usually asymptomatic in healthy individuals, it can lead to severe pathological effects in congenital cases and immunocompromised patients. This study aimed to determine the seroprevalence of T. gondii and its predictors among pregnant women seeking prenatal and medical care at the general maternal and child health facility in Dhamar district of Dhamar governorate, Yemen.

METHODS

A total of 420 pregnant women were randomly selected for this cross-sectional study. Participants were screened for anti-T. gondii antibodies (i.e. immunoglobulin M; IgM and immunoglobulin G; IgG) using electrochemiluminescence immunoassay. Demographic, socioeconomic, obstetric and behavioural data were collected using a pretested questionnaire via face-to-face interview. Univariate and multivariate analyses were used to identify the independent predictors of T. gondii seroprevalence.

RESULTS

The overall seroprevalence of anti-T. gondii antibodies (IgG and/or IgM) among the participants was 21.2% (89/420; 95% CI = 17.3-25.1). Anti-T. gondii IgG antibodies were detected in 20.0% (84/420) of the women of which 12.9% (54/420) were positive for only IgG and 7.1% (30/420) were positive for both IgG and IgM antibodies. Moreover, 5 women (1.2%) were reactive only for IgM antibodies. Significant associations between T. gondii seroprevalence and history of spontaneous abortion (P <  0.001), raw vegetables consumption (P = 0.036), and presence of cats in household (P = 0.049) were reported. Multivariate analysis confirmed that history of spontaneous abortion (AOR = 4.04; 95% CI = [2.46, 6.63]) and presence of cats in household (AOR = 1.77; 95% CI = [1.02, 3.07]) are significant predictors of T. gondii seroprevalence among the studied participants.

CONCLUSION

The study found a high seroprevalence (21.2%) of T. gondii infection during pregnancy in Dhamar district, which is significantly associated with adverse pregnancy outcomes. The provision of adequate maternal healthcare and health education pertaining to the prevention of T. gondii infection is therefore imperative to curtail the prevalence of infection among the studied population.

Detection of Toxoplasma gondii infection in semen of rams used for natural mating in commercial sheep farms in Tunisia

Toxoplasmosis, a parasitic infection, disrupts sexual functions resulting in decline in reproductive and economic performance in sheep. Lacking discernible symptoms, toxoplasmosis is difficult to detect and diagnose in infected animals. Here, to estimate the prevalence of natural infection by Toxoplasma gondii, we used PCR to amplify and detect T. gondii DNA in semen from 92 rams of three breeds from four regions in Tunisia and seroprevalence was determined using a commercial ELISA kit. From the PCR amplifications, 51.09 ± 10.21% of the rams were tested positive for T. gondii with an overall seroprevalence of 39.13 ± 9.97%. Risk factors including ram location and number of accomplished mating seasons significantly (p < .05) affected the sero- and molecular prevalence of T. gondii in semen but, there was a fair concordance between sero- and molecular prevalence (Kappa = 0.33). Sequences of T. gondii from five positive samples were 100% identical (same haplotype). Comparison of these sequences with those archived at the GenBank showed a sequence similarity range between 95 and 100%. The haplotype defining the five Tunisian sequences was similar to the one observed in chicken, cats, European pole cat and humans from Brazil, St Kitts and Nevis, Great Britain and Tunisia, respectively. This indicates its wide geographic distribution and non-species specificity. Our findings suggest a high prevalence of toxoplasmosis in Tunisian matting rams; further studies concerning its venereal transmission capacity are needed prior to recommending a systematic screening of T. gondii DNA in rams' semen used for both natural breeding and artificial insemination.

Epidemiological Investigation of Toxoplasma gondii Infections in Commercial Sheep Flock in an Endemic Area for Ocular Toxoplasmosis in Southern Brazil

INTRODUCTION

Toxoplasma gondii is a widely distributed parasite and of great importance to human and animal health.

METHODS

The objective of this study was to assess the prevalence of T. gondii antibodies and risk factors associated with the infection in sheep in the Northwest region of the State of Rio Grande do Sul, Brazil; this region has a very high rate of human ocular toxoplasmosis. Ovine sera were tested by the modified agglutination test (cut-off 1:25).

