This parasitic disease is relatively common in cats, and can also present a risk to the health of pregnant women as well.
Studies carried out in the UK suggest that at least a third of the cat population has been infected by the microscopic protozoan called Toxoplasma gondii which is responsible for the infection. In parts of central France, medical tests have shown that over 90 per cent of the human population there has been exposed to this parasite.
Although in most cases exposure to cats earring toxoplasmosis causes no illness, children should be taught to handle cats with care, and always wash after coming into contact with them or their faeces.
Pregnant women should take extra hygiene care when cats are around. However, the main danger period is in the early stages of pregnacy.
The life cycle of the Toxoplasma parasite is quite complex, with an infected cat passing out oocysts (eggs) in its faeces. These will take about five days in the environment to become infective. People are
inadvertently infected, usually by picking up oocysts on their hands, transferring them to food and swallowing them. Oocysts are very widely distributed in garden soil, so if you do have contact with Toxoplasma, it may not be your cat that is the source of the infection.
The cat, however, is the ultimate host, and the life cycle can only be completed if a cat eats another animal such as a mouse or a bird, which is infected with Toxoplasma oocysts. In the body, the parasite can spread widely, being found in various areas including the brain and lungs, as well as both cardiac and skeletal muscle. At first, if the host has no resistance to the parasites, they multiply rapidly within the body, but after a short while they will simply encyst in the tissues and become dormant, causing no symptoms.
Cats cannot be infected in the womb, but these parasites will spread across the human placenta, and this is likely to cause a miscarriage or may even result in the abnormal development of a human foetus.
As a result of the potential health hazard, it is probably not a good idea for a pregnant woman to have close contact with a cat, although sensible hygienic precautions should ensure that the risk is minimal.
Although cats only remain infective for about two weeks, they are likely to shed up to two or three million oocysts over this period, resulting in a high level of contamination.
The cysts can survive well in the soil for over a year.
Infective humans cannot pass the infection back to cats, unless they are eaten by them! What precautions should I take as an expectant mother? Always wear gloves when changing a cat’s litter tray, and disinfect it regularly with a suitable non-toxic disinfectant to kill off any oocysts. Do not tip soiled litter on to the garden. Always wear gloves when gardening.
Is there anything else that I can do?
Wash your hands after handling raw meat; be sure to cook meat thoroughly, and never offer raw meat to your cat. If your child has a sand pit, keep it covered so cats cannot use it as a toilet.
Which cats are most susceptible to toxoplasmosis? Farm cats and those that hunt regularly are most vulnerable. Drugs can be used in cats to control the parasite until immunity is acquired.