Environmental transmission of Toxoplasma gondii: Oocysts in water, soil and food

Toxoplasma gondii is a zoonotic protozoan parasite that can cause morbidity and mortality in humans, domestic animals, and terrestrial and aquatic wildlife. The environmentally robust oocyst stage of T. gondii is fundamentally critical to the parasite\u27s success, both in terms of its worldwide distribution as well as the extensive range of infected intermediate hosts. Despite the limited definitive host species (domestic and wild felids), infections have been reported on every continent, and in terrestrial as well as aquatic environments. The remarkable resistance of the oocyst wall enables dissemination of T. gondii through watersheds and ecosystems, and long-term persistence in diverse foods such as shellfish and fresh produce. Here, we review the key attributes of oocyst biophysical properties that confer their ability to disseminate and survive in the environment, as well as the epidemiological dynamics of oocyst sources including domestic and wild felids. This manuscript further provides a comprehensive review of the pathways by which T. gondii oocysts can infect animals and people through the environment, including in contaminated foods, water or soil. We conclude by identifying critical control points for reducing risk of exposure to oocysts as well as opportunities for future synergies and new directions for research aimed at reducing the burden of oocyst-borne toxoplasmosis in humans, domestic animals, and wildlife

Veterinary-physicians collaboration towards the diminution of toxoplasmosis in France

La toxoplasmose est une zoonose de répartition mondiale, due au protozoaire Toxoplasma gondii capable d’infecter tous les animaux à sang chaud. L’infection est généralement inapparente ou bénigne chez l’homme sauf en cas d’immunodépression ou lors de transmission materno-foetale (à l’origine de la toxoplasmose congénitale). Chez les animaux de rente, elle peut être source d’avortements à l’origine de pertes économiques. La contamination se fait le plus souvent par ingestion de kystes (présents dans les viandes) ou d’oocystes souillant les végétaux ou l’eau. Seule la part liée à la contamination des viandes est évoquée dans cet article. Grâce à une coopération entre vétérinaires et médecins du Laboratoire National de Référence Parasites transmis par les aliments (Anses, Maisons-Alfort) et du Centre National de Référence de la Toxoplasmose, Reims (France), des plans de surveillance ont été menés visant à estimer le niveau de contamination des viandes pour mieux comprendre l’épidémiologie humaine.Toxoplasmosis is a globally distributed zoonosis caused by a protozoan Toxoplasma gondii able to infect all warm-blooded animals. Infection is generally asymptomatic or benign in humans except in cases of immunosuppression or maternal-fetal transmission (the cause of congenital toxoplasmosis). In livestock, it can be a source of abortions causing economic losses. Contamination is most often caused by ingestion of cysts (found in meat) or oocysts that contaminate plants or water. Only the part related to meat contamination is mentioned in this article. Thanks to a cooperation between veterinarians and physicians from the National Reference Laboratory of food-borne parasites (ANSES, Maisons-Alfort) and the National Reference Center for Toxoplasmosis, Reims (France), surveillance plans have been conducted aiming to estimate the levels of contamination of meat to better understand human epidemiology

Risk factors for sporadic cryptosporidiosis: a systematic review and meta-analysis

Cryptosporidium spp. is an important cause of gastrointestinal disease worldwide, responsible for 69 million cases of illness in 2016. Information on the sources and transmission pathways of human cryptosporidiosis results mainly from outbreak investigations. A systematic review and a meta-analysis of case-control and cohort studies were performed to determine the main risk factors associated with sporadic cryptosporidiosis. Suitable scientific articles were identified through a systematic literature search and subjected to a methodological quality assessment. From each study, odds ratio (OR) measures were extracted or calculated, as well as study characteristics such as population type, design, type of model and risk factor hierarchy. Mixed-effects meta-analysis models were adjusted by population type to appropriate data partitions. From 1985 identified references, the quality assessment stage was passed by 57 cohort and case-control studies focusing on sporadic cryptosporidiosis. The eligible studies were conducted between 1983 and 2016 and provided 568 OR categorized for meta-analysis. This meta-analysis identified travel, immunocompromising conditions, contact with infected humans, waterborne transmission (contact with recreational waters, wastewater, and consumption of untreated drinking water), contact with animals and food consumption as the relevant risk factors for sporadic cryptosporidiosis. With regards to food exposures, consumption of meat, dairy products (raw milk) and dishes consumed outside home were found significantly associated with cryptosporidiosis. The consumption of poorly washed fruits and vegetables significantly increases ORs. This meta-analysis reveals that some potential sources of Cryptosporidium such as shellfish or vegetables are under-investigated. Future case-control studies for sporadic cryptosporidiosis should include population at risk, and investigate other potential sources in relation to the genotype and the subtype of Cryptosporidium spp.The authors would like to thank ANSES staff and the members of the ANSES Working Group on Source Attribution of Foodborne Diseases: Moez Sanaa, Laurence Watier, Jean Christophe Augustin, Frédéric Carlin, Julie David, Philippe Fravalo, Laurent Guillier, Nathalie Jourdan-Da Silva, Alexandre Leclercq, Lapo Mughini-Gras, Nicole Pavio. Ursula Gonzales-Barron and Vasco Cadavez are grateful to the Foundation for Food Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO UID/AGR/00690/2019.info:eu-repo/semantics/publishedVersio