RESULTS

T. gondii antibodies were detected in 70.2% (224 of 319). According to the logistic regression, the most significant factors associated were age and cat access to food stock facility.

CONCLUSION

Preventive measures are discussed to reduce the risk of transmission of this zoonosis.

Toxoplasma gondii infection and toxoplasmosis in North Africa: a review

Toxoplasmosis is an important zoonosis caused by an obligate intracellular parasitic protozoan, Toxoplasma gondii. The disease is distributed worldwide and can affect all warm-blooded vertebrates, including humans. The present review aimed to collect, compile and summarize the data on the prevalence of T. gondii infection in humans and animals in the five North African countries (Morocco, Algeria, Tunisia, Libya and Egypt). Published data from national and international databases were used. Distribution patterns and risk factors for T. gondii infection are discussed, focusing on biotic and abiotic factors. This review is a comprehensive epidemiological analysis of T. gondii infection in North Africa and will therefore be a useful tool for researchers. It can also be used to propose or enhance appropriate national toxoplasmosis control programs.

Toxoplasma gondii: Prevalence of natural infection in pigeons and ducks from middle and upper Egypt using serological, histopathological, and immunohistochemical diagnostic methods

Toxoplasma gondii is one of the most serious coccidian parasites, which infect human and nearly all warm-blooded animals. Domestic farm birds, which represent a good source of animal protein for humans, are subjected to such infection. Because pigeons and ducks get their feed from the soil, they are susceptible to being infected orally with Toxoplasma oocysts. Consequently, these birds may represent a public health problem for humans. Lack of information on T. gondii infection in pigeons and the insufficient data on its epidemiology in ducks were the main reasons to perform the present study. In the current study, four hundred and fifty-two blood and tissue samples were collected from 310 pigeons and 142 ducks from Asyut, Fayoum, Beni Suef, Minya, and Giza provinces, Egypt. Specific antibodies for Toxoplasma gondii were determined using recombinant TgSAG2t specific surface antigen based ELISA. Histopathological and immunohistochemical (IHC) examinations were also performed. Overall Toxoplasma positivity was 13.55%, 1.61%, and 1.61% in pigeons and 10.56%, 2.11%, and 2.11% in ducks using ELISA, histopathology, and IHC, respectively. Statistically significant difference in the T. gondii prevalence was observed in relation to period of the year. No significant changes were recorded regarding the gender or age. The current study indicated soil contamination and observable Toxoplasma infection in pigeons and ducks, which could represent a major danger for human infection.

Genetic diversity of Toxoplasma gondii isolates from ruminants: A systematic review

Toxoplasma gondii is a protozoan capable of infecting all warm-blooded animals. This parasite has been classified into three major lineages. Our aim was to assess and compare the identified Types and genotypes in ruminants. From November 2014 to April 2015, four English language databases and four Persian databases that reported data on the T. gondii genotyping in ruminants were searched. Overall, typing results of the 250/307 T. gondii isolates in all animals showed that Type II was a predominant Type (81.4%). In addition, genotyping data from the 82/215 T. gondii isolates or strains indicated that atypical genotypes were predominant (38.13%). This systematic review has demonstrated a large degree of genetic diversity in some countries. However, in the new nomenclature of genotyping, there are atypical or exotic genotypes, such as Chinese 1, Types Br (I, II, III and IV), and Type 12. Further genotyping studies are required to corroborate the current results.

First report of Tunisian coastal water contamination by protozoan parasites using mollusk bivalves as biological indicators

In order to establish seawater contamination by emerging protozoan parasites, we used qPCR to molecularly characterize and evaluate the parasitic burden of Giardia duodenalis, Cryptosporidium spp., Toxoplasma gondii, and Cyclospora cayetanensis in 1255 wild bivalve mollusks collected along the Tunisian coasts. T. gondii, G. duodenalis and C. cayetanensis were detected in 6.9% (99% CI=1.6-12.2%) pools of Ruditapes decussatus. None of the samples were found positive to Cryptosporidium spp.; 6.6% pools of R. decussatus were positive for T. gondii Type I, 1.6% for G. duodenalis assemblage A, and 1.6% for the association T. gondii Type I/C. cayetanensis/G. duodenalis assemblage A. R. decussatus harbored up to 77500 oocysts/sample of T. gondii, up to 395 cysts/sample of G. duodenalis, and 526 oocysts/sample of C. cayetanensis. These results provide the first evidence that the Tunisian coasts are contaminated by zoonotic protozoan parasites that can constitute a direct or indirect risk for human health.

