Category Archives: Toxoplasmosis

Research – Toxoplasma gondii Antibodies in Raw Milk and Sera of Cows in China

MDPI

Toxoplasma gondii is a worldwide food-borne protozoa that has harmful influences on animal and human health. Raw milk containing T. gondii has been considered as one of the possible infectious sources for humans. Although China is one of the world’s leading milk consumers, there is still no study to investigate the seroprevalence of T. gondii in raw cow milk in China; especially for cows in rural areas. Thus, we conducted this study to examine the specific anti-T. gondii IgG-antibody in the raw milk and sera of domestic cows in China. In total, 894 cows were randomly selected from rural areas in northeastern China. The positive rate of T. gondii in the milk and serum samples were 6.38% (57/894) and 7.16% (64/894), respectively. Moreover, a history of abortion (OR = 2.03, 95% CI: 1.11–3.72, p = 0.022) was identified as the only risk factor for T. gondii infection in the studied cows. This study investigated the seroprevalence of T. gondii in the raw milk and sera of cows in China; it provided timely and useful data for public health and food safety, especially in rural areas. View Full-Text

Research – Toxoplasma gondii in Foods: Prevalence, Control, and Safety

MDPI

Toxoplasma gondii is an obligate intracellular parasite that causes toxoplasmosis, with approximately one third of the population around the world seropositive. The consumption of contaminated food is the main source of infection. These include meat products with T. gondii tissue cysts, and dairy products with tachyzoites. Recently, contamination has been detected in fresh products with oocysts and marine products. Despite the great health problems that are caused by T. gondii, currently there are no standardized methods for its detection in the food industry. In this review, we analyze the current detection methods, the prevalence of T. gondii in different food products, and the control measures. The main detection methods are bioassays, cell culture, molecular and microscopic techniques, and serological methods, but some of these do not have applicability in the food industry. As a result, emerging techniques are being developed that are aimed at the detection of multiple parasites simultaneously that would make their application more efficient in the industry. Since the prevalence of this parasite is high in many products (meat and milk, marine products, and vegetables), it is necessary to standardize detection methods, as well as implement control measures. View Full-Text

Research – Pathogens can hitch a ride on plastic to reach the sea

Phys Org

Microplastics are a pathway for pathogens on land to reach the ocean, with likely consequences for human and wildlife health, according to a study from the University of California, Davis.

The study, published April 26 in the journal Scientific Reports, is the first to connect microplastics in the ocean with land-based pathogens. It found that microplastics can make it easier for disease-causing pathogens to concentrate in plastic-contaminated areas of the ocean.

The pathogens studied—Toxoplasma gondii, Cryptosporidium (Crypto) and Giardia—can infect both humans and animals. They are recognized by the World Health Organization as underestimated causes of illness from shellfish consumption and are found throughout the ocean.

“It’s easy for people to dismiss plastic problems as something that doesn’t matter for them, like, ‘I’m not a turtle in the ocean; I won’t choke on this thing,'” said corresponding author Karen Shapiro, an infectious disease expert and associate professor in the UC Davis School of Veterinary Medicine. “But once you start talking about disease and health, there’s more power to implement change. Microplastics can actually move germs around, and these germs end up in our water and our food.”

Research – Contamination of Soil, Water, Fresh Produce, and Bivalve Mollusks with Toxoplasma gondii Oocysts: A Systematic Review

MDPI

Toxoplas

Toxoplasma gondii is a major foodborne pathogen capable of infecting all warm-blooded animals, including humans. Although oocyst-associated toxoplasmosis outbreaks have been documented, the relevance of the environmental transmission route remains poorly investigated. Thus, we carried out an extensive systematic review on T. gondii oocyst contamination of soil, water, fresh produce, and mollusk bivalves, following the PRISMA guidelines. Studies published up to the end of 2020 were searched for in public databases and screened. The reference sections of the selected articles were examined to identify additional studies. A total of 102 out of 3201 articles were selected: 34 articles focused on soil, 40 focused on water, 23 focused on fresh produce (vegetables/fruits), and 21 focused on bivalve mollusks. Toxoplasma gondii oocysts were found in all matrices worldwide, with detection rates ranging from 0.09% (1/1109) to 100% (8/8) using bioassay or PCR-based detection methods. There was a high heterogeneity (I= 98.9%), which was influenced by both the sampling strategy (e.g., sampling site and sample type, sample composition, sample origin, season, number of samples, cat presence) and methodology (recovery and detection methods). Harmonized approaches are needed for the detection of T. gondii in different environmental matrices in order to obtain robust and comparable results.

