Toxo: You don’t want it

Toxoplasmosis is a foodborne zoonosis transmitted by Toxoplasma gondii, a cosmopolitan protozoan that infects humans through exposure to different parasite stages, in particular by ingestion of tissue cysts or tachyzoites contained in meat, primary offal (viscera), and meat-derived products or ingestion of environmental sporulated oocysts in contaminated food or water.

The pig is an important species for infection: raw or undercooked pork consumption not subject to treatment able to inactivate the parasite represents a risk to consumers’ health. Broadening knowledge of transmission ways and prevalence concerning this important pathogen in swine, together with a thorough acquaintance with hazard management are key elements to avoid T. gondii spreading within the swine production chain.

This review aims to illustrate why toxoplasmosis should be regarded as a veterinary public health issue through a careful description of the parasite, routes of infection, and inactivation treatments, highlighting the main prevention lines from pig breeding to pork consumption.

Toxoplasma gongii, a foodborne pathogen in the swine production chain form a European perspective

Foodborne Pathogens and Disease, ahead of print, July 2017,  De Berardinis Alberto, Paludi Domenico, Pennisi Luca, and Vergara Alberto, https://doi.org/10.1089/fpd.2017.2305

http://online.liebertpub.com/doi/abs/10.1089/fpd.2017.2305

Toxo in cat poop threatens Hawaiian monk seals

Two wildlife issues have collided in Hawaii, pitting one group of animal defenders against another in an impassioned debate. The point of contention? Deadly cat poop and the feral felines that produce it.

hawaiian-monk-sealsFederal researchers believe feces from the legions of stray cats roaming Hawaii is spreading a disease that is killing Hawaiian monk seals, some of the world’s most endangered marine mammals. Some conservationists advocate euthanizing those cats that no one wants, and that has cat lovers up in arms.

“It’s a very difficult, emotional issue,” said state Sen. Mike Gabbard, chairman of a committee that earlier this year heard a proposal to ban the feeding of feral cats on state land. The panel abandoned the bill after an outcry.

“It struck a nerve in our community,” he said.

The problem stems from a parasite common in cats that can cause toxoplasmosis, a disease that has killed at least five female Hawaiian monk seals and three males since 2001, according to the National Oceanic and Atmospheric Administration.

“While eight seals may not sound like a lot of animals, it actually has pretty large ramifications for an endangered population where there’s only about 1,300 seals in existence at this point in time,” said Michelle Barbieri, veterinary medical officer for NOAA’s Hawaiian monk seal research program. Scientists believe monk seals become exposed by ingesting contaminated water or prey.

Stray cats, meanwhile, have no predators in Hawaii and have ballooned in numbers across the state. Some 300,000 feral cats roam Oahu alone, according to marketing research commissioned by the Hawaiian Humane Society in 2015.

And monkeys may fly out my butt: Cat poop to cure cancer

A parasite found in cat poop could cure ovarian cancer.

A new study carried out in America has found Toxoplasma gondii, the organism that lives in the animal faeces, could be the answer to banishing the potentially fatal illness.

US scientists believe a protein carried by a parasite that infests felines appears to make tumours shrink.

Tests already carried out show the chemical works against ovarian cancer but scientists believe it could also hold the key to the cure for breast, kidney, liver and lung tumours, according to LiveScience.com.

 

Cats: Harbinger of parasites and schizophrenia

Pregnant women are advised to avoid many things, including alcohol, smoking and even their cat’s litter box (what about the refrigerated ready-to-eat foods?). More than 90% of obstetricians and gynecologists in the United States caution patients about handling cat litter during pregnancy, according to a recent survey.

amy.pregnant.catThe reason? A parasite lurking in the pets’ poop.

Cats can shed a parasite called Toxoplasma gondii in their feces, and if a pregnant woman accidentally inhales or eats the parasite and becomes infected, there are serious health risks. In 20% to 50% of cases (PDF), the fetus also becomes infected.

Only a very small number of cats are estimated to be shedding these parasites at any time — about 1%, by some estimates — but if a woman is infected within her first trimester, it could lead to microcephaly and other birth defects, as well as an increased risk of mental disability and blindness later in the child’s life.

People with weakened immune systems, such as those who have HIV or are undergoing chemotherapy, can develop neurological problems including headaches and seizures from the infection.

jauques.fierce.jun.16Other than the groups who were at greater risk, experts had generally thought toxoplasma, or toxo, was of little consequence. But that view started to change in the past decade as reports claimed that the parasite could influence a person’s behavior and even increase the risk of schizophrenia.