Toxoplasma gondii infection in meat animals from Africa: Systematic review and meta-analysis of sero-epidemiological studies

AIM

Toxoplasma gondii is an ubiquitous apicomplexan parasite which causes toxoplasmosis in humans and animals. Felids especially cats are definitive hosts and almost all warm-blooded mammals, including livestock and human can serve as intermediate hosts. Food animals can be reservoirs for T. gondii and act as one of the sources for parasite transmission to humans. The objective of this study is to collect serological data on the prevalence of anti-T. gondii antibody, and risk factors for certain food animals from Africa to provide a quantitative estimate of T. gondii infection among these species from different African countries.

MATERIALS AND METHODS

Four databases were used to search seroepidemiological data on the prevalence of anti-T. gondii antibody in food animals between 1969 and 2016 from African countries. The search focused on data obtained by serologic test in food animals and meta-analyses were performed per species.

RESULTS

A total of 30,742 individual samples from 24 countries, described in 68 articles were studied. The overall estimated prevalence for toxoplasmosis in chicken, camel, cattle, sheep, goat, pig were 37.4% (29.2-46.0%), 36% (18-56%), 12% (8-17%), 26.1% (17.0-37.0%), 22.9% (12.3-36.0%), and 26.0% (20-32.0%), respectively. Moreover, major risk factor of infection was age, farming system, and farm location.

CONCLUSIONS

A significant variation in the seroepidemiological data was observed within each species and country. The results can aid in an updated epidemiological analysis but also can be used as an important input in quantitative microbial risk assessment models. Further studies are required for a better and continual evaluation of the occurrence of this zoonotic infection.

Molecular detection and phylogenetic analyses of Toxoplasma gondii from naturally infected sheep in Northern and Central Tunisia

Toxoplasmosis is a worldwide zoonosis caused by the parasitic protozoan Toxoplasma gondii. It can infect all warm‐blooded vertebrate species and causes abortions and birth defects in pregnant women and pregnant ewes. The objective of this study was to estimate the prevalence of infection with T. gondii in sheep meat in the region of Sidi Bouzid (central Tunisia) and Beja (northern Tunisia), the realization of a descriptive study of risk factors and the phylogenetic analyses of T. gondii. Neck muscle samples were obtained from 174 ewes and ewe lamb slaughtered in Sidi Bouzid and 150 lambs slaughtered in Beja. DNA was extracted from the samples using the Wizard^® genomic DNA purification kit. A nested PCR using two pairs of primers (NN 1 and NN2, Tg‐NP1 and Tg‐NP2) were used to detect infection with T. gondii, which was then confirmed by sequencing. Eight T. gondii amplicons were sequenced (accession number KT896498) and deposited in GenBank. The T. gondii amplicons showed 97–100% identities with GenBank sequences. A phylogenetic tree was then constructed. The nested PCR detected T. gondiiDNA in 31% of animals tested in Sidi Bouzid and 32% of lambs tested in Beja. No significant difference in the prevalence of T. gondii infection was established between the two tested regions. In both regions, no significant variation of the infection depending on age, breed and locality was found.

Seroprevalence of Toxoplasma gondii infection and risk factors in domestic sheep in Henan province, central China

Sheep are highly susceptible to infections with Toxoplasma gondii and play a major role in the transmission of toxoplasmosis to humans. In the present study, 779 serum samples from sheep were collected from Henan province, central China from March 2015 to May 2016, and antibodies to T. gondii were detected by modified agglutination test (MAT). The overall seroprevalence of T. gondii in sheep was 12.71% (99/779). The risk factors significantly associated with T. gondii seroprevalence were the geographical origin, age, presence of cats, and the rearing system. This is the first report of T. gondii infection in sheep in Henan province, central China, and of an association of seropositivity to T. gondii with risk factors.