Analyse sérologique de la toxoplasmose pergravidique: évaluation des risques et

Introduction: La présente étude rapporte les données sérologiques de 306 sérums collectés chez des parturientes au CHU de Bobo Dioulasso et analysés rétrospectivement au CHU de Reims en 2011. Le but était de déterminer le statut sérologique de ces parturientes et d’en déduire la conduite à tenir. Méthodes: La recherche des IgG et des IgM anti toxoplasmiques était systématique. Les techniques d’agglutination haute sensibilisée et celle d’Immunocapture M ont servi à la recherche respective des anticorps spécifiques IgG et des IgM. Résultats: Sur 306 sérums analysés, 95 (31%) avaient des IgG positifs et aucun n’avait des IgM. Deux cent onze (211) sérums (69%) des sérums n’avaient ni IgG, ni IgM. Conclusion: Nos résultats montrent que 31% des femmes en dehors d’une immunodépression sous jacente, possèdent une immunité résiduelle vis à vis de Toxoplasma gondii et n’ont pas la nécessité d’avoir une surveillance sérologique pendant la grossesse. Cependant, 69% (211) des parturientes sont à risque d’une séroconversion, et devraient bénéficier de conseils hygiéno diététiques, associés à une surveillance sérologique durant la grossesse. Ces résultats montrent l’intérêt de mettre en place des mesures de prévention contre la toxoplasmose congénitale, étant l’une des affections materno - foetales les plus fréquentes par la mise en place d’un diagnostic prénatal de la toxoplasmose en routine dans notre hôpital.Pan African Medical Journal 2012; 12:4

Comparative Assessment of Toxoplasma gondii Infection Prevalence in Romania Using 3 Serological Methods

The aim of this study was to evaluate three serological tests used for T. gondii antibodies detection in horses. A commercially available ELISA test (ID Screen Toxoplasmosis Indirect Multi-Species, ID.vet, Innovative Diagnostics, France) and two ‘in house’ methods, indirect immunofluorescent antibody test (IFAT), modified agglutination test (MAT) were compared for their sensitivity and specificity in detection of anti-T. gondii antibodies in naturally infected horses using as standard cumulative seropositivity. Also, their agreement was evaluated by kappa statistic. A good correspondence of test results was observed. The best agreement was seen between ELISA and MAT (k=0.77). ELISA has the higher sensitivity (96.8%) and also the higher specificity (96.1%), followed by MAT (90.3 and 94.1, respectively) both tests proving better diagnostic potency compared with IFAT. The highest seroprevalence was obtained by ELISA (39%), followed by MAT (37.8%) and IFAT (34.1%). Based on our results, we recommend the utilization of indirect ELISA and MAT for detection of T. gondii antibodies in horses

The Life Cycle of Toxoplasma gondii in the Natural Environment

Chapitre 1International audienc

The first isolation and molecular characterization of Toxoplasma gondii from horses in Serbia