Research – Introduction to the Special Issue: Microbiological Safety and Quality of Foods

MDPI

Recent shifts in food production, processing and distribution, linked to the globalization of the food trade and the need to meet new consumers habits, are continuously challenging global food systems. Every effort is being made to ensure healthy and safe, food that is crucial to guarantee public health and wellbeing.
Despite the advancements in food safety management, foodborne diseases (FBD) still remain an important problem worldwide, with a significant negative impact on human health and countries’ economies and development. It has been determined that food unsafe for consumption causes 600 million cases of FBD every year, and 25% of all foods produced globally are lost due to microbial spoilage. Serious outbreaks have occurred, involving both developing and industrialized countries, showing how food safety is a transnational challenge and that a strong joint commitment between food safety authorities is needed.
Despite this awareness, the full extent of the impact of food contamination is still unknown. Foodborne contaminants are numerous, including viruses and bacteria, parasites, chemicals, toxins and allergens that cause a wide range of conditions. Globally, FBD caused by bacteria are more common than those caused by viruses and parasites. [1]. Moreover, between one-third and one-half of all human infectious diseases have a zoonotic origin. Among bacteria, Campylobacter, followed by Salmonella, are the major etiological agents of FBD, while, among viruses, norovirus is the foremost enteric pathogen of foodborne disease worldwide [2].
The most common foodborne parasites instead are protozoa such as Cryptosporidium spp., Giardia intestinalis and Toxoplasma gondii; roundworms such as Trichinella spp. and Anisakis spp.; and tapeworms such as Diphyllobothrium spp. and Taenia spp. [3]. In particular, Anisakiasis is an emerging zoonosis caused by the fish parasitic nematode Anisakis. Humans are accidental hosts that become infected by eating raw or undercooked fish that contain viable Anisakis spp. larvae.
The major determinants for the incidence of FBD are unsafe raw food, abused temperature, inadequate storage, improper handling, undercooking and cross contamination [4]. Food from animal sources, fresh produce and ready-to-eat (RTE) foods are the most at risk. In particular, RTE foods are an emerging issue concerning food safety. Furthermore, they have been demonstrated to contain antimicrobial-resistant strains. Since these products are consumed without any further treatment, they could serve as a vector for the spread of antibiotic-resistant microorganisms, posing a significant threat to public health [5].
The importance of these topics is documented by the increasing number of papers published related to Food Safety. In a basic search using PubMed database, from 1945 to 2021, selecting as the search topic “Microbiological food safety”, a total of 54,210 results were obtained.
Although the first articles concerning microbiological food safety date from 1946, and since then a dozen articles appear in the following years, it is not until 1965 that a significant number of articles are published every year. Figure 1 shows the evolution of the number of papers per year (from 1965 to 2021) published regarding Microbiological food safety. As can be seen in this figure, approximately 80% of these papers have been published in the last 20 years, and the number continues to rise, revealing an increasing and ever-present interest towards the topic addressed in this Special Issue.
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Norway – Cyclospora, Toxoplasma and Cryptosporidium detected in berries sold in Norway

Fresh Plaza

water contamination

Cyclospora, toxoplasma and cryptosporidium have been detected in berries sold in Norway. Blueberries, strawberries and raspberries were tested for Echinococcus multilocularis, Toxoplasma gondii, Cyclospora cayetanensis and Cryptosporidium. Raspberries were the most contaminated, followed by strawberries and blueberries. Strawberries and raspberries were mainly tainted with Cryptosporidium, while blueberries were contaminated mostly with Cyclospora. Toxoplasma and Cyclospora were frequently found in raspberries, according to the study published in the journal Food Microbiology.

However, researchers said it was important to note that only DNA was detected, so there is no certainty that the intact, infective stages of parasites were present, and there is no information on viability.

In Norway, because of the short growing season, many berries come from abroad, with more than 13,000 tons imported in 2020. In total, 86 berry samples were from domestic fruit while others came from countries such as Peru, Morocco, Chile, Netherlands, Portugal and Poland.

Researchers said that while findings are cause for some degree of concern for Norwegian food safety authorities, encouraging consumers to wash berries before consumption could reduce the risk of infection.

Research -Surveillance of berries sold on the Norwegian market for parasite contamination using molecular methods

Science Direct

water contamination

The risk of foodborne parasite infection linked to the consumption of contaminated fresh produce has long been known. However, despite epidemiological links between the outbreaks and contaminated berries, few studies have assessed the magnitude of parasite contamination on fresh produce sold in Europe. The present study was aimed to address the knowledge gap on parasite contamination of berries sold in Norway. Samples of blueberries, strawberries, and raspberries were analysed by multiplex qPCR for detection of Echinococcus multilocularisToxoplasma gondii, and Cyclospora cayetanensis. In addition, a simplex qPCR method was employed for detecting contamination of the berries with Cryptosporidium spp. A total of 820 samples of berries, each of around 30 g (274 samples of blueberries, 276 samples of raspberries, and 270 samples of strawberries), were analysed. We found an overall occurrence of 2.9%, 6.6%, and 8.3% for T. gondii, C. cayetanensis, and Cryptosporidium spp., respectively, whereas E. multilocularis was not detected from any of the samples investigated. Strawberries and raspberries were most often contaminated with Cryptosporidium spp., whereas blueberries were contaminated mostly with C. cayetanensis. Detection of parasite contaminants on fresh berries indicates the need for a system to ensure the parasitological safety of fresh berries.