Investigating the Determinants of Toxoplasma gondii Prevalence in Meat: A Systematic Review and Meta-Regression

BACKGROUND

Toxoplasma gondii is one of the most widespread parasites in humans and can cause severe illness in immunocompromised individuals. However, its role in healthy people is probably under-appreciated. The complex epidemiology of this protozoan recognizes several infection routes but consumption of contaminated food is likely to be the predominant one. Among food, consumption of raw and undercooked meat is a relevant route of transmission, but the role of different meat producing animal species and meats thereof is controversial.

OBJECTIVES

The aim of the present work is to summarize and analyse literature data reporting prevalence estimates of T. gondii in meat animals/meats.

DATA SOURCES

We searched Medline, Web of Science, Science Direct (last update 31/03/2015).

ELIGIBILITY CRITERIA

Relevant papers should report data from primary studies dealing with the prevalence of T. gondii in meat from livestock species as obtained through direct detection methods. Meta-analysis and meta-regression were performed.

RESULTS

Of 1915 papers screened, 69 papers were included, dealing mainly with cattle, pigs and sheep. Pooled prevalences, based on random-effect models, were 2.6% (CI95 [0.5-5.8]) for cattle, 12.3% (CI95 [7.6-17.8]) for pigs and 14.7% (CI95 [8.9-21.5]) for sheep. Due to the high heterogeneity observed, univariable and multivariable meta-regression models were fitted showing that the geographic area for cattle (p = 0.032), the farming type for pigs (p = 0.0004) and the sample composition for sheep (p = 0.03) had significant effects on the prevalences of Toxoplasma detected/estimated. Moreover, the role of different animal species was dependent on the geographic location of animals' origin.

LIMITATIONS

Limitations were due mainly to a possible publication bias.

CONCLUSIONS AND IMPLICATIONS

The present work confirms the role of meat, including beef, as T. gondii sources, and highlights the need for a control system for this parasite to be implemented along the meat production chain. Moreover, consumer knowledge should be strengthened in order to reduce the impact of disease.

First molecular evidence of Toxoplasma gondii in opossums (Didelphis virginiana) from Yucatan, Mexico

Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana were captured in Yucatan, Mexico. Detection of T. gondii was achieved by Polymerase Chain Reaction, which determined an infection of 76.9% (10/13) in brains. Positive amplicons were sequenced for analysis, this produced results similar to T. gondii with identity and coverage values of 98% and 96-100%, respectively. This study presents the first molecular evidence of the circulation of T. gondii in D. virginiana from Mexico.

DNA Amplification Techniques for the Detection of Toxoplasma gondii Tissue Cysts in Meat Producing Animals: A Narrative Review Article

BACKGROUND

Toxoplasma gondii is an intracellular parasite, which infects one-third population of world. Humans and animals acquire infection by ingesting oocytes from feces of cats or by meat of other animals having cysts that may lead to congenital, ocular or cephalic toxoplasmosis. Either it is important to detect T. gondii from meat of food animals from retail shops or directly at slaughterhouses, which is meant for export.

METHODS

The current research was done without time limitation using such terms as follows: "Toxoplasma gondii", "Meat", "Tissue cyst", "PCR", "LAMP", "Screening" and "Immunological assay" alone or in combination, in English language. The used electronic databases for searching included as follows: Pub-Med, Scopus, Google Scholar, Web of Science and Science Direct. The searches were limited to the published papers to English language.

RESULTS

Sensitivity of different molecular techniques for diagnosis of Toxoplasma is real-time PCR > LAMP > conventional PCR. In addition to these DNA analysis tools, bioassay in mice and cats is considered as "gold standard" to detect T. gondii.

