Toxoplasmosis gondii, Pregnancy and Cats – Fact vs. Fiction

Well over halfway through my second pregnancy, I am currently inundated with comments from clients, mostly positive, and it has added a bit of humour and lively conversation to my otherwise increasingly tiring days. ‘Do you know if it’s a boy or a girl?’ ‘How do you think your toddler is going to react to the new baby?’ ‘Are you going to come back to work after two children?’ But one question I wasn’t expecting came from a woman with a lovely ginger tom – ‘Are you sure you’re OK to examine my cat if you’re pregnant?’ I laughed and assured her that despite my expanding waistline I could still reach the table and her cat would be fine. But after a slightly confused and very embarrassed smile, she explained that she had recently been told by a friend that she would have to give up her beloved cat once she became pregnant because it wasn’t safe for pregnant women to be around cats. It had been a while since I had heard that myth and was saddened to hear it again, but I wasn’t terribly surprised. We spent most of the rest of the consultation discussing the real facts about toxoplasmosis, the disease in question, and she left very much relieved that her feline friend was not going to have to be evicted should she ever decide to have a baby, and determined to speak to her GP if she had any further concerns.

What causes toxoplasmosis?

Amber-on-grassToxoplasma gondii, the protozoal parasite responsible for causing the disease known as toxoplasmosis, is a tiny single-celled organism that can infect many different species from mice to sheep to humans. Cats, however, are the only hosts in which the parasite can reproduce, so in addition to being infected themselves, they can also release oocysts (which are essentially the eggs from which new organisms are created) in their faeces. These eggs are very resistant and can survive in some environments for months, allowing other animals to ingest them with their food. When other animals such as mice become infected with the parasite, it develops to form tiny cysts in their muscles and waits there until the animal is eaten by another cat so it can begin the cycle all over again. Most animals, therefore, are capable of spreading the infection through the consumption of their flesh, but only cats are able to spread it via their faeces.

What happens to cats that are infected with toxoplasmosis?

The short answer to this question is, well, usually not much. In fact, unless the cat is otherwise ill or immunocompromised (young kittens, or those with FIV or FeLV), most owners don’t even notice if their cat becomes infected. If cats do show symptoms, these usually include fever, decreased appetite and lethargy. Rarely, more serious cases may develop pneumonia, blindness or inflammation of the eyes, or more commonly, neurological symptoms such as personality changes, loss of balance, walking in circles, difficulty swallowing, or seizures.

How are people infected and why is it so dangerous?

People can become infected by handling the faeces of infected cats (but only during the few weeks after they become infected for the first time, after that they stop shedding the eggs), gardening in soil that has been defecated in by recently infected cats, or more commonly, eating undercooked meat of any kind as animals such as lambs and pigs can also be infected (the cooking process kills the organism). But as you’ll see below, all of these things are easily prevented with simple and common sense measures. There are three main health concerns when it comes to humans. The first and most well-known risk group is pregnant women. Expectant mothers that pick up the disease for the first time during pregnancy (ie, NOT those that have already been exposed to it earlier in life) do not usually show symptoms themselves but are capable of passing the infection on to their unborn child. In these cases, vision and hearing loss, mental disabilities and occasionally even death of the child are possible. So there is certainly cause for concern. The second group of people that are particularly at risk are those that already have immune systems that are deficient, such as those with HIV or AIDS or who are on chemotherapy. Finally, although the vast majority of people who become infected with the toxoplasma organism (and that includes a staggering one third to one half of the world’s human population!) show only mild flu-like symptoms if any at all, it has recently been linked to some pretty serious conditions such as brain tumours, attention deficit disorder, obsessive compulsive disorder, schizophrenia and possibly even an increase in suicide risk. But because most people don’t know they have it, it isn’t something that is routinely screened for so a lot more studies need to be done before we know the true effects of the illness in all species, not just humans.

If toxoplasmosis can do all that, why would anybody own a cat??

Domino-sleepingBecause even though cats spread the disease, we are very unlikely to catch it directly from them. Cats are only capable of spreading the disease for the first 2-3 weeks after they are first infected. After that, they are immune to new infections and although they may later show symptoms, they are not later contagious. And then even if your cat was shedding eggs, there has to be direct ingestion of the contaminated faecal material by humans. Not many of us (perhaps toddlers aside…) will intentionally consume cat faeces, but we will sometimes come inside after gardening and grab a quick sandwich without remembering to wash our hands. This is not a problem with the cat itself, rather our own personal hygiene. It is extremely unlikely that you would pick up toxoplasmosis by petting your cat or being scratched or bitten by your cat, because the organism is not spread by the fur or saliva. You CAN, however, pick up toxoplasmosis by eating undercooked infected meat, particularly lamb and pork. Again, this is not your cat’s fault, rather our own lack of taste or culinary skills, and is by far the most common way of picking up the disease in developed countries.

What’s the best way to avoid becoming infected?

Use common sense, and if you are pregnant, take a few extra precautions and chances are you’ll be just fine. Unless you already have it, which is probably more likely than you care to acknowledge, but chances are you’ll never know it so you might as well do these things anyway!

• Don’t eat raw or undercooked meat or drink unpasteurised milk. And once you’re finished preparing raw meat, wash your hands and all surfaces that it may have touched.

• Wash fruits and vegetables before eating them, even if they came from your own organic garden.

• Wash your hands well after gardening and before eating, especially for children, goodness knows where those hands have been…

• Pregnant women, and people with suppressed immune systems, should not clean the litter tray (I don’t know many pregnant women who wouldn’t jump at the chance to make their partner clean the litter tray). Or if you must clean the litter tray yourself, wear gloves, wash your hands well and try to remove the stools daily as faeces that have been sitting around for a few days are more infectious.

Toxoplasmosis is a serious illness and can cause serious harm to both cats and humans. But contrary to what many people believe, living with a cat only slightly increases your chance of catching the disease and with the help of simple common sense measures like those mentioned above, this risk can be minimised. So yes, I’m perfectly happy to keep working and living with cats, and hopefully you will be too. But if you do have any questions regarding either your own health or that of your family, make an appointment to speak with your GP and make sure everybody is aware of the facts rather than the myths about toxoplasmosis.

If you are worried about your cat talk to your vet or use our Interactive Cat Symptom Guide to check any symptoms they may be showing and see how soon you should visit your vet.

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