Toxoplasmosis
Child; pet; cat; toxoplasmosis; infectious diseases; baby; pregnancy; meat; raw; raw meat; lamb; pig; pork; brain; HIV; HIV/AIDS; parasite; eyes; vision;ears; hearing; development ;
Contents
Toxoplasmosis is rarely a serious illness in healthy children or adults but it can cause problems for an unborn baby if it is caught by the baby's mother during pregnancy. Toxoplasmosis is also a major cause of serious illness in people with a damaged immune system such as people with HIV infection, or those on medication which lessens how well the immune system can work, such as people who have had organ transplants or cancer.
Toxoplasmosis is a common parasite infection that:
- usually does not cause illness,
- can harm an unborn baby if the mother gets the infection during pregnancy,
- can cause severe illness when a person's immune system is seriously damaged, such as by HIV.
The infection can be caught from:
- raw or under cooked meat
- cat faeces (poo).
Infection can be prevented through:
- eating only fully cooked meat,
- avoiding contact with cat faeces
- very careful hygiene including frequent hand washing, and careful washing of knives, cutting boards and other tools used for cooking.
If toxoplasmosis is causing health problems, treatment with antibiotics may be helpful.
People with HIV who become ill with toxoplasmosis may need treatment for the rest of their lives.
What is toxoplasmosis?
- Toxoplasmosis is an infection caused by a small, single celled parasite called Toxoplasma gondii.
- This parasite is found in all parts of the world, and infection is very common.
- Toxoplasma can affect cats, pigs and sheep, as well as humans. Like humans, most animals which are infected do not have an illness.
Symptoms of toxoplasmosis
- Infection with toxoplasma usually does not cause any symptoms because the immune system is able to stop the infection from causing illness.
- A few people (10% to 20%) have a 'flu' like illness with a fever and swollen glands, which can last more than a month.
- After being infected a few parasites remain in the body, in tiny cysts in the muscles, lung and brain. While the immune system is healthy, if any parasites are released from the cysts, the immune system will destroy the parasites immediately.
- If the immune system is badly damaged (such as in the late stages of HIV/AIDS), the parasites can multiply again and can cause serious illness, including toxoplasmic encephalitis (infection of the brain).
- Animals with toxoplasmosis are also rarely ill during the infection.
How does it spread?
Toxoplasma can spread to humans in several ways.
- Cats - people can become infected from touching the poo of cats, or drinking or eating food that has been contaminated by cat poo that has the cysts is it.
- Cats are the primary (main) host for the toxoplasma parasite. They are infected, often when they are young, by eating raw meat, or prey that they have killed or found, which has the toxoplasma cysts in it.
- The cat does not become ill, but it soon starts to pass oocysts in its poo. These oocysts become able to infect humans, other cats, and many other warm blooded animals, such as sheep and pigs after 1 to 5 days.
- Cats only catch toxoplasma once in their lives but they excrete the oocysts for many weeks, and the oocysts can survive in the environment for several months.
- These oocysts are hard to get rid of. They are often not killed by disinfectants or freezing and drying. They are killed by heating to 70 degrees C (160 degrees F).
- The oocysts can be in the soil, on vegetables grown in contaminated soil, in drinking water and in milk.
- People can also get the toxoplasma cyst from handling or eating raw or undercooked meat.
- After becoming infected with toxoplasma, the animal's immune system is able to kill the parasite's cysts in the blood stream after several days, but cysts are able to stay alive in muscle and the nervous system for the rest of that animal's life.
- When raw or under cooked meat from an infected animal is handled or eaten, the cysts can become active, causing infection again.
If a mother becomes infected with toxoplasma during pregnancy (and she has not had the infection before becoming pregnant), the parasites can pass through the placenta to the developing baby.
Spread of the infection from person to person does not occur, so a person with toxoplasmosis does not need to be separated from others.
Toxoplasmosis effects on an unborn child
- If a woman has been infected with toxoplasma before she gets pregnant, her immune system will be able to control the toxoplasma parasites she still has in her body, so that her baby will not get the infection.
- If a woman gets a toxoplasma infection while she is pregnant, her immune system will not be able to kill the parasites straight away (the immune reaction will take several days or weeks to develop), and the toxoplasma parasites can be transmitted through the placenta to her unborn baby.
- Babies exposed to toxoplasma before birth can have damage to their brain, ears, eyes and liver. Signs of damage may be present before birth (eg changes may be seen on ultrasound testing), or at birth, but they also may only become obvious later when the child is found to have hearing loss, vision problems or developmental problems.
- Toxoplasmosis can also cause miscarriage.
- Even though there is a risk of birth defects, most babies exposed to toxoplasmosis before they are born will not be affected.
- Toxoplasmosis often causes severe illness among people with HIV/AIDS. It usually affects the brain or the eyes.
- If a person is healthy and not pregnant, there is no need for any treatment for toxoplasmosis.
- If a woman gets infected during pregnancy, some researchers recommend using antibiotics, while others report that it seems that treatment of the infection does not make any difference for her baby.
- A woman should see her doctor if she becomes unwell with any illness during the pregnancy.
Protecting against toxoplasmosis - food
- If possible, a pregnant woman or other person at risk should not eat or handle raw or undercooked meat.
- If raw meat needs to be handled, use latex gloves if possible, wash hands with soap and warm water, and wash knives, other tools and cutting boards very well in hot water afterwards.
- Fully cook all meat - meat cooked until it is no longer pink inside and the juices are clear should be hot enough to have killed the parasites.
- Wash all vegetables thoroughly before eating, especially salad vegetables.
Protecting against toxoplasmosis - cats
- Cats can only pass on the infection if they have recently had the infection (for a few weeks after the infection), so young cats are likely to be more of a risk.
- During pregnancy is not a good time to get a new kitten.
- Help prevent your cat becoming infected by keeping the cat inside, so that it does not eat raw meat or kill small animals and birds.
- Feed the cat cooked, canned or dry food, no raw meat.
- Do not bring any new cat (which may have been an outdoor cat) into the house.
- Do not handle stray cats or kittens.
- Avoid handing cat litter trays. Or if this is not possible, wear gloves, empty and wash the trays daily with boiling water (the parasite found in cat faeces needs a few days after being passed to become infectious).
- Avoid exposure to soil or sand that may have cat faeces in it
- Wear gloves when doing any gardening or anything outside that involves handling soil, and wash hands very well afterwards. (Cats and other animals may have used the soft soil or sand for a toilet).
- Make sure all sandpits are covered when not in use.
- Wash hands with hot water and soap often.
- You do not need to get rid of your cat if you follow these steps.
Centers for Disease Control and Prevention(CDC) (USA), Toxoplasmosis Fact Sheet'.
http://www.cdc.gov/toxoplasmosis/
CDC 'You can prevent toxo: a guide for people with HIV infection'
http://www.cdc.gov/hiv/resources/brochures/toxo.htm
Department of Health, South Australia. 'Toxoplasmosis'
http://www.dh.sa.gov.au/pehs/ygw/toxoplasmosis-pehs-sahealth-2009.pdf
Division of Parasitic Disease, CDC 'Parasites and Health; Toxoplasmosis'
http://www.dpd.cdc.gov/dpdx/HTML/Toxoplasmosis.htm
Montoya JG, Liensenfeld O 'Toxoplasmosis' The Lancet, Vol 363, June 12, 2004 p1965-76
http://www.thelancet.com
The information on this site should not be used as an alternative to professional care. If you have a particular problem, see a doctor, or ring the Parent Helpline on 1300 364 100 (local call cost from anywhere in South Australia).
This topic may use 'he' and 'she' in turn - please change to suit your
child's sex.