CONCLUSION

This review article will help the readers for grasping advantages and limitations of different diagnostic tools for screening meat samples for T. gondii. This review also makes bibliography about the type of meat sample to be processed for diagnosis and different primers or sequences to be targeted for T. gondii by number of researches for its detection from meat or tissue sample using DNA amplification techniques.

Is toxoplasmosis a potential risk factor for liver cirrhosis?

OBJECTIVE

To document Toxoplasma gondii (T. gondii) antibody status in patients with liver disease, blood samples were taken from 180 hepatic patients and 180 healthy controls.

METHODS

Toxoplasma IgG antibody was detected using enzyme-linked immunosorbent assay and histopathological assessment of liver biopsy METAVIR score was applied.

RESULTS

Anti-T. gondii IgG antibodies were found in 32.8% of patients and in 22.2% of controls (P = 0.02). Toxoplasma seropositivity was significantly associated with lymphadenopathy, history of blood transfusion and reflex impairment in patients. Chronic hepatitis C virus (HCV) and chronic HCV-related cirrhosis groups compared to chronic HBV and chronic HBV-related cirrhosis groups expressed significantly higher prevalence of T. gondii seropositivity (odds ratio (OR) = 4; 95% confidence interval (CI): 1.3-12.6; P = 0.013, OR = 4.8; 95% CI: 1.5-14.9; P = 0.006, respectively). Within the chronic HCV group, T. gondii seropositivity significantly associated disease evolution as regards to METAVIR histopathological system for fibrosis and inflammation (OR = 19.4; 95% CI: 2.3-165.2; P = 0.0008, OR = 0.29; 95% CI: 0.1-0.8; P = 0.01, respectively). Albumin, international normalized ratio (INR) and platelets count were the laboratory parameters significantly altered in Toxoplasma-positive chronic HCV patients (P = 0.001, 0.03, 0.04, respectively). Child-Pugh scoring for cirrhosis in chronic HCV group placed the majority of seropositive patient in class C with significant statistical difference compared to Child A reference group (OR = 0.08; 95% CI: 0.01-0.5; P = 0.003).

CONCLUSIONS

Toxoplasma seropositivity was high in patients with cirrhosis and associated higher grades of inflammation and necrosis signifying disease evolution, suggesting that cirrhotic patients may thus form a risk group for toxoplasmosis.

A meta-analysis of the prevalence of Toxoplasma gondii in animals and humans in Ethiopia

BACKGROUND

Toxoplasmosis is a worldwide zoonosis. The objectives of this study were to estimate the prevalence and assess the potential risk factors of Toxoplasma gondii infections in animals and humans in Ethiopia by using meta-analytical methods.

METHODS

Published studies on T. gondii in animals and humans in Ethiopia were searched in Medline, Google Scholar and the lists of references of articles. Eligible studies were selected by using inclusion and exclusion criteria. The risks of within and across study biases, and the variations in prevalence estimates attributable to heterogeneities were assessed. Pooled prevalence was estimated by the DerSimonian and Laird random effects model.

RESULTS

Thirty two studies were eligible and data from 5689 animals and 5718 humans were used for quantitative syntheses. The pooled IgG seroprevalence in cats, small ruminants and humans were estimated at 87.72% (95% CI = 78.63, 93.28), 34.59% (95% CI = 21.08, 51.12) and 74.73% (95% CI = 61.85, 84.36), respectively. The odds of infections were higher in pregnant than in non pregnant women (OR = 3.96), in individuals that had contact with cats than those with no contact (OR = 2.53), and in urban than in rural inhabitants (OR = 2.06).

CONCLUSIONS

Toxoplasmosis is highly prevalent and could be a cause of considerable reproductive wastage in small ruminants and multiple diseases in humans in Ethiopia. Public education on preventive measures could help reduce the transmission of the parasite to humans.