Once a person is infected, toxo lies dormant in their body throughout their life. A recent study found between 10% and 15% of people in the United States to be latently infected with the parasite.

“The consequences of infection with toxo not during pregnancy is all new and not well understood,” said Dr. E. Fuller Torrey, a research psychiatrist at the Stanley Medical Research Institute, a nonprofit organization that supports research on schizophrenia and bipolar disorder.

There have been so many new studies into the link between toxo infection and schizophrenia that Torrey created a web page to keep track of them all. “I’m adding studies almost every month,” he said.

In a 2007 review, Torrey found that people with schizophrenia were 2.7 times more likely to have antibodies against the parasite — which indicate that someone has been infected — than healthy people. This increase in risk would mean that the rate of schizophrenia would increase from 1 in 100 in the general adult population in the United States to 2.7 in 100 among people who have a toxo infection.

A large study by Torrey and his colleagues found that adults who had schizophrenia were more likely to have grown up in homes that had cats, compared with healthy controls. Parents of young children may therefore want to be careful about bringing a new cat into the home.

Despite the evidence found to date, it is still not possible to say whether toxo infections cause these illnesses, said William Sullivan, professor of pharmacology and toxicology, microbiology and immunology at the Indiana University School of Medicine.

Research has merely suggested that people with psychiatric disorders happen to be more likely to have been exposed to toxo. “Correlation plus correlation plus correlation does not equal causation,” Sullivan said.

Sullivan suspects that toxo is not enough on its own to bring on the illness and that another, as yet unknown, risk factor could also be involved.

A good way to find out whether toxo truly causes mental health disorders and changes in behavior would be to give people with schizophrenia a drug that clears their dormant toxo infection and see whether their symptoms improve, Sullivan said. But no such drug exists.

According to Sullivan, there are other ways to become infected with toxo, including eating raw meat, which can harbor the parasite, and gardening or working with soil, where toxo can survive for several years.

A study by Torrey found that there can be 100 toxo spores, or oocysts, under a gardener’s fingernail. Those with a green thumb can take protective steps, such as wearing gloves and a face mask.

People can also become infected by eating the raw meat of animals harboring the parasite. To prevent this, Sullivan advises that people make sure to cook meat thoroughly or else to freeze the meat before eating it.

 

Farmers targeting toxo-carrying feral cats in NZ

An Ontario friend arranged for three kittens for me and my daughters about 12 years ago from their local shelter.

feral.cat.nov15He was a dairy farmer and used to horrify the kids with how he shot stray kitties.

People would randomly abandon cats on his dairy farm, believing cartoons about cats and milk.

He wasn’t going to lose his livelihood to some unwanted cat.

Farmers in New Zealand are doing the same thing.

Feral cats carrying toxoplasmosis are the target of a predator programme that could save Hawke’s Bay farmers in excess of $4.5 million dollars a year.

A monitoring programme testing ewes on six farms, as part of the Cape to City predator programme, has found that up to 30 per cent of sheep carry the disease, which causes a high abortion rate in pregnant ewes.

Three “experimental” farms within the 26,000-hectare Cape to City footprint tested feral cats and mice for toxoplasmosis while three control farms outside of the footprint tested mice only.

Sixty sheep on each farm have also been sample tested to form a baseline across the farms that have been matched in size, stocking density and habitat.

Hawke’s Bay Regional Council Biosecurity adviser Rod Dickson said the baseline was high but “that was expected” and by reducing feral cats, it is hoped abortion rates will decrease.

braunwynn.kittens.03“Feral cats are one of the main carriers of toxoplasmosis and if we can reduce the numbers of feral cats, we have a good chance of reducing the high abortion rate in ewes.

“This could provide a significant economic benefit for farmers,” he said.

Mr Dickson said toxoplasma is highly prevalent in New Zealand sheep flocks with a recent survey testing 198 ewe flocks revealed 85 per cent of sheep had been exposed to the disease.

Sheep become infected from eating contaminated food such as pasture, concentrate feeds and hay.

Once ingested, the disease spreads to the sheep’s muscles and brain ” and also to the placenta. Shielded from the ewe’s defence system the parasite multiplies rapidly, killing cells as infection spreads.

And my cats? Lucky wasn’t so lucky and didn’t make it out of Guelph. The two black ones had a long life roaming the forest in our Kansas backyard and, brought us gifts every morning.