Background: Consumption of undercooked or insufficiently cured meat is a major risk factor for human infection with Toxoplasma gondii. Although horsemeat is typically consumed rare or undercooked, information on the risk of T. gondii from infected horse meat to humans is scarce. Here, we present the results of a study to determine the presence of T. gondii infection in slaughter horses in Serbia, and to attempt to isolate viable parasites. Methods: The study included horses from all regions of Serbia slaughtered at two abattoirs between June 2013 and June 2015. Blood sera were tested for the presence of specific IgG T. gondii antibodies by the modified agglutination test (MAT), and samples of trypsin-digested heart tissue were bioassayed in mice. Cyst-positive mouse brain homogenates were subjected to DNA extraction and T. gondii strains were genotyped using 15 microsatellite markers (MS). Results: A total of 105 slaughter horses were sampled. At the 1: 6 cut-off 48.6% of the examined horses were seropositive, with the highest titre being 1: 400. Viable parasites were isolated from two grade type mares; both parasite isolates (RS-Eq39 and RS-Eq40) were T. gondii type III, and both displayed an increased lethality for mice with successive passages. These are the first cases of isolation of T. gondii from horses in Serbia. When compared with a worldwide collection of 61 type III and type III-like strains, isolate RS-Eq39 showed a combination of MS lengths similar to a strain isolated from a duck in Iran, and isolate RS-Eq40 was identical in all markers to three strains isolated from a goat from Gabon, a sheep from France and a pig from Portugal. Interestingly, the source horses were one seronegative and one weakly seropositive. Conclusions: The isolation of viable T. gondii parasites from slaughter horses points to horsemeat as a potential source of human infection, but the fact that viable parasites were isolated from horses with only a serological trace of T. gondii infection presents further evidence that serology may not be adequate to assess the risk of toxoplasmosis from horsemeat consumption. Presence of T. gondii type III in Serbia sheds more light into the potential origin of this archetypal lineage in Europe

Toxoplasma gondii in beef consumed in France: Regional variation in seroprevalence and parasite isolation

In France, the consumption of cattle and sheep meat appears to be a risk factor for infection of pregnant women with Toxoplasma gondii. Several nation-wide surveys in France have investigated the prevalence of T. gondii in sheep and pig meat, but little is known at present about the prevalence of the parasite in beef. The main objective of the present cross-sectional survey was to estimate the seroprevalence of T. gondii infection in beef consumed in France. A secondary objective was to attempt to isolate T. gondii from cattle tissues and to study the geographical and age variations of this seroprevalence. The overall estimate of seroprevalence of T. gondii in bovine carcasses (n = 2912), for a threshold of 1:6 was 17.38%. A strong age effect was observed (p lt 0.0001) with a seroprevalence of 5.34% for calves ( lt 8 months) and 23.12% for adults ( gt 8 months). Seroprevalence estimates given by area of birth and area of slaughtering for adults showed that the areas with the highest seroprevalence were not the same between these two variables. Only two strains, corresponding to genotype II, were isolated from heart samples, indicating that there is a limited risk of human infection with T. gondii, which needs to be correlated with the food habit of consuming raw or undercook (bleu or saignant) beef. However, new questions have emerged, especially concerning the isolation of parasites from beef and the precise role of bovines, generally described as poor hosts for T. gondii, in human infection

Cryptosporidium spp. , Giardia duodenalis and Toxoplasma gondii detection in fresh vegetables consumed in Marrakech, Morocco

Background: Protozoan parasites such as Toxoplasma gondii, Giardia duodenalis, and Cryptosporidium spp., can be transmitted to humans via accidental consumption of contaminated water, fresh produce and foodstuffs. There is a lack of epidemiological data about these pathogens in Morocco. Hence the aim of this study, which is the determination of their prevalence in some leafy greens and root vegetables sold in Marrakech. Methods: A total of 132 vegetable samples including carrot, coriander, lettuce, parsley and radish were purchased monthly from three different markets in Marrakech from March 2017 to January 2018, pre-treated and subjected to microscopic and molecular analyses. Results: Of the 132 samples of vegetables analyzed by qPCR, the overall rate of protozoan was 21.21% (28/132); 22 samples were found to be contaminated with T. gondii, 6 with G. duodenalis, and none was positive for C. parvum / hominis . Whereas, modified Ziehl-Neelsen staining allowed the detection of Cryptosporidium spp. in 3% (4/132) of examined samples. Conclusion: This survey on the presence of protozoan parasites in fresh vegetables revealed that vegetables sold in Marrakech are contaminated by these protozoan parasites, as it showed that leafy green vegetables were more susceptible for parasitic contamination than root ones

Mussel as a Tool to Define Continental Watershed Quality

Bivalves appear as relevant sentinel species in aquatic ecotoxicology and water quality assessment. This is particularly true in marine ecosystems. In fact, several biomonitoring frameworks in the world used mollusks since several decades on the base of contaminant accumulation (Mussel Watch, ROCCH) and/or biological responses called biomarker (OSPAR) measurements. In freshwater systems, zebra and quagga mussels could represent alternative sentinels, which could be seen as the counterparts of mussel marine species. This chapter presents original studies and projects underlying the interest of these freshwater mussels for water quality monitoring based on contaminant accumulation and biomarker development measurements. These sentinel species could be used as a tool for chemical/biological monitoring of biota under the European water framework directive and for the development of effect-based monitoring tools