Toxoplasma gondii superinfection and virulence during secondary infection correlate with the exact ROP5/ROP18 allelic combination

The intracellular parasite Toxoplasma gondii infects a wide variety of vertebrate species globally. Infection in most hosts causes a lifelong chronic infection and generates immunological memory responses that protect the host against new infections. In regions where the organism is endemic, multiple exposures to T. gondii likely occur with great frequency, yet little is known about the interaction between a chronically infected host and the parasite strains from these areas. A widely used model to explore secondary infection entails challenge of chronically infected or vaccinated mice with the highly virulent type I RH strain. Here, we show that although vaccinated or chronically infected C57BL/6 mice are protected against the type I RH strain, they are not protected against challenge with most strains prevalent in South America or another type I strain, GT1. Genetic and genomic analyses implicated the parasite-secreted rhoptry effectors ROP5 and ROP18, which antagonize the host’s gamma interferon-induced immunity-regulated GTPases (IRGs), as primary requirements for virulence during secondary infection. ROP5 and ROP18 promoted parasite superinfection in the brains of challenged survivors. We hypothesize that superinfection may be an important mechanism to generate T. gondii strain diversity, simply because two parasite strains would be present in a single meal consumed by the feline definitive host. Superinfection may drive the genetic diversity of Toxoplasma strains in South America, where most isolates are IRG resistant, compared to North America, where most strains are IRG susceptible and are derived from a few clonal lineages. In summary, ROP5 and ROP18 promote Toxoplasma virulence during reinfection.

Toxoplasma gondii is a widespread parasite of warm-blooded animals and currently infects one-third of the human population. A long-standing assumption in the field is that prior exposure to this parasite protects the host from subsequent reexposure, due to the generation of protective immunological memory. However, this assumption is based on clinical data and mouse models that analyze infections with strains common to Europe and North America. In contrast, we found that the majority of strains sampled from around the world, in particular those from South America, were able to kill or reinfect the brains of hosts previously exposed to T. gondii. The T. gondii virulence factors ROP5 and ROP18, which inhibit key host effectors that mediate parasite killing, were required for these phenotypes. We speculate that these results underpin clinical observations that pregnant women previously exposed to Toxoplasma can develop congenital infection upon reexposure to South American strains.

Comparative study on Toxoplasma infection between Malaysian and Myanmar pregnant women

Background

Toxoplasma gondii, an obligate intracellular protozoan parasite, causes a disease called toxoplasmosis which can sometimes be acquired congenitally by a newborn from an infected mother. This study aimed to determine the seroprevalence of Toxoplasma infection and its associated risks among 219 and 215 pregnant women from Malaysia and Myanmar, respectively.

Methods

Anti-Toxoplasma IgG and IgM antibodies were screened by using standard commercial ELISA kits. The socio-demographic, obstetrics and risk factors associated with Toxoplasma infection data were compared between the two countries.

Results

The overall prevalence of Toxoplasma infection in Malaysian pregnant women (42.47%; 95% CI = 36.11-49.09) was significantly higher (p < 0.05) than Myanmar pregnant women (30.70%; 95% CI = 27.92-37.16). By univariate analysis, this study identified that age group, education, parity, awareness on toxoplasmosis and consumption of undercooked meat were significantly associated (p < 0.05) with Toxoplasma seropositive Malaysian pregnant women but none of these factors associated with Toxoplasma seropositive Myanmar pregnant women. In comparison using univariate analysis between the two countries, it was found that Toxoplasma seropositive Malaysian pregnant women was associated with aged 30 years and above, secondary or lower-secondary level of education, the third trimester of pregnancy, having one child or more, lacking awareness of toxoplasmosis, absence of bad obstetrics history, having no history of close contact with cats or soil, living on a farm and also consumption of undercooked meat, unpasterized milk or untreated water. Avidity measurement was used to confirm the stages of Toxoplasma infection in pregnant women who were positive for both IgG and IgM antibodies and found all were infected in the past.

Conclusion

From our study, Toxoplasma screening and its risk measurement in pregnant women is firmly recommended for monitoring purposes and assisting proper management, including diagnosis and treatment during antenatal period. Also, it is necessary to initiate preventive measures for Toxoplasma infection among reproductive-age women in general and seronegative pregnant women in particular. Avidity measurement should be incorporated in Toxoplasma routine screening, especially with the availability of a single serum sample to assist in the diagnosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-014-0564-9) contains supplementary material, which is available to authorized users.