Toxoplasmosis, now found in Giant Panda

The Open Access journal Parasite just published the results on toxoplasmosis in Giant Panda.

giantpandapr3.003In February 2014, China’s Zhengzhou Zoo suffered the loss of a 7-year-old female panda named Jin Yi. The Giant Panda was infected with toxoplasmosis, a disease caused by the protozoan Toxoplasma gondii, which infects virtually all warm-blooded animals (mammals and birds), including humans.

Hongyu Ma, Zedong Wang, Chengdong Wang, Caiwu Li, Feng Wei, and Quan Liu, six researchers from the Jilin Agricultural University in Changchun, the Military Veterinary Institute in Changchun and the China Conservation and Research Center for the Giant Panda, Ya’an, China, have now published their analysis, based on immunological and molecular methods. They confirmed that Jin Yi died from acute gastroenteritis and respiratory symptoms caused by toxoplasmosis.

Jean-Lou Justine, Editor-in-Chief of Parasite says, “This first report of toxoplasmosis in the Giant Panda is a major finding as it is an additional example of the ubiquity of Toxoplasma gondii, a parasite famous for reports of its effects on the behavior of infected mice. To our knowledge, this is the first report of clinical toxoplasmosis in a Giant Panda.”

This paper published in Parasite is available in English with English, French and Chinese abstracts and free to read. Please follow this link, http://dx.doi.org/10.1051/parasite/2015030

Modeling toxo in meat

Toxoplasma gondii is a protozoan parasite that is responsible for approximately 24% of deaths attributed to foodborne pathogens in the United States.

doug.cats.jun.14It is thought that a substantial portion of human T. gondii infections is acquired through the consumption of meats. The dose-response relationship for human exposures to T. gondii-infected meat is unknown because no human data are available. The goal of this study was to develop and validate dose-response models based on animal studies, and to compute scaling factors so that animal-derived models can predict T. gondii infection in humans. Relevant studies in literature were collected and appropriate studies were selected based on animal species, stage, genotype of T. gondii, and route of infection. Data were pooled and fitted to four sigmoidal-shaped mathematical models, and model parameters were estimated using maximum likelihood estimation. Data from a mouse study were selected to develop the dose-response relationship.Exponential and beta-Poisson models, which predicted similar responses, were selected as reasonable dose-response models based on their simplicity, biological plausibility, and goodness fit. A confidence interval of the parameter was determined by constructing 10,000 bootstrap samples. Scaling factors were computed by matching the predicted infection cases with the epidemiological data. Mouse-derived models were validated against data for the dose-infection relationship in rats. A human dose-response model was developed as P (d) = 1–exp (–0.0015 × 0.005 × d) or P (d) = 1–(1 + d × 0.003 / 582.414)−1.479. Both models predict the human response after consuming T. gondii-infected meats, and provide an enhanced risk characterization in a quantitative microbial risk assessment model for this pathogen.

 Development of Dose-Response Models to Predict the Relationship for Human Toxoplasma gondii Infection Associated with Meat Consumption

Risk Analysis, 19 October 2015

M Guo, A Mishra, R Buchanan, J Dubey, D Hill, H Gamble, J Jones, X Du, and A Pradhan

http://onlinelibrary.wiley.com/doi/10.1111/risa.12500/abstract

 

Unborn babies can get toxoplasmosis, listeriosis

ABS-CBN News in the Philippines reports Toxoplasma gondii, a parasite found in raw or undercooked meat, can latch on to pregnant moms and their unborn babies if ingested, potentially causing food poisoning, miscarriage or other complications to the unborn baby.

pregnant.fishAccording to microbiologist Dr. Windell Rivera, “Usually infected newborns would have problems sa mata, sa utak, mga damage talaga at birth (Usually, infected newborns would have eye or brain damages at birth).”

Toxoplasmosis is the disease caused by the Toxoplasma gondii parasite. Naturally thriving in a cat’s stomach, it can contaminate soil, water, or plant material once released via the animal’s feces. Animals that ingest the parasite can be infected. Humans may contract the parasite by consuming contaminated meat products.

According to the World Health Organization, toxoplasmosis is one of the five most commonly “neglected parasitic infections” as the parasite shows no symptoms in people with strong immunity. However, immunodeficient individuals may experience body aches, swollen lymph nodes, head ache, fever, or fatigue. Babies of pregnant mothers are usually the most potent victims as congenital toxoplasmosis can result to fetal death.