Research – Effect of domestic freezing on the viability of Toxoplasma gondii in raw and dry-cured ham from experimentally infected pigs

Journal of Food Protection

Toxoplasma gondii is the causative agent of the parasitic disease toxoplasmosis, which is an important food borne zoonosis. Eating undercooked meat of infected animals has been considered the major transmission route of T. gondii to humans. The present study evaluates the efficacy of domestic freezing on the inactivation of T. gondii bradyzoites in raw and dry-cured ham. Meat (raw and dry-cured ham) of a pig experimentally orally inoculated with 4,000 oocysts of T. gondii VEG strain was subjected to domestic freezing of -20 ºC at different days. The effect was evaluated by bioassay in mice followed by qPCR. In raw ham and dry-cured ham, temperature of -20 ºC for 7 and 14 days respectively did not inactivate T. gondii . More studies are needed to find the right temperature and time needed to render the bradyzoites non-infectious for human. Meanwhile, the recommendations of freezing to inactivate T. gondii in raw or dry-cured meats must be revisited considered that it does not reduce the risk of infection.

Research -EU One Health report: drop in reported zoonotic diseases in humans and foodborne outbreaks in 2020

EFSA

Campylobacteriosis was the most reported zoonosis in the EU in 2020, with 120,946 cases compared to more than 220,000 the previous year. It was followed by salmonellosis, which affected 52,702 people compared to 88,000 in 2019. The number of reported foodborne outbreaks also fell by 47%. These findings are based on the annual EU One Health zoonosis report, by EFSA and ECDC.

Experts acknowledged the impact of the COVID-19 pandemic in Europe in the remarkable drop in reported zoonotic diseases in humans – ranging from 7% to 53% depending on the reported disease in question – and foodborne outbreaks.

Possible factors behind the large decrease in cases include changes in health seeking behaviour, restrictions on travel and on events, the closing of restaurants, quarantine, lockdown, and other mitigation measures such as the use of masks, physical distancing and hand sanitisation.  

The next most commonly reported diseases were yersiniosis (5,668) and infections caused by Shigatoxin-producing E.coli (4,446). Listeriosis was the fifth most reported zoonosis (1,876 cases), mainly affecting people over the age of 64.

Listeriosis and West Nile virus infections were the diseases with the highest case fatality and hospitalisation rates – with most locally acquired human infections of West Nile virus reported in Greece, Spain and Italy.

The report also monitors foodborne outbreaks in the EU, events during which at least two people contract the same illness from the same contaminated food. A total of 3,086 foodborne outbreaks were reported in 2020. Salmonella remained the most frequently detected agent and caused about 23% outbreaks. The most common sources of salmonellosis outbreaks were eggs, egg products and pig meat.

The report also includes data on Mycobacterium bovis/caprae, BrucellaTrichinellaEchinococcus, Toxoplasma gondii, rabies, Q fever and tularaemia.

EFSA is publishing two interactive communication tools on foodborne outbreaks – a story map and a dashboard. The story map provides general information on foodborne outbreaks, their causative agents and implicated food vehicles. The dashboard allows people to search and query the large amount of data on foodborne outbreaks collected by EFSA from EU Member States and other reporting countries since 2015.

Research – A Systematic Review on the Effectiveness of Pre-Harvest Meat Safety Interventions in Pig Herds to Control Salmonella and Other Foodborne Pathogens

MDPI

myco

This systematic review aimed to assess the effectiveness of pre-harvest interventions to control the main foodborne pathogens in pork in the European Union. A total of 1180 studies were retrieved from PubMed® and Web of Science for 15 pathogens identified as relevant in EFSA’s scientific opinion on the public health hazards related to pork (2011). The study selection focused on controlled studies where a cause–effect could be attributed to the interventions tested, and their effectiveness could be inferred. Altogether, 52 studies published from 1983 to 2020 regarding Campylobacter spp., Clostridium perfringens, Methicillin-resistant Staphylococcus aureusMycobacterium avium, and Salmonella spp. were retained and analysed. Research was mostly focused on Salmonella (n = 43 studies). In-feed and/or water treatments, and vaccination were the most tested interventions and were, overall, successful. However, the previously agreed criteria for this systematic review excluded other effective interventions to control Salmonella and other pathogens, like Yersinia enterocolitica, which is one of the most relevant biological hazards in pork. Examples of such successful interventions are the Specific Pathogen Free herd principle, stamping out and repopulating with disease-free animals. Research on other pathogens (i.e., Hepatitis E, Trichinella spiralis and Toxoplasma gondii) was scarce, with publications focusing on epidemiology, risk factors and/or observational studies. Overall, high herd health coupled with good management and biosecurity were effective to control or prevent most foodborne pathogens in pork at the pre-harvest level. View Full-Text