Introduction
The protozoan parasite Toxoplasma gondii causes toxoplasmosis. Toxoplasma infection is known to affect 11 percent of the population aged six and above in the United States. More than 60 percent of some populations are infected with Toxoplasma in various parts of the world. Because the oocysts survive better in hot, humid climates and lower altitudes, infection is often highest in these areas of the world.
What Is Toxoplasma gondii Infection?
Toxoplasmosis is an illness caused by Toxoplasma gondii, a single-celled parasite. Toxoplasma parasites can live in humans (and other animals) for extended periods, possibly even a lifetime. However, very few infected people experience symptoms because a healthy person's immune system usually prevents the parasite from causing illness. On the other hand, pregnant women and people with weakened immune systems should be cautious; a Toxoplasma infection could lead to serious health issues.
Toxoplasma infections are caused by one of the following agents:
1. Consuming raw or undercooked meat (particularly pork, lamb, and venison) or shellfish (for example, oysters, clams, or mussels).
2. After handling undercooked, contaminated meat or shellfish, failing to wash hands thoroughly, and consuming them. (Toxoplasma cannot be absorbed through intact skin).
3. Consuming food tainted by knives, utensils, cutting boards, and other foods that have come into contact with raw, contaminated meat or shellfish.
4. Toxoplasma gondii contaminated drinking water.
5. Swallowing the parasite by accident after coming into contact with Toxoplasma-containing cat feces. This could happen when:
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Cleaning a cat's litter box after it has shed Toxoplasma in its feces.
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Touching or consuming anything that has come into contact with Toxoplasma-containing cat feces.
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Ingesting contaminated soil by accident (not washing hands after gardening or consuming unwashed fruits or vegetables from the garden).
6. Mother-to-child transmission (congenital).
7. Undergoing an infected organ transplant or transfusion of infected blood, though, is uncommon.
What Are the Risk Factors for Toxoplasma gondii Infection?
The risk factors identified for T. gondii infection in humans and warm-blooded animals include:
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Consuming raw or undercooked meat that contains T. gondii tissue cysts.
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Consuming water, vegetables, soil, or anything contaminated with oocysts is shed in an infected animal's feces. Cat feces is especially dangerous because just one cyst ingested by a cat can result in thousands of oocysts. These oocysts resist harsh environmental conditions and can survive in contaminated soil for up to a year. Therefore, doctors advise pregnant or ill women not to clean their cat's litter box at home.
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Transplacental transmission from mother to fetus, especially when T. gondii is contracted during pregnancy.
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Drinking unpasteurized goat milk contaminated with raw and treated sewage.
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Eating bivalve shellfish contaminated with treated sewage.
The transmission of Toxoplasma gondii to humans is a common point of contention in the debate over whether cat ownership is ethical. However, one study found that living in a household with a litter box-using cat was strongly associated with infection; living with many kittens or any cat under one year of age has some significance. Several other studies claim that staying in a household with a cat is not a significant risk factor for T. gondii infection.
The seawater in California is assumed to be contaminated by T. gondii oocysts that originate from cat feces, survive or bypass sewage treatment, and move to the coast through river systems. Polymerase chain reaction and DNA (deoxyribonucleic acid) sequencing were used to identify T. gondii in a California mussel. Because of the possibility of T. gondii contamination, pregnant women and immunocompromised people should avoid eating raw oysters, clams, and mussels.
Although T. gondii can infect, transmit, and reproduce asexually in humans. T. gondii has also been sexually transmitted in warm-blooded animals such as brown rats, sheep, and dogs. In nearly all other warm-blooded animals, the parasite can only reproduce sexually in the intestines of cat family members (felids). Felids are thus the definitive hosts of T. gondii, with all other hosts (such as humans or other mammals) serving as intermediate hosts.
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Toxoplasma gondii Infection In Immunocompromised People:
If one has HIV (human immunodeficiency virus), cancer, or takes immune-suppressing medications, the immune system will be unable to fight infections like T. gondii. This means they have a weakened immune system. While most people can fight toxoplasmosis without symptoms, a new or reactivated infection can result in life-threatening complications in people with weakened immune systems. T. gondii lives in people with previous Toxoplasma gondii infection. When the immune system is compromised, it can reactivate and make them sick. Toxoplasmosis, if left untreated, can cause organ damage in people with weakened immune systems. This may eventually result in death.
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Toxoplasma gondii Infection In Pregnancy:
Toxoplasmosis can be passed to the fetus through the placenta if one gets it during pregnancy or shortly before. This increases the child's chances of miscarriage, stillbirth, or serious health problems. Toxoplasmosis complications include vision problems, blindness, developmental delays, and learning differences.
How to Prevent Toxoplasma gondii Infections?
One can do several things to reduce the chances of contracting Toxoplasma gondii.
1. Food should be cooked to safe temperatures. Using a food thermometer, measure the internal temperature of the meat. Meat should only be tasted once it has been completely cooked. Color is not a reliable indicator of whether meat has been cooked to a high enough temperature to kill harmful pathogens such as Toxoplasma. The USDA suggests the following methods for preparing meat:
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Whole meat must be cooked to at least 145 degrees Fahrenheit (63 degrees Celcius), checked using a food thermometer placed in the thickest portion of the meat, then rested for three minutes before carving or eating. A rest time is when the product stays at the final temperature after it has been removed from a grill, oven, or other heat sources, according to the USDA (United States department of agriculture). Three minutes after the meat is removed from the heat source, its temperature remains constant or rises, killing pathogens.
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Grounded meat must be cooked to at least 160 degrees Fahrenheit (71 degrees Celcius), and ground meats do not need to rest.
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For poultry, cook until the temperature reaches 165 degrees Fahrenheit (74 degrees Celcius). Internal temperature should be taken in the thickest portion of the breast, the innermost portion of the thigh, and the innermost portion of the wing. Poultry does not require rest.
2. To significantly reduce the risk of infection, meat must be frozen for several days at sub-zero (0 degrees Fahrenheit) temperatures before cooking.
3. Other parasites found in meat (such as certain species of Trichinella) or harmful bacteria are not reliably killed by freezing. Cooking meat to USDA-recommended internal temperatures is the most effective way to kill all parasites and pathogens.
4. Before eating, thoroughly peel or wash fruits and vegetables.
5. Oysters, mussels, and clams should not be eaten raw or undercooked.
6. Unpasteurized goat's milk should not be consumed.
7. After handling raw meat, seafood, poultry, or unwashed fruits and vegetables, wash cutting boards, dishes, counters, utensils, and hands with soapy water.
8. Wear gloves when gardening or working with soil or sand because it could contaminate Toxoplasma-containing cat feces. After gardening or touching soil or sand, wash your hands with soap and water.
9. Make sure the litter box of the cat is changed regularly. Toxoplasma parasites do not become infectious until one to five days after they are shed in a cat’s feces.
10. After cleaning a cat's litter box, wash your hands with soap and water.
Conclusion
Toxoplasma gondii is a parasite that causes infections in humans and warm-blooded animals. Toxoplasmosis can cause flu-like symptoms in some people, but most infected people never show any signs or symptoms. If otherwise healthy and diagnosed with toxoplasmosis, it probably will not require any treatment other than rest. Pregnant women or people with a weakened immune system may need medical attention to avoid complications. Food must be completely cooked, and raw meat must be avoided. However, prevention is the best approach.
