toxoplasma-gondii

If you’re not getting any, get a cat

Quote of the day from an infectious diseases consultant, giving us advice on how to have more sex.

Apparently people previously infected by Toxoplasma gondii (a protozoan that is carried by cats) were shown to have behavioural changes that caused them to take more risks and have more sexual partners

I have been looking for a source online and can’t find a good one so not sure how true this is. 

Toxoplasma gondii

Toxoplasma gondii. 7 syllables sure to strike fear in to any pregnant woman’s heart. I thought I’d do a little post today to summarise what toxoplasma actually is and how it affects us and the animals around us.

Toxoplasma gondii is a single celled parasite known as a protozoa. It has a complex lifecycle involving felines as its only final host. It does, however, have a vast array of ‘intermediate hosts’ thought to include virtually all warm blooded animals. It’s a very successful parasite infecting animals and humans worldwide. In France, 84% of people are thought to be infected.

Its lifecycle is as follows:

  • A cat becomes infected through consuming the raw meat of infected prey
  • The parasite infects the epithelial cells of the cat’s gut, sexually reproducing in these cells
  • Sexual reproduction produces oocysts which are shed in the cat’s faeces. The time period from consumption to shedding is around 3-10 days. Shedding only occurs for a few weeks before the cat’s immune system fights off the parasite, resulting in a persistent but non-shedding infection that can remain for life. After one infection it is highly unlikely the cat will get infected and shed again due to its raised immune response, however immunosuppression can result in subsequent shedding
  • These oocysts develop in the environment and after 1-5 days are developed enough to infect an intermediate host
  • Intermediate host ingests the oocysts through consumption of an item or fluid infected with cat faeces. Intestinal enzymes break down the oocyst wall releasing the parasite in to the gut
  • Acute asexual multiplication occurs in the intermediate host cells and the parasite is spread around the body in the blood
  • After around 2 weeks the host develops immunity but the infection enters a chronic phase as slow-growing forms of the parasite are ‘walled off’ into what is known as a cyst, protected from the immune system. These can remain infectious for months to years and can revert to the acute form if the host’s immune system becomes depressed (FIV, AIDs, canine distemper). They are often found in the brain and muscle.
  • This cyst-infected meat is consumed by the cat and the whole cycle begins again

Cats can also get infected by consuming oocysts from other cats, however they are a lot less susceptible to this than other intermediate hosts so a large number of oocysts would need to be consumed. To make it even more confusing, intermediate hosts can get infected via carnivorism/ scavenging when they consume meat infected with cysts (e.g. a human eating undercooked, infected pork). As well as this, transplacental transmission can occur in some host species during the acute phase of the infection (however this is not seen in dogs or cats). This creates a complex web of infection. The cysts are killed when meat is cooked.

Toxoplasmosis is most often asymptomatic, with flu-like symptoms possible during the acute phase. It can be fatal in immunosuppressed individuals, however this is rare. You may have heard the parasite’s name mentioned in relation to sheep. If a non-immune ewe is infected during pregnancy it can cause foetal death, reabsorption, abortion, mummified foetuses, still births and weak lambs, depending on when in pregnancy the ewe was infected. In cases of abortion, you can see tiny white spots on the placenta and foetal tissue. Diagnosis can be confirmed through stained impression smears or serological examination of the foetal fluid or blood from the ewe. Prevention in sheep includes a vaccine which primes the immune system to the parasite. Sheep are often infected from eating infected hay or concentrates, so keeping cats away from these can help reduce infection rates.

Toxoplasma is also a favourite in the press, who claim that it ‘controls our brains’ and causes abortions and deformities. Like in sheep, infection of a non-immune, pregnant mother can indeed cause deformities in her child. Does this mean we should all kill off our cats when expecting? Definitely not, and I’ll explain why.

As I stated earlier, infected cats will only shed for 2-3 weeks in their entire lifetime, unless immunologically supressed. To become infected by your cat, you would need to have never been infected before yourself (because if you have, your immune system is primed and ready to fight it off), your cat would have to be in the shedding phase and you’d have to ingest oocytes (that take 1-5 days to become infective, so changing the litter box daily can hugely reduce this risk).  If worried, a blood test to see if you’ve been previously exposed and a blood test in your cat to see if they’ve been previously exposed may put your mind at rest. Indoor cats are less likely to become infected if their only food is tinned or dried. Humans are much more likely to be exposed to the infection through handling and eating undercooked infected meat, soil infected with cat faeces and unwashed vegetables. If you’re a vet in the making and have been on a lambing placement, you may well have been asked if you’re pregnant. This is because being in contact with aborted material from sheep with toxoplasmosis is another way to contract the infection.

