One of the most famous parasites, especially among animal lovers, is Toxoplasma gondii, otherwise known as the “cat parasite”. Sadly, however, misinformation about this parasite has brought and still brings great misfortune to cat companions, while many people remain oblivious of how to properly protect themselves against an infection with said parasite. In this article, we will attempt to provide some information about Toxoplasma gondii that you may need to know (especially if you are a cat lover).
Toxoplasma gondii is a unicellular parasite (not a bacterium or virus) that infects and lives inside nucleated cells of hosts, such as brain cells, and has a complex life cycle.
T. gondii has been found to be capable of infecting 350 different animal species so far, including humans, where it establishes a life-long infection that currently has no definitive cure.
Symptoms of contracting the parasite can range from no symptoms at all to flu-like symptoms in healthy individuals, and the infection does not cause any significant disease unless the individual’s immune system is compromised.
Newly acquiring the infection while pregnant can also be problematic as pregnant females run the risk of transmitting this parasite to their fetus, which can potentially lead to various abnormalities. It is important to note that females who had been previously infected before becoming pregnant do not run this risk. This is why it is recommended that females who intend to become pregnant, or who learn they are pregnant, see their gynecologist for the purpose of getting tested, to check whether they had previously contracted the parasite, have recently contracted the parasite, or had never contracted it at all.
In 2010, Bou Hamdan et al. released the results of their study “SEROPREVALENCE OF TOXOPLASMA ANTIBODIES AMONG INDIVIDUALS TESTED AT HOSPITALS AND PRIVATE LABORATORIES IN BEIRUT” where they screened 3516 individuals overall and found that the percentage of people who were infected with T. gondii was 62.2%. In some areas of the world, this percentage can be as high as 90%, and it is estimated that 30% of the world’s entire human population is infected with T. gondii.
Contrary to what people tend to think, some studies suggest that the major source of infection to humans is from the ingestion of undercooked contaminated meat, since farm animals that are infected harbor the parasite inside their tissues.
The reason that T. gondii is called “the cat parasite” is because felines are its primary hosts, and therefore it can sexually replicate in their intestines. Cats can become infected by ingesting raw or undercooked meat that contains this parasite; they then shed it in their stools for approximately 3 weeks. The parasite in the cat stools then needs 1-5 days to become infective, depending on environmental conditions.
How might we become infected?
- Eating undercooked meat that comes from an infected animal
- Eating undercooked meat that has been contaminated by an unhygienic handler
- Eating food with contaminated utensils, such as forks and knives
- Drinking water contaminated with T. gondii
- Unwashed fruits and vegetables from soil contaminated with the parasite
- Cat stools:
- Not cleaning the cat litter daily and not washing hands after touching or handling the stools of an infected cat or objects that had come in contact with an infected cat’s stools
- Children playing outside risk getting infected by playing with soil that contains the stools of an infected cat and not washing their hands before placing them in their mouths or touching objects they contaminate then placing these objects in their mouths.
- Pregnant mother to fetus
- Rarely, an individual can contract the parasite by receiving an organ or blood transfusion from an infected individual.
How can we protect ourselves against an infection?
According to the CDC (Centers for Disease Control and Prevention), these are the guidelines we must follow:
- Risks from Food
To prevent the risk of toxoplasmosis from food:
- Cook food to safe temperatures.
- For Whole Cuts of Meat (excluding poultry)
Cook to at least 145° F (63° C) as measured with a food thermometer placed in the thickest part of the meat, then allow the meat to rest* for three minutes before carving or consuming.
- For Ground Meat (excluding poultry)
Cook to at least 160° F (71° C); ground meats do not require a rest* time.
- For All Poultry (whole cuts and ground)
Cook to at least 165° F (74° C), and for whole poultry allow the meat to rest* for three minutes before carving or consuming.
*According to USDA, “a ‘rest time’ is the amount of time the product remains at the final temperature, after it has been removed from a grill, oven, or other heat source. During the three minutes after meat is removed from the heat source, its temperature remains constant or continues to rise, which destroys pathogens.”
- Freeze meat for several days at sub-zero (0° F) temperatures before cooking to greatly reduce chance of infection.
- Peel or wash fruits and vegetables thoroughly before eating.
- Wash counter tops carefully.
- Wash cutting boards, dishes, counters, utensils, and hands with hot soapy water after contact with raw meat, poultry, seafood, or unwashed fruits or vegetables.
- Risks from the Environment
To prevent the risk of toxoplasmosis from the environment:
- Avoid drinking untreated drinking water.
- Wear gloves when gardening and during any contact with soil or sand because it might be contaminated with cat feces that contain Toxoplasma. Wash hands with soap and warm water after gardening or contact with soil or sand.
- Teach children the importance of washing hands to prevent infection.
- Keep outdoor sandboxes covered.
- Feed cats only canned or dried commercial food or well-cooked table food, not raw or undercooked meats.
- Change the litter box daily if you own a cat. The Toxoplasma parasite does not become infectious until 1 to 5 days after it is shed in a cat’s feces. If you are pregnant or immunocompromised:
- Avoid changing cat litter if possible. If no one else can perform the task, wear disposable gloves and wash your hands with soap and warm water afterward.
- Always keep your cats indoors.
- While pregnant, do not adopt stray cats or handle stray cats, especially kittens. Do not get a new cat.
It is important to discuss this topic with your doctor if you are planning to become pregnant, are pregnant, or suffer from an immunodeficiency disorder.
Feature Photo and Article cat photo Credit: Adham Temsah Photography
Centers for Disease Control and Prevention. “Parasites-toxoplasmosis (toxoplasma infection).” (2011).
Bouhamdan, S. F., et al. “Seroprevalence of Toxoplasma antibodies among individuals tested at hospitals and private laboratories in Beirut.” Le Journal medical libanais. The Lebanese medical journal 58.1 (2010): 8-11
Robert-Gangneux, Florence, and Marie-Laure Dardé. “Epidemiology of and diagnostic strategies for toxoplasmosis.” Clinical microbiology reviews25.2 (2012): 264-296.
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