Experts, however, said that mothers who contracted the parasite before pregnancy could be safer as their bodies may have already developed immunity.

Treatment of the toxoplasmosis, in general, is also possible through medication, according to experts; however, completely removing all the parasites from the body may not be possible.

Beyond the Toxoplasma gondii, experts add that mother must also look out for the Listeria bacteria.

amy_pregnantRivera warned, “Ang listeria delikado. Twenty times at risk ang mga buntis. Pwedeng malaglag yung bata kung ma-food poison yung nanay. O kaya sakitin yung bata paglabas (Listeria is 20 times more harmful to pregnant mothers. Mothers may experience miscarriage if they contract food poisoning. If not, the baby may turn out to be sickly).”

The Listeria bacteria may be contracted from raw milk, vegetable salad, and processed meat such as hotdogs or luncheon meat. In general, people infected by the bacteria experience mild fever and are treated with antibiotics. However, experts say, people experiencing worse symptoms ought to receive medical attention.

To avoid further complications by parasites and bacteria, experts warn, prevention is key.

 

Toxo imported meat might alter nation’s behavior, warns Iceland’s PM

Contrary to the claims of The Reykjavík Grapevin, toxoplasmosis is not a virus; it’s a parasite.

Prime Minister Sigmundur Davíð GunnlaugssonBut according to Iceland’s Prime Minister Sigmundur Davíð Gunnlaugsson, “Because this is such an interesting topic, maybe I will get one more minute to cover it, because it is extremely important that we, precisely, protect the wholesomeness of Icelandic products, that we don’t use additives, steroids and hormones and such in the production of Icelandic meat,’ Sigmundur Davíð pleaded in a live interview on radio-station Bylgjan on Thursday. … Another thing, no less important, is that we remain free of all sorts of infections which are, unfortunately, all to common in very many places. These are not just harmful to the animals but can be very detrimental to people. For example, there is a virus that causes people’s behavior to change. If they eat, for instance, meat in other countries, that has not been cooked particularly well, then people are at risk of ingesting this infection. And it can lead to changes in behavioral patterns. People have even posed the question, and researched, if this might be changing the behavior of whole nations. This sounds like science fiction, but …’

At this point the radio host intervened to ask: Where has this come up?

‘This is very common,’ Sigmundur Davíð replied, ‘for example widely in East-Europe, France, not least Belgium. Actually all over the world. The prevalence is variable, but there are some countries that stand out, where this toxoplasma is rare. That’s Iceland. And Norway. And the UK, actually. Remarkably. There, people are rather safe against this critter.’

The Prime Minister then recommended that the radio hosts interview a scientist or a doctor about this ‘extremely interesting’ phenomenon.

Toxoplasmosis: cats control my mind, or the sink

We have two Persian fluff balls for cats, and one insists on sleeping in the sink.

According to The Atlantic, the parasite Toxoplasmosis gondii comes into us by undercooked meat, well-intentioned placentas (what?), gardening soil, or, most infamously, cats. It is the reason that pregnant women are not supposed to empty litter boxes.

“If you’re young and healthy and have it already, it might provide some benefit, as we saw in our research,” says Ann-Kathrin Stock, a cognitive neurophysiology researcher at the jacques.cat.dec.13University of Dresden in Germany. “But the adverse effects are potentially huge. If you ever really get sick it might be what kills you.”

Many people have what feels like a cold after they get infected with Toxo. The symptoms pass, and the person feels fine. But the Toxo lives on inside them, hidden dormant in little cysts, kept in check by constant pressure from the person’s immune system. If our immune systems become weak, because of a serious illness later in life, though, the Toxo can break out and attack organs like the brain or retina.

“You might lose your ability to see, or lose your cognitive faculties,” Stock said.

Neuroscientist Joraslov Flegr, an eminent voice in Toxo research, told The Atlantic last year that, “Toxoplasma might even kill as many people as malaria, or at least a million people a year.”

What does it mean to learn that it can also have beneficial effects?

Toxo has been all over the news in recent years, since it became known that the parasite manipulates people’s behavior. Maybe most interestingly and notoriously, it seems to make men more introverted, suspicious, unattractive to women, and oblivious to the way others see them.

Clearly, I have Toxo.

Infected women, inversely, have been shown to be more outgoing, trusting, sexually adventurous, attractive to men, and image-conscious.

Clearly Amy has Toxo.