As for the ‘mind control’, it has been found that mice infected with toxoplasma are attracted to the smell of cat urine and a lot less frightened of cats than those without infection. This is an incredibly clever mechanism and probably one of the reasons the parasite is so wide-spread. In humans, when analysing the number of people who are involved in car accidents, it was found that a significantly high proportion were infected with toxoplasma gondii. It has been suggested that the parasite is responsible for making people more reckless and argumentative. Toxoplasma cysts in the brain could definitely be responsible for parts of your personality, however conclusions at the moment suggest that although the infection may have some effect, the brain and concept of ‘personality’ are so complex and involve so many factors that its overall influence seems negligible.  

I hope this made sense, it’s quite confusing to explain! I’ve drawn a quick diagram to try and demonstrate the different scenarios in which we could become infected. Enjoy!

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How Your Cat Is Making You CrazyJaroslav Flegr is no kook. And yet, for years, he suspected his mind had been taken over by parasites that had invaded his brain. So the prolific biologist took his science-fiction hunch into the lab. What he’s now discovering will startle you. Could tiny organisms carried by house cats be creeping into our brains, causing everything from car wrecks to schizophrenia?

http://www.theatlantic.com/magazine/archive/2012/03/how-your-cat-is-making-you-crazy/308873/

Top 10 Facts Of The Day (March 8, 2017)

1. A 45-year-old Bosnian man named Amir Vehabovic faked his death back in 2007 because he wanted to see who would attend his funeral. Only his mother attended. After this debacle, he wrote dozens of angry letters to his so-called friends and what he thought of their friendship going forward.

2. Segway accused its Chinese copycat of violating its patents. The copycat responded by buying the Segway company.

3. Robert Downey Jr. credits Burger King for getting him off drugs: Apparently, he ate a burger that was so nasty, it made him rethink his life choices and throw all of his drugs into the ocean.

4. The louder the monkey, the smaller its testicles according a study published by researchers in Utah.

Keep reading

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Is ‘crazy cat lady syndrome’ real?

Can cats really turn women into crazy cat ladies? Some scientists think it’s possible.

miodaisgay  asked:

I figured all my emotional bullshit would make you unfollow me, But you're still there..

having emotions is a normal human thing and i think tumblr is a great way to vent and express yourself in a safe environment :). don’t give up it gets better :D

averyniceway-deactivated2014070  asked:

I am enjoying your blog a lot! I am currently about to submit a thesis on Toxoplasma gondii and wondered if you had any interesting facts or pictures?

ooh that’s an interesting one!  Toxoplasma is the reason that pregnant women should never change a cat’s litter, especially if the cat has access to the outdoors, as the protozoa can be transferred to the fetus during gestation, causing congenital toxoplasmosis.

External image

This is a cyst inside the brain of a mouse

It is filled with the parasite Toxoplasma gondii

This parasite spends one stage of its life cycle in cats, and the other in different mammals - including humans. The parasite causes flu like symptoms in the host, and can rarely be fatal. When the parasite is in the brain of a mouse, it will change the animal’s behavior so that instead of being afraid of the scent of a cat, it is drawn to it. By doing this, the parasite gets a quick ride back into the stomach of a cat so it can reproduce and start over.

Tehehehe. I have my parasites exam today and I’m going over extra reading for Toxoplasmosis. Some findings suggest that Toxoplasma gondii infection increases jealousy and antisocial behaviour in men but increases morality, promiscuity and a ‘higher level of intelligence’ in women. In contrast, there is a higher prevalence of T. gondii infection among schizophrenics and people with depression and bipolar disorders. Scientists don’t know anything. It is also known to increase male births but the reasons for this are unknown.

So ja. I’ve fully covered 2 topics out of 7 and briefly covered 2 others. Malaria and Toxoplasma have appeared every year the past 4 years. If they don’t appear this year, I’m screwwwed :D And now I’ve started to get a cold, a sore throat and my wisdom tooth infection is coming back. Great timing since I need to pull a full alnighter tonight.

Formation of Toxoplasma gondii daughter cells.

T. gondii is a common parasite with a worldwide distribution. Infection is usually benign and a healthy individual’s immune system is usually strong enough to kill the parasite. With that said, T. gondii can be fatal to individuals who are immunodeficient (toxoplasmosis encephalitis, for example, is one of the leading causes of death among AIDS patients).

It’s wide host range and worldwide distribution make it one of the most “successful” parasites on earth.

myoldcatships  asked:

What kinds of brain parasites can you get from cats? A disease jumping from species to species is really uncommon as far as what I've heard so? What do cats (or other household pets) carry that could be transmitted to humans?

The main two are toxoplasma gondii (causes toxoplasmosis) and bartonella henselae (causes cat scratch fever). They’re both pretty minor in most cases - toxoplasmosis is generally asymptomatic although kids tend to feel a little sick at first, and cat scratch fever generally only really hits kids under the age of 15. Neither is really treated - they’re only concerns if you’re immunosuppressed, or for toxo, if you’re pregnant. Congenital toxoplasmosis can definitely be dangerous to babies, which is why they really highly suggest pregnant women not clean litterboxes (exposure is most likely from cat feces). 

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The reasons behind the Hawaiian crow’s terrible decline are still not well understood.  Introduced predators such as cats, rats, and mongooses will prey on eggs, chicks, and fledglings.  Fruit farmers have been known to shoot crows for fear they will damage crops, despite government protection.  Deforestation has wiped out much of the birds’ original habitat.  But perhaps most damaging of all has been the introduction of deadly avian diseases, such as avian malaria, fowlpox, and Toxoplasma gondii (a parasite most commonly found in domestic cats).

Parasitology - Treatment
  • Metronidazole: Giardia lamblia, Trichomona vaginalis, Entamoeba hystolytica
  • Nitazoxanide: Cryptosporidium
  • Pyrimethamine + Sulfadiazine: Toxoplasma gondii
  • Suramin: Trypanosma bruceii (blood borne)
  • Melarsoprol: Trypanosoma bruceii (CNS)
  • Nifurtimox or Benznidazole: Trypanosoma cruzi
  • Amphotericin B: Naegleria fowleri, Leishmania donovani
  • Sodium stibogluconate (Pentavalent Antimony): Leishmania donovani
  • Cloroquine: Plasmodium falciparum, Plasmodium malariae
  • Cloroquine + Primaquine: Plasmodium ovale, Plasmodium vivax
  • Quinidine (IV): severe Plasmodium infx
  • Mefloquine or Atovaquone/Proguanil: Plasmodium resistant
  • Atovaquone + Azythromycin: Babesia
  • Diethylcarbamazine (DEC): Loa loa, Wucheria bancrofti
  • Ivermectin: Onchocerca volvulus, Strongyloides stercolaris
  • Bendazoles or Pyrantel Pa M oate: Enterobius vermicularis, Ascaris lumbricoides, Ancylostoma duodenale, Necator americanus (ne M atodes)
  • M ebendazole: Toxocara canis
  • Albendazole: Strongyloides stercolaris, Toxocara canis, neurocysticercosis, Echinococcus granulosus.
  • P raziquantel: Taenia solium, Schistosoma, Diphylobotrium latum, Clonorchis (P latyhelminthes)

It’s an International Cat Day and Microbiome Monday mashup!

Microbes affect not just your body, but your innermost thoughts and feelings. Early research suggests that appetite, mood, mental illness—even bizarrely specific behaviors like the way we dress—can all be manipulated by microbes.

A parasite called Toxoplasma gondii lives inside many animals, including some mice. But it can only reproduce inside cats. So how does it get from mice to cats? Incredibly, several studies show that this tiny, single-celled protozoan alters the mouse’s brain and controls its behavior.

1) Mouse swallows T. gondii

2) Parasite enters brain, making mouse lose its fear of cats

3) Fearless mouse is easily eaten

4) Parasite reproduces in cat intestines and exits with feces

Roughly a third of all humans are infected with Toxoplasma gondii, the parasite that turns mice into zombies—and it appears to influence our behavior as well. Some studies show infected men break more rules and dress more sloppily, while infected women become more sociable and dress better. Both men and women have slower reaction times and get in more car accidents.

Learn more about your microbiome in The Secret World Inside You, closing August 14.